TY - JOUR A1 - Lambert, Christoph A1 - Kaupp, Martin A1 - Schleyer, Paul von Rague T1 - “Inverted” Sodium-Lithium Electronegativity: Polarity and Metalation Energies of Organic and Inorganic Alkali-Metal Compounds N2 - No abstract available KW - Anorganische Chemie Y1 - 1993 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-60054 ER - TY - JOUR A1 - Braunschweig, Holger A1 - Dewhurst, Rian D. A1 - Schwab, Katrin A1 - Wagner, Katharina T1 - {N ',N ''-Bis[2,6-bis(1-methylethyl)phenyl]-N,N-dimethylguanidinato-kappa N-2 ',N ''}dibromidoborane N2 - In the molecular structure of the title compound, C27H40N3BBr2, the B atom is connected to two bromide substituents and a guanidinate scaffold, forming a four– membered ring. An aryl group is connected to each N atom in the ring that contains two isopropyl groups in positions 2 and 6. KW - Anorganische Chemie Y1 - 2010 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-67622 ER - TY - JOUR A1 - Tacke, Reinhold A1 - Wuttke, F. A1 - Henke, H. T1 - Zur Stereochemie der mikrobiellen Reduktion von rac-Acetyl( t-butyl)methylphenylsilan mit Trigonopsis variabilis (DSM 70714) und Corynebacterium dioxydans (ATCC 21766): Aufklärung der absoluten Konfiguration der Biotransformationsprodukte (SiR,CR)- und ( SiS ,CR)-t-Butyl( 1-hydroxyethyl)methylphenylsilan N2 - No abstract available KW - Anorganische Chemie Y1 - 1992 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-64176 ER - TY - JOUR A1 - Tacke, Reinhold A1 - Becht, J. A1 - Mattern, G. A1 - Kuhs, W. F. T1 - Zur Existenz zwitterionischer \(\lambda_5\)-(Ammonioorganyl)tetrafluorosilicate: Synthese sowie Kristall- und Molekülstruktur von Tetrafluoro(pyrrolidiniomethyl)silicat T1 - On the Existence of Zwitterionic \(\lambda_5\)-(Ammonioorganyl)tetrafluorosillcates: Synthesis and Crystal and Molecular Structure of Tetrafluoro(pyrrolidiniomethyl)silicate N2 - The zwitterionic tetrafluoro(pyrrolidiniomethyl)silicate (6) was synthesized by the reaction of trimethoxy(pyrrolidinomethyl) silane (7) with hydrogen fluoride in ethanol/hydrofluoric acid (yield 83%). 6 crystallizes in the space group P2\(_1\)fc with two crystallographically distinct molecules in the asymmetric unit. In both molecules the pentacoordinate silicon atom is surrounded by four fluorine atoms and one carbon atom, the latter being in an equatorial position. The coordination polyhedron of the silicon atoms can be described as a slightly distorted trigonal bipyramid. The zwitterionic structure was also proved for dissolved 6 (solution in CD\(_3\)CN, NMRspectroscopic studies). KW - Anorganische Chemie KW - Fluorosilicates KW - zwitterionic KW - Pentacoordinate silicon Y1 - 1992 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-64217 ER - TY - JOUR A1 - Mühleisen, M. A1 - Tacke, Reinhold T1 - Twofold deprotonated citric acid as a bidentate ligand of pentacoordinate silicon: synthesis and structural characterization of the zwitterionic \(\lambda_5\)Si-spirosilicate bis[citrato(2-)-O\(^3\),O\(^4\)][(dimethylammonio)methyl]silicate hydrate N2 - The zwitterionic \(\lambda_5\) Si-spirosilicate bis[ citrato(2-)-0\(^3\) ,0\(^4\) )[ ( dimethylammonio) methyl]silicate (4) was synthesized by reaction of (MeO)\(_3\)SiCH\(_2\)NMe\(_2\) (3) with citric acid (molar ratio 1 :2) in acetonitrile at room temperature and isolated, after crystallization from water, as the hydrate 4 · H\(_2\)O (yield 81 %). The crystal structure of 4 · H\(_2\)O was studied by single-crystal X-ray diffraction. The alcoxide oxygen atoms and central carboxylate oxygen atoms of two citrato(2-) ligands and one carbon atom coordinate to the silicon atom of 4 · H\(_2\)O. The coordination polyhedron around the pentacoordinate silicon atom (SiO\(_4\)C framework) can be described as a distorted trigonal bipyramid, the two carboxylate oxygen atoms occupying the axial sites. The \(\lambda_5\) Si~silicon(IV) complex 4 also exists in solution (DMSO, H\(_2\)O). KW - Anorganische Chemie KW - Silicon KW - pentacoordinate KW - Lambda5Si-Spirosilicate KW - zwitterionic KW - Citrato(2-)-03 KW - 04ligand Y1 - 1994 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-64388 ER - TY - JOUR A1 - Tacke, Reinhold A1 - Lange, H. T1 - Thermisch induzierte Umlagerung von (Acyloxymethyl)- diorganylsilanen T1 - Thermally Induced Rearrangement of (Acyloxymethyl)diorganylsilanes N2 - Die (Acyloxymethyl)diorganylsilane R\(^1\)R\(^2\)Si(H)CH\(_2\)OC(O)R\(^3\) (2a- d) unterliegen einer thermisch induzierten Umlagerung zu den entsprechenden Acyloxy(methyl)diorganylsilanen R\(^1\)R\(^2\)Si(CH\(_3\))OC(O)R\(^3\) (3a- d). Diese Reaktion beinhaltet formal einen Austausch des am Silicium gebundenen Wasserstoffs mit dem am Kohlenstoff gebundenen Acyloxy-Rest. Bezüglich der 1,2- Wasserstoff-Verschiebung konnte experimentell ein intramolekularer Prozeß bewiesen werden. N2 - The (acyloxymethyl)diorganylsilanes R\(^1\)R\(^2\)Si(H)CH\(_2\)OC(O)R\(^3\) (2a-d) rearrange to the corresponding acyloxy(methyl)diorganylsilanes R\(^1\)R\(^2\)Si(CH\(_3\))OC(O)R\(^3\) (3a-d). This reaction is formally equivalent to an exchange of the hydrogen bound to silicon and the acyloxy group bound to carbon. The 1 ,2-hydrogen shift could be shown experimentally to be an intramolecular process. KW - Anorganische Chemie Y1 - 1983 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-63752 ER - TY - JOUR A1 - Kaupp, Martin A1 - Stoll, Hermann A1 - Preuss, Heinzwerner A1 - Kaim, Wolfgang A1 - Stahl, Thomas A1 - van Koten, Gerard A1 - Wissing, Elmo A1 - Smeets, Wilberth J. J. A1 - Spek, Anthony L. T1 - Theoretical and Experimential Study of Diamagnetic and Paramagnetic Products from Thermal and Light-Induced Alkyl Transfer between Zinc or Magnesium Dialkyls and 1,4-Diaza-1,3-butadiene Substrates N2 - No abstract available KW - Anorganische Chemie Y1 - 1991 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-60173 ER - TY - JOUR A1 - Kaupp, Martin A1 - Schleyer, Paul von Rague T1 - The Structure and Stability Trends Fluoro(methyl)plumbanes N2 - No abstract available KW - Anorganische Chemie Y1 - 1992 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-60105 ER - TY - JOUR A1 - Kaupp, Martin A1 - Schleyer, Paul. von Rague T1 - The Structural Variations of Monomeric Alkaline Earth MX\(_2\)-Compounds (M = Ca, Sr, Ba; X = Li, BeH, BH\(_2\), CH\(_3\), NH\(_2\),OH, F). An ab Initio Pseudopotential Study N2 - No abstract available KW - Anorganische Chemie Y1 - 1992 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-60152 ER - TY - JOUR A1 - Kaupp, Martin A1 - Schleyer, Paul. von Rague A1 - Stoll, Hermann A1 - Preuss, Heinzwerner T1 - The Question of bending of the Alkaline Earth Dihalides MX\(_2\) (M = Be, Mg, Ca, Sr, Ba; X = F, C1, Br, I). An ab Initio Pseudopotential Study N2 - No abstract available KW - Anorganische Chemie Y1 - 1991 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-60166 ER - TY - JOUR A1 - Kaupp, Martin A1 - Schleyer, Paul von Rague T1 - The Peculiar Coordination of Brium: Ab Initio Study of the Molecular and Electronic Structures of the Group 2 Dihydride Dimers M\(_2\)H\(_4\) (M=Mg, Ca, Sr, Ba) N2 - No abstract available KW - Anorganische Chemie Y1 - 1993 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-60048 ER - TY - JOUR A1 - Kaupp, Martin A1 - Charkin, Oleg P. A1 - Schleyer, Paul von Rague T1 - The Ions MCp\(^{2+}\) (M = Sc, La): Significantly Bent Sandwich Species N2 - No abstract available KW - Anorganische Chemie Y1 - 1992 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-60082 ER - TY - JOUR A1 - Tacke, Reinhold A1 - Mühleisen, M. A1 - Jones, P. G. T1 - The first zwitterionic, optically