Electrochemical and spectrophotometric methods for evaluation of NO dissociation rate constants from nitrosyl metal complexes activated through reduction

Electrochemical and spectrophotometric methods are described for measuring the rate of nitric oxide (NO) dissociation (k(NO)) from coordination compounds. Electrochemical methods based on double-potential step chronoamperometry and rotating ring-disc electrode voltammetry techniques proved to be suitable for measuring NO dissociation from 0.03 to 4.0 s(-1). The spectrophotometric method using an ancillary ligand as a colorimetric indicator is illustrated on measuring k(-NO) = 0.002 s(-1). This methodology is limited only by the rate of the ancillary ligand substitution.