Synthesis of selenophosphinic and tellurophosphinic amides and amidato complexes. Crystal structures of But2P(Te)NH(C6H11), [Ti(η-C5H5)Cl2{But2P(Se)NPri}] and [TiCl2{But2P(Se)N(C6H11)}2]·C7H8

Abstract

The reaction of Bu^t₂PNHR′ with selenium or tellurium affords the chalcogenophosphinic amides Bu^t₂P(E)NHR′(E = Se or Te; R′= Prⁱ or cyclo-C₆H₁₁). The compounds [Bu^t₂P(E)NHCH₂]₂ were prepared similarly. The crystal structure of Bu^t₂P(Te)NH(C₆H₁₁) was determined; it shows a short P–Te bond of 2.371(1)Å and a rather long P–N bond of 1.781(4)Å. The lithium salts Li[Bu^t₂P(Se)NR′] react with [TiCl₃(cp)](cp =η-C₅H₅) to give [TiCl₂(cp){Bu^t₂P(Se)NR′}]. The reaction of Li[Bu^t₂P(Se)NPrⁱ] with [TiCl₄(thf)₂](thf = tetrahydrofuran) affords [TiCl₃{Bu^t₂P(Se)NPrⁱ}], while a similar reaction with Li[Bu^t₂P(Se)N(C₆H₁₁)] leads to the isolation of [TiCl₂{Bu^t₂P(Se)N(C₆H₁₁)}₂]. The structures of [TiCl₂(cp){Bu^t₂P(Se)NPrⁱ}] and [TiCl₂{Bu^t₂P(Se)N(C₆H₁₁)}₂]·C₇H₈ have been determined by X-ray crystallography. The selenophosphinic amidato ligands are bidentate in all cases. The former complex adopts a distorted square-pyramidal geometry with apical cp, while the latter is octahedral with cis-CI ligands and trans stereochemistry for the nitrogen donors.