This article reports on a project that measured normal Raman (NR) and surface enhanced Raman scattering (SERS) spectra of 3-hydroxyflavone (3-HF).
The SERS spectra were obtained both on an electrode surface and on Ag colloid. Spectral bands were assigned using DFT calculations for the NR, SERS, and FTIR spectra. The IR, normal Raman, and SERS results were compared and in conjunction with a DFT calculation were used to interpret the low-frequency carbonyl stretching vibration in 3-HF. The experimental results supported the DFT geometry calculations, which show that an adatom site at the vertex of Ag20 cluster binding with the 3-HF molecular plane tilted at an angle of about 53° to the surface is a low-energy structure. This is consistent with the enhancement of in-plane vibrational modes. (publisher abstract modified)