RAMAN-SPECTRA AND STRUCTURE OF BIPHENYL ISOATOMERS (THE S(0), S(1), T(1) STATES AND THE CATION AND ANION-RADICALS)

The Raman and transient resonance Raman spectra of biphenyl (BP) and i ts perdeuterated analogue (BP-d10) in three different electronic state s (S0, S1 and T1) and in two different ionized states (cation and anio n) have been recorded in solution. The S0 Raman spectra have also been measured for the crystalline state. The obtained set of spectra are a nalysed on the basis of the established vibrational assignments for th e ground state of the planar (crystal) and the non-planar (solution) s tructures. The analysis suggests that BP in solution exists as a twist ed structure in the S1 state, but that it takes planar or nearly plana r structures in the T1, the cationic and the anionic states.