active disilicate with pentacoordinate silicon N2 - No abstract available KW - Anorganische Chemie Y1 - 1994 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-64358 ER - TY - JOUR A1 - Kaupp, Martin A1 - Schleyer, Paul von Rague A1 - Dolg, Michael A1 - Stoll, Hermann T1 - The Equilibrium Structures of Monomeric Group 2 and Lanthanide(II) Metallocenes MCp2 (M = Ca, Sr, Ba, Sm, Eu, Yb) Studied by ab Initio Calculations N2 - No abstract available KW - Anorganische Chemie Y1 - 1992 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-60139 ER - TY - JOUR A1 - Kaupp, Martin A1 - Schnering, Hans Georg von T1 - The Dominance of Linear 2-Coordination in Mercury Chemistry: Quasirelativistic and Nonrelativistic ab Initio Pseudopotential Study of (HgX\(_2\))\(_2\) (X=F, Cl, Br, I, H) N2 - No abstract available KW - Anorganische Chemie Y1 - 1994 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59995 ER - TY - JOUR A1 - Tacke, Reinhold A1 - Rafeiner, K. A1 - Strohmann, C. A1 - Mutschler, E. A1 - Lambrecht, G. T1 - Synthesis of the selective antimuscarinic agent 4-{[cyclohexylhydroxy(2-methoxyphenyl)silyl]methyl}-1,1-dimethylpiperazinium methyl sulfate (o-methoxy-sila-hexocyclium methyl sulfate) N2 - The synthesis of the potent and highly selective silicon-containing antimuscarinic agent o-methoxysila- hexocyclium methyl sulfate and its corresponding tertiary amine (isolated as the dihydrochloride) is described. The quarternary compound is an omethoxy derivative of sila-hexocyclium methyl sulfate, which represents one of the tools currently used in experimental pharmacology for the subclassification of muscarinic receptors. The omethoxy derivative, the pharmacological profile of which differs substantially from tbat of the nonmethoxy compound, is also recommended as a tool for the investigation of muscarinic receptor heterogeneity. KW - Anorganische Chemie KW - o-methoxy-sila-hexocyclium KW - silahexocyclium KW - sila-drugs KW - antimuscarinics KW - muscarinic receptor subtypes Y1 - 1989 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-63930 ER - TY - JOUR A1 - Tacke, Reinhold A1 - Wagner, S. A. A1 - Brakmann, S. A1 - Wuttke, F. A1 - Eilert, U. A1 - Fischer, L. A1 - Syldatk, C. T1 - Synthesis of acetyldimethyl(phenyl)silane and its enantioselective conversion into (R)-(1-hydroxyethyl)dimethyl(phenyl)silane by plant cell suspension culytures of Symphytum officinale L. and Ruta graveolens L. N2 - Starting from chlorodimethyl(phenyl)silane (3), acetyldimethyl(phenyl)silane (l) was prepared by a two-step synthesis in a total yield of 90% [PhMe\(_2\)SiCl (3)-> PhMe\(_2\)SiCCOMe)=CH\(_2\) (4)-> PhMe\(_2\)SiC(O)Me (1)]. The prochiral acetylsilane 1 was transfonned enantioselectively into (R)-(1-hydroxyethyl)dimethyl(phenyl)silane [(R)-2] using plant cell Suspension cultures of Symphytum officinale L. or Ruta graveolens L. Under preparative conditions (300-mg scale, not optimized), (R)-2 was isolated in 15% (Symphytum) and 9% yield (Ruta), respectively. The enantiomeric purities of the products were 81% ee (Syrnphytum) and 60% ee (Ruta), respectively. KW - Anorganische Chemie Y1 - 1993 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-64299 ER - TY - JOUR A1 - Hengelsberg, H. A1 - Tacke, Reinhold A1 - Fritsche, K. A1 - Syldatk, C. A1 - Wagner, F. T1 - Synthesis and enantioselective enzymatic hydrolysis of rac-dimethylphenyl[1-(phenylacetamido)- ethyl]silane N2 - Racemic dimethylphenyl(l-(phenylacetamido)ethyl)silane [rac-5) has been made by a four-step synthesis starting from (chloromethyl)dimethylphenylsilane [PhMe\(_2\)SiCH2Cl (1) ~ PhMe\(_2\)SiCH(Cl)Me (rac-2) - PhMe\(_2\)SiCH(l)Me (rac-3) - PhMe2SiCH(NH2)Me (rac-4) ~ PhMe\(_2\)SiCH[N(H)C(O)CH\(_2\)Ph]Me ( rac-5); total yield 41% ). Enantioselective enzymatic hydrolysis of rac-5, catalyzed by immobilized penicillin G acylase (E.C. 3.5.1.11) from Escherichia coli 5K (pHM 12), gave (R)-(1- aminoethyl)dimethylphenylsilane [( R )-4] in 40% yield with an enantiomeric purity of 92% ee. KW - Anorganische Chemie Y1 - 1991 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-64153 ER - TY - JOUR A1 - Tacke, Reinhold A1 - Becht, J. A1 - Lopez-Mras, A. A1 - Sheldrick, W. S. A1 - Sebald, A. T1 - Syntheses, X-ray crystal structure analyses, and solid-state NMR studies of some zwitterionic organofluorosilicates N2 - No abstract available KW - Anorganische Chemie Y1 - 1993 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-64272 ER - TY - JOUR A1 - Tacke, Reinhold A1 - Lopez-Mras, A. A1 - Jones, P. G. T1 - Syntheses, crystal structure analyses, and NMR studies of [2-(dimethylammonio)phenyl]bis[glycolato(2-)-O1,O2]silicate and related zwitterionic spirocyclic \(\lambda_5\)Si-silicates N2 - No abstract available KW - Anorganische Chemie Y1 - 1994 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-64339 ER - TY - JOUR A1 - Tacke, Reinhold A1 - Lopez-Mras, A. A1 - Sheldrick, W. S. A1 - Sebald, A. T1 - Synthesen, Einkristall-Röntgenstrukturanalysen und \(^{29}\)Si-Festkörper-NMR-Untersuchungen eines zwitter- ionischen \(\lambda_5\)-Spirosilicats und eines käfigartigen Octa(silasesquioxans) : [Professor Hartmut Bärnighausen zum 60. Geburtstage gewidmet] T1 - Syntheses, Single-Crystal x ... Ray Analyses and Solid-State \(^{29}\)Si NMR Studies of a Zwitterionic \(\lambda_5\)-Spirosilicate and a Cage-like Octa(silasesquioxane) N2 - No abstract available KW - Anorganische Chemie Y1 - 1993 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-64243 ER - TY - THES A1 - Öchsner, Andreas T1 - Synthese, Struktur und Reaktivität von [2]Borametallocenophanen der Gruppe 4 Metalle : Ihr katalytisches Verhalten und die Eigenschaften der erhaltenen Polymere T1 - Synthesis, structure and reactivity of [2]borametallocenophanes of group 4 metals : Their catalytic behaviour and properties of the obtained polymers N2 - In der vorliegenden Arbeit wird die Darstellung einer Reihe monoarylsubstituierter Bisdimethylamino-1-bromo-2-arlydiborane(4) beschrieben. Sowohl die Umsetzung der monoarylsubstituierten Ligandenvorstufen mit einem weiteren Äquivalent Lithium- oder Natriumaryl in einem Ether/Toluol-Gemisch als auch die Umsetzung von 1,2-Dibrom-bis(dimethylamino)diboran(4) mit einem mehrfachen Überschuss Lithium- oder Natriumaryl führte zur Bildung von diarylsubstituierten Diboranen(4). Umsetzung der Ligandenvorstufen mit Lithiumorganylen, wie beispielsweise Li[CH3] oder Li[C4H9] führt zu doppelt deprotonierten Verbindungen. Werden die dilithiierten Verbindungen mit Metallhalogeniden der Gruppe 4 in einem Toluol/Ether-Gemisch umgesetzt, können [2]Borametallocenophane erhalten werden. Von einigen der Verbindungen konnte die Struktur im Festkörper mittels Einkristallstrukturanalyse bestimmt werden. Die Verbindungen zeigen in Lösung ein dynamisches Gleichgewicht, welches durch die Flexibilität der B-B-Brücke ermöglicht wird. Dieses konnte mittels NMR Spektroskopie untersucht werden. Auch die Reaktivität der Verbindungen wurde erforscht. Versuche zur oxidativen Addition von Platin(0) in die B-B-Bindung, wie sie bereits für ähnliche Systeme beschrieben waren, scheiterten. Ebenfalls nicht erfolgreich war der versuchte Austausch der Dimethylaminogruppen an den Bor-Atomen. Di(fluorenyl)substituierte [2]Borametallocenophane zeigen in der Reihe der dargestellten Verbindungen ein einzigartiges Verhalten. Wird die dilithiierte Liganden-Vorstufe bei der Umsetzung mit den Metallhalogeniden der Gruppe 4 Licht ausgesetzt, so lagert sie zum 1,3-Diboretan um. Auch oxidativ kann diese Umlagerung ausgelöst werden. Das Umlagerungsprodukt war von anderen Reaktionen bereits bekannt, konnte