Mono- and bis-(iminophosphoranyl)methane titanium complexes

The reaction of the bis(iminophosphoranyl)methanes, CH2(R2P=NSiMe3)(2) (R=P h 1, Me 2 or Cy 3) with two equivalents of Cp*TiCl3 (Cp*=C5Me5) gave, via e limination of two moles of trimethylsilyl chloride, the air and moisture se nsitive bimetallic titanium bis(iminophosphoranyl)methane complexes, [(Cp*T iCl2)(2){mu-(N=PR2)(2)CH2-kappaN,N}] (R=Ph 7, Me 8 or Cy 9). The monometall ated complexes, [Cp*TiCl2{(N=PR2)CH2(R2P=NSiMe3)-kappaN}] (R=Ph 4, Me 5 or Cy 6) were observed as intermediates in the reaction by P-31 NMR spectrosco py but attempts to isolate the pure monosubstituted products from reactions of the bis(silyliminophosphoranyl)methane and the titanium reagent conduct ed under equimolar stoichiometry were not successful; instead only mixtures of the mono- and di-substituted complexes were generated. Crystal structur es of 7 and 8 revealed different molecular structures; in 7 the imidotitani um groups lie in a mutual trans orientation across the molecule whereas in 8 they lie on the same side of the molecule.