Kinetics of the cis-to-planar interconversion of cis-diaqua(1,4,7,11-tetraazacyclotetradecane)nickel(II) ion

The kinetics of the cis-to-planar interconversion of cis-diaqua(1,4,7,11-tetraazacyclotetradecane)Ni(II) perchlorate has been performed spectrophotometrically in basic aqueous solution. The first order rate law is followed. And the large ΔH≠ (61.7 kJ mol−1) and the large positive ΔS≠ (30.2 J K−1 mol−1) values strongly support a free-base-catalyzed mechanism for this reaction.