Highly Thermal Stable Main-Chain Nonlinear Optical Polyimide Based on Two-Dimensional Carbazole Chromophores

Alphabet-Inspired Design of (Hetero)Aromatic Push-Pull Chromophores

Push-pull molecules represent a unique and fascinating class of organic π-conjugated materials. Herein, we provide a summary of their recent extraordinary design inspired by letters of the alphabet, especially focusing on H-, L-, T-, V-, X-, and Y-shaped molecules. Representative structures from each class were presented and their fundamental properties and prospective applications were discussed. In particular, emphasis is given to molecules recently prepared in our laboratory with T-, X-, and Y-shaped arrangements based on indan-1,3-dione, benzene, pyridine, pyrazine, imidazole, and triphenylamine. These push-pull molecules turned out to be very efficient charge-transfer chromophores with tunable properties suitable for second-order nonlinear optics, two-photon absorption, reversible pH-induced and photochromic switching, photocatalysis, and intercalation.

Research of the optimum molar ratio between guest and host chromophores in binary chromophore systems for excellent electro-optic activity

A series of binary chromophore systems were designed and prepared. The optimum molar ratio (OMR) between guest and host chromophores was first systematically explored in the BCSs. When at the OMR, there is the biggest EO coefficient growth rate.

Spectroscopic studies on the influence of 10 mol% of glycine on nonlinear optical crystal L-valinium picrate

Nonlinear optics is a fascinating field, which plays a vital role in the emerging field of photonics and optoelectronics. A new nonlinear optical crystal of glycine mixed L-valine picrate (GVP) have been grown from saturated aqueous solution by slow evaporation method at a temperature of 36°C using a constant temperature bath of accuracy of ±0.01°C. The synthesized organic optical material has been purified by repeated recrystallization. Single crystal X-ray diffraction analysis has been made to determine the cell parameters and it confirms the crystal lattice to be orthorhombic. UV-vis-NIR spectrum have recorded for GVP crystals in the range from 190 nm to 1100 nm and it is found that the crystal has cut-off at 450 nm. Fourier transform infrared transmission has confirmed the presence of the functional group present in the title compound. The spectrum has been recorded by KBr pellet technique. The (1)H and (13)C NMR spectra have been recorded to elucidate the molecular structure of GVP crystals. The second harmonic generation (SHG) of the grown crystal have been confirmed by Kurtz-Perry method using Nd:YAG laser as source.

From Controllable Attached Isolation Moieties to Possibly Highly Efficient Nonlinear Optical Main-Chain Polyurethanes Containing Indole-Based Chromophores

For the first time, the indole-based NLO chromophores were embedded into the polymer main chain, and different isolation groups were attached to their donor side with the efforts of adjusting the NLO properties of the resultant main-chain polyurethanes, according to the site isolation principle. Thanks to the main-chain structure and the advantages of the indole-based chromophores, all the polymers show excellent transparency, good processability, thermal stability, and relatively good NLO effects. The tested NLO properties of the polymers demonstrate that there is a suitable isolation group present for the sulfonyl-based chromophore to boost its microscopic beta value to a possibly higher macroscopic NLO property efficiently.