TY  - JOUR
A1  - Bringmann, Gerhard
A1  - Zagst, Rainer
A1  - Schöner, Bernd
A1  - Busse, Holger
A1  - Hemmerling, Martin
A1  - Burschka, Christian
T1  - Acetogenic Isoquinoline Alkaloids. XXIII. Structure of the Naphthyl Isoquinoline Alkaloid Dioncophylline A
N2  - No abstract available
KW  - Chemie
Y1  - 1991
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-31331
ER  - 
TY  - JOUR
A1  - Albert, Bernhard
A1  - Berning, Wilfried
A1  - Burschka, Christian
A1  - Hünig, Siegfried
A1  - Martin, Hans-Dieter
A1  - Prokschy, Frank,
T1  - Transanulare Wechselwirkung des Azo-Chromophors inisodrinanalogen Systemen
T1  - Transanular Interactions of the Azo Chromophore in Isodrin-type Systems
N2  - No abstract available
KW  - Chemie
Y1  - 1981
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-31328
ER  - 
TY  - JOUR
A1  - Ries, Wolfgang
A1  - Albright, Thomas
A1  - Silvestre, Jerome
A1  - Bernal, Ivan
A1  - Malisch, Wolfgang
A1  - Burschka, Christian
T1  - Unusual structural features of a siloxane
N2  - Crystals of the R, S diastereoisomer of [Cp(CO)\(_2\)-FeSiCH\(_3\)F]\(_2\)O are monoclinic, space group ndc (No. 14), with a = 846.0(3) [836.4(1»), b = 768.0(3) [757.1(1»), c = 1548.5(4) [1522.3(2)] pm, {3 = 97.34(3t [97.47(3t] at 300 K [120 K] with Z = 2. Even at 120 K the Si-O-Si fragment is found to be strictly linear due to crystallographically imposed symmetry. To explain the unusual electron distribution derived from the X-ray data collected, several types of possible disorders are discussed, none of which leads to a satisfying explanation. Retaining the Ci symmetry (linear Si-O-Si fragment in the final model) the important bond lengths are Fe-Si 226.7(1) [226.5(1)] pm, Si-F 160.9(2) [161.8(2)] pm, Si-O 160.3(1) [161.1(1)] pm, Si-C 185.0(3) [185.6(3)] pm. The electronic features of this compound were probed via molecular orbital calculations of the extended Hiickel type. It was found that the lone pairs on the siloxane oxygen were tipped away from cylindrical symmetry. The tipping was directed toward the fluorine substituents on the silicon atoms and away from the CpFe(CO)\(_2\) units. A pertubational approach was utilized to rationalize this effect.
KW  - Chemie
Y1  - 1986
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-31925
ER  - 
TY  - JOUR
A1  - Wieber, M.
A1  - Schmidt, E.
A1  - Burschka, Christian
T1  - Dimethyl-tellur-bis(alkylxanthogenate)
T1  - Tellurium-Dimethyl-bis(alkylxanthates)
N2  - Man erhält Dimethyl-tellur-bis(alkylxanthogenate) des Typs R2Te(S2COR'lz mit R = CH3, sowie R' = CHs, C2Hs, i-CsH7 durch Umsetzung von Dimethyltellur-diiodid mit den stöchiometrischen Mengen der jeweiligen Natriumxanthogenate. Ebemalls führt eine Einschiebung von CS2 in die Te-O-Bindung von Dimethyl-tellur-bis(alkoxyden) zu den Dimethyl-tellur-bis(alkylxanthogenaten). Die Röntgenstrukturanalyse von (CH3hTe(S2COCH3)2 zeigt, daß das Molekül im Kristall als V'-pentagonale Bipyramide vorliegt.
N2  - Tellurium dimethyl-bis(alkylxanthates) of the type R2Te(S2COR')2 with R = CH3 and R' = CH3, C2H5, i-CsH 7 are obtained by reaction of tellurium dimethyldiiodide with freshly prepared sodium xanthates. Another preparative method is the insertion of CS2 in tellurium dimethylbis(alkoxydes). The X-ray analysis of (CH3)2Te(S2COCHsh shows, that in the crystal the molecule has a IjJ-pentagonal bipyramidal configLlration around tellurium.
KW  - Chemie
Y1  - 1985
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-31934
ER  - 
TY  - JOUR
A1  - Wieber, M.
A1  - Wirth, D.
A1  - Burschka, Christian
T1  - Methyldixanthogenatostibane
N2  - Methyldixanthogenatostibane CH\(_3\)Sb(S\(_2\)COR)\(_2\) erhält man entweder durch Reaktion von Methyldibromstiban mit entsprechenden Natriumxanthogenaten bei tiefen Temperaturen (-78°C) oder durch Einschiebung von CS\(_2\) in Methyldialkoxistibane. Die Röntgenstrukturanalyse von CH\(_3\)Sb(S\(_2\)COC\(_2\)H\(_5\))\(_2\) zeigt, daß im Kristall die Chelatliganden das Antimonatom intraund intermolekular koordinieren, so daß eine pentagonal-pyramidale bzw. unter Einbezug des freien Elektronenpaars pentagonal-bipyramidale Koordination am Antimon vorliegt.
N2  - Methyldi:x:anthatostibanes CH\(_3\)Sb(S\(_2\)COR)\(_2\) are obtained either byreacting sodium xanthates with methyldibromostibanes at low temperatures (-78°0) or by insertion of CS\(_2\) in methyldialkoxistibanes. An X-ray analysis of CH\(_3\)Sb(S\(_2\)COC\(_2\)H\(_5\))\(_2\) is given. It shows that in the crystal the Sb atom is chelated fivefold - inter and intramolecular - by sulfur atoms, so that a pentagonal pyramidal or pentagonal bipyramidal, with inclusion the lone pair, geometry is observed.
KW  - Chemie
Y1  - 1983
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-31952
ER  - 
TY  - JOUR
A1  - Peach, Michael E.
A1  - Burschka, Christian
T1  - Metal carbonyl complexes of some aromatic ortho bis(methylthio)ethers
N2  - Various complexes of the type M(CO)4L and [M(CO)4lzL, M = Cr, Mo, W, have been prepared and characterized. A series of aromatic ortho bis(methylthio)ethers were used as the ligand L. The crystal structures of the free ligand C6(SCH)6 and of the complex Cr(CO)4C6(SCH)6 are reported.
N2  - On a prepare divers complexes du type M(CO)4L et [M(CO)4]2L, ou M = Cr, Mo, W, et on les a identifies. On a utilise une serie d'ortho bis (methylthio) ethers aromatiques comme ligand L. On rapporte la structure cristalIine du ligand libre C6(SCH)6 et celle du complexe Cr(CO)4C6(SCH)6.
KW  - Chemie
Y1  - 1982
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-31964
ER  -