51286-38-5Relevant academic research and scientific papers
ECE mechanisms as a tool for the investigation of unstable metal complexes. 3. Polarographic studies of ligand dissociation of dibromocobalt(II) and dibromocobalt(III) complexes
Yamada, Akifumi,Yoshikuni, Tadatsugu,Tanaka, Nobuyuki
, p. 2090 - 2093 (1981)
The electrode reaction of trans-[CoBr2(N)4]+ ((N)4 = (en)2, (pn)2, (tn)2, and (NH3)4; en = ethylenediamine, pn = propylenediamine, tn = trimethylenediamine) has been examined in 0.1 M sodium acetate buffer solutions at mercury electrodes. All complexes exhibit the complicated electrode processes in which both the parallel ECE reaction and the Br- dissociation of cobalt(III) complexes take place. The dissociation rates of Br- from the Co(III) and Co(II) complexes are determined. The Br--dissociation rate constant (s-1) at 25°C, ΔH≠ (kcal mol-1), and ΔS≠ (cal K-1 mol-1) for trans-[CoIIIBr2(N)4]+ complexes are as follows: en, 1.51 × 10-4, 27.2, +15; pn, 3.30 × 10-4, 19.1, -10; NH3, 4.20 × 10-3, 26.8, +20; tn, 2.12 × 10-2, 15.2, -15. Also, the Br--dissociation rate constant (s-1) at 25°C, ΔH≠ (kcal mol-1), and ΔS≠ (cal K-1 mol-1) for trans-[CoIIBr2(N)4] complexes are as follows: en, 0.508, 1.3, -55; pn, 0.538, 2.9, -50; NH3, 0.610, 1.3, -55; tn, 0.571, 6.5, -38.
