pH-Dependent Surface-Enhanced Raman Scattering of 8-Hydroxy Quinoline Adsorbed on Silver Hydrosol

The Fourier-transform infrared and Fourier-tranform Raman spectra of phenyl phosphate disodium salt were recorded and analyzed. The surface-enhanced Raman scattering (SERS) spectrum was recorded in a silver colloid. The vibrational wavenumbers of the compound were computed using the Hartree-Fock/6-31G * basis and compared with the experimental values. The molecule is adsorbed on the silver surface with the benzene ring in a tilted orientation. The presence of the phenyl ring and the phosphate group vibrations in the SERS spectrum reveal the interactions between the phenyl ring and the phosphate group with the silver surface. The first hyperpolarizability is calculated, and the calculated molecular geometry is compared with those of similar reported structures.

Section: Ir and Raman Spectramentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Vibrational spectroscopic studies and ab initio calculations of phenyl phosphate disodium salt

Anto¹,

Anto²,

Varghese³

et al. 2009

“…It is now well established that on the silver colloidal surface, maximum enhancement of the Raman signal is observed when a monolayer of the adsorbate molecule is formed on the surface and that as multilayers are formed the SERS signal decreases. 8,9 This conjecture assumes that the orientation of the adsorbate molecules does not change with the surface coverage and the predicted behaviour holds for all the SERS bands.…”

Section: Concentration-dependent Sers Spectra Of Isomeric Bpsmentioning

confidence: 99%

Adsorption of 3‐ and 4‐benzoylpyridine on colloidal silver particles: a surface‐enhanced Raman scattering study

Chowdhury

Ghosh

2004

Self Cite

Surface-enhanced Raman scattering (SERS) spectra of 3-and 4-benzoylpyridine (BP) adsorbed on silver hydrosols were compared with the FTIR and normal Raman spectra in bulk and in solution. With a small fractional change in adsorbate concentration, the SER spectra of isomeric BPs show significant changes in their features, indicating different orientational changes of the different parts of the flexible molecule on the colloidal silver surface with adsorbate concentration. The appearance of a broad, long-wavelength band in the absorption spectra of the silver sol due to solute-induced coagulation of colloidal silver particles is found to be red shifted with increase in adsorbate concentration. The SER excitation profiles indicate that the resonance of the Raman excitation radiation with the new aggregation band contributes more to the SERS intensity than that with the original sol band.

“…SERS spectra in silver sol and Raman spectra in the bulk and in solution of 8-hydroxyquinoline 77 and 2,2 0 -biquinoline (BQ) molecules have also been reported. 78 For the latter, the existence of both the cis and trans forms of the BQ molecule in solution and in the bulk is inferred from the normal Raman and FTIR spectra, whereas the SERS study revealed that in the surface-adsorbed state the molecule exists in the cis form.…”

Section: Quinolinesmentioning

confidence: 98%

Identification and characterization of pharmaceuticals using Raman and surface‐enhanced Raman scattering

Pinzaru

Pavel

Leopold

et al. 2004

130

Many recent papers reflect ongoing research and development concerning pharmaceutical applications of Raman techniques. This short review highlights different Raman techniques (dispersive, Fourier transform, resonance Raman, SERS, SERRS, FT-SERS) employed in pharmaceutical investigations. Several Raman applications such as fundamental structural investigations, quantitative analysis, drug-excipient interaction, formulation, limit of detection, pH-dependent pharmaceutical species, adsorption geometry at a given surface and functional groups involved in adsorption for several widely used pharmaceutical compounds are presented.