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  • Density functional theory study on surface-enhanced Raman scattering of 4,4'-azopyridine on silver.

Density functional theory study on surface-enhanced Raman scattering of 4,4'-azopyridine on silver.

Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy (2009-02-03)
Zhiping Zhuang, Xiaohong Shang, Xu Wang, Weidong Ruan, Bing Zhao
ABSTRACT

Surface-enhanced Raman scattering (SERS) of 4,4'-azopyridine (AZPY) on silver foil substrate was measured under 1064nm excitation lines. Density-functional theory (DFT) methods were used to calculate the structure and vibrational spectra of models such as Ag-AZPY, Ag(4)-AZPY and Ag(6)-AZPY complexes with B3LYP/6-31++G(d,p)(C,H,N)/Lanl2dz(Ag) basis set. The Raman bands of AZPY were identified on the ground of analog computation of potential energy distribution. The calculated spectra of Ag(4)-AZPY and Ag(6)-AZPY models were much approximated to the experimental results than that of Ag-AZPY model. The DFT results showed that the angles between two pyridyl rings keep 0 degrees from AZPY to Ag-AZPY, Ag(4)-AZPY and Ag(6)-AZPY model. The energy gaps between the HOMO and LUMO changed from 363 to 1140nm for AZPY-Ag complexes according to the DFT results. An conclusion was conceived that chemical enhancement mechanism may play an important role in the SERS of AZPY on silver substrate.

MATERIALS
Product Number
Brand
Product Description

Silver, foil, light tested, 50x50mm, thickness 0.0125mm, 99.95+%
Silver, foil, not light tested, 100x100mm, thickness 0.0025mm, 99.97%
Silver, foil, not light tested, 100x100mm, thickness 0.0125mm, 99.95+%
Silver, foil, 6mm disks, thickness 0.015mm, 99.97%
Silver, foil, 6mm disks, thickness 0.125mm, annealed, 99.95+%
Silver, foil, 8mm disks, thickness 0.007mm, 99.97%
Silver, foil, 8mm disks, thickness 0.035mm, as rolled, 99.95+%
Silver, foil, light tested, 100x100mm, thickness 0.025mm, as rolled, 99.99+%
Silver, foil, light tested, 150x150mm, thickness 0.05mm, annealed, 99.95+%
Silver, foil, light tested, 50x50mm, thickness 0.015mm, 99.97%
Silver, foil, 8mm disks, thickness 0.25mm, as rolled, 99.95+%
Silver, foil, 8mm disks, thickness 0.008mm, 99.95+%
Silver, foil, not light tested, 100x100mm, thickness 0.003mm, 99.9%
Silver, foil, 6mm disks, thickness 0.5mm, as rolled, 99.99+%
Silver, foil, light tested, 150x150mm, thickness 0.05mm, as rolled, 99.95+%
Silver, foil, not light tested, 150x150mm, thickness 0.025mm, as rolled, 99.95+%
Silver, foil, 8mm disks, thickness 1.0mm, as rolled, 99.95+%
Silver, foil, 6mm disks, thickness 0.5mm, as rolled, 99.95+%
Silver, foil, 6mm disks, thickness 1.0mm, as rolled, 99.95+%
Silver, foil, light tested, 150x150mm, thickness 0.025mm, as rolled, 99.95+%
Silver, foil, not light tested, 25x25mm, thickness 0.006mm, 99.97%
Silver, foil, 8mm disks, thickness 0.5mm, as rolled, 99.95+%
Silver, foil, 8mm disks, thickness 0.009mm, 99.97%
Silver, foil, light tested, 150x300mm, thickness 0.05mm, as rolled, 99.95+%
Silver, foil, light tested, 100x100mm, thickness 0.02mm, 99.97%
Silver, foil, not light tested, 150x150mm, thickness 0.02mm, 99.97%
Silver, foil, 8mm disks, thickness 0.05mm, as rolled, 99.95+%
Silver, foil, light tested, 50x50mm, thickness 0.025mm, as rolled, 99.99+%
Silver, foil, light tested, 100x100mm, thickness 0.05mm, as rolled, 99.95+%
Silver, foil, 8mm disks, thickness 0.125mm, as rolled, 99.95+%