Diphosphine dioxide complexes of lanthanum and lutetium - The effects of ligand architecture and counter-anion

The reaction of bis(diphenylphosphino)methane dioxide (dppmO(2)) with LaCl3, Lab or LaCl3/[NH4][PF6] produces [La(dppmO(2))(4)]Y-3 (Y = Cl, I, PF6) which contain eight-coordinate, distorted square antiprismatic cations. In contrast, LaCl3 or LaCl3/[NH4][HPF6]] and 1,2-bis(diphenylphosphino)ethane dioxide (dpPeO(2)) produce the polymer [LaCl3(dppeO(2))(1.5)](n), which has a six-coordinate La centre with three mer-chlorides and three Ph2P(O)CH2-donors from three different diphosphine dioxide ligands. The bulkier 1,2-bis (diphenylphosphino)benzene dioxide (PPO2) forms [LaCl2(PPO2)(2)(H2O)(2)]Cl and [LaCl2(PPO2)(2)(H2O)(2)] [PF6], which contain eight-coordinate La, and also the seven-coordinate [LaCl(PPO2)(3)][PF6]. The smaller lutetium ion favours six-coordination in [LuCl2(dppmO(2))(2)]Cl, [Lul(2)(dppmO(2))(2)]I, [LuCl(dppmO(2))(2)(H2O)] [PF6](2).2H(2)O, [LuCl2(PPO2)(2)]Cl, [LuI2(PPO2)(2)]I and [Lu(PPO2)(2)(H2O)(2)][PF6](3). All complexes were characterised by microanalysis, IR, H-1 and P-31{H-1) NMR spectroscopy. X-ray crystal structures are reported for [La(dppmO(2))(4)]Y-3 (Y = 1, PF6), [LaCl2(dPPeO(2))(1.5)](n), [LaCl2(PPO2)(2)(H2O)(EtOH)]Cl and [LaCl(PPO2)(3)][PF6](2). (C) 2017 The Author(s). Published by Elsevier Ltd.