Experimental and theoretical studies on the one-photon and two-photon properties of a series of carbazole derivatives containing styrene

A Novel One-Dimensional Porphyrin-Based Covalent Organic Framework

A novel one-dimensional covalent organic framework (COF-K) was firstly designed and synthesized through a Schiff-based reaction from a porphyrin building block and a nonlinear right-angle building block. The COF-K exhibited high BET surface area and narrow pore size of 1.25 nm and gave a CO₂ adsorption capacity of 89 mg g⁻¹ at 273K and 1bar.

Novel carbazole derivatives with quinoline ring: synthesis, electronic transition, and two-photon absorption three-dimensional optical data storage

We designed carbazole unit with an extended π conjugation by employing Vilsmeier formylation reaction and Knoevenagel condensation to facilitate the functional groups of quinoline from 3- or 3,6-position of carbazole. Two compounds doped with poly(methyl methacrylate) (PMMA) films were prepared. To explore the electronic transition properties of these compounds, one-photon absorption properties were experimentally measured and theoretically calculated by using the time-dependent density functional theory. We surveyed these films by using an 800 nm Ti:sapphire 120-fs laser with two-photon absorption (TPA) fluorescence emission properties and TPA coefficients to obtain the TPA cross sections. A three-dimensional optical data storage experiment was conducted by using a TPA photoreaction with an 800 nm-fs laser on the film to obtain a seven-layer optical data storage. The experiment proves that these carbazole derivatives are well suited for two-photon 3D optical storage, thus laying the foundation for the research of multilayer high-density and ultra-high-density optical information storage materials.

Novel pyridinium inner salt dye and its complexes: synthesis, crystal structures and photophysical properties

Two novel metal complexes, namely [Tb2(L)6(H2O)4]·(NO3)6·L2·(H2O)18 (1) and [Hg(L)Cl2]n (2), were obtained by the reaction of D-π-A (D = donor, π = conjugated spacer, A = acceptor) type pyridinium inner salt dye, trans-4-[(p-N,N-dimethylamino)styryl]-N-(2-propanoic-acid) pyridinium (L) with corresponding metal salts. Single crystal X-ray diffraction analyses reveal that compound 1 possesses dinuclear motif in which two Tb(III) ions are linked by four carboxylate groups while complex 2 exhibits 1D chain structure based on Hg(II) ions bridged by carboxylate groups. The linear and non-linear optical properties of complexes 1 and 2 have been studied. Both 1 and 2 exhibit intense single-photon excited fluorescence (SPEF) and two-photon excited fluorescence (TPEF) in the red range. Results show that the replacement of central ions from Hg(2+) to Tb(3+) influence the two-photon absorption cross-section significantly through increasing the density of the chromophore. However, the peak positions of two-photon excited fluorescence are only slightly affected. Compared with L molecule, complex 1 shows enhanced two-photon absorption cross-section and decreased fluorescent lifetime.

Fluorescent styryl dyes based on novel 4-methoxy-9-methyi-9H-carbazole-3-carbaldehyde--synthesis, photophysical properties and DFT computations

Novel carbazole based styryl derivatives (6a-6c) having styryl group at third position and a methoxy substitution were synthesized by condensing 4-methoxy-9-methyl-9H-carbazole-3-carbaldehyde 3 and different active methylene derivatives (5a-5c). Evaluated photophysical properties of these synthesized novel chromophores, studied the effect of solvent polarity on absorption, emission and quantum yield of these styryl derivatives. DFT and TD-DFT computations are carried out to study structural, molecular, electronic and photophysical parameters of dyes. The ratio of ground state to excited state dipole moment was calculated using Bakhshiev and Kawski-Chamma-Viallet correlations.