Zusammenfassung
M(CO)5L (M = Cr, Mo, W; L = 2,1,3-benzoxadiazole (bod), 2,1,3-benzothiadiazole (btd), 2,1,3-benzoselenadiazole (bsd)), M1(CO)52L1 (M1 = Cr, W; L1 = bod, btd, bsd, quinoxaline, 2,1,3-thiadiazole) were prepd. and characterized by cyclic voltammetry, UV-visible adsorption and emission spectroscopy. The complexes exhibit low-lying metal-to-ligand charge transfer (MLCT, d $\rightarrow$ p*) transitions as evident from long wavelength absorptions and are easily reduced to yield persistent anion radicals. W(CO)52L1 (L1 = btd, bsd) show weak near IR (\textgreater750 nm) emission from rather short-lived MLCT excited states. While quinoxaline and monocyclic 2,1,3-thiadiazole also form binuclear W(CO)5 complexes, the related 2-methyl-1,2,3-benzotriazole does not bind W(CO)5 fragments in the neutral state but only as the more basic anion radical as evident from ESR spectroscopy. on SciFinder(R)
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