Two novel π-conjugated carbazole derivatives with blue two-photon-excited fluorescence

The phosphinoboration of acyl chlorides

This investigation examines the reactivity of phosphinoboronate esters Ph₂PBpin (pin = 1,2-O₂C₂Me₄) and Ph₂PBcat (cat = 1,2-O₂C₆H₄), as well as other phosphinoboron species, with various aryl and aliphatic acyl chlorides.

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.

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.

Three Asymmetrical Conjugated D-π-D' Sulfur-Containing Chromophores with a Focus on Two-Photon Absorption

Three novel asymmetrical D-π-D′ type sulfur-containing chromophores, (E)-4-(4-(benzylthio)styryl)-N,N-diethylbenzenamine (S1), (E)-4-(4-(tert-butylthio)styryl)-N,N-diethylbenzenamine (S2) and (E)-4-(4-(thio)styryl)-N,N-diethylbenzenamine (S3), were synthesized and characterized. Two kinds of substituents and hydrogen were introduced into the three different chromophores to investigate the influence of electron distribution on the sulfur atom. Meanwhile, a simple synthetic strategy of π-conjugated 4-(thio)styrene derivatives was performanced successfully. Linear and non-linear optical properties of S1, S2 and S3 were investigated both experimentally and theoretically. The optical properties indicate that they all have obvious characteristics of asymmetrical dipole molecules. The measured maximum two-photon cross-sections of S1–3 are 79, 57 and 19 GM (Goeppert-Mayer), respectively. It shows that the different substituents on the sulfur atom in molecules S1–3 lead to different electronic structures, which affect the optical properties. In these structures, the aromatic benzyl substituent (in S1) is superior for optimizing two-photon activity in the designed molecular framework.