Solvent effect and photo-physical properties of 2,3-diphenylcyclopropenone

The photo-physical properties of the strained ring 2,3-diphenylcyclopropenone (DPCP) containing donor-acceptor moieties in polar and non-polar solvent are reported. The transition dipole moment (Δμ), transition polarizability (Δα), oscillator strength (fij) and molar absorptivity (ε(ν¯)) of its different transition bands were determined using solvatochromic shifts theory. The determined Δα is positive, signifying the strong activity of this compound and its excited states being more polar than ground states. Its Δμ follows the trend observed for the fij and Δα. This conforms to the expectations that the more allowed a transition, the higher the probability that the transition dipole moments will be greater than zero. The transition dipole moment shows gradation of values, being smallest for the weak and forbidden transitions but increases considerably for the fully allowed transitions. The solvents perturbation allows the assignment of the transitions in this compound to be both n→π∗ and π→π∗ transitions.