Syntheses and X-ray structures of boraamidinate complexes of lithium, phosphorus, and tellurium
Autor: | Gabriele Schatte, Tristram Chivers, Justin K. Brask, Chantall Fedorchuk |
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Rok vydání: | 2002 |
Předmět: | |
Zdroj: | Canadian Journal of Chemistry. 80:821-831 |
ISSN: | 1480-3291 0008-4042 |
DOI: | 10.1139/v02-111 |
Popis: | The dilithiated boraamidinate complexes {Li2[RB(N-t-Bu)2]}2 (1a, R = Ph; 1b, R = t-Bu), prepared by the reaction of B[N(H)-t-Bu]3 with three equivalents of LiR, are shown by X-ray crystallography to have dimeric structures consisting of a distorted Li4N4 cube capped on two opposite faces by RB units. Reactions of 1a with TeCl4 or PX3 (X = Cl, Br) yielded complexes PhB(μ-N-t-Bu)2TeCl2 (2) and PhB(μ-N-t-Bu)2PX (4a, X = Cl; 4b, X = Br), respectively. The structures of 2 and 4b were determined by X-ray crystallography. In the solid state, complex 2 forms a dimer with weak Te···Cl contacts (3.2411(6) Å). Complex 4b is monomeric with a PBr bond length of 2.3047(11) Å. The reactions of 2 and 4a with the appropriate amounts of Li[N(H)-t-Bu] produce the monomeric tellurium imide PhB(μ-N-t-Bu)2Te=N-t-Bu and the amido derivative PhB(μ-N-t-Bu)2PN(H)-t-Bu (4c), respectively. The X-ray structure of 4c was determined. Deprotonation of 4c with n-BuLi produces the dimeric monolithium derivative {Li[PhB(μ-N-t-Bu)2PN-t-Bu]}2 (5), which was shown by X-ray crystallography to have a centrosymmetric structure with a central transoid Li2N2 ring.Key words: boraamidinates, lithium, tellurium, phosphorus, X-ray structures. |
Databáze: | OpenAIRE |
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