Calcium-bis{[tris(trimethylsilyl)silyl]tellanid} · 4 THF : Synthese, spektroskopische Charakterisierung und Struktur

Abstract

Calcium bis {[tris(trimethylsilyl)silyl]tellanide} · 4THF is obtained by metallation of tris(trimethylsilyl)silyl)tellane using dimeric calcium bis[bis(trimethylsilyl)amide] in toluene, followed by recrystallisation from tetrahydrofuran. The compound is characterized by a remarkable highfield shift of the 1 2.5 Te{1H}-NMR resonance (-2204 ppm vs. Me2Te). The X-ray structure determination (triclinie, pI; Z = 1; a = 1042.6(2), b = 995.7(2), c = 1379.6(3) pm; α= 90.06(2), β= 92.76(2),), γ= 94.03(2)° at -100 "C) shows a distorted octahedral coordination sphere of the calcium atom (Ca-Te 319; Ca-O 236 and 241 pm). The two [tris(trimetbylsilyl)silyl}-tellanide ligands are in a trans position; the angle Ca-Te-Si is widened to 129°.