Premium
Polarity‐Dependant Intramolecular Charge Transfer Characteristics of 9‐Cyano‐10‐(1H‐pyrrol‐1‐yl)anthracene: Photophysical Investigations
Author(s) -
Gharat Poojan Milan,
Muralidharan Sukumaran,
Sundararajan Mahesh,
Pal Haridas,
Dutta Choudhury Sharmistha
Publication year - 2017
Publication title -
chemistryselect
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.437
H-Index - 34
ISSN - 2365-6549
DOI - 10.1002/slct.201701916
Subject(s) - excited state , intramolecular force , chromophore , anthracene , fluorescence , photochemistry , materials science , ground state , acceptor , charge (physics) , polarity (international relations) , molecular physics , solvatochromism , chemical physics , chemistry , atomic physics , stereochemistry , optics , physics , biochemistry , quantum mechanics , cell , condensed matter physics
The photophysics of a newly synthesized donor‐acceptor substituted chromophore, 9‐cyano‐10‐(1H‐pyrrol‐1‐yl)anthracene (CPAN), reveals interesting features that suggest the involvement of two types of charge transfer configurations in its excited state. Dual emission bands are observed in polar and nonpolar solvents due to fluorescence from both locally excited (LE) and intramolecular charge transfer (ICT) states. From detailed analysis of the time‐resolved fluorescence data, it is proposed that by increasing the polarity of the medium the nature of the emissive ICT state is switched from a molecular conformation that is more planar (ICT1) to one that is more twisted (ICT2), compared to the ground state. Preliminary geometry optimizationsand calculated molecular parameters of CPAN in the ground and excited states, lend support to the experimental results. Qualitative potential energy diagrams are presented to substantiate the proposed model and rationalize the observed photophysics.