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The normal and UV near-resonance Raman (UVRR) spectra of 1,1'-bi-2-naphthol (BN) in basic solution were measured and analyzed. Density functional theory (DFT) calculations were carried out to study the ground state geometry structure, vibrational frequencies nu, off-resonance Raman intensities I, and depolarization ratios rho of 1,1'-bi-2-naphtholate dianion (BN(2-)). On the basis of the calculated and experimental results of nu, I, and rho, the observed Raman bands were assigned in detail. The 1612 cm(-1) Raman band of BN in basic solution was found dramatically enhanced in the UV resonance Raman spectrum in comparison with the normal Raman spectrum. Analyzing the depolarization ratios of the 1366 and 1612 cm(-1) bands in the RR spectra manifests that both the symmetric and antisymmetric parts of transition polarizabilities contribute to the 1366 cm(-1) band, but that only the symmetric part contributes to the 1612 cm(-1) band.

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Resonance Raman spectra of aggregated meso-tetra(4-pyridinium)porphyrin diacid (H8TPyP6+) were studied with excitation near the exciton absorption bands of 470 nm. The UV-Vis absorption and resonance light scattering spectra of H8TPyP6+ monomers and aggregates were also measured. The observed Raman bands of monomeric and aggregated H8TPyP6+ were assigned on the basis of the observed deuteration shifts and by comparing with the Raman spectra of analogous porphyrin diacids. Aggregation causes moderate downshifts (26 cm1) for high-frequency modes involving the in-plane CC/CN stretches of the porphyrin core and a dramatic upshift (12 cm1) for the out-of-plane saddling mode of the porphyrin ring. The structural changes induced by aggregation and the possible hydrogen bonding interaction between the H8TPyP6+ molecules in the aggregate are discussed based on the spectral observations.