Hydrates and tertiary amine complexes of cobalt(II) and nickel(II) trifluoromethanesulfonates

Abstract

The compounds [Co(H 2O) 6](CF 3SO 3) 2·H 2O, Co(CF 3SO 3) 2, [Ni(H 2O) 6](CF 3SO 3) 2, and Ni(CF 3SO 3) 2 have been prepared and characterized. The metal ion coordination is octahedral high-spin in all cases. Phase diagrams indicate that triethylamine forms extremely unstable 2:1 adducts with both anhydrous trifluoromethanesulfonates. In contrast, the less sterically demanding ligand quinuclidine (QUIN) gives the tetrahedral [Co(QUIN) 4](CF 3SO 3) 2 and the six-coordinate [Ni(QUIN) 2(CF 3SO 3) 2]. Water and trifluoromethanesulfonate anion absorptions in the near IR region of the spectrum are found to be useful, in conjunction with magnetic and visible spectroscopic data, in assigning coordination numbers and geometries.