Kinetics and mechanism of the reaction of a quasi-aromatic copper(II) complex, [Cu(PnAO)-6H](0), with formaldehyde

The kinetics of the reaction of CH2O with a quasi-aromatic metal complex (1 ,1,2,8,9,9-hexamethyl-4,6-dioxa-5-hydro-3,7,10,14-tetraazacyclotetradecane- 2,7,10,12-tetraene)copper(II), [Cu(PnAO)-6H](0) (AH), have been studied spe ctrophotometrically under neutral conditions in 1/3(v/v) MeOH-H2O. The Cu, 2N, 3C quasi-aromatic heterocyclic ring in AH is highly reactive towards CH 2O at the central-aromatic-carbon atom, C(12) and the following reaction me chanism is proposed. [GRAPHICS] The compounds AH, A-CH2OH and A-CH2-A were isolated and identified by i.r s pectroscopy and by elemental analysis. The kinetic data supported the propo sed reaction sequence. All reactions were second order overall. The rate co nstants and corresponding activation parameters for every step were obtaine d and are discussed.