Lanthanide nitrate complexes of diphenylmethylphosphine oxide:: synthesis and spectroscopic studies.: Crystal structures of [La(Ph2MePO)3(NO3)3], [La(Ph2MePO)4(NO3)3]• xMe2CO and [Yb(Ph2MePO)4(NO3)2]PF6

The reaction of Ln(NO3)(3). 6H(2)O (Ln = lanthanide except Pm) with Ph2MePO in a 1:3 or 1:4 ratio in acetone or ethanol produces [Ln(Ph2MePO)(3)(NO3)(3)] which have been characterised by analysis, IR, H-1 and P-31{H-1} NR IR spectroscopy and conductance measurements. The [Ln'(Ph2MePO)(3)(NO3)(3)] (Ln' = Pr-Tb) exist only as tris complexes in solution and are unaffected by the presence of excess Ph2MePO. In contrast the [Ln(Ph2MePO)(3)(NO3)(3)] (Ln = Ho-Lu) partially decompose in CH2Cl2 solution into [Ln(Ph2MePO)(4)(NO3)(2)](+), and [Ln(Ph2MePO)(4)(NO3)(2)]PF6 are readily isolated from Ln(NO3)(3), Ph2MePO and NH4PF6 in acetone. For lanthanum only, a neutral 1:4 complex [La(Ph2MePO)(4)(NO3)(3)] was isolated. X-ray crystal structures show that [La(Ph2MePO)(3)(NO3)(3)] contains nine-coordinate La, whilst [La(Ph2MePO)(4)(NO3)(3)]. xMe(2)CO contains a ten-coordinate metal centre. The structure of [Yb(Ph2MePO)(4)(NO3)(2)]PF6 reveals an eight-coordinate cation and all complexes contain bidentate nitrate-groups. (C) 2001 Elsevier Science Ltd. All rights reserved.