作者:B. G. Kimel"、V. V. Tumanov、V. I. Faustov、V. M. Promyslov、M. P. Egorov、O. M. Nefedov
DOI:10.1023/a:1020943913739
日期:——
Reactions of a number of germylenes and dimethylsilylene with a phosphaalkene, 2,2-bis(uimethylsilyl)-1-phenyl-1-phosphaethene (1),,were studied. The reaction of short-lived dimethylgermylene with 1 produced a phosphagermirane 3 (the first representative of a new class of heterocyclic compounds). Compound 3 was characterized m solution by H-1, C-13, P-31, and Si-29 NMR spectroscopy Subsequent reaction of 3 with dimethylgermylene rmltsin2,2,3,3-tetramethyl-4,4-bis(trimethylsilyl)-1-phenyl-2,3-digerma-1-phosphacyclo-butane 4, which has not been reported so far. In order to rationalize different reactivities of germylenes towards alkenes and phosphaalkenes, the addition products of GeH2 to ethylene and phosphaethene (HP=CH2) were studied using the G2 computational scheme and DFT PBE technique. The adducts of GeMe2 (GeCl2) with HP=CH2, and of GeMe2 with PhP=C(SiH3)(2) were also calculated by the DFF PBE method. According to calculations, the exothermicity, DeltaE of cycloaddition of GeH2 and GeMe2 to the phosphaalk-enes HP=CH2 and PhP=C(SiH3)(2) (43.5-39.7 k-cal mol(-1)) is nearly twice as high as the exothermicity of cycloaddition of these germylenes to ethylene In addition to the minimum corresponding to the three-membered cycle, a number of minima corresponding to quite stable donor-acceptor complexes in which the Ge atom. is coordinated by the lone electron pair of the P atom in the phosphaalkene molecule were located on the potential energy surface of the gennylene-phosphaalkene system. The complexation energy of the complex of GeH2 (GeMe2) with, phosphaethene is 25.0 (16.9) kcal mol(-1). For GeCl2, the exothermicity of cycloaddition to HP=CH2 decreases to 7.6 kcal mol(-1) and the complexation energy decreases to 8.2 kcal mol(-1).