Reversible methanol addition to copper Schiff base complexes: a kinetic, structural and spectroscopic study of reactions at azomethine C[double bond, length as m-dash]N bonds.

The reversible methanolysis of an azomethine C[double bond, length as m-dash]N in a series of copper(ii) Schiff base complexes has been investigated through combined spectroscopic, structural, and kinetic studies. Pentadentate copper(ii) complexes [L-Cu(X)]Y (L = 1,2-bis[(1-methyl-2-imidazolyl)methyleneamino]ethane; X = Y = ClO (1); X = Y = TfO (2); X = Y = BF (3); X = HO, Y = (ClO) (4) spontaneously add methanol in a ligand centered reaction to yield stable, isolable hemiaminal ether product complexes 5-8. In methanol free solution, 5-8 spontaneously release alcohol to regenerate 1-4.