A trinuclear [Cd3(ox)2(bipy)5](ClO4)2 (1) and a dinuclear [Pb2(ox)(bipy)2(NO3)2(H2O)2] (2) oxalatobridged complex, where ox = oxalate dianion and bipy = 2,20-bipyridine, have been synthesized and characterized by elemental analysis, IR spectroscopy and X-ray crystallography. Structural determination for complex 1 reveals a cationic species of C2 symmetry having two Cd(bipy)2 fragments connected through bridging oxalate to a central Cd(bipy) unit. Complex 2 is a neutral centrosymmetric species having two Pb (bipy)(NO3)(H2O) units connecting through the bridging oxalate. The dinuclear fragments through Hbonding as well as p–p interactions result in a 2D supramolecular network. Since complex 1 exhibits intense fluorescence (kex = 284 nm, kem = 315, 329 and 356 nm) in methanol at room temperature with a fluorescence quantum yield Us = 0.41, it was tested in association with several aromatic compounds. The results show a pronounced fluorescence quenching and enhancement in presence of nitrobenzene and m-toluidine, respectively. The outcome from DFT calculations is discussed and compared with the experimental electronic, IR spectral and X-ray structural data.
Titolo: | Oxalato-bridged oligonuclear complexes of cadmium(II)/lead(II) with bipyridine coligands: Synthesis, crystal structure, electronic spectra, density functional theory calculation and effect of organic compounds on the fluorescence property |
Autori: | |
Data di pubblicazione: | 2014 |
Rivista: | |
Abstract: | A trinuclear [Cd3(ox)2(bipy)5](ClO4)2 (1) and a dinuclear [Pb2(ox)(bipy)2(NO3)2(H2O)2] (2) oxalatobridged complex, where ox = oxalate dianion and bipy = 2,20-bipyridine, have been synthesized and characterized by elemental analysis, IR spectroscopy and X-ray crystallography. Structural determination for complex 1 reveals a cationic species of C2 symmetry having two Cd(bipy)2 fragments connected through bridging oxalate to a central Cd(bipy) unit. Complex 2 is a neutral centrosymmetric species having two Pb (bipy)(NO3)(H2O) units connecting through the bridging oxalate. The dinuclear fragments through Hbonding as well as p–p interactions result in a 2D supramolecular network. Since complex 1 exhibits intense fluorescence (kex = 284 nm, kem = 315, 329 and 356 nm) in methanol at room temperature with a fluorescence quantum yield Us = 0.41, it was tested in association with several aromatic compounds. The results show a pronounced fluorescence quenching and enhancement in presence of nitrobenzene and m-toluidine, respectively. The outcome from DFT calculations is discussed and compared with the experimental electronic, IR spectral and X-ray structural data. |
Handle: | http://hdl.handle.net/11368/2836960 |
Digital Object Identifier (DOI): | http://dx.doi.org/10.1016/j.ica.2013.10.001 |
Appare nelle tipologie: | 1.1 Articolo in Rivista |