Metal-nitrido photo-oxidants: synthesis, photophysics, and photochemistry of [Os VI (NH3)4(N)](X)3(X = Cl, CF3SO3)

[OsVI(NH3)4(N)](X)3(X = Cl, CF3SO3) which is strongly emissive both in solid state and in fluid solutions at room temperature (τ0∼ 1.5 µs in MeCN) is readily synthesised by CeIV oxidation of [Os(NH3)5Cl]Cl2 in water; the (dxy)1(dπ*)1(dπ*= dxz, dyz) excited state of trans [OsVI(NH3)4(N)]3+ is a powerful one-electron oxidant {[OsVIN]3++ e-→[OsVN]2+, Ef0∼ 2.1 V vs. normal hydrogen electrode} in aqueous solution, reacting with organic substrates through an electron-transfer pathway.