RESUMEN
Surface-enhanced Raman scattering (SERS) was used to study the interactions of the normal modes of the bis(diethyldithiocarbamate)zinc(II) complex, [Zn(DDTC)2], on nano-structured silver surfaces. The electronic spectrum of this complex was measured and the charge transfer bands were assigned through the TD-PBE1PBE procedure. To see the electronic dispersion, the Mulliken electronic charges were calculated for each normal mode and correlated with the SERS effect. Full assignment of the SERS spectra was also supported by carefully analysis of the distorted geometries generated by the normal modes.
Asunto(s)
Complejos de Coordinación/química , Ditiocarba/química , Zinc/química , Electrones , Modelos Moleculares , Espectrofotometría Ultravioleta , Espectrometría RamanRESUMEN
Theoretical and experimental bands have been assigned for the Fourier Transform Infrared (FT-IR) and Fourier Transform Raman (FT-Raman) spectra of the bis-(diethydithiocarbamate)Zn(II) complex, [Zn(DDTC)(2)]. The calculations and spectra interpretation have been based on the DFT/B3LYP method, infrared and Raman second derivative spectra as well as band deconvolution analysis. To assign the metal-ligand normal modes the deviation percentage of the geometrical parameters was used. Results confirms a pseudo tetrahedral structure around the Zn(II) cation. The calculated infrared and Raman spectra has an excellent agreement with the experimental spectra. The Natural Bond Orbital analysis (NBO) was carried out as a way to study the Zn(II) hybridization leading to the pseudo tetrahedral geometry of the framework of the [Zn(DDTC)(2)] complex, and to study also which are the donor NBO and the acceptor NBO in meaningful charge transfer through the Second Order Perturbation Theory Analysis of Fox Matrix in NBO basis.
Asunto(s)
Complejos de Coordinación/química , Ditiocarba/química , Zinc/química , Modelos Moleculares , Teoría Cuántica , Espectroscopía Infrarroja por Transformada de Fourier , Espectrometría RamanRESUMEN
Theoretical and experimental bands have been assigned for the Fourier Transform Infrared (FT-IR) and FT-Raman spectra of the bis(diethydithiocarbamate)Cu(II) complex, [Cu(DDTC)(2)]. The calculations and spectra interpretation have been based on the DFT/B3LYP method, infrared and Raman second derivative spectra, and band deconvolution analysis. To better assign the metal-ligand normal modes in the spectral region of low energy, the deviation percentage of the geometrical parameters was used, with values from the interpretation of the normal modes of L matrix. Results indicate a planar structure around the Cu(II) cation. The calculated infrared and Raman spectra, based on the proposed geometrical structure of the bis(diethyldithiocarbamate)copper(II) complex, agreed with the experimental spectra.
Asunto(s)
Complejos de Coordinación/química , Cobre/química , Ditiocarba/química , Complejos de Coordinación/síntesis química , Ditiocarba/síntesis química , Modelos Moleculares , Espectroscopía Infrarroja por Transformada de Fourier , Espectrometría RamanRESUMEN
The aspartateguanidoacetatenickel (II) complex, [Ni(Asp)(GAA)], was synthesized and structural analysis was performed by means of the experimental methods: determination of the C, H, N and O contents, thermogravimetry, infrared and Raman spectroscopy. DFT:B3LYP/6-311G(d, p) calculations have been performed giving optimized structure and harmonic vibrational wavenumbers. Second derivative of the FT-infrared, FT-Raman and Surface Raman Enhanced Scattering (SERS) spectra, and band deconvolution analysis were also performed. Features of the FT-infrared, FT-Raman and SERS confirmed theoretical structure prediction. Full assignment of the vibrational spectrum was also supported by a carefully analysis of the distorted geometries generated by the normal modes. The Natural Bond Orbital analysis (NBO) was also carried out as a way to study the Ni (II) hybridization leading to the pseudo planar geometry of the framework, and the extension of the atomic N and O hybrid orbital of the different amino acids in the bond formation. Bands of charge transfer and d-d transitions were assigned in the UV-Vis spectrum.