Benner K  Klüfers P  Vogt M 《Angewandte Chemie (International ed. in English)》2003,42(9):1058-1062

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Dmitriev A  Spillmann H  Lin N  Barth JV  Kern K 《Angewandte Chemie (International ed. in English)》2003,42(23):2670-2673

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J. W. Schultze  Jrg Grunenberg  Gunter Festel  Klaus Alberti 《Nachrichten aus der Chemie》2003,51(2):208-216

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Klaus Banert  Frank Khler 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2001,113(1):173-176

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Jens Beckmann  Klaus Jurkschat  Stephanie Rabe  Markus Schürmann 《无机化学与普通化学杂志》2001,627(10):2413-2419

The single‐crystal X‐ray structure analysis of hexakis(2,4,6‐triisopropylphenyl)cyclotristannoxane, cyclo‐[(2,4,6‐i‐Pr₃‐C₆H₂)₂SnO]₃ ( 1 ), is reported and reveals this compound to contain an almost planar six‐membered ring. Redistribution reactions of 1 with cyclo‐(t‐Bu₂SnO)₃ and t‐Bu₂SiCl₂, respectively, failed and indicate an unusual kinetic inertness of the Sn–O bonds in 1 as compared to related molecular diorganotin oxides containing less bulkier substituents. The redistribution reaction of cyclo‐(t‐Bu₂SnO)₃ with cyclo‐(t‐Bu₂SnS)₂ leads to an equilibrium involving the trimeric diorganotin oxysulphides cyclo‐t‐Bu₂Sn(OSnt‐Bu₂)₂S ( 2 a ) and cyclo‐t‐Bu₂Sn(SSnt‐Bu₂)₂O ( 2 b ).  相似文献   

    

Detlef Selent  Dieter Hess  Klaus‐Diether Wiese  Dirk Rttger  Christine Kunze  Armin Brner 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2001,113(9):1739-1741

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Hannes H. Loeffler  Christoph A. Sotriffer  Rudolf H. Winger  Klaus R. Liedl  Bernd M. Rode 《Journal of computational chemistry》2001,22(8):846-860

The relative free energies of hydration of the dipeptides glycylalanine and alanyl‐glycine in their naturally occurring form have been calculated both for the zwitterionic and protonated species. Emphasis was laid on comparisons between the conventional cutoff method and the Particle Mesh Ewald method to account for possible differences in electrostatic contributions to the free energy. Furthermore, the convergence behavior of the total free energy and its individual contributions were examined. The results, obtained by means of the thermodynamic integration technique as implemented in the free energy module of the AMBER program suite, suggest that in aqueous solution glycylalanine is more stable than alanylglycine by 2.7 kcal/mol in the zwitterionic form and by 3.5 kcal/mol in the protonated form. © 2001 John Wiley & Sons, Inc. J Comput Chem 22: 846–860, 2001  相似文献   

    

David Scheschkewitz  Matthias Menzel  Matthias Hofmann  Paul von Ragu Schleyer  Gertraud Geiseler  Werner Massa  Klaus Harms  Armin Berndt 《Angewandte Chemie (International ed. in English)》1999,38(19):2936-2939

Remarkably short distances to the ring plane are shown by the η⁵-bound lithium ions in the first compound with a triply negatively charged five-membered ring, 1 , which was obtained by reduction of 2 with lithium. R=CH(SiMe₃)₂, Dur=2,3,5,6-tetramethylphenyl.  相似文献   

    

Jörn Berninger  Rolf Krauss  Hans-Georg Weinig  Ulrich Koert  Burkhard Ziemer  Klaus Harms 《European journal of organic chemistry》1999,1999(4):875-884

2,3,6,7-Tetrasubstituted perhydroanthracenes with the relative configuration 2β,3α,4aα,6β,7α,8aβ,9aα,10aβ have been synthesized stereoselectively. The biconformationality of these compounds has been investigated in solution by NMR and in the solid state by X-ray crystallography. A triple-ring flip 2 → 3 was realized for the first time by the covalently induced transition 29 → 30 .  相似文献   

    

Dieter Sellmann  Klaus Engl  Torsten Gottschalk-Gaudig  Frank W. Heinemann 《欧洲无机化学杂志》1999,1999(2):333-339

In search of a tetradentate thioether thiolate ligand that is more stable toward reductive C–S bond cleavage than the parent ligand ′S₄′-H₂ [′S₄′-H₂ = 1,2-bis(2-mercaptophenylthio)ethane], the novel tris-phenylene ligand ′tpS₄′-H₂ ( 3 ) [′tpS₄′-H₂ = 1,2-bis(2-mercaptophenylthio)phenylene] was synthesized via the nitro and amine compounds ′tpS₂(NO₂)₂′ ( 1 ) and ′tpS₂(NH₂)₂′ ( 2 ). The coordination of ′tpS₄′^2– to ruthenium centers resulted in the formation of six-coordinate [Ru(L)(PR₃)(′tpS₄′)] complexes (R = Et, L = PEt₃ 4 ; R = Ph, L = PPh₃ 5 , CO 6 , DMSO 7 ). The X-ray structure analyses of 4 and 6 revealed that the thiolate donors occupy trans positions; consequently the ′tpS₄′^2– ligand coordinates in the same way as the ′S₄′^2– ligand. The stability of the ′tpS₄′^2– ligand toward reductive C–S cleavage reactions was shown by the synthesis of [Os(PEt₃)₂(′tpS₄′)] ( 8 ). In contrast to [Os(PEt₃)₂(′S₄′)], 8 is stable for unlimited periods of time. The X-ray structure analysis of [Ru(Cl)₂(PPh₃)(′tpS₂(NH₂)₂′)] ( 9 ) demonstrates that the potentially tetradentate ligand ′tpS₂(NH₂)₂′ coordinates in 9 through three donors leaving one NH₂ donor dangling.  相似文献