Synthesis of selenophosphinic and tellurophosphinic amides and amidato complexes. Crystal structures of Bu^t₂P(Te)NH(C₆H₁₁), [Ti(η-C₅H₅)Cl₂{Bu^t₂P(Se)NPrⁱ}] and [TiCl₂{Bu^t₂P(Se)N(C₆H₁₁)}₂]·C₇H₈

Abstract

The reaction of But2PNHR′ with selenium or tellurium affords the chalcogenophosphinic amides But2P(E)NHR′(E = Se or Te; R′= Pri or cyclo-C6H11). The compounds [But2P(E)NHCH2]2 were prepared similarly. The crystal structure of But2P(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[But2P(Se)NR′] react with [TiCl3(cp)](cp =η-C5H5) to give [TiCl2(cp){But2P(Se)NR′}]. The reaction of Li[But2P(Se)NPri] with [TiCl4(thf)2](thf = tetrahydrofuran) affords [TiCl3{But2P(Se)NPri}], while a similar reaction with Li[But2P(Se)N(C6H11)] leads to the isolation of [TiCl2{But2P(Se)N(C6H11)}2]. The structures of [TiCl2(cp){But2P(Se)NPri}] and [TiCl2{But2P(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.