title: Characterization of compounds derived from copper-oxamate and imidazolium by X-ray absorption and vibrational spectroscopies.
abstract: In this work, compounds derived from copper-oxamate anions (ortho, meta, and para)-phenylenebis (oxamate) and imidazolium cations (1-butyl-3-methylimidazolium) were synthesized. The compounds were characterized by Raman and FTIR spectroscopies and the band assignments were supported by DFT calculations. Strong IR bands from 1610 to 1700cm(-1) dominated the spectra of the complex and can be assigned to νCO vibrations of the [Cu(opba)](2-) anions by the comparison with the DFT data. In opposition to the FTIR spectra, the main vibrational bands in the Raman spectra are observed in the 1350-1600cm(-1) range. All bands in this region are associated to the modified benzene vibrations of the copper-phenylenebis(oxamate) anions. X-ray absorption near edge (XANES) at different energies (NK and Cu L2,3 edges) was also used to probe the interionic interactions. XANES data show that anion-cation interaction in the Cu-oxamate-imidazolium changes the electronic structure around the CuN sites in the oxamate anion.
authors.affiliation: Departamento de Química, Instituto de Ciências Exatas, Universidade Federal de Minas Gerais, Brazil; Centro de Ciências Naturais e Humanas (CCNH), Universidade Federal do ABC, Brazil. Electronic address: gustavo.morari@ufabc.edu.br.
authors.forename: Gustavo M
authors.initials: GM
authors.lastname: do Nascimento
authors.affiliation: Departamento de Química, Instituto de Ciências Exatas, Universidade Federal de Minas Gerais, Brazil; Centro Federal de Educação Tecnológica de Minas Gerais, CEFET-MG, Brazil.
authors.forename: Walace D
authors.initials: WD
authors.lastname: do Pim
authors.affiliation: Departamento de Química, Instituto de Ciências Exatas, Universidade Federal de Minas Gerais, Brazil.
authors.forename: Daniella O
authors.initials: DO
authors.lastname: Reis
authors.affiliation: Departamento de Química, Instituto de Ciências Exatas, Universidade Federal de Minas Gerais, Brazil.
authors.forename: Tatiana R G
authors.initials: TR
authors.lastname: Simões
authors.affiliation: Departamento de Química Fundamental, Instituto de Química, Universidade de São Paulo, Brazil.
authors.forename: Noriberto A
authors.initials: NA
authors.lastname: Pradie
authors.affiliation: Departamento de Química, Instituto de Ciências Exatas, Universidade Federal de Minas Gerais, Brazil.
authors.forename: Humberto O
authors.initials: HO
authors.lastname: Stumpf
mesh_terms: D000838:Anions / Q000737:chemistry; D003300:Copper / Q000737:chemistry*; D007093:Imidazoles / Q000737:chemistry*; D052578:Ionic Liquids / Q000737:chemistry*; D008958:Models, Molecular; D010072:Oxamic Acid / Q000737:chemistry; D017550:Spectroscopy, Fourier Transform Infrared; D013059:Spectrum Analysis, Raman
chemical_list: C525963:1-butyl-3-methylimidazolium; D000838:Anions; D007093:Imidazoles; D052578:Ionic Liquids; D003300:Copper; D010072:Oxamic Acid
keywords: DFT calculations; Imidazolium; Ionic liquids; Raman; XANES