Heterocyclic quinol-type fluorophores. Synthesis of novel imidazoanthraquinol derivatives and their photophysical properties in benzene and in the crystalline state

2005 ◽  
Vol 29 (3) ◽  
pp. 447 ◽  
Author(s):  
Yousuke Ooyama ◽  
Takato Nakamura ◽  
Katsuhira Yoshida
2021 ◽  
Author(s):  
Tomohiko Nishiuchi ◽  
Hikaru Sotome ◽  
Kazuto Shimizu ◽  
Hiroshi Miyasaka ◽  
Takashi Kubo

We report the Negishi coupling based synthesis of 1,2,3-tri(9-anthryl)benzene derivatives, containing three radially arranged anthracenes in a π-cluster. In the crystalline state of the unsubstituted derivative, intermolecular π-π and CH-π interactions between the anthracene units drive the formation of a two-dimensional packing structure. Owing to though-space π-conjugation between anthracene units, the substances have unique electronic properties. The excited state dynamic behavior occurring between the three radially arranged anthracene moieties, such as exciton localization/delocalization, was elucidated by means of transient absorption measurements and quantum chemical calculations. Interestingly, even though the three anthracenes are closely oriented with a ca. 3.0 Å distances between their C-9 positions, exciton localization on two anthracene units is energetically favorable because of the flexible nature of the radially arranged aromatic rings.


Molecules ◽  
2021 ◽  
Vol 26 (8) ◽  
pp. 2274
Author(s):  
Masato Morita ◽  
Shigeyuki Yamada ◽  
Tsutomu Konno

In this study, we synthesized a series of fluorinated and non-fluorinated tolanes, in which one or more fluorine atoms were systematically introduced into one aromatic ring of a tolane scaffold, and systematically evaluated their photophysical properties. All the tolanes with or without fluorine substituents were found to have poor photoluminescence (PL) in tetrahydrofuran (THF) solutions. On the other hand, in the crystalline state, non-fluorinated and fluorinated tolanes with one or four fluorine atoms were less emissive, whereas fluorinated tolanes with three or five fluorine atoms exhibited high PL efficiencies (ФPL) up to 0.51. X-ray crystallographic analyses of the emissive fluorinated tolanes revealed that the position of the fluorine substituent played a key role in achieving a high ФPL. Fluorine substituents at the ortho (2/6) and para (4) positions led to tight and rigid packing due to plural π–π stacking and/or hydrogen bonding interactions, resulting in enhanced ФPL caused by the suppression of non-radiative deactivation. Additionally, fluorinated tolanes with three fluorine atoms exhibited notable aggregation-induced PL emission enhancement in THF/water mixed solvents. This demonstrates that the PL characteristics of small PL materials can be tuned depending on the usage requirements.


2003 ◽  
Vol 771 ◽  
Author(s):  
Pavel I. Lazarev ◽  
Michael V. Paukshto ◽  
Elena N. Sidorenko

AbstractWe report a new method of Thin Crystal Film deposition. In the present paper we describe the method of crystallization, structure, and optical properties of Bisbenzimidazo[2,1-a:1',2',b']anthra[2,1,9-def:6,5,10-d'e'f']-diisoquinoline-6,9-dion (mixture with cis-isomer) (abbreviated DBI PTCA) sulfonation product. The Thin Crystal Film has a thickness of 200-1000 nm, with anisotropic optical properties such as refraction and absorption indices. X-ray diffraction data evidences a lyotropic liquid crystalline state in liquid phase and crystalline state in solid film. Anisotropic optical properties of the film make it useful in optical devices, e.g. liquid crystal displays.


2020 ◽  
Author(s):  
Masaki Saigo ◽  
Kiyoshi Miyata ◽  
Hajime Nakanotani ◽  
Chihaya Adachi ◽  
Ken Onda

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>


2020 ◽  
Author(s):  
Zeyu Liu ◽  
Shugui Hua ◽  
Tian Lu ◽  
Ziqi Tian

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.


Author(s):  
Aron Huckaba ◽  
sadig aghazada ◽  
iwan zimmermann ◽  
giulia grancini ◽  
natalia gasilova ◽  
...  

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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