| Abstrakt: |
-The kinetics of formation and decomposition of mono- and binuclear copper(II) complexes of the macrocycle 3,6,9,17,20,23-hexaazatricyclo[23.3.1.111,15]triaconta-1(29), 11(30),12,14,25(26),27-hexaene (L) has been studied at 25°C and 1.0 M ionic strength under a variety of conditions. All reactions occur in the stopped-flow time-scale and results indicate that upon addition of a large excess of H+binuclear complexes convert rapidly into mononuclear species in which some nitrogens of the ligand are uncoordinated. The kinetics of decomposition of the resulting mononuclear species is intermediate between that of complexes with linear polyamines and those with mononucleating macrocycles. On the other hand, the formation of CuIIcomplexes at high concentrations of OH-occurs essentially through reaction of Cu(OH)3-with the unprotonated form of the ligand, at a rate similar to that observed for reactions with simpler ligands. Coordination of the second CuIIis very rapid under these conditions. |
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