@article{TackeMuehleisen1994, author = {Tacke, Reinhold and M{\"u}hleisen, M.}, title = {Bis[benzilato(2-)-O\(^1\),O\(^2\)][2-(dimethylammonio)ethoxy]silicate: synthesis and structural characterization of a zwitterionic \(\lambda^5\)Si-silicate with a SiO\(_5\) framework}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-64400}, year = {1994}, abstract = {No abstract available}, subject = {Anorganische Chemie}, language = {en} } @article{TackePikiesWiesenbergeretal.1994, author = {Tacke, Reinhold and Pikies, J. and Wiesenberger, F. and Ernst, L. and Schomburg, D. and Waelbroeck, M. and Christophe, J. and Lambrecht, G. and Gross, J. and Mutschler, E.}, title = {Sila-biperiden und endo-Sila-biperiden: Synthesen, Kristallstrukturen und antimuscarinische Eigenschaften}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-64303}, year = {1994}, abstract = {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.}, subject = {Anorganische Chemie}, language = {en} } @article{TackeMuehleisenJones1994, author = {Tacke, Reinhold and M{\"u}hleisen, M. and Jones, P. G.}, title = {Das erste zwitterionische, optisch aktive Disilicat mit pentakoordiniertem Silicium}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-64343}, year = {1994}, abstract = {No abstract available}, subject = {Anorganische Chemie}, language = {de} } @article{TackeMuehleisenJones1994, author = {Tacke, Reinhold and M{\"u}hleisen, M. and Jones, P. G.}, title = {The first zwitterionic, optically active disilicate with pentacoordinate silicon}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-64358}, year = {1994}, abstract = {No abstract available}, subject = {Anorganische Chemie}, language = {en} } @article{TackeMuehleisen1994, author = {Tacke, Reinhold and M{\"u}hleisen, M.}, title = {Hexakoordiniertes Silicium in einer molekularen Verbindung mit einer F\(_5\)SiC-Einheit}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-64365}, year = {1994}, abstract = {No abstract available}, subject = {Anorganische Chemie}, language = {de} } @article{TackeMuehleisen1994, author = {Tacke, Reinhold and M{\"u}hleisen, M.}, title = {Hexacoordinate silicon in a compound with an F\(_5\)SiC unit}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-64378}, year = {1994}, abstract = {No abstract available}, subject = {Anorganische Chemie}, language = {en} } @article{TackeLinkZilch1985, author = {Tacke, Reinhold and Link, M. and Zilch, H.}, title = {Eine neue in situ-Darstellung von (Trimethyl-silyl)trifluormethansulfonat durch thermisch induzierte Umlagerung}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-63784}, year = {1985}, abstract = {A new in situ preparation of trimethylsilyl trifluoromethanesulfonate (3) is described: 3 is generated by a thermally induced rearrangement of (dimethylsilyl)methyl trifluoromethanesulfonate (2), which can be prepared by reaction of (CH\(_3\))\(_2\)Si(H)CH\(_2\)OH (1) with (CF\(_3\)SO\(_2\))\(_2\)O. Starting with C\(_6\)H\(_5\)(CH\(_3\))Si(H)CH\(_2\)OH (5), the derivative (methylphenylsilyl)methyl trifluoromethanesulfonate (6) can be obtained by a similar method. Its thermally induced rearrangement Ieads to dimethylphenylsilyl trifluoromethanesulfonate (7). The rearrangements 2---> 3 and 6---> 7 were found to be first-order reactions with half-lifes at 80 oc of 0.75 and 1.7 h, respectively.