title: Reaction of metallotetraphenylporphyrins on hydroxyl-modified silver colloid and Ag2O colloid by surface-enhanced Raman scattering.
abstract: This paper reports a novel reaction of metallotetraphenylporphyrins on hydroxyl-modified silver colloid and Ag2O colloid. Surface-enhanced Raman spectra of Ag(II) and Cu(II) complexes of tetraphenylporphyrin (TPP) adsorbed on the hydroxyl-modified Ag colloid and Ag2O colloid have been studied. The time-dependent SERS spectra of MTPP (M = Ag, Cu) on hydroxyl-modified Ag colloid were recorded and dramatic change on SERS spectra was observed. The final spectra were found to be strikingly different from the corresponding normal Raman spectra (NRS), with the appearance of new Raman bands at 1614. 1417, 947, 674 and 292 cm(-1). The UV-visible absorption spectrum of MTPP on hydroxyl-modified Ag colloid exhibits a broad shoulder near 460 nm. Similar spectral phenomena were also observed for AgTPP and CuTPP adsorbed on Ag2O colloid. The observed spectral alterations were ascribed to new species formation due to the irreducible oxidation of MTPP on the colloids.
authors.affiliation: Department of Chemical Physics, University of Science and Technology of China, Hefei, Anhui, People's Republic of China.
authors.forename: Y H
authors.initials: YH
authors.lastname: Zhang
authors.forename: D M
authors.initials: DM
authors.lastname: Chen
authors.forename: T
authors.initials: T
authors.lastname: He
authors.forename: F C
authors.initials: FC
authors.lastname: Liu
mesh_terms: D003102:Colloids / Q000737:chemistry; D003300:Copper; D009942:Organometallic Compounds / Q000032:analysis*; D010087:Oxides / Q000737:chemistry; D011166:Porphyrins / Q000032:analysis*; D018030:Silver Compounds / Q000032:analysis* / Q000737:chemistry; D013059:Spectrum Analysis, Raman
chemical_list: D003102:Colloids; D009942:Organometallic Compounds; D010087:Oxides; D011166:Porphyrins; D018030:Silver Compounds; C409084:tetraphenylporphyrin; D003300:Copper; C040225:disilver oxide