im Rahmen dieser Arbeit aber erstmals strukturell charakterisiert werden. Die Dichloroverbindungen der [2]Borametallocenophane können mittels Li[CH3] in die entsprechenden Dimethylkomplexe überführt werden. Damit besteht die Möglichkeit, die Verbindungen nicht nur mit MAO, sondern auch mit alternativen Co-Katalysatoren, wie beispielsweise Tris-(pentafluorphenyl)boran für die Olefinpolymerisation zu aktivieren. Die Aktivierung mittels MAO wurde sowohl mittels NMR- als auch mittels UV/Vis-Spektroskopie bei verschiedenen [Al]/[Zr] Verhältnissen untersucht. Neben den [2]Borametallocenonphanen konnte mit Verbindung [(n5-C29H37)2ZrCl2] das erste Metallocen mit dem neuen OctafluH-Liganden und zwei koordinierenden Arylgruppen dargestellt werden. Um die Polymerisationseigenschaften der Verbindungen zu untersuchen, wurde ein neuer Versuchsaufbau entworfen. Zur Überwachung der Polymerisationen wurde ein Programm entwickelt, was in der Lage war, verbrauchte Gasmenge und Temperatur im Reaktoraufzuzeichnen. Hier wurden die katalytischen Eigenschaften einer Serie von [2]Borametallocenophanen und des dargestellten Metallocens [(n5-C29H37)2ZrCl2] in der Ethen-Homopolymerisation untersucht. Diese Polymere wurden mittels DSC auf ihre thermischen Eigenschaften hin geprüft. Ausgewählte Polymere wurden in Zusammenarbeit mit der LyondellBasell Industries, Basell Polyolefine GmbH, Frankfurt mittels GPC auf ihr mittleres Molekulargewicht und dessen Verteilung hin untersucht. Alle Daten wurden mit denen von industriell verwendeten Katalysatoren und den von Kraft bekannten [1]Borametallocenophanen verglichen. In weiteren Untersuchungen wurde überprüft, in wie weit die Polymerisationsbedingungen, wie beispielsweise das [Al]/[Zr]-Verhältnis, die Temperatur oder der Druck Auswirkungen auf die Eigenschaften des Polymers haben. Eine Reihe von Komplexen wurde überdies in der Ethen/[1]Hexen-Copolymerisation untersucht. Die erhaltenen Copolymere wurden mittels DSC-, GPC-, IR- und NMR- Spektroskopie analysiert. Zusammenfassend lässt sich feststellen, dass eine Reihe neuer Verbindungen dargestellt und charakterisiert werden konnte, wobei insbesondere der neuartige Ligand OctafluH (C29H38) eingesetzt wurde. Die dargestellten [2]Borametallocenophane sind aktive Katalysatoren in der Ziegler-Natta ähnlichen Olefinpolymerisation. Die dargestellten Polymere wurden mittels verschiedener Methoden untersucht. Es zeigte sich, dass [2]Borametallocenophane langkettige Polyolefine und Ethen/1-Hexen Copolymere liefern können. N2 - Based on Krafts work on [1]borametallocenophanes, a various number of monoarylsubstituted bisdimethylamino-1-bromo-2-aryldiboranes(4) were synthesized in the present work. Either the reaction of these monoarylsubstituted compounds with one equivalent of a lithiumaryl in toluene/ether or direct reaction of 1,2-dibromo-bis(dimethylamino)diborane(4) with a large excess of the lithiumaryl leads to the formation of diaryl substituted diboranes(4). Reaction of the ligand precursors with lithium organyls, e.g. Li[CH3] or Li[C4H9] leads to double deprotonation. [2]Borametallocenophanes are accessible via reaction of the dilithiated species with metal halides of Group 4 in toluene/ether. Due to the flexibility of the B-B-bridge, these complexes show dynamic behaviour in solution, which can be monitored by NMR spectroscopy. The solid state structure of some of these complexes could be examined by X-Ray diffraction. The reactivity of the new [2]borametallocenophanes also was reviewed. An oxidative addition reaction of platinum(0) was published for similar systems, but failed in this case. Neither was it possible to substitute the bisdimethylamino-groups bound to the boron-atoms. The prepared di(fluorenyl)substituted [2]borametallocenophanes show a unique feature. If the dilithiated precursor is exposed to visible or UV light during reaction with metal halides of group 4, these complexes rearrange to the 1,3-diboretane. This rearrangement also can be performed oxidatively. The Compound has been previously characterized in solution by multinuclear NMR spectroscopy; its structure in the solid state is now reported for the first time. The [2]borametallocenophanedichlorides can be reacted with Li[CH3], resulting in the corresponding dimethyl complexes. This allows for an alternative activation of the complexes with co-catalysts like tris(pentafluorophenyl)borane, in addition to the common activation with MAO. A model reaction for this alternative activation was performed using K[B(C6F5)4] to obtain a ion pair via chlorine abstraction. The common activation of the metal complexes using MAO was monitored either by NMR- or by UV/Vis-spectroscopy at various [Al]/[Zr] ratios. In addition to the [2]borametallocenophanes, [(n5-C29H37)2ZrCl2] could be prepared. It is the first metallocene with two aryl groups of the new octafluH-ligand (C29H38). To analyse the activity of the compounds in olefin polymerization processes, a new experimental set-up was designed. To control the polymerisation reactions, a Software program was developed, which allowed us to record gas-consumption and temperature in the reactor simultaneously. The catalytic behaviour of a whole series of [2]borametallocenophanes and of compound [(η5-C29H37)2ZrCl2] was studied in ethene homopolymerization. The thermal properties of all produced polymers where analyzed by DSC. The molecular weight distribution of selected examples was studied in cooperation with LyondellBasell Industries, Basell Polyolefine GmbH with GPC analyses. All data where directly compared to reference catalysts and to the [1]borametallocenophanes made by Kraft. The data show, that [2]borametallocenophanes have lower activities than [1]borametallocenophanes, but produce polymers of significantly higher average molecular weight. One can see clear differences throughout the data of the DSC measurements, for instance in the melting point and metling range, or crystallinity of the polymer. The melting points of the polymers obtained from [2]borametallocenophanes and compound [(n5-C29H37)2ZrCl2] are significantly higher than those of the reference catalysts. Additional experiments gave some insight into the relationship between polymerization conditions, e.g. the [Al]/[Zr] ratio, temperature or pressure and the key features of the polymers. It was shown that all these parameters influence the melting point and other specific values of the polymer. Additionally, selected examples were tested in the ethene/1-hexene copolymerization. The copolymers have been analyzed using DSC, GPC, IR and NMR spectroscopy. In conclusion, some new products were prepared and analyzed, in many cases with OctafluH (C29H38) as a substituent. All [2]borametallocenophanes are active catalysts in Ziegler-Natta type olefin polymerization processes. Analyses of the produced polymers revealed that [2]borametallocenophanes can produce long-chain polyethylene and ethene/1-hexene copolymers. KW - Anorganische Chemie KW - Homogene Katalyse KW - Ziegler-Natta-Katalysator KW - Metallocene KW - Bor KW - Polyolefine KW - Metallocenophane KW - metallocenophanes Y1 - 2009 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-44444 ER - TY - THES A1 - Bissinger, Philipp T1 - Synthese, Struktur und Reaktivität Basen-stabilisierter Borane und Diborene T1 - Synthesis, Structure and Reactivity of Base Stabilized Boranes and Diborenes N2 - Umsetzungen N-heterocyclischer Carbene mit Boranen führen zur Bildung von „Lewis-Säure-Base-Addukten“. In Abhängigkeit des Substitutionsmusters der eingesetzten Borane bzw. Carbene eignen sich