The first hafnium methandiide complexes: the assembly of an entire triad of group 4 metal ‘pincer’ bis(phosphinimine) complexes possessing the MC carbene–ylide structure

Abstract

Dichlorobis[bis(trimethylsilylamido)]hafnium(IV) reacts with (R₂PNSiMe₃)₂CH₂ (R = Cy, Ph) cleaving the C–H bonds of the P–C–P backbone methylene group and eliminating 2 mol of hexamethyldisilazane to yield the hafnium methandiide (carbene) complexes 3 and 4, thus completing the triad of group 4 metal complexes containing the MC moiety.