Synthesis and coordination chemistry of 2,6-bis(diphenylphosphinomethyl)phenol P,P'-dioxides.

The 2,6-bis(diphenylphosphinomethyl)phenol-P,P'-dioxides, [Ph(2)P(O)CH(2)](2)C(6)H(2)(R)OH, with R = H (2a), Br (2b), Me (2c), (t)Bu (2d), were prepared via Arbusov reactions between Ph(2)POEt and the phenol derivatives (ClCH(2))(2)C(6)H(2)(R)OH. The compounds have been characterized by spectroscopic methods, and their coordination chemistry with lanthanide nitrates, Ln(NO(3))(3), has been surveyed. The 1:1 complexes [Er(2c)(NO(3))(3)].Me(2)CO and [Nd(2d)(NO(3))(3).Me(2)CO].Me(2)CO have been structurally characterized by single-crystal X-ray diffraction methods, and the ligands found to act as neutral tridentate chelates. No evidence was found for the formation of 2:1 L:M complexes suggesting that these derivatives of 2 are weaker chelators than the related 2,6-bis(diphenylphosphinomethyl)pyridine N,P,P'-trioxide chelates.