die erhaltenen Addukte als Ausgangsverbindungen zur Realisierung verschiedener Strukturmotive. Mit geeigneten Übergangsmetallfragmenten gelingt die Darstellung von sigma-Boran-Komplexen bzw. Basen-stabilisierter Boryl-Komplexe, welche mittels spektroskopischer Methoden sowohl im Festkörper, als auch in Lösung untersucht wurden. Ebenfalls gelingt die Synthese Basen-stabilisierter Borirane und einer tetraedrischen Borid-Spezies. Zudem wird ein selektiver Zugang zu Basen-stabilisierten Diborenen entwickelt, wobei deren Bindungssituation und Reaktivität im Detail diskutiert wird. So kann das B=B-Fragment in polymere Spezies eingebunden werden oder als Ligand an Übergangsmetalle koordinieren. N2 - Reaction of boranes with N-heterocyclic carbenes results in the formation of „Lewis-acid-base-adducts“. Depending on the substitution pattern of the boranes and carbenes, respectively, these adducts represent versatile starting materials for the realization of a diversity of different structural motifs. Treatment with suitable transition-metal fragments for instance afforded sigma-borane complexes and base-stabilized boryl complexes. These species are characterized in the solid state by X-ray diffraction, as well as by spectroscopy in solution. In addition, the synthesis of base-stabilized boriranes and a tetrahedral boride species is described. Moreover, a selective approach for the synthesis of base-stabilized diborenes is developed and their bonding situation and reactivity is studied in detail. Thus, the B=B moiety can be incorporated into polymeric structures or act as a ligand in the coordination sphere of transition-metals. KW - Borane KW - Carbene KW - Lumineszenz KW - Polymere KW - boron KW - inorganic chemistry KW - carbenes KW - luminescence KW - polymers KW - Bor KW - Anorganische Chemie Y1 - 2013 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-79144 ER - TY - THES A1 - Junold, Konstantin T1 - Synthese, Struktur und Eigenschaften neuer höherkoordinierter Silicium(II)- und Silicium(IV)-Komplexe T1 - Synthesis, structure, and reactivity of novel higher-coordinate silicon(II) and silicon(IV) complexes N2 - Die vorliegende Arbeit stellt einen Beitrag zur Chemie des höherkoordinierten Siliciums dar. Im Vordergrund standen die Synthese und Charakterisierung neuer neutraler penta- und hexakoordinierter Silicium(IV)-Komplexe sowie die Synthese, Charakterisierung und Untersuchung der Reaktivität eines neuartigen Donor-stabilisierten Silylens. N2 - This thesis is a contribution to the chemistry of higher-coordinate silicon. The main focus of this work was the synthesis and characterization of novel neutral five- and six-coordinate silicon(IV) complexes as well as the synthesis, characterization, and reactivity of a novel donor-stabilized silylene. KW - Siliciumkomplexe KW - Silicium(IV)-Komplexe KW - Silicium(II)-Komplexe KW - Silicon(IV) Complexes KW - Silicon(II) Complexes KW - Höherkoordinierte Verbdinungen KW - Higher-coordinate Compounds KW - Pentakoordination KW - Hypervalentes Molekül KW - Silylen KW - Anorganische Chemie Y1 - 2014 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-104848 ER - TY - JOUR A1 - Tacke, Reinhold A1 - Fritsche, K. A1 - Tafel, A. A1 - Wuttke, F. T1 - Synthese von racemischem Acetyl(t-butyl)methylphenylsilan und Acetylmethylphenyl[(trimethylsilyl)methyl]silan: Substrate für stereoselektive mikrobielle Reduktionen KW - Anorganische Chemie Y1 - 1990 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-64055 ER - TY - JOUR A1 - Tacke, Reinhold A1 - Wagner, S. A. A1 - Sperlich, J. T1 - Synthese von (-)-(Acetoxymethyl)(hydroxy-methyl)methyl(phenyl)german [(-)-MePhGe(CH\(_2\)OAc)(CH\(_2\)OH)] durch eine Esterase-katalysierte Umesterung: Die erste enzymatische Synthese eines optisch aktiven Germans N2 - No abstract available. KW - Anorganische Chemie KW - Germane KW - optically active KW - Biotransformation KW - stereoselective Transesterification KW - enzymatic KW - Porcine liver esterase Y1 - 1994 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-64310 ER - TY - JOUR A1 - Tacke, Reinhold A1 - Becker, B. T1 - Synthese und Eigenschaften von (Hydroxymethyl)dimethylgerman und (Hydroxymethyl)diphenylgerman N2 - Die (Hydroxymethyl)diorganylgermane (CH\(_3\))\(_2\)Ge(H)CH\(_2\)OH und (C\(_6\)H\(_5\))\(_2\)Ge(H)CH\(_2\)OH wurden - ausgehend von GeCl\(_4\) - durch eine jeweils vierstufige Synthese mit einer Gesamtausbeute von 15 bzw. 32% dargestellt (GeCl\(_4\) ---+ Cl\(_3\)GeCH\(_2\)Cl -> R \(_2\)Ge(Cl)CH \(_2\)Cl ->R \(_2\)Ge(OAc)CH\(_2\)OAc--) R \(_2\)Ge(H)CH\(_2\)OH; R = CH\(_3\) bzw. C\(_6\)H\(_5\) ). Die chemische Reaktivität der Germane (CH\(_3\))\(_2\)Ge(H)CH\(_2\)OH und (C\(_6\)H\(_5\))\(_2\)Ge(H)CH\(_2\)OH wird durch deren Ge-H- und 0-H-Bindung bestimmt. N2 - Starting from GeCl\(_4\) , the (hydroxymethyl)diorganylgermanes (CH\(_3\)) \(_2\)Ge(H)CH\(_2\)- 0H and (C\(_6\)H\(_5\)) \(_2\)Ge(H)CH\(_2\)OH were prepared by a four-step synthesis in total yields of 15 and 32%, respectively (GeCl\(_4\) ---. Cl\(_3\)GeCH\(_2\)Cl -> R \(_2\)Ge(Cl)CH\(_2\)Cl -> R \(_2\)Ge(OAc)CH\(_2\)OAc--+ R \(_2\)Ge(H)CH\(_2\)OH; R = CH\(_3\) or C\(_6\)H\(_5\) ). The chemical reactivity of (CH\(_3\) ) \(_2\)Ge(H)CH\(_2\)OH and (C\(_6\)H\(_5\)) \(_2\)Ge(H)CH \(_2\)OH was found to be determined by their Ge-Hand 0-H bonds. KW - Anorganische Chemie Y1 - 1988 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-63895 ER - TY - JOUR A1 - Tacke, Reinhold A1 - Lange, H. A1 - Bentlage, A. T1 - Synthese und Eigenschaften von (Hydroxy-methyl)diorganylsilanen T1 - Synthesis and Properties of (Hydroxymethyl)diorgaoylsilanes N2 - The synthesis of the (hydroxymethyl)diorganylsilanes R\(^1\)R\(^2\)Si(H)CH\(_2\)OH (4a: R\(^1\) = R\(^2\) = CH\(_3\), 2-silaisobutanol; 4b: R\(^1\) = CH\(_3\), R\(^2\) == C\(_6\)H\(_5\); 4c: R\(^1\) == R\(^2\) = C\(_6\)H\(_5\))is achieved bythereactionof R\(^1\)R\(^2\)Si(Cl)CH\(_2\)Cl (2a-c) with AcOH/NEt\(_3\) to R\(^1\)R\(^2\)Si(OAc)CH\(_2\)OAc (Ja-c), followed by treating with LiAlH\(_4\) and hydrolysis. KW - Anorganische Chemie Y1 - 1982 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-63727 ER - TY - JOUR A1 - Tacke, Reinhold A1 - Linoh, H. A1 - Zilch, H. A1 - Wess, J. A1 - Moser, U. A1 - Mutschler, E. A1 - Lambrecht, G. T1 - Synthese und Eigenschaften des selektiven Antimuskarinikums Cyclohexylphenyl(3-piperidinopropyl)silanol T1 - Syntbesis and Properries of the Selective Antimuscarinic Agent Cyclohexylphenyl(3-piperidinopropyl)silanol N2 - Die Synthese des selektiven Antimuskarinikums Cyclohexylpheny\{3-piperidinopropyl)sila· nol (1 b) wird beschrieben. 1 b wurde - ausgehend von (3·Chlorpropyl)trimethoxysilan - durch eine vierstufige Reaktionsfolge erhalten und als Hydrochlorid 2b mit einer Gesamtausbeute von etwa 45°/o isoliert. - 1 b ist aufgrund seiner großen pharmakologischen Se· lektivität zu einer Standardsubstanz in der experimentellen Pharmakologie bei der Differenzierung von Muskarinrezeptoren geworden. N2 - The synthesis of thc selective antimuscarinic agent cyclohexylphenyl(3-piperidinopropyl)silanol (1 b) is described. Starting with (3-chloropropyl)trimethoxysilane, I b was obtained by four reaction steps and isolated as hydrochloride 2b with a total yield of about 45°/o. - Because of its high pharmacological selectivity 1 b has become a reference drug in experimental pharmacology for the differentiation of muscarinic rcceptors. KW - Anorganische Chemie Y1 - 1985 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-63798 ER - TY - JOUR A1 - Tacke, Reinhold A1 - Linoh, H. A1 - Rafeiner, K. A1 - Lambrecht, G. A1 - Mutschler, E. T1 - Synthese und Eigenschaften des selektiven Antimuscarinikums Sila-Hexocyclium-methylsulfat N2 - Sila-Hexocyclium-methylsulfat (7b), ein Silicium-Analogon des therapeutisch eingesetzten Antimuscarinileums Hexocyclium-methylsulfat (7a), wurde durch eine sechsstufige Synthese - ausgehend von (CH\(_3\)0)\(_3\)SiCH\(_2\)Cl - dargestellt (Gesamtausbeute 16%). Außerdem wurden die hiervon abzuleitende freie Base 9b (fünfstufige Synthese, ausgehend von (CH\(_3\)0)\(_3\)SiCH\(_2\)O; Gesamtausbeute 29%) und das strukturverwandte (Aminomethyl)silanol 13 (dreistufige Synthese, ausgehend von cyclo-C\(_6\)H\(_{11}\)(C\(_6\)H\(_5\))Si(OCH\(_3\))CH\(_2\)Cl, Gesamtausbeute 46$) synthetisiert. 