DFT based computational study on the excited state intramolecular proton transfer processes in o-hydroxybenzaldehyde.
Potential energy (PE) curves for the intramolecular proton transfer in the ground (GSIPT) and excited (ESIPT) states of o-hydroxybenzaldehyde (OHBA) were studied using DFT-B3LYP/6-31G(d) and TD-DFT-B3LYP/6-31G(d) level of theory, respectively. Our calculations suggest the non-viability of ground state intramolecular proton transfer in this compound. Excited states PE calculations support the ESIPT process in OHBA. The contour PE diagram and the variation of oscillator strength along the proton transfer co-ordinate support the dual emission in OHBA. Our calculations also support the experimental observations of Nagaoka et al. [S. Nagaoka, U. Nagashima, N. Ohta, M. Fujita, T. Takemura, J. Phys. Chem. 92 (1988) 166], i.e. normal emission of the title compound comes from S(2) state and the red-shifted proton transfer band appears from the S(1) state. ESIPT process has also been explained in terms of HOMO and LUMO electron density of the enol and keto tautomer of OHBA and from the potential energy surfaces.
De
Sankar Prasad
SP
Department of Chemistry and Chemical Technology, Vidyasagar University, Midnapore 721102, West Bengal, India.
Ash
Sankarlal
S
Bhui
Dipak kumar
Dk
Bar
Harekrishna
H
Sarkar
Priyanka
P
Sahoo
Gobinda Prasad
GP
Misra
Ajay
A
D001547:Benzaldehydes / Q000737:chemistry*; D003198:Computer Simulation; D004355:Drug Stability; D004735:Energy Transfer / Q000502:physiology; D006860:Hydrogen Bonding; D008954:Models, Biological; D008956:Models, Chemical; D008958:Models, Molecular; D015394:Molecular Structure; D011522:Protons; D013059:Spectrum Analysis, Raman; D013237:Stereoisomerism
D001547:Benzaldehydes; D011522:Protons; C538871:o-hydroxybenzaldehyde