A comprehensive study has been made in solution at room temperature (293 K), low temperature (77 K), and in thin films (Zeonex matrixes) of the spectral and photophysical properties of six arylthienyl- and bithienyl-benzothiazole derivatives functionalized with different donor groups. Similar experiments have been carried out with two related precursors (containing the arylthienyl and aryl-bithienyl conjugated systems), and results are compared. Singlet-singlet and triplet-triplet absorption spectra, emission spectra together with lifetimes and quantum yields have been obtained, and from these data the rates for all the radiative and nonradiative processes determined, providing information on the dominant decay processes. The arylthienyl-benzothiazole derivatives show high fluorescence quantum yields (phi(F)) with negligible internal conversion (phi(IC)), whereas the bithienyl-benzothiazoles display lower but still significant phi(F) values, but now radiationless processes (phi(IC) and phi(ISC)) are competitive. A comparison with the analogous oligothiophenes is made. Singlet oxygen yields were also determined and the triplet energy transfer to (3)O2 to produce (1)O2 was found to be highly efficient with values of S(Delta)(= phi(Delta)/phi(T)) varying from 0.4 to 1.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1021/jp0730646 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Visible-Light-Fueled Polymerizations for 3D Printing.
Acc Chem Res
January 2025
Department of Chemistry, The University of Texas at Austin, 105 East 24th Street, Austin, Texas 78712, United States.
ConspectusLight-driven polymerizations and their application in 3D printing have revolutionized manufacturing across diverse sectors, from healthcare to fine arts. Despite the popularized notion that with 3D printing "imagination is the only limit", we and others in the scientific community have identified fundamental hurdles that restrict our capabilities in this space. Herein, we describe the group's efforts in developing photochemical systems that respond to nontraditional colors of light to elicit the rapid, spatiotemporally controlled formation of plastics.
View Article and Find Full Text PDFTheoretical basis of all-optical modulation of a probe laser beam due to photothermal modulation of the aggregation state in organic dyes, with experimental proof of the principle.
Spectrochim Acta A Mol Biomol Spectrosc
December 2024
Anhembi Morumbi University (UAM), Rodovia Dr Altino Bondensan 500, São José dos Campos 12247-016, SP, Brazil; Center of Innovation, Technology and Education (CITE), Rodovia Dr Altino Bondensan 500, São José dos Campos 12247-016, SP, Brazil. Electronic address:
The inherent potential for self-assembly is a well-known attribute of organic dye molecules. This work takes advantage of the changes in dye photochemical and photophysical properties produced by the aggregation phenomenon, to investigate the behavior of all-optical modulation in molecular aggregates. The theoretical principles for a dual beam all-optical modulation, as well as the conception of an optical logic gate by exploring the aggregation phenomenon are discussed throughout the article.
View Article and Find Full Text PDFDual-fluorescent starch biopolymer films containing 5-(4-nitrophenyl)-1,3,4-thiadiazol-2-amine powder as a functional nanofiller.
Sci Rep
December 2024
Department of Biophysics, Faculty of Environmental Biology, University of Life Sciences in Lublin, Akademicka 13, Lublin, 20-950, Poland.
Physical and photophysical properties of starch-based biopolymer films containing 5-(4-nitrophenyl)-1,3,4-thiadiazol-2-amine (NTA) powder as a nanofiller were examined using atomic force microscopy (AFM), Fourier-transform infrared spectroscopy (FTIR), stationary UV-Vis and fluorescence spectroscopy as well as resonance light scattering (RLS) and time-resolved measurements, and where possible, analyzed with reference to pristine NTA solutions. AFM studies revealed that the addition of NTA into the starch biopolymer did not significantly affect surface roughness, with all examined films displaying similar Sq values ranging from 70.7 nm to 79.
View Article and Find Full Text PDFEffect of protonation induced distortions on the spectral properties and electronic structure of Octaphenylporphyrins: UV-vis, electrochemical, VT-NMR and ab initio studies.
Chem Asian J
December 2024
IIT Roorkee: Indian Institute of Technology Roorkee, Department of Chemistry, Room No D-307, Department of Chemistry, Indian Institute of Technology Roorkee, 247667, Roorkee, INDIA.
The extent of conformational alteration of the porphyrin macrocycle during the course of protonation was observed, both experimentally and theoretically. For synthesized β-substituted octaphenylporphyrin (OPP) ring systems this macrocyclic distortions have been investigated by spectroscopic and computational analysis. Protonation induced nonplanarity in macrocyclic system is experimentally observed in a single step during spectrophotometric titration.
View Article and Find Full Text PDFDesigning a Simple Quinoline-Based Chromo-Fluorogenic Receptor for Highly Specific Quantification of Copper (II) Ions: Environmental and Bioimaging Applications.
Luminescence
December 2024
Department of Chemistry, Karpagam Academy of Higher Education, Coimbatore, Tamil Nadu, India.
Many industries use copper metal ions (Cu ions), and their salts are utilized as supplemental materials in both agriculture and medicine. Identifying and monitoring these Cu ions in biological and environmental specimens is crucial due to their association with several health issues. In this investigation, we have designed a simple quinoline-based receptor (E)-3-(((2,4-di-tert-butyl-5-hydroxyphenyl)imino)methyl)-6-methoxyquinolin-2(1H)-one (QAP) containing imine functional groups to inspect its capability to identify metal ions in a semi-aqueous medium.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!