Second-harmonic generation and absorption spectra of platinum organometallic complexes incorporated in PMMA films

Pt-acetylides with different end-side groups have been synthesized and inco rporated in poly(methylmethacrylate) (PMMA) films for second-order nonlinea r optics through high-temperature corona-poling. By using two complementary optical techniques, i.e. in-situ second-harmonic generation (SHG) and angl e-resolved spectroscopy, the order parameter and the molecular hyperpolariz ability beta of the chromophores have been characterized inside the polymer matrix. The relaxation of orientational after order poling fits a hi-expon ential equation in agreement with the Debye model for guest/host systems. A comparison with the ate-dye Disperse Red 1 (DR1) is discussed within the t wo-level model and the role of the platinum moiety for conjugated molecules . (C) 2000 Elsevier Science B.V. All rights reserved.