Terpyridine Zn(II), Ru(III), and Ir(III) complexes: the relevant role of the nature of the metal ion and of the ancillary ligands on the second-order nonlinear response of terpyridines carrying electron donor or electron acceptor groups.
Coordination of 4'-(C6H4-p-X)-2,2':6',2''-terpyridines [X = NO2, NBu2, (E)-CH=CH-C6H4-p-NBu2, (E,E)-(CH=CH)2-C6H4-p-NMe2] to Zn(II), Ru(III), and Ir(III) metal centers induces a significant enhancement of the absolute value of the second-order nonlinear optical (NLO) response of the terpyridine, measured by means of both electric field induced second harmonic generation and solvatochromic methods. By varying the nature of the metal center, the enhanced second-order NLO response shifts from positive to negative. Such a shift is controlled by electronic charge-transfer transitions, such as metal-to-ligand or ligand-to-metal transitions, in addition to the intraligand charge transfer. The enhancement generated by coordination is also controlled by the chelation effect and by fine-tuning of the ancillary ligands.
Tessore
Francesca
F
Dipartimento di Chimica Inorganica, Metallorganica e Analitica dell'Università di Milano, Centro di Eccellenza CIMAINA, Unità di Ricerca di Milano dell'INSTM e Istituto di Scienze e Tecnologie Molecolari del CNR, Milano, Italy. francesca.tessore@unimi.it
Roberto
Dominique
D
Ugo
Renato
R
Pizzotti
Maddalena
M
Quici
Silvio
S
Cavazzini
Marco
M
Bruni
Silvia
S
De Angelis
Filippo
F