Ni(I)(1,4,8,11-tetraazacyclotetradecane)(+), Ni(I)L(+), was produced in neutral aqueous solutions by radiolytic techniques. The mechanism and kinetics of the reaction of Ni(I)L(+) with maleate and fumarate were studied applying pulse-radiolysis and analysis of the final products. Surprisingly the mechanisms of reduction of maleate and fumarate differ considerably. Based on the results it was also shown that Ni(II)L(2+) is an electrocatalyst for the reduction of alkenes in aqueous solutions.

Ni(I)(1,4,8,11-tetraazacyclotetradecane)(+) reduces ethylene quantitatively to ethane plus butane (and hexane traces) in neutral aqueous solutions. A radical mechanism is proposed.