title: DFT based computational study on the excited state intramolecular proton transfer processes in o-hydroxybenzaldehyde.
abstract: 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.
authors: Department of Chemistry and Chemical Technology, Vidyasagar University, Midnapore 721102, West Bengal, India.
authors: Sankar Prasad
authors: SP
authors: De
authors: Sankarlal
authors: S
authors: Ash
authors: Dipak kumar
authors: Dk
authors: Bhui
authors: Harekrishna
authors: H
authors: Bar
authors: Priyanka
authors: P
authors: Sarkar
authors: Gobinda Prasad
authors: GP
authors: Sahoo
authors: Ajay
authors: A
authors: Misra
mesh_terms: 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
chemical_list: D001547:Benzaldehydes; D011522:Protons; C538871:o-hydroxybenzaldehyde