ELECTROCHEMICAL AND SPECTROSCOPIC STUDIES ON NICKEL(II III) COMPLEXESWITH NOVEL 14-MEMBERED HEXAAZA MACROCYCLE FUNCTIONALIZED WITH PROPENYL GROUPS/

A nickel(II) macrocyclic complex functionalized with propenyl groups, penyl)-1,3,6,8,10,13-hexaazacyclotetradecane)](2+) {abbreviated as [Ni (A)](2+)} has been synthesized by a simple template condensation react ion of the Ni2+ ion, ethylenediamine, allylamine and formaldehyde in m ethanol. Spectral and electrochemical properties of the [Ni(A)](2+) co mplex in various media have been investigated and compared with those of ialkyl-1,3,6,8,10,13-hexaazacyclotetradecane)](2+) complexes. The i nteraction of olefinic groups appended to the macrocycle with the nick el metal center is recognized by the spectral and electrochemical stud ies; in acetonitrile solution, the molar extinction coefficient of [Ni (A)](2+) at lambda(max) = 458 nm grows up gradually and attains a maxi mum, and at the same time the cyclic voltammetric peak currents for th e [Ni(A)](2+/3+) redox couple decrease slowly with a concomitant growt h of a new redox wave at Inert positive potentials. The first-order ki netic rate constants for the time dependent decrease of the peak curre nts of [Ni(A)](2+/3+) redox couple are determined. (C) 1998 Elsevier S cience Ltd. All rights reserved.