Solvent effects on electronic absorption spectra of nitrochlorobenzenes, nitrophenols and nitroanilines—I. Studies in nonpolar solvents

Prabhumirashi, L. S.; Kunte, Soumitra

doi:10.1016/0584-8539(86)80036-8

Cited by 26 publications

(8 citation statements)

References 29 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…All bond lengths of both dzv N* and dzp calculations generally show good agreement with the experimental bond lengths. The dzp calculated dipole moment is 4.275 D, which is in good agreement with the experimental value (4.0, , 4.2 3 D). Although the dzv N* calculated dipole moment (4.536 D) is slightly larger than the experimental value, the discrepancy is not so large.…”

Section: Resultssupporting

confidence: 87%

“…The characters of the excited states have been investigated mostly from the absorption spectra in various solvents. For example, the character, , and dipole moments − of the excited singlet states were estimated from the peak shifts of absorption spectra in several solvents. The lowest excited triplet (T 1 ) state was assigned to be of nπ* character from the reactivity, and the energy of the T 1 state was estimated to be greater than 20.6 × 10 3 cm -1 using the energy transfer from NB to piperylene .…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Geometries and Energies of Nitrobenzene Studied by CAS-SCF Calculations

et al. 1997

View full text Add to dashboard Cite

Optimized geometries and energies in the ground (S0) and excited states of nitrobenzene were calculated using the CAS-SCF method. The optimized geometries in the S1, S2, T1, T2, and T3 states are very different from that in the S0 state. Most significantly, the nitro group is largely bent out of the phenyl plane in the excited states. The potential curves along the nitro rotation coordinate around the C−N bond and the out-of-plane bending mode of the nitro group in the S0, S1, T1, and T2 states were calculated in relation to the excited states dynamics. It is found that the potential curves along the bending mode in the excited states are very flat compared with that in the S0 state. The mechanisms for the fast relaxation from the S1 and T1 states are discussed based on the ab initio results.

show abstract

Section: Resultssupporting

confidence: 87%

Section: Introductionmentioning

confidence: 99%

Geometries and Energies of Nitrobenzene Studied by CAS-SCF Calculations

et al. 1997

View full text Add to dashboard Cite

show abstract

“…[12][13][14][15][16][17][18] Furthermore, derivatives of NB and nitro substituted aromatic hydrocarbons have attracted the interest many scientists because of their unique properties such as the prominent charge transfer phenomena. [19][20][21][22][23][24][25] In spite of the fundamental importance of the photophysical characters of NB, the photophysical properties, dynamics, and nature of the excited states of NB have not been well understood. In 1970, Khalil et al reported phosphorescence at low temperature with a lifetime 0.1-1 s, 26 which suggested that the lowest excited triplet (T 1 ) state is of 3 ππ* character.…”

Section: Introductionmentioning

confidence: 99%

Nonradiative Relaxation Processes and Electronically Excited States of Nitrobenzene Studied by Picosecond Time-Resolved Transient Grating Method

1997

View full text Add to dashboard Cite

The exothermic nonradiative relaxation processes from photoexcited nitrobenzene (NB) are studied by the picosecond time-resolved transient grating method. The decay rate constants and energy of the excited NB are determined. The lifetime of the lowest excited singlet state is found to be very short (≤10 ps) and a surprisingly short lifetime of the lowest excited triplet state (∼480 ps) is detected. From quantitative measurements of the thermal energies released from the excited states of NB, the lowest excited triplet state is determined to be located at (22−27) × 103 cm-1. The triplet formation is very efficient and its quantum yield is found to be grater than 0.80. From the temperature and solvent dependence of the triplet lifetime, it is suggested that motions of the nitro group may cause the surprisingly rapid relaxation from the lowest excited triplet state to the ground state. The photophysical properties and excited states of monosubstituted nitrobenzenes are also discussed.

show abstract

“…[86][87][88][89][90][91][92][93][94][95][96][97][98][99][100][101][102][103][104][105] (see Fig.1for their structures and atom labelling) are discussed.…”

mentioning

confidence: 99%

Electronic transitions for a fully polarizable QM/MM approach based on fluctuating charges and fluctuating dipoles: Linear and corrected linear response regimes

Giovannini

Riso

Ambrosetti

et al. 2019

The Journal of Chemical Physics

View full text Add to dashboard Cite

Fully polarizable QM/MM approach based on fluctuating charges and fluctuating dipoles, named QM/FQFµ (J. Chem. Theory Comput. 2019, 15 2233-2245), is extended to the calculation of vertical excitation energies of solvated molecular systems. Excitation energies are defined within two different solvation regimes, i.e. linear response (LR), where the response of the MM portion is adjusted to the QM transition density, and corrected-Linear Response (cLR) in which the MM response is adjusted to the relaxed QM density, thus being able to account for charge equilibration in the excited state. The model, which is specified in terms of three physical parameters (electronegativity, chemical hardness, and polarizability) is applied to vacuo-to-water 1 arXiv:1906.03852v1 [physics.chem-ph] 10 Jun 2019 solvatochromic shifts of aqueous solutions of para-nitroaniline, pyridine and pyrimidine. The results show a good agreement with their experimental counterparts, thus highlighting the potentialities of this approach. IntroductionExcited-state phenomena play a crucial role in many application fields, as for instance photocatalysis, optical information storage and solar cells. In the past decades, theoretical modeling of excited-state properties of molecules in the gas-phase has become a widespread strategy of investigation, 1 giving precious information on, for instance, the nature of the electronic excitation, 2-4 nuclei-electron coupling effects 5-7 and excited state electron dynamics. [8][9][10] However, for electronic phenomena taking place in the condensed phase, 11-19 the interplay between the molecule and its environment can substantially alter the electronic response to external electromagnetic fields. Therefore, any accurate modeling of excited states of solvated systems asks for reliable theoretical approaches to include the effects of the environment at all levels of the excitation phenomenon.Most of the currently available approaches to describe the effects of the external environment on molecular properties belong to the class of the so-called focused models; 20-25 the attention is focused on the molecule and the environment is treated a lower level of sophistication as it modifies, but not determines, the molecular response to the external radiation. In order to keep the atomistic description of the environment, thus substantially overcoming well-known and amply used continuum solvent descriptions, 23,25-29 multiscale QM/Molecular Mechanics (MM) approaches have been developed. 30,31 In such models, the molecule (solute) is treated at the QM level, whereas the environment (solvent) is modelled by means of classical MM force fields (FF). The interaction between the QM and MM portions is usually described in terms of electrostatic forces, although approaches to include non-electrostatic QM/MM interactions have been proposed recently. [32][33][34] In order to fully capure the physics of solute-

show abstract

Solvent effects on electronic absorption spectra of nitrochlorobenzenes, nitrophenols and nitroanilines—I. Studies in nonpolar solvents

Cited by 26 publications

References 29 publications

Geometries and Energies of Nitrobenzene Studied by CAS-SCF Calculations

Geometries and Energies of Nitrobenzene Studied by CAS-SCF Calculations

Nonradiative Relaxation Processes and Electronically Excited States of Nitrobenzene Studied by Picosecond Time-Resolved Transient Grating Method

Electronic transitions for a fully polarizable QM/MM approach based on fluctuating charges and fluctuating dipoles: Linear and corrected linear response regimes

Contact Info

Product

Resources

About