This paper summarizes our research on the synthesis and properties of several kinds of functionalized polysilanes (FPSs) containing nonlinear optic (NLO) chromophores in the side chain. They have been synthesized successfully through utilizing different synthetic strategies: chloromethylation of poly(methylphenylsilanes) and the following etherification with the hydroxycontaining NLO chromophore in water /chloroform two-phase system with Brij35 as a phase-transfer catalyst; hydrosilylation of polyhydrosilanes with the NLO chromophore containing the terminal double bond; etherification of chlorine-containing polysilanes with the hydroxy-containing NLO chromophore; and postunctionalization of phenyl group-containing polysilanes through azo coupling with p-nitrobenzenediazonium fluoroborate or tricyanovinylation with the oxidant tetracyanoethylene. FPSs were characterized with FT-IR, UV/vis spectra, differential scanning calorimetry (DSC), gel permeation chromatography (GPC), and elemental analysis. The second-order optical nonlinear properties of the polysilanes were determined by in situ second harmonic generation (SHG) experiments.

)mc, with a=7.7281(14) Å, b=7.7281(14) Å, c=6.742(2) Å,α=90°, β=90°, γ=120°, Z=2. It was obtained by a new preparation procedure different from that reported in the literature that gave a centrosymmetric structure. The structure contains Cd-Br octahedrons, which are connected in a plane-sharing way to form edimensional long chains. Each octahedron is slightly distorted, as the three Cd-Br bond lengths are 2.774 Å, while the other three Cd-Br bond lengths are 2.804 Å. The distortion directions of all of the octahedrons are almost parallel and give rise to the accumulation of the microcosmic nonlinear optical (NLO) coefficient. The Kurtz powder technique shows that CsCdBr3 has a powder second harmonic generation of about 2 times as large as that of potassium dihydrogen phosphate (KDP). It shows excellent ransparency in the visible and infrared regions. The thermal stability is also good. Therefore it may be utilized as a potential nonlinear optical crystal for the IR region.

The relationships between structure and nonlinear optical (NLO) properties of coordination compounds in terms of influence of molecular configuration on linear and NLO properties are reviewed. The molecular configurations involved are square pyramidal, tetrahedral, square planar, octahedral, sandwich and linear. Based on the experimental results, empirical rules of these relationships have been proposed, which may help the design of new NLO materials from organometallic and coordination compounds.

A new strategy for postfunctionalization performed on poly(N-vinylcarbazole) (PVK) has been explored to develop PVK-based nonlinear optical (NLO) polymers with a high density of chromophores and improved comprehensive properties. Thus, under the standard Vilsmeier reaction conditions, PVK is partially formylated to a high degree (up to 52% molar ratio), and these formyl groups of high reactivity are condensed with cyanoacetylated DR-1 to afford a DR-1 functionalized PVK in almost complete conversion. The Tg of the resulting polymer is 185℃, and the orientation behavior of its poled film is studied by UV-visible spectroscopy. The NLO activity, which is estimated to be 20pm/V by in situ second harmonic generation measurement, remains unchanged at 120℃ for over 1000h after a minor initial drop.

Two new extended chromophoric systems, in which a 4-aminoazobenzene moiety is linked to a cyclo-bridged hexatriene electron withdrawing group, have been synthesized, and show large optical nonlinearities and unexpected blue-shifted absorption in comparison with shorter chain analogues.