}, subject = {Anorganische Chemie}, language = {de} } @article{SchomburgLinkLinohetal.1988, author = {Schomburg, D. and Link, M. and Linoh, H. and Tacke, Reinhold}, title = {Molek{\"u}lstruktur der Akarizide Chlortrineophylstannan, Chlortris[(dimethylphenylsilyl)methyl]stannan und Trineophyl(1,2,4-triazol-1-yl)stannan-hemihydrat sowie des 2,5-Dimethyl-2,5-diphenylhexans (Bineophyl)}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-63840}, year = {1988}, abstract = {Die Kristall- und Molek{\"u}lstrukturen der Akarizide Chlortrineophylstannan (Ia), Chlortris[ ( dimethylphenylsilyl)methyl]stannan (tb) und Trineophyl(1,2,4-triazol-1- yl)stannan-hemihydrat (2a · 0.5H\(_2\)0) wurden durch Einkristall-R{\"o}ntgenstrukturanalysen bestimmt. Zu V ergleichszwecken wurde ausserdem die Struktur des 2,5-Dimethyl-2,5-diphenylhexans (Bineophyl, 4) untersucht. Die Kn{\"u}pfung von drei sehr raumerf{\"u}llenden N eophyl-Resten an ein Zinnatom f{\"u}hrt zu einer deutlichen Verzerrung der tetraedrischen Geometrie [ta: C-Sn-C 117.2°, C-Sn-Cl99.7°; 2a·0.5H20: C-Sn-C 116.9° (Mittelwert), C-Sn-N 100.2° (Mittelwert)]. Austausch der zentralen Kohlenstoffatome in den Neophyt-Substituenten von la durch Siliciumatome f{\"u}hrt zu einer Verringerung des Raumbedarfs und dadurch zu einer erkennbaren Angleichung an die tetraedrische Geometrie [lb: C-Sn-C 113.3° (Mittelwert), C-Sn-Cl 105.3° (Mittelwert)].}, subject = {Anorganische Chemie}, language = {de} } @article{PolidoriMassiLambrechtetal.1990, author = {Polidori, C. and Massi, M. and Lambrecht, G. and Mutschler, E. and Tacke, Reinhold and Melchiorre, C.}, title = {Selective antagonists provide evidence that M\(_1\) muscarinic receptors may mediate carbachol-induced drinking in the rat}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-64044}, year = {1990}, abstract = {The present study served to investigate the ability of seven selective muscarinic antagonists to inhibit carbachol-induced drinking in the rat. The muscarinic antagonists were given by intracerebroventricular (i.c.v.) injection 1 min before the i.c.v. injection of carbachol (1 \(\mu\)g/rat). The M\(_2\) antagonist, methoctramine, was inactive up to 80.3 nmol/rat. The M\(_3\) antagonist, p-fluoro-hexahydro-sila-difenidol, elicited a modest (42\%) but statistically significant inhibition of drinking only at 80 nmol/rat. On the other band, the selective M\(_1\) antagonists, (R)-trihexyphenidyl, o-methoxy-sila-hexocyclium and pirenzepine, produced a marked and dose-dependent inhibition of carbachol-induced drinking, their 1050 values being 0.51. 7.36 and 9.31 nmoljrat. Also the M\(_1\)/M\(_3\) antagonists, 4-diphenylacetoxy-Nmethylpiperidine methiodide and hexahydro-sila-difen.idol, were potent inhibitors of carbachol-induced drinking, their ID\(_50\) values (0.28 and 11.09 nmoljrat) being related to their pA\(_2\) values for M1 receptors in rabbi t vas deferens. These data suggest that carbachol-induced drinking may be mediated by activation of muscarinic M\(_1\) receptors.}, subject = {Anorganische Chemie}, language = {en} } @article{DoerjeWessLambrechtetal.1991, author = {D{\"o}rje, F. and Wess, J. and Lambrecht, G. and Tacke, Reinhold and Mutschler, E. and Brann, M. R.}, title = {Antagonist binding profiles of five cloned human muscarinic receptor subtypes}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-64113}, year = {1991}, abstract = {A variety of muscarinic antagonists are currently used as tools to pharmacologically subclassify muscarinic receptors into M\(_1\), M\(_2\) and M\(_3\) subtypes. ln the present study I we have determined the affinity proflies of several of these antagonists at five cloned human muscarinic receptors (m1-m5) stably expressed in Chinesehamster ovary cells (CHO-K1). At all five receptorsl the (R)-enantiomers of trihexyphenidyl and hexbutinol displayed considerably higher affinities (up to 525-fold) than their corresponding (S)-isomers. The stereoselectivity ratios [inhibition constant( S)/inhibition constant(R)] for both pairs of enantiomers were lowest at m2 receptors, suggesting that less stringent configurational demands are made by this receptor subtype. The "M\(_1\)-selective" antagonist (R)-trihexyphenidyl displayed high affinities for m1 and m4 receptors. The "M\(_2\)-selective" antagonists himbacinel (±}-5, 11-dihydro-11-1[(2-[(dipropylamino)methyl]-1- piperidinyllethyl)amino]carbonyii-6H-pyrido(213-b)(1 ~4)benzodiazepine- 6-one (AF-DX 384)1 