Yttrium Alkyl Complex with a Linked Bis(amidinate) Ancillary Ligand

The dilithium salt of a linked bis(amidinate) dianionic ligand, Li 2 [Me 3 SiNC(Ph)N(CH 2 ) 3 NC(Ph)NSiMe 3 ] ( 1 ), was prepared by reaction of dilithiated N, N ‘-bis(trimethylsilyl)-1,3-diaminopropane with benzonitrile. Reaction of 1 with YCl 3 (THF) 3.5 gave [Me 3 SiNC(Ph)N(CH 2 ) 3 NC(Ph)NSiMe 3 ]YCl(THF) 2 ( 2 ), which, by reaction with Li[CH(SiMe 3 ) 2 ], was converted to the alkyl complex [Me 3 SiNC(Ph)N(CH 2 ) 3 NC(Ph)NSiMe 3 ]Y[CH(SiMe 3 ) 2 ](THF) ( 3 ). A structure determination of 3 showed that linking together the amidinate functionalities opens up the coordination sphere to allow the bonding of an additional molecule of THF not present in the unbridged bis(amidinate) analogue [PhC(NSiMe 3 ) 2 ] 2 Y[CH(SiMe 3 ) 2 ].