The crystal structure of copper glutamate dihydrate.
10 Oct 1966-Acta Crystallographica (International Union of Crystallography)-Vol. 21, Iss: 4, pp 594-600
About: This article is published in Acta Crystallographica.The article was published on 1966-10-10. It has received 65 citations till now. The article focuses on the topics: Copper.
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TL;DR: A homochiral three-dimensional zinc aspartate has been synthesised via reflux and solvothermal methods, which due to the coordinative flexibility of zinc displays three distinct coordination geometries and three coordination modes of aspartic acid to zinc.
33 citations
TL;DR: In this paper, the stability, optical and magnetic properties of the copper(II) complexes were described and the biological connextions of these studies were emphasized in the discussion of the various sections.
30 citations
TL;DR: Numerical simulations of the angular variation of the EPR spectra showed that the narrowing of the hyperfine structure is due to an exchange-mediated mechanism in which transitions between any pair of lines are equally likely.
Abstract: We report an EPR study at X- and Q-bands of polycrystalline and single crystal samples of the mixed copper(II) complex with l-glutamic acid (glu) and 1,10-phenantroline (phen), [Cu(glu)(phen)(H2O)]+ NO3–·2(H2O). The polycrystalline sample spectrum at Q-band showed well resolved g∥ and g⊥ features and partially solved hyperfine structure at g∥, typical for weakly exchange coupled systems. This is confirmed from the angular variation of the EPR spectra which shows for certain magnetic field orientations a partially solved hyperfine structure characteristic of weak exchange, whereas a single Lorentzian line corresponding to strong exchange is observed for others. Analysis and simulation of the single crystal EPR spectra were performed using the random frequency modulation model of Anderson. Numerical simulations of the angular variation of the EPR spectra showed that the narrowing of the hyperfine structure is due to an exchange-mediated mechanism in which transitions between any pair of lines are equally li...
29 citations
TL;DR: In this article, the ESR spectra at 1 : 1 and 1 : 4 metal-ligand concentration ratios over different pH regions have been recorded in frozen aqueous solutions and the parallel and perpendicular components of the g and A tensors, the nitrogen superhyperfine coupling constants in the different directions, and the numbers of equatorial nitrogen donor atoms have been determined by computer simulation of the spectra.
Abstract: Various copper(II) complexes of potentially terdentate α-amino acids and, for comparison, those of ethylenediamine and histamine have been investigated. The ESR spectra at 1 : 1 and 1 : 4 metal-ligand concentration ratios over different pH regions have been recorded in frozen aqueous solutions. The parallel and perpendicular components of the g and A tensors, the nitrogen superhyperfine coupling constants in the different directions, and the numbers of equatorial nitrogen donor atoms have been determined by computer simulation of the spectra. The energies of the d-d electronic transitions have been determined by Gaussian analysis of the visible absorption bands. Molecular orbital coefficients characteristic of the metal-ligand bonds have been derived for an effective D 4h local symmetry. Near the freezing point, the equilibrium for the complexes involving bis(glycinato) coordination is shifted towards the trans isomer. The amino groups of R,S-2,3-diaminopropionic acid and R,S-2,4-diaminobutyric a...
26 citations
TL;DR: EPR measurements in single-crystal samples at the microwave frequencies 9.8 and 34.3 GHz and magnetic susceptibility measurements in polycrystalline samples for the ternary complex of copper with aspartic acid and phenanthro line, (L-aspartato)(1,10-phenanthroline)copper(II) hydrate indicate a Curie-Weiss behavior in the studied temperature range (2-300 K).
Abstract: We report EPR measurements in single-crystal samples at the microwave frequencies 9.8 and 34.3 GHz and magnetic susceptibility measurements in polycrystalline samples for the ternary complex of copper with aspartic acid and phenanthroline, (l-aspartato)(1,10-phenanthroline)copper(II) hydrate. The crystal lattice of this compound is composed of two dissimilar copper ions identified as Cu(A) and Cu(B), which are in two types of copper chains called A and B, respectively, running parallel to the b crystal axis. The copper ions in the A chains are connected by the aspartic acid molecule, and those in the B chains by a chemical path that involves a carboxylate bridge and a hydrogen bond. Both chains are held together by a complex network of hydrogen bonds and by hydrophobic interactions between aromatic amines. Magnetic susceptibility data indicate a Curie−Weiss behavior in the studied temperature range (2−300 K). The EPR spectra at 9.8 GHz display a single exchange collapsed resonance for any magnetic field o...
22 citations
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