Kinetics and mechanisms of the oxidation of Ni(II) and Cu(II) macrocycles by aquasilver(II) in acidic perchlorate media

Document Type

Article

Date of Original Version

5-15-1987

Abstract

The oxidation of NiIIcyclam, CuIIcyclam (cyclam = [18]aneN4) and CuIICT (CT = Me6[14]-4,11-dieneN4) by aquasilver(II) has been investigated kinetically in perchlorate media in the range [HClO4] = 1-4 mol dm-3. The reaction stoichiometry indicates 1 mol of oxidant reacting with 1 mol of M(II). Stopped-flow studies indicate a single reaction pathway involving MIIL + Ag2+ with k = 2.3 × 105, 3.5 × 105 and 1.5 × 104 dm3 mol-1 s-1 for NiIIcyclam, CuIIcyclan and CuIICT respectively, at 10 °C. While NiIIIcyclam is stable enough to allow UVVis characterization, CuIIIcyclam and CuIII decay by a first-order process with rate constants of 1.5 and 0.053 s-1 respectively. Reliable kinetic results could not be obtained for the oxidation of NiIICT by silver(II), but the oxidation product does, like NiIIIcyclam, have a significant lifetime. © 1987.

Publication Title, e.g., Journal

Inorganica Chimica Acta

Volume

129

Issue

1

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