Reliable prediction of optical spectra via optimal tuning of range separated hybrid functionals
Jagrity Chaudhary, Vibhor Mittal, Inamur Rahman Laskar and Ram Kinkar Roy*
Department of Chemistry, Birla Institute of Technology and Science, Pilani.
Pilani Campus, Rajasthan- 333031, India.
E-mail: p2016014[at]pilani.bits-pilani.ac.in, *rkroy2[at]rediffmail.com
Donor-Acceptor (D-A) type of organic dyes with fluorescence emission in the near-infrared NIR region (650-1000 nm) have attracted considerable attention in the biomedical and bioimaging fields due to their high cell penetration, better spatial resolution, and negligible auto-fluoroscence. However, currently reported organic NIR fluorophores are still limited and there is great demand to develop more novel NIR fluorophores. Despite its obvious importance, there is a lack of an appropriate level of theory capable of providing both efficient and accurate predictions of optical and electronic properties of these molecules.
In this work, we have designed and synthesized a new D-A kind of NIR molecule with successful application of time-dependent density functional theory (TDDFT) using optimally-tuned range-separated hybrid (RSH) functional ω*B97XD for calculations of both absorption and fluorescence spectral properties. That has been demonstrated and compared with the experimental data. Optimally tuned RSH functionals with smart choice of basis set provide very good prediction for these types of molecules and significantly outperform conventional functionals.
References
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