Exploring the isomer dependent SERS spectra of (diphenylphosphoryl) (pyridin-2, -3, and -4-yl)methanol adsorbed on gold nanocolloids

The surface-enhanced Raman scattering (SERS) spectra of three aminophosphonate derivatives of pyridine: (diphenylphosphoryl)(pyridin-2-yl)methanol (-Pyr), (diphenylphosphoryl)(pyridin-3-yl)methanol (-Pyr), and (diphenylphosphoryl)(pyridin-4-yl)methanol (-Pyr) were measured after immobilization onto colloidal gold surface. Changes in the wavenumber, broadness, and enhancement between the corresponding Raman and SERS bands allowed to deduce orientation of the -, -, and -isomers (-, -, and -refer to the position of the substituent relative to the ring nitrogen atom) of aminophosphonate derivatives of pyridine on the gold surface. Briefly, it was demonstrated that the -Pyr and -Pyr show the same mode of adsorption, whereas the adsorption process of the -Pyr isomer differs in this regard that pyridine assists in the interaction with the gold surface.