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Hydrolysis and Photolysis of Tris(tetraethylammonium) Pentacyanoperoxynitritocobaltate(III): Evidence for a Novel Complex, Pentacyanonitratocobaltate(III)

“…1, a). The first-order fit matches the kinetic trace better than in unbuffered solution [12], and the rate constant is higher. Protonation of the O-atom coordinated to Co, as has been described for the m-bridged peroxo Co-complex [14], as well as protonation of the axial CN À , would weaken the ligand bond to ONOO À and initiate the exchange of this ligand.…”

“…± We reported previously [12] that 1 is unstable in H 2 O and in MeOH. However, in both solvents, its lifetime is much longer than that of uncoordinated ONOOH.…”

“…This conclusion is supported by a lack of nitration and hydroxylation of PhOH when 1 and PhOH are kept in a buffered solution at pH 6 for 6 days: ONOO À is not released, and coordinated ONOO À does not react with PhOH. However, in an unbuffered solution, nitration and hydroxylation were observed [12].…”

“…Recently, we reported the first synthesis and characterization of a stable complex between a metal and ONOO À , namely tris(tetraethylammonium) pentacyanoperoxynitritocobaltate(III) (1) [12]. The UV/ VIS spectrum of 1 shows a band at 280 nm and a shoulder at 350 nm.…”

“…During previous experiments [12], the shutter between the lamp and sample was closed between spectral measurements to prevent photolysis of 1. To determine whether 1 is indeed sensitive to photolysis, we flashed a 0.4 mm solution of 1 with 355-nm light from a YAG laser and measured the UV/VIS spectrum after every fifth flash (Fig.…”