Single Crystal X-Ray Analyses of a Series of Hexamethylphosphoramide-Coordinated Complexes of Rare Earth Triflates: Existence of Tetrad Effects in the Coordinate Bonds

The molecular structures of [M(OTf)2(hmpa)4]OTf·CHCl3(OTf = OSO2CF3; M = Y, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu), [Sc(OTf)2(hmpa)4]OTf, and [La(η2-OTf)(OTf)(hmpa)4]OTf·CHCl3 were accurately determined by single crystal X-ray analyses. Tetrad effects are manifested in the series of the coordinate bond lengths.