Complexes of Bismethyl-imido-triphosphoric-acid-pentakis-dimethyl-amide (TRIPA), a New Tridentate Ligand

Abstract

A number of new complexes containing TRIPA, chemical formula [ (CH3) 2N]2 P (O) N (CH3)P (O) [N (CH3) 2] N (CH3) P (O) [N (CH3) 2] 2, is reported The compounds have the general formula M (TRIPA) n (anion) p, where M = Mg, Ca, Mn, Fe, Co, Ni, Cu, Zn, Cd (p = 2) and Al, Fe (p = 3), n=1,2 and anion stands for BF4⁻, [B (C6H5)4]⁻, NO3⁻ and Cl⁻. They are characterized and identified by chemical analysis and physical measurements. It is shown that the bis-compounds contain octahedrally solvated metal ions, the ligand acting as a tridentate phosphoryl donor. Electron paramagnetic resonance measurements show some distortion of the octahedrons. The mono-compounds with the nitrate anion probably possess a fivecoordinated structure whereas the chloride complexes are probably dimeric. The occurrence of more than one geometric isomer for the group [M (TRIPA) 2] P* is discussed. It is concluded that the s-facial and u-facial isomers may occur; a possible connection with the size of the metal ions is indicated. The mer form is rejected because of steric requirements.