L2,3-edge x-ray absorption near-edge spectroscopy analysis of photoisomerism in solid ruthenium-sulfur dioxide complexes.

Ru L(2,3) edge x-ray absorption near-edge spectroscopy spectra of four compounds [Ru(SO(2))(NH(3))(4)X]Y (X =  water, Y = (±)-camphorsulfonate(2); X =water, Y = tosylate(2); X =isonicotinamide, Y = tosylate(2); X =pyridine, Y = triflate(2)) are reported before and after optical excitation, which causes photoinduced linkage isomerism of the SO(2) ligand. Principal component analysis reveals consistent changes in the spectra upon photoisomerization, suggesting a partial oxidation of the Ru ion. These results demonstrate that x-ray absorption near-edge spectroscopy is an effective means of probing photoinduced linkage isomerism.