Nonlinear Optical and Two-Photon Absorption Properties of Octupolar Tris(bipyridyl)metal Complexes

Abstract

The linear (absorption and emission) and nonlinear optical (NLO) properties of a series of D(3) [(Fe(II), Ru(II), Ni(II), Cu(II), Zn(II)] octupolar metal complexes featuring the 4,4'-bis[(dibutylamino)styryl]-2,2'-bipyridine ligand are reported. Zinc(II), nickel(II), and copper(II) complexes exhibit similar absorption spectra in the visible region (lambda(ILCT) = 474-476 nm) which are assigned to intraligand charge-transfer (ILCT) bands. The quadratic and cubic NLO properties are strongly influenced by the nature of the metallic center. Harmonic light scattering studies at lambda = 1.91 microm reveal that these chromophores display large first hyperpolarizabilities beta(1.91) in the range of (211-340) x 10(-30) esu; replacing the Zn(II) metal ion by Ni(II) or Cu(II) results in a decrease of the static beta(0) coefficient by a factor of 1.5-1.6. Z-scan measurements at 765 and 965 nm reveal relatively large two-photon absorption cross-sections [650 < sigma(2) < 2200 GM], showing that both beta and sigma(2) values can be tuned by simple modification of the metal ion.

Excitonically Coupled Oligomers and Dendrimers for Two-Photon Absorption

“…Le Bozec et al designed a series of octahedral Ru(II), Ni(II), Cu(II) and Zn(II) tris(bipyridyl) LB complexes (Fig. 20) [120]. This work shows clearly that TPA properties can be strongly tuned by the nature of the metal, since σ TPA values of 2200, 1900, 1700, 1050 and 650 GM at 765 nm were observed for Ru(II), Fe(II), Zn (II), Cu(II) and Ni(II), respectively.…”

Mono and dinuclear complexes of half-sandwich platinum group metals (Ru, Rh and Ir) bearing a flexible pyridyl-thiazole multidentate donor ligand

“…Metal complexes based on polypyridyl ligands constitute versatile components for the construction of multifunctional supramolecular systems in molecular photonics and molecular electronics, sensors, photo-catalysis, solar energy conversion, artificial photosynthesis, non-linear optics, and electrochemo-luminescence amongst others [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15]. Despite the diversity of these potential applications, relatively little is known about how the properties of electron transfer between a single donor and acceptor is influenced by their inclusion into larger supramolecular assemblies.…”

Spectroelectrochemical properties of homo- and heteroleptic ruthenium and osmium binuclear complexes: intercomponent communication as a function of energy differences between HOMO levels of bridge and metal centres

“…Metal complexes based on polypyridyl ligands constitute versatile components for the construction of multifunctional supramolecular systems in molecular photonics and molecular electronics, 1 sensors, 2 photocatalysis, 3 solar energy 5 conversion, 4 artificial photosynthesis, 5 non-linear optics, 6 and electrochemoluminescence 7 amongst others. 8, 9 The myriad of applications are founded on the well defined chemistry of these compounds and take advantage of the versatile photophysical, 10 photochemical 11 and electrochemical 12 properties that are associ-10 ated with the metal-to-ligand charge-transfer (MLCT) excitation in these metal complexes.…”

“…The goal of the present study is to evaluate the extent 40 of electronic communication between the two metal centres as a function of the electronic properties of the bridging ligand and the positioning of the two metal centres. In particular, attention is directed towards the homo-and heterodinuclear complexes of ruthenium and osmium [(bipy) 2 Ru(qpy)Ru(bipy) 2 (6) (Fig. 1).…”