11-(14-[4-(diethylamino)butyl)-1-piperidinyll acetyl)-5~ 11-dihydro-6H-pyrido(2~3-b) (1~4)benzodiazepine-6-one (AQ-RA 741) and (+K11-(12-[(diethylamino)methyl]-1-piperidinyll acetyl)-5~ 11-di-hydro-6H-pyrido(2~3-b)(1,4)benzodiazepine-6-one (AF-OX 250; the (+)-enantiomer of AF-DX 116] exhibited high affinities for m2 and m41 intermediate affinities for m1 and m3 and low affinities for m5 receptors. This selectivity profile was most prominent for AQ-RA 7 41 I which displayed 195- and 129-fold higher affinities for m2 and m4 receptors than for mS receptors. The "M\(_3\)-selective" antagonist (±)-p-fluoro-hexahydro-sila-difenidol hydrochloride (pFHHsiD) exhibited high affinity for m1 I m3 and m4 receptors. 4-diphenylacetoxy-N-methylpiperidine methiodide (4-DAMP) bound with up to 7 -fold higher affinities to m1 I m31 m4 and m5 receptors than to m2 receptors. Although none of the tested antagonists showed more than 2-fold selectivity for one subtype over all other subtypes, each receptor displayed a unique antagonist binding profile.}, subject = {Anorganische Chemie}, language = {en} } @article{TackeWiesenbergerBeckeretal.1992, author = {Tacke, Reinhold and Wiesenberger, F. and Becker, B. and Rohr-Aehle, R. and Schneider, P. B. and Ulbrich, U. and Sarge, S. M. and Cammenga, H. K. and Koslowski, T. and Niessen, W. von}, title = {Ester von (Hydroxymethyl)diorganylsilanen: Synthese und thermisch induzierte Umlagerung}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-64188}, year = {1992}, abstract = {Twenty silanes of the type R\(^1\)R\(^2\)Si(H)CH\(_2\)OR\(^3\) (A) were syn- and entropy of activation) of these reactions were studied by thesized {R\(^1\), R\(^2\) = Me, Ph, 1-naphthyl, PhCH\(_2\), Me\(_3\)SiCH\(_2\); OR\(^3\) means of d{\"u}ferential scanning calorimetry (DSC). In addition, = OC(O)Me, OC(O)Ph, OC(O)CF\(_3\) , OS(0)\(_2\)CF\(_3\), OP(O)Ph\(_2\), the kinetics of all reactions were investigated by 1H-NMR OC(O)Cl, and studied for their thermal behaviour. The silanes spectroscopy. The transition state of the rearrangement was A undergo a thermally induced rearrangement to give the investigated by an ab initio study based on the model comcorresponding silanes R\(^1\)R\(^2\)Si(OR\(^3\))Me (B). For compounds with pound H\(_3\)SiCH\(_2\)OC(O)H (-> MeH\(_2\)SiOC(O)H]. The theoretical OR3 = OC(O)Cl, an additional decarboxylation takes place to data and the experimentally obtained energetic and kinetic yield the chlorosilanes R1R2Si(Cl)Me. Except for the deriva- data are discussed in terms of mechanistic aspects of the retives with OR\(^3\) = OC(O)Cl, the energetic (reaction enthalpy) arrangement reaction A -> B. and kinetic data (reaction order, frequency factor, enthalpy ...}, subject = {Anorganische Chemie}, language = {de} } @article{TackeStreckerNiedner1981, author = {Tacke, Reinhold and Strecker, M. and Niedner, R.}, title = {Cholinesterase-hemmende Organophosphors{\"a}ureester und ihre Sila-Analoga}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-63689}, year = {1981}, abstract = {Die Organophosphors{\"a}ureester la-4a und ihre Sila-Analoga lb-4b des Typs R\(^1\)R\(^2\)P(O)( p-OC\(_6\)H\(_4\)ElMe\(_3\)) (EI = C, Si) wurden synthetisiert. Die Kohlenstoff-Verbindungen 1 a- 4a zeigen hinsichtlich ihrer Anticholinesterase-Aktivit{\"a}t die gleichen Struktur-Wirkungs-Beziehungen wie die Silicium-Verbindungen 1 b- 4 b. Letztere sind jeweils wirksamer als die entsprechenden C-Analoga.}, subject = {Anorganische Chemie}, language = {de} } @article{EltzeGmelinWessetal.1988, author = {Eltze, M. and Gmelin, G. and Wess, J. and Strohmann, C. and Tacke, Reinhold and Mutschler, E. and Lambrecht, G.