In situ quenching of monoaryl bismuth (III) dihalides with nitrogen donor ligands: Isolation of adducts and their spectral characterization

Abstract The molecular addition of amphoteric molecules of organobismuth (III) compounds namely, o -tolylbismuth and p -tolylbismuth dihalides with nitrogen donor bidentate ligands 1, 10 phenanthroline and 2, 2′-bipyridine have been isolated and characterized by UV–visible, IR, NMR and Photoluminescence (PL) spectroscopy. The compounds have been isolated from non-aqueous media; they have empirical formulae of the type ArBiX 2 - L (X = Cl, Br, I; L = Phen, Bipy). IR study indicate that there are strong extended interactions existing crystalline phases of the phenyl derivatives, while UV absorption for o -and p -tolylbismuth dihalides shows bathochromic effect due to + I nature of methyl substituent and corresponding hypsochromic shift in complexes due to coordination at bismuth center. 1 HNMR spectra of complex exhibit the peaks for free ligands thereby suggesting the dissociation of complex in solution phase. Room temperature PL spectra suggest the presence of monomeric-dimeric species with Bi 3+ luminescence in the complex in comparison with organobismuth (III) dihalides.