N-hetero atomic effect on the photophysics of 2,2'-dipyridylketone.

Emission characteristics of 2,2'-dipyridylketone (DPK) have been studied in the rigid glass matrices of ethanol (EtOH) and methyl cyclohexane (MCH) at 77 K. As in the case of the aromatic analogue benzophenone (BOP), DPK is found to exhibit only phosphorescence emission. Although both BOP and DPK have the lowest triplet states chiefly of n pi* nature, the presence of other triplet states in the neighbourhood of the lowest triplet one is found to play some significant roles in determining the photophysical properties of DPK, specially in the non-polar solvent (MCH). All the photophysical properties including the polarization characteristics have been explored in both the molecules. Experimental observations are corroborated with necessary quantum chemical calculations.

Vibrational dynamics and structural investigation of 2,2'-dipyridylketone using Raman, IR and UV-visible spectroscopy aided by ab initio and density functional theory calculation.

Detailed investigation on the vibrational and electronic spectra has been carried out in order to study various properties of 2,2'-dipyridylketone molecule in its ground and excited electronic states. To get insight into the structural and symmetry features of the molecule, Raman excitation profiles of several normal modes have been analyzed. The polarized Raman spectra in different environments along with their IR counterpart have been critically surveyed and different normal modes have been assigned. The knowledge in regard to the positions of different excited electronic states has been acquired from the study of electronic absorption spectra. All the experimental observations have been substantiated and corroborated theoretically by the quantum chemical calculation. Possibility of exciton splitting of the 1La band has been explored both from theoretical and experimental points of view.