(Amidomethyl)dimethylsilanol hydrohalides: Synthesis, NMR and IR studies. Characteristic features of the electronic structure from high-resolution X-ray study and quantum chemical calculation
作者:Alexander A. Korlyukov、Sergey A. Pogozhikh、Yuri E. Ovchinnikov、Konstantin A. Lyssenko、Mikhail Yu. Antipin、Aleksander G. Shipov、Oksana A. Zamyshlyaeva、Evgeniya P. Kramarova、Vadim V. Negrebetsky、Igor P. Yakovlev、Yuri I. Baukov
DOI:10.1016/j.jorganchem.2006.05.047
日期:2006.9
(C,O)-chelate silanol hydrohalides RC(O)NHCH2SiMe2OH center dot HHal (2a,b and 5b), and their precursors, (C,O)-chelate chlorosilanes RC(O)NHCH2SiMC2Cl (6a,b) and disiloxanes [RC(O)NHCH2SiMe2](2)O (8a,b) (R = Me (a), Ph (b); Hal = Cl (2), Br (5)), were obtained by several routes. The original scheme of hydrolysis of the above chlorides was discussed in detail. X-ray analysis has shown that the silanol hydrohalogenides PhC(O)NHCH2SiMe2OH center dot HX (2b and 5b) in the crystal exist in the form of cation-anion pairs [PhC(O)NHCH2SiMe2,(OH2)(+) center dot X- (14b center dot Cl- and 14b center dot Br-) assembled by H-bonds in a 3D framework. The Si atom in the cation has a trigonal bipyramidal configuration with the oxygen atom of the carbonyl group and protonated hydroxyl exo-substituent in axial positions. The endocyclic Si-O bonds are equal with an average of 1.905 angstrom while the exocyclic Si-O bonds are 1.979 and 2.009 angstrom, for Hal = Cl and Br, respectively.Quantum chemical calculations have shown that the cation [PhC(O)NHCH2SiMe2(OH2)(+) (14b) is stable only in the crystal. Based on a high-resolution X-ray study and a quantum chemical calculation, it was found that the chemical bonding pattern in the OSiO axial fragment of the cation 14b corresponds to a three-centred four electron interaction. The cation 14b should be considered as a silylium cation stabilized by coordinated H2O molecules rather than a silyloxonium ion. (c) 2006 Elsevier B.V. All rights reserved.
(C,O)-螯合的硅醇盐酸盐 RC(O)NHCH2SiMe2OH·HHal (2a,b和5b),以及它们的前体,(C,O)-螯合的氯硅烷 RC(O)NHCH2SiMe2Cl (6a,b) 和二硅氧烷 [RC(O)NHCH2SiMe2]2O (8a,b) (R = Me (a), Ph (b); Hal = Cl (2), Br (5)),通过多种途径获得。详细讨论了上述氯化物水解的原始方案。X射线分析表明,晶体中存在的苯甲酰胺基硅醇盐酸盐 PhC(O)NHCH2SiMe2OH·HX (2b 和 5b) 以离子对形式存在,由氢键在三维框架中组装的 [PhC(O)NHCH2SiMe2(OH2)+·X− (14b·Cl− 和14b·Br−)]. 阳离子中的 Si 原子具有三棱双锥形构型,其中羰基氧原子和质子化羟基的外取代基位于轴向位置。环内的 Si-O 键相等,平均为 1.905 埃,而环外的 Si-O 键分别为 1.979 和 2.009 埃,对应于 Hal = Cl 和 Br。量子化学计算表明,阳离子 [PhC(O)NHCH2SiMe2(OH2)+ (14b) 只能在晶体中稳定存在。基于高分辨率 X 射线研究和量子化学计算,发现阳离子 14b 中 OSiO 轴向片段的化学键合模式对应于三个中心四个电子的相互作用。阳离子 14b 应被视为由配位的 H2O 分子稳定的硅基阳离子,而不是硅氧ultiun 阳离子。© 2006 Elsevier B.V. 保留所有权利。