Spectral Dispersion of Third-Harmonic Generation in Thin Films Containing Transition Metal Complexes

Abstract

The optical third-harmonic generation technique has been used in a study of several transition metal complexes having different near-infrared (NIR) absorption features. The complexes were dispersed in polymer matrices, and the molecular second hyperpolarizabilities γ(3ω;ω,ω,ω) were derived from thin film Maker fringe measurements at 1064 and 1907 nm. Dispersion measurements of the complexes TBA[Ni(dmit)2] and TBA[Pd(dmit)2], both having strong NIR transitions, were performed in the region from 1065 to 1480 nm, revealing resonances in the NIR. For the TBA[Ni(dmit)2] complex a maximum γ-value of 20 × 10-33 esu was observed at approximately 1325 nm, red-shifted by 172 nm (0.14 eV) compared with the position of the NIR absorption peak at 1153 nm. For the TBA[Pd(dmit)2] complex the exact location of the resonance could not be determined definitively but was shifted to or even beyond 1480 nm. The maximum γ-value of the Pd-complex was more than 2.5 times that of the Ni-complex. The γ-values were strongly influenced by a number of resonances (one-, two-, and three-photon resonances); however, no clear correlation with the near-infrared transition was observed.

Synthesis and non-linear optical properties of some novel nickel derivatives

“…Another source of difficulty when comparing experimental and theoretical results are possible one-, two-or more-photon resonant enhancements that can occur in experimental work [64][65][66], while theoretical calculations are frequently performed at the static limit. In that respect, the dithiolenes studied in this work provide a very good example.…”

Syntheses of bis(organomercury)1,3-dithiole-2-thione-4,5-dithiolates and related compounds: Crystal structure of bis(phenylmercury)1,3-dithiole-2-one-4,5-dithiolate

“…The great interest in metal complexes of these ligands, especially of d 8 transition metals of [dmit] 2À has stemmed largely from such applications as superconducting materials [3][4][5][6][7][8]. Moreover, much attention has been paid to their uses in other applications including as chemosensors [9], transistors [10], magnetic [11][12][13][14] and non-linear optical materials [15][16][17][18][19][20][21].…”