Synthesis and structures of bis(iminophosphorano)methanide chelate complexes with zinc and group 13

Abstract

The organolithium bis(iminophosphorano)methandiide dimer [Li2C(Ph2PNSiMe3)2]2 ([Li2-1]2) reacts with 4 equiv of AlCl3 in THF to generate the novel bimetallic aluminum carbene complex of [Li(THF)4][{C(Ph2PNSiMe3)2}Al2Cl5] (1). In addition, several new bis(iminophosphorano)methanide chelate-coordinated complexes of [{CH(Ph2PNSiMe3)2}AlCl2] (2), [{CH(Ph2PNSiMe3)2}GaBr2] (3), [{CH(Ph2PNSiMe3)2}InCl2] (4), and [{CH(Ph2PNSiMe3)2}InBr2] (5) are synthesized in situ while organolithium bis(iminophosphorano)methandiide ([Li2-1]2) reacts with 2 equiv of metal halides AlCl3, GaBr3 InCl3 and InBr3 respectively in THF. Furthermore, an unexpected complex of [{CH2(Ph2PNSiMe3)2}ZnCl2] (6) is formed as [Li2-1]2 dimer reacted with 2 equiv of ZnCl2 in situ. All six synthesized complexes (1, 2, 3, 4, 5 and 6) in situ were isolated in solid and were structurally characterized by X-ray diffraction. Complexes containing particular carbene to metal or ionic linking interaction bonds (1, 2, 3 and 4) were selected and further characterized in detail by DFT calculations using Gaussian03 program. The DFT calculation demonstrates the existence of a carbeneAl σ bond in structure 1 and ionic linkage interaction in structures 2–4.