Effect of donor (tetradecyloxy) and acceptor (carboxamide) groups in trans-stilbene for DSSCs: quantum chemical investigations

Exploration of intramolecular charge transfer in para-substituted nitrobenzofurazan: Experimental and theoretical analyses

The present work aims at exploring the high electrophilic character of 4-chloro-7-nitrobenzo-2-oxa-1,3-diazole (NBD-Cl) toward the morpholine group by an S_NAr reaction in acetonitrile or water (thereafter referred to as NBD-Morph). The electron-donating ability of the morpholine causes intra-molecular charge transfer (ICT). In this report, we present a comprehensive study on the optical characteristics using UV-Vis, photoluminescence (cw-PL) and its time-resolved (TR-PL) to determine the properties of the emissive intramolecular charge transfer (ICT) in the NBD-Morph donor-acceptor system. An exhaustive theoretical investigation utilizing the density functional theory (DFT) and its extension TD-DFT methods is an essential complement of experiments to rationalize and understand the molecular structure and related properties. The findings from QTAIM, ELF, and RDG analyses establish that the bonding between morpholine and NBD moieties is of the electrostatic or hydrogen bond type. In addition, the Hirshfeld surfaces have been established to explore the types of interactions. Further, the non-linear optical (NLO) responses of the compound have been examined. The structure-property relationships obtained through the combined experimental and theoretical offer valuable insights for designing efficient NLO material.

A quantum study on novel azo-dyes containing a fullerene C60 unit as a smart material for optoelectronic applications

Quantum chemical calculations of some novel azo-dyes containing a fullerene C60 unit as a smart material have been carried out with the aims to determine their cis and trans electronic properties and to describe the change of their quantum parameters as a result of the trans/cis isomerization of these molecules. The effects of electron-withdrawing or electron-releasing groups on the R-position of these molecules on electronic, optical, spectroscopic, and other properties of these molecules have been considered with DFT and TDDFT calculations. The obtained results of the calculations show that compounds "b" and "c" with the strongest electron-releasing groups in the R-position of these molecules, particularly the trans isomers of these compounds, with higher chemical softness, higher electrophilicity index, higher thermodynamic properties, and higher charge transfer values, have the better electronic and optical properties and therefore the better chemical reactivity compared to the other compounds. Graphical abstract.

Second order hyperpolarizability of triphenylamine based organic sensitizers: a first principle theoretical study

Designed metal-free dyes have been investigated by Density Functional Theory (DFT) and Time-Dependent DFT (TD-DFT) to evaluate the ground state and excited state geometries of triphenylamine-based organic sensitizers.