New 5-substituted-8-hydroxyquinoline ligands HLn (1-3), in which the quinoline and the p-N,N-dimethylphenyl fragments are connected through the -N=N- (1), -CH=N- (2) or -CH2-NH- (3) group, were designed and synthesised. Their reaction with a Zn(II) salt gave the pertinent Zn(L-n)(2) complexes (4-6). The compounds 1-4 and 6 are stable in solution and their photophysical properties were explored. Zinc complexes 4 and 6 are both luminescent (4, lambda(em) : 620 nm, Phi< 1 x 10(-4); 6, λ(em) : 475 nm, &UPhi; = 7 x 10(-3)), although the states responsible for the radiative deactivation processes were different: CT in nature for 4 and from π-π* transition localised on the quinoline fragment for 6. The roles exerted by both the metal and bridge on the photophysical properties are discussed.
Synthesis and Photophysical Characterisation of Luminescent Zinc Complexes with 5-Substituted-8-Hydroxyquinolines
M. Ghedini;M. La Deda;I. Aiello;A. Grisolia
2002-01-01
Abstract
New 5-substituted-8-hydroxyquinoline ligands HLn (1-3), in which the quinoline and the p-N,N-dimethylphenyl fragments are connected through the -N=N- (1), -CH=N- (2) or -CH2-NH- (3) group, were designed and synthesised. Their reaction with a Zn(II) salt gave the pertinent Zn(L-n)(2) complexes (4-6). The compounds 1-4 and 6 are stable in solution and their photophysical properties were explored. Zinc complexes 4 and 6 are both luminescent (4, lambda(em) : 620 nm, Phi< 1 x 10(-4); 6, λ(em) : 475 nm, &UPhi; = 7 x 10(-3)), although the states responsible for the radiative deactivation processes were different: CT in nature for 4 and from π-π* transition localised on the quinoline fragment for 6. The roles exerted by both the metal and bridge on the photophysical properties are discussed.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
