Surface Enhanced Raman Scattering and Normal Coordinate Analysis of 1,10-Phenanthroline Adsorbed on Silver Sols

Abstract

The surface enhanced Raman scattering of 1,10-phenanthroline adsorbed on silver sol has been obtained and analyzed by using normal mode calculations based on a valence force field suitably determined for this molecule. Evidence has been found for Ag-N bond formation with the silver surface, supporting the validity of a chemisorption process. The experimental and calculated data suggest an adsorbate-substrate interaction with perpendicular or tilted orientation of the molecule with respect to the colloidal surface. The halide anion effect on the SER spectrum improves a charge-transfer enhancement process involving adsorbate and metal electronic states. The results obtained on colloids agree with those detected by measurements performed on silver electrode. The similarity between SERS and normal Raman spectra of the corresponding 1:2 Ag(I)phenanthroline complex indicates that the molecule is perturbed upon adsorption as well as upon coordination in the argentous complex.

Electrochemical Properties of a Conducting Film Derived from Iron(II) Tris(diaminopolypyridyl) Complex in the S(IV) Oxoanions Reduction

“…Comparing Figure 5c with Figure 5b, a new group of bands between 832 cm À1 and 926 cm À1 can be observed. This group of new bands are ascribed to vibrational modes involving the diaminophenantroline suggesting a stacked order at polymeric film onto the electrodic surface [22] Another quasi-irreversible wave with an E 1/2 = + 0.12 V (III/III') it can be observed. There are two irreversible waves at E pa + 0.97 V (process II) and another with an E pc = À0.62 V (process IV').…”

Investigations on 1,5‐diaminoanthraquinone by laser excitation

“…38,39 A strong Ag-N stretching band is observed at 230 cm 1 in the case of 1,10-phenanthroline in silver sols. 40 In the case of phthalimide, this band is observed at 214 cm 1 . 41 In the present case, the observed SERS weak band at 220 cm 1 is assigned to the Ag-N stretching vibrational mode.…”

The vibrational assignment of phenanthridine molecule based on normal coordinate analysis and DFT

“…The initial set of FCs is judiciously transferred from previous work on napthalene, 4,5 quinoline, 39 isoquinoline, 39 phenanthrene, 4,16,38,40 benzo(c)cinoline 17 and 1,10-phenanthroline. 41,42 Some off-diagonal FCs, which are thought to be important, are also introduced to account for the interaction between different rings. By cautiously varying the initial set, the final set of the force field is generated.…”

“…The ringbond stretching (CC) FCs are slightly modified to account for the presence of the C-N bond in the molecule. The initial set of the force fields has been transferred from those derived previously for phenanthrene 16 and 1,10-phenanthroline 41 and are shown in Table S2 (Supplementary Materials) along with the final set of the force fields calculated for phenanthridine molecule.…”