Dinuclear Chlorido‐, Alkyl(chlorido)‐, and Hydridoyttrium Complexes Supported by μ‐Bridging‐Silyl‐Linked Bis(amidinate) Ligands

A chloridoyttrium complex supported by a silyl‐linked bis(amidinate) ligand, [(Me 2 Si{NC(Ph)N(2,6‐ i Pr 2 –C 6 H 3 )} 2 ) 2 (YCl) 2 (μ‐Cl)] – [Li(thf) 4 ] + ( 2 ) (thf = tetrahydrofuran), was synthesized by the reaction of equimolar amounts of anhydrous YCl 3 and lithium amidinate [(Me 2 Si{NC(Ph)N(2,6‐ i Pr 2 –C 6 H 3 )} 2 ) 2 Li 3 ] – [Li(thf) 4 ] + ( 1 ) in thf at 20 °C. Complex 2 was isolated after recrystallization from a thf/hexane mixture in 72 % yield. Single‐crystal X‐ray structure analysis has revealed that 2 is a dinuclear compound composed of a discrete complex anion [(Me 2 Si{NC(Ph)N(2,6‐ i Pr 2 –C 6 H 3 )} 2 ) 2 (YCl) 2 (μ‐Cl)] – , containing one μ‐bridging and two terminal chloride ligands, and a cation [Li(thf) 4 ] + . The formation of a dimeric structure results from the coordination of amidinate fragments of the same dianionic ligand on two different yttrium ions and the presence of a μ‐bridging chloride ligand. Alkylation of 2 with one equivalent of Me 3 SiCH 2 Li in toluene afforded an alkyl(chlorido)yttrium complex, [Me 2 Si{NC(Ph)N(2,6‐ i Pr 2 –C 6 H 3 )} 2 ] 2 [Y(thf)](μ‐Cl)[Y(CH 2 SiMe 3 )] ( 3 ). X‐ray crystal structure investigation has shown that 3 is a dimeric complex as a result of the “spanning” coordination mode of the ansa ‐bis(amidinate) ligands and the presence of one μ 2 ‐chloride ligand, while the alkyl group remains terminal. Treatment of the in situ generated alkyl derivative [Me 2 Si{NC(Ph)N(2,6‐ i Pr 2 –C 6 H 3 )} 2 ] 2 [Y(CH 2 SiMe 3 )] 2 ( 4 ) with PhSiH 3 in toluene results in the formation of the corresponding hydridoyttrium complex [Me 2 Si{NC(Ph)N(2,6‐ i Pr 2 –C 6 H 3 )} 2 Y(μ‐H)] 2 ( 5 ), which was isolated after recrystallization from toluene in 73 % yield. According to the X‐ray crystal structure analysis, 5 adopts a dimeric structure with two μ‐bridging bis(amidinate) and two μ 2 ‐hydrido ligands.