Osmium-carbonyl complexes of naphthylazoimidazoles. Single crystal X-ray structure of [Os(H)(CO)(PPh3)2(α-NaiEt)](PF6) {α-NaiEt = 1-ethyl-2-(naphthyl-α-azo)imidazole}

[Os(H)(Cl)(CO)(PPh3)3] reacts with 1-alkyl-2-(naphthyl-α/β-azo)imidazole (α/β-NaiR) to prepare [Os(H)(CO)(PPh3)2(α/β-NaiR)](PF6). The X-ray structure of [Os(H)(CO)(PPh3)2(α-NaiEt)](PF6) shows a distorted octahedral geometry. Addition of Cl2 in MeCN gives [Os(Cl)(CO)(α/β-NaiR)(PPh3)2](PF6) which were characterized spectroscopically. Cyclic voltammetry shows Os(III)/Os(II), Os(IV)/Os(III) and azo reductions.