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The reactions (CuTL + 'R -LCun-R and the mechanism of decomposition of the transient complexes LCu11-R were studied using the pulse-radiolysis technique (L1 = H2O, L* 12 = 2,5,8,ll-tetramethyl-2,5,8,ll-tetraazadodecane; 'R = 'CH3, 'CH2COOH, 'CH(CH3)COOH, •-CH2CH2COOH.) The kinetics of formation of the transient complexes obey pseudo-firstorder rate laws. The rate constants measured for these reactions are in the range (2-4) x 109 M-1 s-1 for L1 and 6 x 106 7*-1 x 10s M-1 s-1 for L2. The mechanisms of decomposition of the transient complexes depend on the nature of R and L as follows: 1. For R = CH3 ethane is the final product. The kinetics of its formation obey second-order rate laws. Free methyl radicals are not intermediates in these processes. 2. For R = CH2CH2COOH the transient complexes decompose via an analogous mechanism to that of R = CH3 for L1 and via homolysis of the copper-carbon a bond for L2. 3. For R = CH2COOH and CH(CHs)-COOH the transient complexes decompose via heterolysis of the copper-carbon a bonds forming CunL. The effect of the nature of R and L on the kinetics of these reactions is discussed.

The ligands R(2)NCH(2)CH(2)N(R)CH(2)CH(2)N(R)CH(2)CH=CH(2), where R = H, CH(3), were synthesized. The stability constants of their complexes with Cu(II) and Cu(I) in aqueous solutions were determined. Both ligands stabilize Cu(I) in aqueous solutions, though the reduction potentials of both (CuL(i)())(2+/+) couples are shifted cathodically in comparison to the Cu(2+/+)(aq) couple. These properties indicate that these complexes should be good catalysts for a variety of processes that are catalyzed by Cu(I).

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