7b ist ein hochwirksames und selektives Antimuscarinikum, das in der experimentellen Pharmakologie aufgrund seines bemerkenswerten Selektivitätsprofils zur Klassifizierung von Subtypen muscarinischer Rezeptoren eingesetzt wird. N2 - Sila-hexocyclium methyl sulfate (7b), a silicon analogue of the antimuscarinic agent hexocyclium methyl sulfate (7a), has been prepared by a six-step synthesis (total yield 16%) starting from (CH\(_3\)O)\(_3\)SiCH\(_2\)Cl. In addition, the corresponding free base (a five-step synthesis, starting from (CH\(_3\)O)\(_3\)SiCH\(_2\)Cl; total yield 29%) and the structurally related (aminomethyl)silanol (a three-step synthesis, starting from cyclo-C\(_6\)H\(_{11}\)(C\(_6\)H\(_5\))Si(OCH\(_3\))CH\(_2\)Cl; total yield 46%) have been synthesized. 7b is a potent and highly selective antim.uscarinic agent. Because of its remarkable selectivity profile, it is used in experimental phannacology to classify the various subtypes of musearlnie receptors. KW - Anorganische Chemie Y1 - 1989 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-63921 ER - TY - JOUR A1 - Tacke, Reinhold A1 - Lopez-Mras, A. A1 - Becht, J. A1 - Sheldrick, W. S. T1 - Synthese sowie Kristall- und Molekülstruktur von Tetrafluoro[2-(pyrrolidinio)ethyl]silicat T1 - Synthesis and Crystal and Molecular Structure of Tetrafluoro[2-(pyrrolidinio)etbyl]silicate N2 - Das zwitterionische Tctratluoro[2-(pyrrolidinio) ethyl]silicat (4) wurde durch Reaktion von Trimethoxy( 2-pyrrolidinoethyl)silan (5) mit Fluorwasserstoff in einem Ethanol/Flußsäure-Gemisch bei 0 °C synthetisiert. Die Kristall- und Molekülstruktur von 4 wurde bei - 100 °C mittels einer Einkristall-Röntgenstrukturanalyse untersucht. Außerdem wurde 4 durch NMR-Untersuchungen in Lösung charakterisiert (CD\(_3\)CN: \(^1\)H, \(^{13}\)C). N2 - The zwitterionic tetrafluoro[2-(pyrrolidinio) ethyl]silicate (4) was synthesized by reaction of trimethoxy( 2-pyrrolidinoethyl)silane (5) with hydrogen fluoride in elhanollhydrofluoric acid at 0 °C. The crystal and mo1ecular structure of 4 was studied at - 100 °C by singlc-crystal X-ray diffraction. ln addition, 4 was characterized by solution-state NMR sturlies (CD\(_3\)CN: \(^1\)H, \(^{13}\)C). KW - Anorganische Chemie KW - Zwitterionic KW - Lambda5-organofluorosilicate KW - pentacoordinate silicon KW - crystal structure Y1 - 1993 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-64269 ER - TY - JOUR A1 - Tacke, Reinhold A1 - Hengelsberg, H. A1 - Klingner, E. A1 - Henke, H. T1 - Synthese der Si-funktionellen Acetylsilane tBu(Me\(_3\)SiCH\(_2\))[MeC(O)]SiF und tBu(Me\(_3\)SiCH\(_2\))[MeC(O)]SiH sowie Synthese und Kristallstruktur des Acetylsilanols tBu(Me\(_3\)SiCH\(_2\))[MeC(O)]SiOH: Substrate für mikrobielle Reduktionen N2 - The racemic Si-functional acetylsilanes tBu(Me\(_3\)SiCH\(_2\))[ MeC(O)]SiF (1) and tBu(Me\(_3\)SiCH\(_2\))[MeC(O)]SiH (2) and the racemic acetylsilanol tBu(Me\(_3\)SiCH\(_2\))[MeC(O)]SiOH (3) were synthesized from Si(OMe)\(_4\) (4) as substrates for microbial reductions [4 -> tBuSi(OMe)\(_3\) (5) -> tBu(Me\(_3\)SiCH\(_2\))Si(OMe)\(_2\) (6) -> tBu(Me\(_3\)SiCH\(_2\))SiF\(_2\) (7)-> tBu(Me\(_3\)SiCH\(_2\))(CH\(_2\) = C(OMe))SiF (8) -> 1; 8 -> tBu(Me\(_3\)SiCH\(_2\))[CH\(_2\) = C(OMe)]SiH (9) -> 2; 6 -> tBu(Me\(_3\)SiCH\(_2\))[CH\(_2\) = C(OMe)]SiOMe (10) -> 3]. Compounds 1-3 were found to be reduced by cells of Trigonapsis variabilis (DSM 70714) ( = SiC(O)Me -> = SiCH(OH)Me}. The crystal and molecular structure of 3 was studied by singlecrystal X-ray diffraction. In the crystal, racemic 3 forms infinite chains built up by intermolecular 0-H .. ·O bonds between the hydroxyl and acetyl groups of molecules of the same absolute configuration. KW - Anorganische Chemie KW - Silanes KW - acetyl- KW - Si-functional KW - Silanol KW - crystal structure of KW - Microbial reduction Y1 - 1992 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-64192 ER - TY - JOUR A1 - Werner, Helmut A1 - Kuehn, Alfred A1 - Burschka, Christian T1 - Strukturdynamische Organometall-Komplexe II: Synthese, Struktur und Dynamik der Komplexe C\(_5\)H\(_5\)M(2-R'C\(_3\)H\(_4\))PR\(_3\) (M = Pd, Pt) T1 - Structurally dynamic organometallic complexes II: Synthesis, structure, and dynamics of the complexes C\(_5\)H\(_5\)M(2-R'C\(_3\)H\(_4\))PR\(_3\) (M = Pd, Pt) N2 - No abstract available KW - Anorganische Chemie Y1 - 1980 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-57853 ER - TY - JOUR A1 - Kaupp, Martin A1 - Schleyer, Paul von Rague T1 - Struktur- und Stabilitätstrends bei Fluor(methyl)plumbanen N2 - No abstract available KW - Anorganische Chemie Y1 - 1992 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-60091 ER - TY - JOUR A1 - Waelbroeck, M. A1 - Camus, J. A1 - Tastenoy, M. A1 - Lambrecht, G. A1 - Mutschler, E. A1 - Tacke, Reinhold A1 - Christophe, J. T1 - Stereoselectivity of procyclidine binding to muscarinic receptor subtypes M\(_1\), M\(_2\) and M\(_4\) N2 - The goals of the present study were: (1) to investigate thc binding properlies oi (R)- and (S)-procyclidine and two aehiral derivatives of muscarinic M\(_1\)• M\(_2\) and M\(_4\) receptor subtypes and (2) to identify the interaetions which allow these receptors to diseriminate between the two stereoisomers. (R)-Procyclidine showed a higher affinity for human neuroblastoma NB-OK 1 muscarinie M\(_1\) and rat striatum musearinie M\(_4\) receptors. a~ compared to rat cardiac M\(_2\) receptors. (S)-Procyclidine had a 130-iold lower affinity than (R)-procyclidine for M\(_1\) and M\(_4\) receptors. and a 40-fold lower affinity for M\(_2\) receptors. Pyrrinol. the aehiral diphenyl derivative with the eyclohexyl g.roup of (S}-procyclidine replaeed by a phenyl group, has an eight-fold lower affinity for M\(_1\) and M\(_4\) receptors. as eompared to (R)-procyclidine, and a three-fold lower affinity for M\(_2\) receptors. Hexahydro-procyclidine. the eorresponding achiral dicyclohexyl compound, had a 10- to 20-fold lower affinity than (R)-procyclidine for the three reeeptors. The inerease in binding free energy, which is observed when the phenyl and eyclohexyl groups of procyelidine are separately replaeed by cyclohexyJ and phenyl groups, respectively. was additive in the ease of M\(_1\)• M\(_2\) and M\(_4\) receptcrs. This indicates that the musearinic reeeptor s!ereoseleetivity was based on the eoexistence of two binding sites, one preferring a phenylrather than eyclohexyl group and the seeond preferring a cyclohexyl rather than a phenyl group. In addition. there were aiso binding sites for the hydroxy moiety and the protonated amino group of the ligands. The greater affinity and stereoselectivity of M\(_1\) and M\(_4\) muscarinic receptors for (R)-procyelidine reflected the better fit of the eyclohexyl group of (R)-procyclidine to the subsite of M\(_1\) and M\(_4\) as compared to M\(_2\) receptors. KW - Anorganische Chemie KW - Musearlnie M1 KW - receptors KW - Muscarinie