title: Raman, surface-enhanced Raman, and density functional theory characterization of (diphenylphosphoryl)(pyridin-2-, -3-, and -4-yl)methanol.
abstract: This work presents near-infrared Raman spectroscopy (FT-RS) and surface-enhanced Raman scattering (SERS) studies of three pyridine-α-hydroxymethyl biphenyl phosphine oxide isomers: (diphenylphosphoryl)(pyridin-2-yl)methanol (α-Py), (diphenylphosphoryl)(pyridin-3-yl)methanol (β-Py), and (diphenylphosphoryl)(pyridin-4-yl)methanol (γ-Py) adsorbed onto colloidal and roughened in oxidation-reduction cycles silver surfaces. The molecular geometries in the equilibrium state and vibrational frequencies were calculated by density functional theory (DFT) at the B3LYP 6-311G(df,p) level of theory. The results imply that the most stable structure of the investigated molecules is a dimer created by two intermolecular hydrogen bonds between the H atom of the α-hydroxyl group (in up (HOU) or down (HOD) stereo bonds position) and the O atom of tertiary phosphine oxide (═O) of the two monomers. Comparison the FT-RS spectra with the respective SERS spectra allowed us to predict the orientation of the hydroxyphosphonate derivatives of pyridine that depends upon both the position of the substituent relative to the ring N atom (in α-, β-, and γ-position, respectively) and the type of silver substrate.
authors.affiliation: Faculty of Foundry Engineering, AGH University of Science and Technology , ul. Reymonta 23, 30-059 Krakow, Poland.
authors.forename: Edyta
authors.initials: E
authors.lastname: Proniewicz
authors.forename: Ewa
authors.initials: E
authors.lastname: Pięta
authors.forename: Krzysztof
authors.initials: K
authors.lastname: Zborowski
authors.forename: Andrzej
authors.initials: A
authors.lastname: Kudelski
authors.forename: Bogdan
authors.initials: B
authors.lastname: Boduszek
authors.forename: Tomasz K
authors.initials: TK
authors.lastname: Olszewski
authors.forename: Younkyoo
authors.initials: Y
authors.lastname: Kim
authors.forename: Leonard M
authors.initials: LM
authors.lastname: Proniewicz
mesh_terms: D006860:Hydrogen Bonding; D007536:Isomerism; D053768:Metal Nanoparticles / Q000737:chemistry; D046529:Microscopy, Electron, Transmission; D008956:Models, Chemical; D010084:Oxidation-Reduction; D011725:Pyridines / Q000737:chemistry*; D018030:Silver Compounds / Q000737:chemistry; D013059:Spectrum Analysis, Raman; D014732:Vibration
chemical_list: D011725:Pyridines; D018030:Silver Compounds