A NOVEL W(V)-W(IV) REVERSIBLE SYSTEM - THE PREPARATION AND CHARACTERIZATION OF [W(CN)6(PHEN)](2-) AND [W(CN)6(PHEN)]- SALTS

Thermal decomposition of (phenH)3(H3O)[W(CN)8].6H2O (phen = 1,10-phena nthroline) in glycerol at 200-degrees-C gives the new species, [W(CN)6 (phen)]2-. A sodium salt, Na2[W(CN)6(phen)].3phen.2H2O, was isolated a s a solid and converted into (AsPh4)2[W(CN)6(phen)].3H2O. The latter w as then nearly quantitatively oxidized to (AsPh4)[W(CN)6(phen)].H2O. T he UV-vis, IR, ESR, H-1 and C-13 NMR spectra and the electrochemistry of these products are discussed. The photosubstitution of phen by H2O/ OH- of [W(CN)6(phen)]2- and photoreduction of [W(CN)6(phen)]- to [W(CN )6(phen)]2- were found to occur with the initial quantum yields PHI360 o = 8.5(+/-0.1) x 10(-3) (in H2O) and PHI360o = 0.187(+/-0.002)(in MeO H), respectively.