Bis[2,2,4,4,6,6-hexamethyl-2,4,6-trisila-cyclo-hexyl]zink und sein 2,2 Bipyridyl-Addukt - spektroskopische Charakterisierung und Struktur
摘要:
The alpha-CHSi2 group of bis[2,2,4,4,6,6-hexamethyl-2,4,6-trisila-cyclo-hexyl]zinc, prepared by the metathesis reaction of the corresponding lithium alkanide and zinc(II) chloride, shows a remarkable low field shift of 13 ppm in the C-13-NMR spectrum. The small 1J(C-13-H-1) and 1J(C-13-Si-29) coupling constants with values of 105 and 40 Hz can be attributed to the flattening of the coordination sphere of this carbon atom, bonded to the metal center. The X-ray structure reveals with Zn-C-Si- and Si-C-Si-angles of 110-degrees and 117-degrees, respectively, the planarisation of the alpha-C-atom. The molecules of this compound, which crystallize from n-pentane in the monoclinic space group P2(1)/n with a = 663,9(1), b = 1350,8(2), c = 1624,5(2) pm, beta = 98,22(l)degrees and Z = 2, show a crystallographically enforced linear CZnC-moiety with Zn-C bond lengths of nearly 194 pm. The complexation of 2,2'-bipyridine to this compound leads to a strong high field shift of the a-carbon atom of approximately 8 ppm.
Bis[2,2,4,4,6,6-hexamethyl-2,4,6-trisila-cyclo-hexyl]zink und sein 2,2 Bipyridyl-Addukt - spektroskopische Charakterisierung und Struktur
摘要:
The alpha-CHSi2 group of bis[2,2,4,4,6,6-hexamethyl-2,4,6-trisila-cyclo-hexyl]zinc, prepared by the metathesis reaction of the corresponding lithium alkanide and zinc(II) chloride, shows a remarkable low field shift of 13 ppm in the C-13-NMR spectrum. The small 1J(C-13-H-1) and 1J(C-13-Si-29) coupling constants with values of 105 and 40 Hz can be attributed to the flattening of the coordination sphere of this carbon atom, bonded to the metal center. The X-ray structure reveals with Zn-C-Si- and Si-C-Si-angles of 110-degrees and 117-degrees, respectively, the planarisation of the alpha-C-atom. The molecules of this compound, which crystallize from n-pentane in the monoclinic space group P2(1)/n with a = 663,9(1), b = 1350,8(2), c = 1624,5(2) pm, beta = 98,22(l)degrees and Z = 2, show a crystallographically enforced linear CZnC-moiety with Zn-C bond lengths of nearly 194 pm. The complexation of 2,2'-bipyridine to this compound leads to a strong high field shift of the a-carbon atom of approximately 8 ppm.