}, title = {Presynaptic muscarinic receptors mediating inhibition of neurogenic contractions in rabbit vas deferens are of the ganglionic M\(_1\)-type}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-63912}, year = {1988}, abstract = {The present study was designed to further charaeterize the presynaptie musearlnie M\(_1\)-reeeptor responsible for the inhibition of neuragenie eontraetions in the isolated rabbit vas deferens. Eleetrically induced twiteh eontraetions of this preparation were inhibited by the M\(_1\)-agonist, MeN-A-343, and by some of its analogs: 4-ehloro-phenyl derivative> MeN-A-343 > trans-olefinie analog> cis-olefinie analog. The same rank order of potency was observed for these agonists to raise the blood pressure of pithed rats by stimulation of M\(_1\)-receptors in sympathetie ganglia. A highly signifieant eorrelation was found between the antimusearinie potencies of atropine, pirenzepine and a series of 9 antagonists strueturally related to the ganglionie M\(_{1\beta}\)-receptor selective compounds, hexocyclium and hexahydro-difenidol, to antagonize the MeN-A-343-indueed inhibition of twitch eontraetions in rabbit vas deferens or the musearine-indueed depolarization in rat isolated superior eerVieal ganglia. It is suggested that the presynaptie musearlnie receptor that mediates inhibition of neuragenie contraetions in rabbit vas deferens is of the ganglionic M\(_{1\beta}\)-type.}, subject = {Anorganische Chemie}, language = {en} } @article{PfeifferHanackKoppetal.1990, author = {Pfeiffer, A. and Hanack, C. and Kopp, R. and Tacke, R. and Moser, U. and Mutschler, E. and Lambrecht, G. and Herawi, M.}, title = {Human Gastric Mucosa Expresses Glandular M3 Subtype of Muscarinic Receptors}, series = {Digestive Diseases and Sciences}, volume = {35}, journal = {Digestive Diseases and Sciences}, number = {12}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-128286}, pages = {1468-1472}, year = {1990}, abstract = {Five subtypes of muscarinic receptors have been distinguished by pharmacological and molecular biological methods. This report characterizes the muscarinic subtype present in human gastric mucosa by radioligand binding studies. The receptor density was 27 ± 6 fmol/mg protein and the tritiated ligand N-methylscopolamine had an affinity of (Kn) 0.39 ± 0.08 nM (n = 11). The M1 receptor selective antagonist pirenzepine and the M2 receptor selective ligand AF-DX 116 had low affinities of 148 ± 32 nM (n = 13) and 4043 ± 1011 nM (n = 3) K n , respectively. The glandular M3 antagonists hexahydrosiladifenidol and silahexocyclium had high affinities ofKn 78 ± 23 nM (n = 5) and 5.6 ± 1.8 nM (n = 3). The agonist carbachol interacted with a single low-affinity site and binding was insensitive to modulation by guanine nucleotides. Antagonist and agonist binding studies thus showed an affinity profile typical of M3 receptors of the glandular type.}, language = {en} } @article{TackeSchuberthBeckeretal.1982, author = {Tacke, M. and Schuberth, W. and Becker, Charles R. and Haas, L. D.}, title = {The dielectric constant of PbTe at 4.2 K and \(\tilde ν\)=84.15 cm\(^{-1}\), 96.97 cm\(^{-1}\), 103.60 cm\(^{-1}\)}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-30821}, year = {1982}, abstract = {The dielectric constant of a PbTe epitaxial layer has been measured by surface wave spectroscopy using an optically pumped far-infrared laser and the technique of attenuated total reflection.}, language = {en} } @article{TackeSaad1977, author = {Tacke, Reinhold and Saad, S. M.}, title = {Silylation of cellulose}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-78368}, year = {1977}, abstract = {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.}, subject = {Anorganische Chemie}, language = {en} } @article{SaadTacke1977, author = {Saad, S. M. and Tacke, Reinhold}, title = {Zur Darstellung von 1,1,3,3-Tetramethyl-1,3-disila-2,4,7-trioxa-cycloheptan (1) und 1,1,3,3-Tetramethyl-1,3-disila-2,4,8-trioxa-cyclooctan (2)}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-86958}, year = {1977}, abstract = {No abstract available.}, subject = {Anorganische Analyse}, language = {de} }