A convenient preparation of pentaaquanitrosylchromium(2+) sulfate: The crystal structure revisited

The complex pentaaquanitrolsylchromium(2+) sulfate, [Cr(OH2)5(NO)]SO4 has been prepared in a high yield by the hydrolysis of [Cr(NCCH3)5(NO)](BF4)2 in dilute sulfuric acid. Crystals of [Cr(OH2)5(NO)]SO4 · H2O have been grown and characterized by X-ray crystallography. Continuous photolysis of [Cr(NCCH3)5(NO)]2+ in acetonitrile solution with 404 nm light results in a release of NO with the quantum yield Φ = 0.55 mol einstein−1 at 298 K with the resulting solvated Cr2+ ion being trapped by molecular dioxygen present in the solution.