485815-51-8Relevant articles and documents
Synthesis and x-ray structures of dilithium complexes of the phosphonate anions [PhP(E)(NtBu)2]2- (E = O, S, Se, Te) and dimethylaluminum derivatives of [PhP(E)(NtBu)(NhtBu)]- (E = S, Se)
Briand, Glen G.,Chivers, Tristram,Krahn, Mark,Parvez, Masood
, p. 6808 - 6815 (2002)
The dilithium salts of the phosphonate dianions [PhP(E)(NtBu)2]2- (E = O, S, Se) are generated by the lithiation of [PhP(E)(NHtBu)2] with n-butyllithium. The formation of the corresponding telluride (E = Te) is achieved by oxidation of {Li2[PhP(NtBu)2]} with tellurium. X-ray structural determinations revealed dimeric structures {Li(THF)2[PhP(E)-(NtBu)2]}2 in which the monomeric units are linked by Li-E bonds. In the case of E = Se or Te, but not for E = S, transannular Li-E interactions are also observed, resulting in a six-rung ladder. By contrast, for E = O, this synthetic approach yields the Li2O-templated tetramer {(THF)Li2[PhP(O)(Nt Bu)2]}4·Li2O in THF or the tetramer {(Et2O)0.5Li2[PhP(O) (NtBu)2]}4 in diethyl ether. The reaction of trimethylaluminum with PhP(E)(NHtBu)2 produces the complexes Me2Al[PhP(E)(NtBu)(NHtBu)] (E = S, Se), which were shown by X-ray crystallography to be N,E- chelated monomers.