Study of intramolecular charge transfer of Michler’s ketone using time dependent density functional theory

Excited State Kinetics in Crystalline Solids: Self-Quenching in Nanocrystals of 4,4′-Disubstituted Benzophenone Triplets Occurs by a Reductive Quenching Mechanism

“…Since it has been previously shown that the excited state dynamics of amino-substituted benzophenones are strongly solvent dependent, − it was not surprising that femtosecond excitation of 4,4′-bis(dimethylamino)benzophenone ( 3 ) produced different transients in acetonitrile and as a nanocrystal suspension. Excitation with 150 fs pulses at λ ex = 258 nm in polar acetonitrile produced results in agreement with those reported by Mondel et al , which include up to four excited states within a spectral window from 450 to 1000 nm.…”

“…Although the excitation of the amino-substituted benzophenones 2 and 3 leads to the formation of ICT and TICT structures in solution, there appears to be no formation of such transients upon excitation of the nanocrystals. Computational modeling of 4,4 0 -bis(dimethylamino)benzophenone (3) by Pal et al 34 predicts that as the medium becomes less polar the excited state energy order is inverted. In acetonitrile, the local excitation (LE) is 85.8 kcal/mol above the ground state and the final twisted intramolecular charge transfer state (TICT) is 80.5 kcal/mol above the ground state.…”

Evaluation of intramolecular charge transfer state of 4-N, N-dimethylamino cinnamaldehyde using time-dependent density functional theory

“…[15][16][17] Several other authors also used similar basis set to optimize the ground state geometry of a small molecule. 8,16 A rigorous formalism (time-dependent density functional theory, TDDFT) was used for transition energy calculation within the DFT framework using 6-31G+(d, p) basic set. [15][16][17][18][21][22][23] Solvation energy was calculated using time dependent density functional theory-polarizable continuum model (TDDFT-PCM).…”

“…The nature of charge transfer (CT) state within a molecule remains obscure despite decades of experimental and theoretical research. [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18] 4-N ,Ndimethylamino benzonitrile (DMABN) molecule with an inherent donor and an acceptor group exhibits dualemission feature in its emission spectrum. 1 Grabowski explained this phenomenon by proposing a twisted intermediate charge transfer (TICT) model.…”

“…2 Evidence suggests that the intramolecular TICT process from a donor to an acceptor could be achieved by a twisting motion of the donor moiety that promotes initially generated locally excited (LE) state to an energetically relaxed charge transfer state (CT). [2][3][4][5][6]8,13 Besides TICT model, a planner intramolecular charge transfer (PICT) and wagged intramolecular charge transfer (WICT) model have also been adopted by some other groups. 5,6 Dual-fluorescence of a molecule carrying an inherent donor and acceptor is strongly influenced by the electronic energy gap of first two excited states nπ*(HOMO-1 to LUMO, HOMO-highest occupied molecular orbital, LUMO-lowest unoccupied molecular orbital) and ππ*(HOMO to LUMO).…”