M2 receptors KW - Musearinic M4 receptors KW - Pyrrinol KW - Hexahydro-procyclidine KW - Muscarinic receptors Y1 - 1990 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-64034 ER - TY - JOUR A1 - Waelbroeck, M. A1 - Camus, J. A1 - Tastenoy, M. A1 - Mutschler, E. A1 - Strohmann, C. A1 - Tacke, Reinhold A1 - Lambrecht, G. A1 - Christophe, J. T1 - Stereoselectivity of (R)- and (S)-hexahydro-difenidol binding to neuroblastoma M\(_1\), cardiac M\(_2\), pancreatic M\(_3\), and striatum M\(_4\) muscarinic receptors N2 - (R)-Hexahydro-difenidol has a higher affinity for M\(_1\) receptors in NB-OK 1 cells, pancreas M\(_3\) and striatum M\(_4\) receptors (pKi 7.9 to 8.3) than for cardiac M2 receptors (pKi 7 .0). (8)-Hexahydro-difenidol, by contrast, is nonselective (pKi 5.8 to 6.1). Our goal in the present study was to evaluate the importance ofthe hydrophobic phenyl, and cyclohexyl rings of hexahydro-difenidol for the stereoselectivity and reeeptor selectivity of hexahydro-difenidol binding to the four muscarinic receptors. Our results indieated that replacement of the phenyl ring of hexahydro-difenidol by a cyclohexyl group <~ dicyclidol) and ofthe cyclohexyl ring by a phenyl moiety <~ difenidol) indueed a !arge (4- to 80-fold) decrease in binding affinity for all musearlnie receptors. Difenidol had a signifieant preference for M\(_1\) , M\(_3\) , and M\(_4\) over M\(_2\) receptors; dicyclidol, by eontrast, had a greater affinity for M\(_1\) and M\(_4\) than for M\(_2\) and M\(_3\) receptors. The binding free energy deerease due to replacement ofthe phenyl and the cyelohexyl groups of(R)-hexahydro-difenidol by, respectively, a eyclohexyl and a phenyl moiety was almostadditive in the ease of M\(_4\) (striatum) binding sites. In the ease ofthe cardiac M\(_2\), pancreatic M\(_3\) , or NB-OK 1 M\(_1\) receptors the respective binding free energies were not eompletely additive. These results suggest that the four (R)-hexahydro-difenidol ''binding moieties" (phenyl, cyclohexyl, hydroxy, and protonated amino group) cannot simultaneously form optimal interaetions with the M\(_1\), M\(_2\), and M\(_3\) muscarinic receptors. When eaeh of the hydrophobic groups is modified, the position of the whole molecule, relative to the four subsites, was changed to allow an optimal overall interaction with the musearlnie receptor. KW - Anorganische Chemie KW - hexahydro-difenidol enantiomers KW - muscarinic receptor subtypes KW - stereoselective interaction KW - difenidol KW - dicyclidol Y1 - 1991 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-64135 ER - TY - JOUR A1 - Tacke, Reinhold A1 - Brakmann, S. A1 - Wuttke, F. A1 - Fooladi, J. A1 - Syldatk, C. A1 - Schomburg, D. T1 - Stereoselective microbial reduction of racemic acetyl(t-butyl)methylphenylsilane by Trigonopsis variabilis (DSM 70714) and Corynebacterium dioxydans (ATCC 21766) N2 - (SiR,CR)- and (SiS,CR)-t-butyl(l-hydroxyethyl)methylphenylsilane [(SiR,CR)-2 and (SiS,CR)-3] have been prepared by (R)-selective microbial rcduction of racemic acetyl(t-butyl)methylphenylsilane (rac-1) using resting free cells of the yeast Trigonopsis variabilis (DSM 70714) or the bacterium Corynebacterium dioxydans (ATCC 21766). The biotransfonnations were carried out on a 10 g scale. Afterseparation by column chromatography on silica gel, the optically active diastereomers (SiR,CR)-2 and (SiS,CR)-3 produccd by T. variabilis were obtained in good yields [74% ((SiR,CR)-2). 78% ((SiS,CR)-3)]. The products obtained from the reduction with C. dioxydans were isolated in significantly lower yields [20% ((SiR,CR)-2), 20% ((SiS,CR)-3)]; reaction conditions not optimized). Both bioconversions gave products with high enantiomeric purities (T. variabilis: 91% ee ((SiR,CR)-2), 96% ee ((SiS,CR)-3); C. dioxydons: ~ 991 ee ((SiR,CR)-l), ~ 99% ee ((SiS,CR)-3)). To throw light on the stereochemical aspects of these biotransfonnations, an X-ray diffraction study was carried out on the 3,5-dinitrobenzoate of rac-(SiR,CS/SiS,CR)-3. In addition, 1H NMR spectroscopic stereochemical correlation studies were performed with the (S)-MTPA esters derived from (SiR,CR)-l, (SiS,CR)-3, rac-(SiR,CRjSiS,CS)-2 and rac-(SiR,CSjSiS,CR)-3 [rac-(SiR,CR/ SiS,CS)-2 and rac-(SiR,CS/SiS,CR)-3 were obtained by reduction of rac-1 with LiAIH\(_4\) in diethylether, followed by chromatographic separation of the diastereomers on silica gel]. These stereochemical studies allowed assignment of the absolute configurations and enantiomeric purities of the biotransformation products. KW - Anorganische Chemie Y1 - 1991 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-64109 ER - TY - JOUR A1 - Waelbroeck, M. A1 - Camus, J. A1 - Tastenoy, M. A1 - Mutschler, E. A1 - Strohmann, C. A1 - Tacke, Reinhold A1 - Schjelderup, L. A1 - Aasen, A. A1 - Lambrecht, G. A1 - Christophe, J. T1 - Stereoselective interaction of procyclidine, hexahydro-difenidol, hexbutinol and oxyphencyclimine, and of related antagonists, with four muscarinic receptors N2 - Wc invcstigatcd thc binding properlies of thc (R)- and (Sl-cnantiomcrs of thc muscarinic antagonists trihcxyphcnidyl, procyclidinc, hcxahydro-difcnidol. p-fluoro-hcxahydro-difcnidol. hcxbutinol, p-fluoro-hcxbutinnl. and thcir corrcsponding methiodidcs at muscarinic M\(_1\), M\(_2\)• M\(_3\) and M\(_4\) receptor subtypes. In addition. binding properlies of thc (R)- and (S)-cnantiomcrs of oxyphcncycliminc wcrc studicd. The {R)- cnantiomcrs (cutomcrs} of all the compounds had a grcatcr affinity than the (S)-isomcrs for thc four muscarinic rcccptor subtypcs. Thc binding pattcrns of thc (R)- and (S)-enantiomers wcrc gcncrally different. We did not obscrvc any gcncral corrclation hctwccn thc potcncy of thc high-affinity enantiomer and Lhc affinity ratio (cudismic ratio) of the two cnantiomcrs. Thc rcsuhs arc discusscd in tcrms of a 'four suhsitcs' binding modcl. KW - Anorganische Chemie KW - Muscarinic receptors KW - Hexahydro-difenidol KW - Oxyphencyclimine Y1 - 1992 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-64237 ER - TY - JOUR A1 - Feifel, R. A1 - Wagner-Röder, M. A1 - Strohmann, C. A1 - Tacke, Reinhold A1 - Waelbroeck, M. A1 - Christophe, J. A1 - Mutschler, E. A1 - Lambrecht, G. T1 - Stereoselective inhibition of muscarinic receptor subtypes by the enantiomers of hexahydro-difenidol and acetylenic analogues N2 - 1 Tbc affinities of the (R)- and (S)-enantiomers of hexahydro-difenidol (1) and its acetylenie analogues hexbutinol (2), hexbutinol methiodide (3) and p-fluoro-hexbutinol (4) (stereochemieal purity > 99.8%) for musearlnie receptors in rabbit vas deferens (M1), guinea-pig atria (M2) and guinea-pig ileum (M3) were measured by dose-ratio experiments. 2 The (R)-enantiomers consistently showed higher aßinities than the (S)-isomers. The stereosclectivity ratios [(R)/(S)] wcrc greatest with thc enantiomers of 1 (vas deferens: 550; ilcum: 191; atria: 17) and least with thosc ofthc p-Fluoro-analogue 4 (vas defercns: 34; ileum: 8.5; atria: 1.7). 3 The enantiomerie potency ratios for compounds 1-4 were highest in rabbit vas deferens, intermediate in guinea-pig ileum and much less in guinea-pig atria. Thus, these ratios may serve as a predietor of muscarinic receptor subtype identity. 