Comparison of Photophysical Properties of the Hemicyanine Dyes in Ionic and Nonionic Solvents

We have investigated the solvent-dependence of structural changes along with intersystem crossing of a thermally activated delayed fluorescence (TADF) molecule, 3,4,5-tri(9H-carbazole-9-yl)benzonitrile (o-3CzBN), in toluene, tetrahydrofuran, and acetonitrile solutions using time-resolved infrared (TR-IR) spectroscopy and DFT calculations. We found that the geometries of the S1 and T1 states are very similar in all solvents though the photophysical properties mostly depend on the solvent. In addition, the time-dependent DFT calculations based on these geometries suggested that the thermally activated delayed fluorescence process of o-3CzBN is governed more by the higher-lying excited states than by the structural changes in the excited states.<br>

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Theoretical Framework of 1,3-Thiazolium-5-Thiolates Mesoionic Compounds: Exploring the Nature of Photophysical Properties and Molecular Nonlinearity

10.26434/chemrxiv.12063261 ◽

2020 ◽

Author(s):

Zeyu Liu ◽

Shugui Hua ◽

Tian Lu ◽

Ziqi Tian

Keyword(s):

Optical Properties ◽

Rational Design ◽

Rayleigh Scattering ◽

Function Analysis ◽

Theoretical Calculations ◽

Photophysical Properties ◽

Optical Nonlinearity ◽

Nonlinear Properties ◽

Photoelectric Performance ◽

Wave Function Analysis

Inspired by a previous experimental study on the first-order hyperpolarizabilities of 1,3-thiazolium-5-thiolates mesoionic compounds using Hyper-Rayleigh scattering technique, we theoretically investigated the UV-Vis absorption spectra and every order polarizabilities of these mesoionic molecules. Based on the fact that the photophysical and nonlinear properties observed in the experiment can be perfectly replicated, our theoretical calculations explored the essential characteristics of the optical properties of the mesoionic compounds with different electron-donating groups at the level of electronic structures through various wave function analysis methods. The influence of the electron-donating ability of the donor on the optical properties of the molecules and the contribution of the mesoionic ring moiety to their optical nonlinearity are clarified, which have not been reported by any research so far. This work will help people understand the nature of optical properties of mesoionic-based molecules and provide guidance for the rational design of molecules with excellent photoelectric performance in the future.

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Exploration of Bis(Arylimidazole) Iridium Picolinate Complexes

10.26434/chemrxiv.5331460.v1 ◽

2017 ◽

Cited By ~ 1

Author(s):

Aron Huckaba ◽

sadig aghazada ◽

iwan zimmermann ◽

giulia grancini ◽

natalia gasilova ◽

...

Keyword(s):

Cyclic Voltammetry ◽

Photophysical Properties ◽

Structure Property ◽

Aryl Group ◽

Ligand Modification ◽

Property Relationship ◽

Structure Property Relationship

The straightforward synthesis and photophysical properties of a new series of heteroleptic Iridium (III) bis(2-arylimidazole) picolinate complexes is reported. Each complex has been characterized by NMR, UV-Vis, cyclic voltammetry, and the emissive properties of each is described. By systematically modifying first the cyclometallating aryl group on the arylimidazole ligand and then the picolinate ligand, the ramifications of ligand modification in these complexes was better understood through the construction of a structure-property relationship.

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