The radiation chemistry of aqueous solutions of sodium nitroprusside

Abstract

The radiation chemistry of aqueous solutions of nitroprusside has been studied by pulse and steady-state methods. The data show that nitroprusside is reduced by e aq −, H and CO 2 −, and oxidized by OH, and therefore, contrary to a previous proposal, it is not a specific reagent for excited water molecules. The relevant rate constants are: k(e aq − + Fe(CN) 5NO 2-) = 2·2 × 10 10 1 mol −1s −1, k(CO 2 − + Fe(CN) 5NO 2- = 3·7 × 10 8 1 mol −1 s −1, k(OH + Fe(CN) 5NO 2−) = 1·2 × 10 7 l mol −1 s −1. The photodecomposition of nitroprusside at λ > 300 nm proceeds by two mechanisms: 1. (i) Fe(CN) 5NO 2− + hv → Fe(CN) 5 2− + NO, 2. (ii) Fe(CN) 5NO 2− + hv → Fe(CN) 5NO − + e aq −.