Surface Enhanced Raman Scattering (SERS) of tetrasodium meso-tetrakis (4-sulfonatophenyl) porphine (H2TSPP) and silver tetraphenylporphyrin (Ag(Ⅱ)TSPP)adsorbed spontarleously on uniform Fe3O4 colloids are recorded. T...Surface Enhanced Raman Scattering (SERS) of tetrasodium meso-tetrakis (4-sulfonatophenyl) porphine (H2TSPP) and silver tetraphenylporphyrin (Ag(Ⅱ)TSPP)adsorbed spontarleously on uniform Fe3O4 colloids are recorded. The enhancement of Raman bands is approximately 30. An analysis of the SERS spectrum shows that on the Fe3O4 surface H2TSPP takes its diacid form H42+TSPP.展开更多
The effect of cations(H +,Li +,Na + and K +) on the J aggregation of tetrakis( p sulfonatophenyl) porphyrin diacid (H 2+ 4TSPP 4- ) was studied by UV Vis absorption spectra.It was demonstrated that the presence of the...The effect of cations(H +,Li +,Na + and K +) on the J aggregation of tetrakis( p sulfonatophenyl) porphyrin diacid (H 2+ 4TSPP 4- ) was studied by UV Vis absorption spectra.It was demonstrated that the presence of these cations promotes the J aggregation of H 2+ 4TSPP,implying that the external cations are necessary to balance the Coulomb repulsion between the sulfonate groups of adjacent H 2+ 4TSPP 4- molecules in the J aggregate.The excitionic energy of the J aggregate was evaluated under the dipole dipole interaction,which is qualitatively consistent with the experimental result.The results support the staircase structural model of the aggregate.展开更多
It is proposed in this paper that the comparison experiments on SERS excitation profiles of coadsorbed molecules can provide a critical test of the nature of SERS resonance mechanisms.O-nitrobenzoic acid and pyridine ...It is proposed in this paper that the comparison experiments on SERS excitation profiles of coadsorbed molecules can provide a critical test of the nature of SERS resonance mechanisms.O-nitrobenzoic acid and pyridine coadsorbed on Ag sol have different resonant maxima in their SERS excitation profiles.Unlike usual excitation experiments on SERS,the results show that there must be a non-electromagnetic enhancement mechanism on SERS.展开更多
文摘Surface Enhanced Raman Scattering (SERS) of tetrasodium meso-tetrakis (4-sulfonatophenyl) porphine (H2TSPP) and silver tetraphenylporphyrin (Ag(Ⅱ)TSPP)adsorbed spontarleously on uniform Fe3O4 colloids are recorded. The enhancement of Raman bands is approximately 30. An analysis of the SERS spectrum shows that on the Fe3O4 surface H2TSPP takes its diacid form H42+TSPP.
文摘The effect of cations(H +,Li +,Na + and K +) on the J aggregation of tetrakis( p sulfonatophenyl) porphyrin diacid (H 2+ 4TSPP 4- ) was studied by UV Vis absorption spectra.It was demonstrated that the presence of these cations promotes the J aggregation of H 2+ 4TSPP,implying that the external cations are necessary to balance the Coulomb repulsion between the sulfonate groups of adjacent H 2+ 4TSPP 4- molecules in the J aggregate.The excitionic energy of the J aggregate was evaluated under the dipole dipole interaction,which is qualitatively consistent with the experimental result.The results support the staircase structural model of the aggregate.
基金This work was supported by the Science Fund of The Chinese Academy of Science。
文摘It is proposed in this paper that the comparison experiments on SERS excitation profiles of coadsorbed molecules can provide a critical test of the nature of SERS resonance mechanisms.O-nitrobenzoic acid and pyridine coadsorbed on Ag sol have different resonant maxima in their SERS excitation profiles.Unlike usual excitation experiments on SERS,the results show that there must be a non-electromagnetic enhancement mechanism on SERS.
