204861-07-4Relevant academic research and scientific papers
Structural and spectral studies of N-alkyloxamates and their complexes: X-ray structures of MeHNCOCOOK and [Cu(EtHNCOCOO)2], and vibrational studies
Papaefstathiou,Peeters,Lenstra,Desseyn,Perlepes
, p. 167 - 177 (2001)
This work is devoted to structural and vibrational studies of N-alkyloxamates and their complexes. The structures of MeHNCOCOOK and [Cu(EtHNCOCOO)2] have been determined by single-crystal X-ray crystallography. The potassium salt crystallizes in the monoclinic space group P21/n and the copper(II) complex in the triclinic space group P1?. The lattice constants are a = 3.882(2), b = 10.175(1), c = 13.004(1), β = 97.04(1)° for MeHNCOCOOK and a = 5.013(1), b = 6.996(1), c = 8.575(1) ?, α = 73.54(1), β = 85.66(1), γ = 71.22(1)° for [Cu(EtHNCOCOO)2]. The salt has a trans secondary amide group and the K- ion is surrounded by seven O atoms belonging to six different N-methyloxamate(-1) moieties. The ligand EtHNCOCOO- behaves as a bidentate chelate in the trans square planar copper(II) complex with ligated atoms being the amide and one of the carboxylate oxygens. The copper(II) complex was characterized by its room-temperature magnetic susceptibility and solid-state d-d spectrum. A detailed comparison of the vibrational spectra (FT-IR, FT-Raman) of [Cu(EtHNCOCOO)2] with the corresponding potassium salt, EtHNCOCOOK, is presented. The vibrational data are discussed in terms of the nature of bonding and the known structure of the copper(II) complex. Quantum-chemical calculations were performed to obtain the equilibrium geometries and torsional energies for an isolated oxamate(-1) ion (H2NCOCOO-) and its hypothetical square planar zinc(II) complex.
