Theoretical study of the excitation of proflavine H-dimers in an aqueous solution: the effect of functionals and dispersion corrections

Abstract

Analysis of the ground and excited states of the H-dimer of the proflavine dye cation (PF) in an aqueous solution was performed by the DFT/TD-DFT method with an implicit specification...

Intramolecular excimers of open forms of 2H-benzopyran, 2H- and 3H-naphthopyrans in solution: TD-DFT/DFT analysis

“…From previous studies of excited aromatic dimers (ref. 50 and references therein), it is known that for this one should use: (1) functionals with built-in dispersion correction; (2) functionals without built-in dispersion correction in combination with external dispersion correction (for example, D3(BJ) 51 from Grimme); and (3) functionals from Truhlar's group specialized for describing weak molecular interactions, without dispersion correction. Therefore, in this work, three types of hybrid functionals were used:…”

TD‐DFT analysis of the excitation of H‐dimers of cationic dyes in an aqueous solution using functionals without additional dispersion correction

“…The Sholes group in 2016 optimized the ground state of the MB dimer in an aqueous solution and calculated the energies of vertical transitions for it at the M052X/6‐311++G(d,p)/PCM and CIS/6‐311++G(d,p)/PCM theory levels [8] without DC. We recently showed [9] for the proflavine dimer (PF) that its stability in both the ground and excited states can be ensured using the M052X, M06 [3], M062X, M06HF [10] functionals (Minnesota series, developed by the Truhlar group with parameterization of weak intermolecular interactions) also without DC, as well as APFD [11] and ωB97XD [12] with a built‐in DC. A further selection of these functionals based on the results of calculations using them revealed [9] that M052X, M062X, M06HF, and ωB97XD are suitable for modeling the PF H‐dimer.…”

“…We recently showed [9] for the proflavine dimer (PF) that its stability in both the ground and excited states can be ensured using the M052X, M06 [3], M062X, M06HF [10] functionals (Minnesota series, developed by the Truhlar group with parameterization of weak intermolecular interactions) also without DC, as well as APFD [11] and ωB97XD [12] with a built‐in DC. A further selection of these functionals based on the results of calculations using them revealed [9] that M052X, M062X, M06HF, and ωB97XD are suitable for modeling the PF H‐dimer. These four functionals gave the fulfillment of the M (monomer) < M (dimer) condition for the transition moments, which follows from the strong coupling theory for H‐aggregates [13], as well as the λ max (monomer) > λ max (dimer) condition from the exciton Kasha theory [14].…”

“…After analyzing the results of Reference [9], the following questions, still unanswered, were formulated as appropriate directions for its further development. What other hybrid functionals reliably stabilize H‐dimers of aromatic cations both in the ground and in excited states without additional DC? It is already known [9] that one should consider functionals with a significant HF proportion as well as with long‐range correction. Do the patterns found for PF 2 hold for H‐dimers of other aromatic cationic dyes? Do the bulky side groups of molecules prevent their displacement upon excitation of the H‐dimer? This fixation would make it possible to calculate the vibronic absorption spectra of the dimers. Consequence of questions 2 and 4: what functionals give the calculated vibronic absorption spectra of H‐dimers of aromatic cations that are closest to the experimental ones?…”

“…This fixation would make it possible to calculate the vibronic absorption spectra of the dimers. Consequence of questions 2 and 4: what functionals give the calculated vibronic absorption spectra of H‐dimers of aromatic cations that are closest to the experimental ones? For PF 2 , M062X, M06HF, and ωB97XD functionals gave a significant discrepancy between the calculated spectra [9] and the experimental results.…”