4 (S)-p-Fluoro-hexbutinol [(S)-4] showed a novel receptor selectivity profile with preference for M\(_3\) receptors: M\(_3\) > M\(_2\) \(\geq\) M\(_1\)• 5 These results do not conform to Pfeiffer's rule that aetivity differences between enantiomers are greater with more potent compounds. KW - Anorganische Chemie Y1 - 1990 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-64002 ER - TY - JOUR A1 - Schenk, Wolfdieter A. A1 - Leissner, Johanna A1 - Burschka, Christian T1 - Stabilisierung von Schwefelmonoxid durch Koordination an Übergangsmetalle T1 - Stabilization of sulfur monoxide by coordination on transition metals N2 - No abstract available KW - Anorganische Chemie Y1 - 1984 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-57848 ER - TY - JOUR A1 - Tacke, Reinhold A1 - Saad, S. M. T1 - Silylation of cellulose N2 - Ethane-l:2-diol and propane-l:3-diol reaet with 1: 1:3:3-tetramethyl-l:3-dichlorodisiloxane forming the corresponding rings. However, no ring compounds could be traced tbrough the reaction between butane-l :4-diol, glycerol and the dichlorodisiloxane respectively, where only polymeric compounds are formed. The silylation products of the di- and trihydroxy alcohols, as model compounds, has confirmed that the ring formation during silylation of cellulose with dichlorodisiloxane is uncertain. KW - Anorganische Chemie Y1 - 1977 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-78368 ER - TY - JOUR A1 - Tacke, Reinhold A1 - Pikies, J. A1 - Linoh, H. A1 - Rohr-Aehle, R. A1 - Gönne, S. T1 - Sila-Procyclidin: Eine neue Synthese sowie Untersuchungen zur peripheren und zentralen anticholinergen Wirkung N2 - Sila-Procyclidin (1 b) sowie dessen Derivate 2b (Sila-Tribexyphenidyl), 3b und 4b (Sila-Cycrimin) wurden - ausgehend von Cl\(_3\)SiCH\(_2\)Cl - durch eine neue, sechsstufige Synthese mit einer Gesamtausbeute von 16 (lb), t9 (2b), 8 (3b) bzw. 7% (4b) dar· gestellt. - Vergleichende in-vivo-Untcrsuchungen (Maus, per-osApplikation) hinsichtlich der peripheren und zentralen auticholincrgen Wirkung haben gezeigt, daß die Silicium-Verbindung 1 b dem Kohlenstoff-Analogon Ia (Procyclidin) überlegen ist. N2 - Starting with Cl\(_3\)SiCH\(_2\)Cl. sila-procycUdine (I b) as well as its derivatives 2b (sila-trihexyphenidyl), 3b, and 4b (sila-cycrimine) were prepared by a new six-step synthesis witb a total yield of 16 (lb), 19 (2b), 8 (31) aud 7% (4b), respectively. - Comparative in vivo investigations (mice per os administration) with respect to the peripheral and centrat anticholinergic activity bavc shown that the silicon compound 1 b is advantageous over the c:arbon aualogue t a (procyclidine). KW - Anorganische Chemie Y1 - 1987 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-63815 ER - TY - JOUR A1 - Tacke, Reinhold A1 - Strecker, M. A1 - Sheldrick, W. S. A1 - Ernst, L. A1 - Heeg, E. A1 - Berndt, B. A1 - Knapstein, C.-M. A1 - Niedner, R. T1 - Sila-Pridinol und Pridinol: Darstellung und Eigenschaften sowie Strukturen im kristallinen und gelösten Zustand T1 - Sila-Pridinol and Pridinol: Preparation and Properties as weil as Structures ln the Solid Stateand in Solution N2 - Sila-Pridinol (2 b), ein Sila-Analogon des Anticholinergicums Pridinol (2a), wurde auf zwei verschiedenen Wegen dargestellt. Die Kristall- und Molekülstrukturen von 2 a und 2 b wurden röntgenstrukturanalytisch bestimmt. 2a bildet im festen Zustand intramolekulare Wasserstoffbrückenbindungen aus, während sich in kristallinem 2 b zentrosymmetrische, durch intermolekulare H-Brückenbindungen verknüpfte cyclische Dimere finden. IR- und \8^1\)H-NMR-spektroskopische sowie kryoskopische Untersuchungen ergaben Informationen über die Strukturen von 2a und 2 b in verschiedenen Lösungsmitteln. - Die pharmakologischen und toxikologischen Eigen" schaften von 2a und 2b wurden unter dem Gesichtspunkt bekannter Struktur-Wirkungs-Beziehungen vergleichend untersucht. 2 b erwies sich als ein etwa fünfmal so starkes Anticholincrgicum wie 2a. N2 - Sila"pridinol (2 b), a sila"analogue of the anticholinergic pridinol (2a). was prepared by two different routes. The crystal and molecular structures of 2 a and 2 b were determined by X-ray structural analyses. 2a forms intramolecular hydrogen bonds in the solid state, whereas centrosymrnetric cyclic dimers linked through intermolecular hydrogen bonds are observed for crystalline 2 b. IR- and \(^1\)H NMR spectroscopic as weil as cryoscopic studies yielded information ab out the structures of 2a and 2 bin different solvents. - The pharmacological and toxicological properties of2a and 2b were compared with one another on the basis ofknown structure-activity relationships. The anticholinergic properties of 2b were found tobe about five times as strong as those of 2a. KW - Anorganische Chemie Y1 - 1980 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-63654 ER - TY - JOUR A1 - Tacke, Reinhold A1 - Bentlage, Anke A1 - Towart, Robertson A1 - Möller, Eike T1 - Sila-pharmaca, XXV. Sila-analogues of nifedipine-like dialkyl 2,6-dimethyl-4-aryl-1,4 dihydropyridine-3,5-dicarboxylates, III N2 - IS neue C/Si-Analogenpaare (C-Verbindungen und sila- bzw. disila-substituierte Derivate), die sich strukturell vom Nifedipin ableiten, wurden synthetisiert. Diese und einige weitere C/Si-Paare wurden hinsichtlich ihrer physikochemischen und pharmakologischen Eigenschaften vergleichend untersucht. Mittels reversed-phase-Dünnschichtchromatographie wurde gezeigt, daß die Sila- bzw. Disila-Analoga lipophiler sind als die entsprechenden C-Verbindungen. Bezüglich der spasmolytischen in vitra-Aktivitäten zeigen die Si-Verbindungen in erster Näherung ähnliche Struktur-Wirkungs-Beziehungen wie ihre Carba-Analoga. Dagegen konnten hinsichtlich der ill vlva-Effekte (cardiovasculäre und antihypertensive Aktivität) in einigen Fällen große Unterschiede nachgewiesen werden. N2 - 15 new C/Si-analogue pairs (C-compounds and sila- or disila-substituted derivatives, respectively), which are structurally related to nifedipine, have been synthesized. These and some further C/Si-pairs have been investigated comparatively with respect to their physicochemical and pharmacological properties. Using reversed-phase thin-layer chromatography it was shown that both the sila- and disila-analogues are more Iipophilic than the corresponding C-compounds. With respect to the in vitra spasmolytic potencies the Si-compounds show approximately similar structure-activity relationships to their carba-analogues. However, in some cases marked differences in in vivo effects (cardiovascular and antihypertensive activity) could be demonstrated. KW - Anorganische Chemie Y1 - 1983 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-78357 ER - TY - JOUR A1 - Tacke, Reinhold A1 - Pikies, J. A1 - Wiesenberger, F. A1 - Ernst, L. A1 - Schomburg, D. A1 - Waelbroeck, M. A1 - Christophe, J. A1 - Lambrecht, G. A1 - Gross, J. A1 - Mutschler, E. T1 - Sila-biperiden und endo-Sila-biperiden: Synthesen, Kristallstrukturen und antimuscarinische Eigenschaften N2 - Starting from trichloro(vinyl)silane (Cl\(_3\)SiCH=CH\(_2\)), the musearinic antagonists sila-biperiden [rac-(SiRS,C2SR>-ao-2] and endosila- biperiden [rac-(SiRS,C2SR)-endo-2] were prepared by a seven-step synthesis. Both silanols are configurationally stableininert organic solvents but undergo slow epimerization in aqueous solution (pH 7.4, 32°C) by inversion of the configuration at the silicon atom. The relative configurations of sila-biperiden and endo-sila-biperiden were detennined by single-crystal X-ray diffraction. Both compounds form intennolecular 0-H · · · N hydrogen bonds in the crystal leading to the fonnation of centrosymmetric dimers (sila-biperiden) and infinite chains (endo-sila-biperiden), respectively. Sila-biperiden is a silicon analogue (C/Si exchange) of the antiparkinsonian drug biperiden [rac-(CRS/C2SR}-exo-1]. In functional phannacological experiments, as well as in radioligand competition studies, biperiden, sila-biperiden and endo-sila-biperiden