Synthesis and Characterization of the Organoindium Phosphides R2InPPh2(R =i-Pr, CH2Ph) and the Heterocubane [MesInPMes]4

The reaction of i-Pr2InCl and (PhCH2)2InCl with LiPPh2 in Et2O/THF or Et2O/n-pentane gives the organoindium phosphides i-Pr2InPPh2 (1) and (PhCH2)2InPPh2 (2), respectively. The tetrameric compound [MesInPMes]4 (3) has been prepared by the treatment of MesInCl2 with MesPLi2 in Et2O. 1−3 have been characterized by NMR, IR, and MS techniques as well as by X-ray diffraction. According to cryoscopic molecular weight determinations in benzene, 1 and 2 are present as a monomer−dimer equilibrium mixture, while 3 is tetrameric in solution. The X-ray analyses of 1 and 2 confirm the existence in the solid state of trimers in [i-Pr2InPPh2]3 and [(PhCH2)2InPPh2]3·OEt2 with distorted In3P3 six-membered rings in boat conformations. According to its structural characterization [MesInPMes]4·4.5THF is a heterocubane with an In4P4 core shielded by the bulky organic groups.