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1.
Spectrochim Acta A Mol Biomol Spectrosc ; 169: 95-107, 2016 Dec 05.
Article in English | MEDLINE | ID: mdl-27344520

ABSTRACT

Theoretical and experimental bands have been assigned for the Fourier Transform Infrared and Raman spectra of the bis(diethyldithiocarbamate)Mn(II) complex, [Mn(DDTC)2]. The calculations have been based on the DFT/B3LYP method, second derivative spectra and band deconvolution analysis. The UV-vis experimental spectra were measured in acetonitrile solution, and the calculated electronic spectrum was obtained using the TD/B3LYP method with 6-311G(d, p) basis set for all atoms. Charge transfer bands and those d-d spin forbidden were assigned in the UV-vis spectrum. The natural bond orbital analysis was carried out using the DFT/B3LYP method and the Mn(II) hybridization leading to the planar geometry of the framework was discussed. Surface enhanced Raman scattering (SERS) was also performed. Mulliken charges of the normal modes were obtained and related to the SERS enhanced bands.

2.
Spectrochim Acta A Mol Biomol Spectrosc ; 146: 192-203, 2015 Jul 05.
Article in English | MEDLINE | ID: mdl-25813176

ABSTRACT

Theoretical and experimental bands have been assigned to the Fourier Transform Infrared (FT-IR) and FT-Raman spectra of the bis(diethyldithiocarbamate)Cd(II) complex, abbreviated as ([Cd(DDTC)2]). The calculations and spectral interpretation have been based on the DFT/B3LYP method, infrared and Raman second derivative spectra, and band deconvolution analysis to assist in the assignment of observed fundamentals. This study validated the unusual pseudo tetrahedral molecular structure formed around the Cd(II) cation. Surface-enhanced Raman scattering (SERS) was used to determine the interactions of the normal-modes of the diethyldithiocarbamate cadmium (II) complex on nano-structured silver surfaces. Natural bond orbital (NBO) analysis was also carried out to study the Cd(II) hybridization causing the pseudo tetrahedral geometry of the framework of the [Cd(DDTC)2] complex, and to confirm the charge transfer mechanisms through second order perturbation theory analysis of the Fox Matrix. In order to find out the electronic dispersion of the Mulliken atomic charges (MAC) in the normal modes, we calculated the MAC for each normal mode and correlated these values with the SERS effect. Experimental UV-Vis spectra were obtained and charge transfer bands were assigned. Good agreement between the calculated and experimental values for the vibrational and UV-Vis spectra was obtained.


Subject(s)
Cadmium/chemistry , Ditiocarb/chemistry , Models, Molecular , Spectrum Analysis, Raman
3.
Article in English | MEDLINE | ID: mdl-23978740

ABSTRACT

Surface-enhanced Raman scattering (SERS) was used to study the interactions of the normal modes of the diethyldithiocarbamate copper (II) complex, [Cu(DDTC)2] on nano-structured mixture silver-gold surfaces and on silver surfaces. The electronic spectrum of this complex was measured and the charge transfer bands were assigned through the TD-PBE1PBE procedure. Natural bond orbital (NBO) were also carried out to study the Cu(II) hybridation leading to the square planar geometry of the framework of the [Cu(DDTC)2] complex, and to study which are the donor NBO and the acceptor NBO in meaningful charge transfer through the Second Order Perturbation Theory Analysis of the Fox Matrix in NBO basis. To see the electronic dispersion, the Mulliken electronic charges (MAC) 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.


Subject(s)
Coordination Complexes/chemistry , Copper/chemistry , Ditiocarb/chemistry , Electrons , Models, Molecular , Spectrophotometry, Ultraviolet , Spectrum Analysis, Raman
4.
Article in English | MEDLINE | ID: mdl-23588299

ABSTRACT

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.


Subject(s)
Coordination Complexes/chemistry , Ditiocarb/chemistry , Zinc/chemistry , Electrons , Models, Molecular , Spectrophotometry, Ultraviolet , Spectrum Analysis, Raman
5.
Article in English | MEDLINE | ID: mdl-23314390

ABSTRACT

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.


Subject(s)
Coordination Complexes/chemistry , Ditiocarb/chemistry , Zinc/chemistry , Models, Molecular , Quantum Theory , Spectroscopy, Fourier Transform Infrared , Spectrum Analysis, Raman
6.
Spectrochim Acta A Mol Biomol Spectrosc ; 105: 259-66, 2013 Mar 15.
Article in English | MEDLINE | ID: mdl-23314391

ABSTRACT

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.


Subject(s)
Coordination Complexes/chemistry , Copper/chemistry , Ditiocarb/chemistry , Coordination Complexes/chemical synthesis , Ditiocarb/chemical synthesis , Models, Molecular , Spectroscopy, Fourier Transform Infrared , Spectrum Analysis, Raman
7.
Article in English | MEDLINE | ID: mdl-22925980

ABSTRACT

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.


Subject(s)
Aspartic Acid/chemistry , Electrons , Models, Molecular , Nickel/chemistry , Organometallic Compounds/chemistry , Quantum Theory , Spectrum Analysis, Raman , Vibration , Molecular Conformation , Spectrophotometry, Ultraviolet , Spectroscopy, Fourier Transform Infrared , Thermodynamics
8.
Article in English | MEDLINE | ID: mdl-16716653

ABSTRACT

The structure of [Co(gly)(2)(OH)(2)].1.5(H(2)O) was solved by X-ray diffraction. It crystallizes in the space group P-1, with two independent dimmers in the unit cell. The results for the calculated vibrational spectra are in good agreement with the experimental one. The infrared spectrum and ab initio calculations are consistent with the crystallographic results.


Subject(s)
Cobalt/chemistry , Glycine/analogs & derivatives , Glycine/chemistry , Organometallic Compounds/chemical synthesis , Carbon/analysis , Crystallization/methods , Glycine/chemical synthesis , Hydrogen/analysis , Models, Molecular , Molecular Structure , Nitrogen/analysis , Oxidation-Reduction , Oxygen/analysis , Spectrum Analysis/methods , Vibration
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