behaved as simple competitive antagonists at muscarinic Ml-, M2-, M3- and M4-receptors. The three compounds displayed the highest affinity for Ml-receptors (pA\(_2\) values: 8.72-8.80; pK\(_i\) values: 8.8-9.1), intermediate affinity for M4- and M3-receptors, and lowest affinity for M2-receptors (pA\(_2\) values: 7.57-7.79; pK\(_i\) values: 7.7-7.8). The affinity profile (Ml >. M4 > M3 > M2) of biperiden, sila-biperiden and endo-sila-biperiden is qualitatively similar to that of the M1-selective muscarinic antagonist pirenzepine. The antimuscarinic properlies of the C/Si analogues biperiden and sila-biperiden are almost identical. N2 - Die Antimuscarinica Sila-biperiden [rac-(SiRS,C2SR)-exo-2] und endo-Sila-biperiden [rac-(SiRS,C2SR)-endo-2] wurden ausgehend von Trichlor(vinyl)silan (Cl\(_3\)SiCH=CH\(_2\)) durch eine siebenstufige Synthese dargestellt. Die beiden Silanoie sind in inerten organischen Solvenzien konfigurationsstabil, unterliegen aber in wässeriger Lösung (pH 7.4, 3ZOC) einer Epimerisierung durch Inversion der Konfiguration am Silicium-Atom. Die relativen Konfigurationen von Sila-biperiden und endo-Sila-biperiden wurden durch Einkristall-Röntgenstrukturanalysen bestimmt. Beide Verbindungen bilden im Kristall intermolekulare 0-H · · · N-Wasserstoff- Brückenbindungen aus, die zum Aufbau von zentrosymmetrischen Dimeren (Sila-biperiden) bzw. unendlichen Ketten (endo-Sila-biperiden) führen. Sila-biperiden ist ein Silicium-Analogon (C/Si-Austausch) des Antiparkinsonmittels Biperiden [rac-(CRS,C2SR>-ao-1). Sowohl in funktionellen pharmakologischen Untersuchungen als auch in Radioligand-Kompetitionsexperimenten erwiesen sich Biperiden, Sila-biperiden und endo-Sila-biperiden als rein kompetitive Antagonisten an muscarinischen M1-, M2-, M3- und M4-Rezeptoren. Alle drei Verbindungen zeigten die höchste Affinität zu den Mt-Rezeptoren (pA\(_2\)-Werte: 8.72-8.80; pKrWerte: 8.8-9.1), eine deutlich geringere Affinität zu den M4- und M3-Rezeptoren und die niedrigste Affinität zu den kardialen M2-Rezeptoren (pA\(_2\)-Werte: 7.57-7.79; pKi-Werte: 7.7-7.8). Das Affinitätsprofil (Ml > M4 > M3 > M2) von Biperiden, Sila-biperiden und endo-Sila-biperiden ist dem des Mt-selektiven Antimuscarinicums Pirenzepin qualitativ sehr ähnlich. Die antimuscarinischen Eigenschaften der C/Si-Analoga Biperiden und Sila-biperiden sind nahezu identisch. KW - Anorganische Chemie KW - Silicon KW - Silanol KW - Sila-biperiden KW - Bioorganosilicon chemistry KW - Muscarinic antagonist KW - Muscarinic receptor subtype Y1 - 1994 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-64303 ER - TY - JOUR A1 - Tacke, Reinhold A1 - Zimonyi-Hegedüs, E. A1 - Strecker, M. A1 - Heeg, E. A1 - Berndt, B. A1 - Langner, R. T1 - Sila-Analogon des Tiemoniumiodids T1 - Sila-Analogue of Tiemonium Iodide N2 - Sila-Tiemoniumiodid (16b), ein Sila-Analogon des Anticholinergicums Tiemoniumiodid (16a), und das Sila-Analogon 14b der entsprechenden Tiemonium-Base 14a wurden erstmalig synthetisiert.14b und 16b sowie die Vorstufen 10-13 und 15 wurden in ihren physikalischen und chemischen Eigenschaften charakterisiert und in ihrer Struktur durch Elementaranalysen sowie \(^1\)H-NMR- und Massenspektren sichergestellt. Die spasmolytischen Eigenschaften der Paare 14a/14b und 16a/16b wurden am isolierten Meerschweinchendarm vergleichend untersucht. N2 - Silatiemonium iodide (16b), a sila-analogue of the anticholinergic tiemonium iodide (16a), and the siJa-analogue 14b of the corresponding free base 14a were synthesized for the first time. Compounds 14b and 16b as weil as their precursors 10-13 and 15 were characterized by their physical and chemical properties. Their structures were confirmed by elementary analyses, (^1\)H NMRand massspectroscopy. The spasmolytic properties of the pairs 14a/14b and 16a/16b were compared on the isolated guinea pig ileum. KW - Anorganische Chemie Y1 - 1980 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-63669 ER - TY - JOUR A1 - Tacke, Reinhold A1 - Heeg, E. A1 - Berndt, B T1 - Sila-Analogon des Rythmols T1 - Sila Analogue of Rythmol N2 - Sila-Rythmol (llb), ein Sila-Analogon des Antiarrhythmieums Rythmol (lla), wurde erstmalig dargestellt. llb sowie die Vorstufen und Nebenprodukte 4, 5, 6, 7, 9b und lOb wurden in ihren physikalischen und chemischen Eigenschaften charakterisiert und in ihrer Struktur sichergestellt. Die pharmakologischen und toxikologischen Eigenschaften der Analoga lla und llb wurden vergleichend untersucht. N2 - Silarythmol (llb), a sila analogue of the antiarrhythmic rythmol (lla), was synthesized for the first time. llb as weil as the precursors and byproducts 4, 5, 6, 7, 9b, and lOb were characterized by their physical and chemical properties. The pharmacological and toxicological properties of the analogues lla and llb were also investigated. KW - Anorganische Chemie Y1 - 1980 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-63642 ER - TY - JOUR A1 - Tacke, Reinhold A1 - Wannagat, U. T1 - Sila-Analogon des Cicloniumbromids T1 - Sila-Analogue of Ciclonium Bromide N2 - Sila-Analogues B 2 and A 2 of the spasmolytic ciclonium bromide (B 1) respectively the corresponding free base A 1 were synthesized for the first time according to the reaction steps sho·wn in scheme 1, and they and their precursors I and II were characterized by ph;ysical (Table 1} and chemical properties and their structures confirmed by NMR, and mass spectroscopy (Tables 2 and 3}. The pharmacological effects of A 2 and B 2 were investigated and compared with those of the parent carbon compound B 1 (chapter 5). KW - Anorganische Chemie Y1 - 1976 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-63556 ER - TY - JOUR A1 - Wrobel, D. A1 - Tacke, Reinhold A1 - Wannagat, U. A1 - Harder, U. T1 - Sila-Analoga tertiärer Carbinole mit Duftwirkung T1 - Sila Analogues of Tertiary Carbinols as Perfumes N2 - Es wurden Silanale RR'R"SiOH 7 dargestellt, die Carbinolen RR'R"COH 1 (R = CH\(_3\) , R' = CH\(_3\) , CH = CH\(_2\) , C\(_2\)H\(_5\) , R" = CH\(_2\)C\(_6\)H\(_5\) , CH\(_2\)CH\(_2\)C\(_6\)H\(_5\)) mit starker Duftwirkung im Bereich blumiger Noten (Maiglöckchen-Hyazinthe-Rose) analog waren. Ihr Syntheseweg verläuft über die Reaktionsschritte (3) mit teilweise bisher unbekannten Zwischenstufen 6. Die Sila-Riechstoffe 7 sind in Intensität und Duftbereich den Carbinolen 1 ähnlich, doch ist allgemein eine Verschiebung der Duftnote von Maiglöckchen zu Hyazinthe zu beobachten. N2 - Silanals RR'R"SiOH 7 which areanalog to carbinols 1 with strong odour in the region of flowery notes (lily of the valley-hyacinth-rose) were prepared via reaction steps (3) and partially unknown intermediates 6. Sila perfumes 7 are similar in intensity and spectrum of odour to 1 but a shift from lily of the valley towards hyacinth notes is generally observed. KW - Anorganische Chemie Y1 - 1982 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-63705 ER - TY - JOUR A1 - Tacke, Reinhold A1 - Wannagat, U. T1 - Sila-Analoga des Mephenhydramins T1 - Sila-Analogues of Mephenhydramine N2 - Sila-Analogues A 2, B 2 and C 2 of the drug mephenhydramine from the class of benzhydryl ethers were synthesized for the first time by the steps shown in scheme 1, and they and their precursors I-V characterized by their physical {table 1) and chemical properties, and their structures confirmed by NMR, n1ass and infrared spectroscopy (tables 3-5). Their physiological effects were investigated a.nd compared -with those of the parent carbon compounds (section 5). KW - Anorganische Chemie Y1 - 1975 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-63525 ER -