Structural differences of half-sandwich complexes of scandium and yttrium containing bulky substituents

Scandium and yttrium half-sandwich chloride complexes (eta(5)-C5Me4R)ScCl2(THF)(2) R = CH2Ph (3) or SiMe2CH2CH2Ph (5) and (eta(5)-C(5)me(4)R)YCl2(TFIF)(2)R = CH2Ph (4) or SiMe2CH2CH2Ph (6) were prepared by metathetic reactions of the corresponding substituted lithium or potassium cyclopentadienides with scandium or yttrium trichloride. A mutual comparison of the determined solid state structures of 4 and 5 revealed the tetranuclear character in the case of scandium complex containing C5Me4SiMe2CH2CH2Ph ligand, while a formation of the trinuclear ate-complex 4 incorporating lithium was observed for the combination of yttrium and the benzyl substituted tetramethyl cyclopentadienyl. Moreover, the steric effect of addition of another differently substituted cyclopentadienyl ring into the molecule was evaluated. (C) 2017 Elsevier B.V. All rights reserved.