Structural and magnetic properties of a copper–amino acid salt: Copper (II) bis (α-amino isobutyrato)

Calvo, Rafael; Mesa, Manuel A.; Oliva, Glaucius; Zukerman-Schpector, Júlio; Nascimento, Otaciro Rangel; Tovar, M.; Arce, R.

doi:10.1063/1.447389

Cited by 32 publications

(19 citation statements)

References 26 publications

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“…There are many investigations of their properties but questions and controversies still exist. 22 Furthermore, even though many electron paramagnetic resonance (EPR) studies in copper-amino acid and peptide compounds have been reported, [23][24][25][26][27][28][29][30][31] single crystal studies of the more complex ternary copper amino acid compounds are scarce, 21,32 even when this is a sensitive spectroscopic technique to investigate the electronic structure of the metal ions and to estimate the weak interactions between them supported by the non-covalent couplings mentioned before. 31 Ternary compounds involving glycine, 1,10phenanthroline and copper nitrate or copper chloride, named [Cu(Gly)(phen)(H 2 O)]•NO 3 •1.5H 2 O (1) or [Cu(Gly)(phen)Cl] 2 •7H 2 O (2), having Cu II ions connected by paths including carboxylate and stacking interactions between Cu II ions were reported by Zhang et al 17 and Yodoshi et al 18 , respectively.…”

Section: Introductionmentioning

confidence: 99%

Electron paramagnetic resonance study of ternary CuII compounds with glycine and phenanthroline

et al. 2014

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We report here electron paramagnetic resonance (EPR) measurements at 9 and 34 GHz, and room temperature (T), in powder and single crystal samples of the ternary compounds of copper nitrate or copper chloride with glycine and 1,10-phenanthroline [Cu(Gly)(phen)(H 2 O)]•NO 3 •1.5H 2 O (1) and [Cu(Gly)(phen)Cl] 2 •7H 2 O (2). In compound 1, the copper ions are arranged in 1-D chains along one of the crystal axes connected by syn-anti carboxylate ligands, while in 2 the array is nearly 3-D and the connections involve H-bonds and stacking interactions. The angular variation of the squared g-factor and the line width were measured as a function of orientation of the magnetic field (B 0) in three orthogonal crystal planes. In both compounds we observed one resonance without hyperfine structure for any magnetic field orientation which we attribute to the collapse of the hyperfine coupling and of the resonances of two chemically identical but rotated coppers in the unit cell, produced by exchange interactions. We analyse the results in terms of the structures of the compounds and chemical paths connecting neighbour copper ions which support the exchange interactions between neighbour spins in the lattice. Considering the collapse of the EPR signals of rotated sites in the lattices we are able to set lower limits to the exchange interactions, which are supported by weak equatorialapical carboxylate bridges in 1, and by paths containing hydrogen bonds and aromatic π-π interactions in 2. Broadening due to dipole-dipole couplings and hyperfine interactions are strongly reduced by these exchange couplings and their role in the EPR line width is more difficult to recognize.

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Section: Introductionmentioning

confidence: 99%

Electron paramagnetic resonance study of ternary CuII compounds with glycine and phenanthroline

et al. 2014

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“…In most of the Cu 2+ doped compounds, the Cu 2+ ions replace divalent cations. Saccharin (sac) is extensively used as a non-caloric sweeting agent [6], and forms [M(sac) 2 -(H 2 0) 4 ]-2H 2 0 complexes, where M is a divalent metal ion, such as Fe 2+ , Co 2+ , Ni 2+ , Cu 2+ , and Zn 2+ [7], Single crystal X-ray analyses of these complexes reveal that they are isostructural and crystallize in the monoclinic space group P2j/c [7]. All the metal ions have octahedral geometry, surrounded by four water molecules and two saccharinate anions, (C 7 H 4 N0 3 S)~, by breaking a N-H bond, in the trans positions.…”

Section: Introductionmentioning

confidence: 99%

EPR Studies of Cu²⁺ Doped Zinc Saccharin, [Zn(sac)₂·(H₂0)₄ ]·2H₂0 Single Crystals

Kartal

Karabulut

Köksal

et al. 2000

Zeitschrift Für Naturforschung A

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The EPR spectra of Cu 2+ in zinc saccharin crystalline powder and single crystals have been recorded at room temperature. The angular variation of the spectra indicates the substitution of the host Zn 2+ with Cu 2+ . Two magnetically inequivalent sites for Cu 2+ have been observed. The spectra were fitted with a rhombic spin-Hamiltonian, and the ground state wave function of the complex has been constructed.

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“…The hyperfine structure of copper is of interest as being the first to be discovered in the solid state by EPR method. Using paramagnetic ion as an impurity probe, one can study the behavior of paramagnetic ions and estimate the site symmetry of the ion present in the lattice [10][11][12][13]. The substitution of a divalent impurity ion in monovalent lattice has been subject by many researchers [14,15].…”

Section: Introductionmentioning

confidence: 99%

EPR studies of Cu(II) doped glycine lithium sulphate single crystals – a case of low hyperfine coupling constant

Selvakumar

Natarajan

Rao

et al. 2008

Cryst. Res. Technol.

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In order to rationalize the low hyperfine value for the parallel component of copper nucleus, another system with lithium as host has been investigated using Electron Paramagnetic Resonance (EPR) technique. Single crystal EPR studies have been carried out at 300 K on Cu(II) doped glycine lithium sulphate system. Angular variation of hyperfine structure lines in the three orthogonal planes show the presence of two sites which are magnetically inequivalent but chemically equivalent with g and A values as: g xx = 2.084, g yy = 2.057, g zz = 2.311 and A xx = 8.96 mT, A yy = 3.26 mT, A zz = 15.95 mT respectively. The impurity entered the lattice interstitially. The admixture and molecular coefficients are evaluated by collaborating EPR data with optical data.

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Structural and magnetic properties of a copper–amino acid salt: Copper (II) bis (α-amino isobutyrato)

Abstract: ESR and ENDOR studies on the structure of primary oxidation products in irradiated αamino acids

Cited by 32 publications

References 26 publications

Electron paramagnetic resonance study of ternary CuII compounds with glycine and phenanthroline

Electron paramagnetic resonance study of ternary CuII compounds with glycine and phenanthroline

EPR Studies of Cu²⁺ Doped Zinc Saccharin, [Zn(sac)₂·(H₂0)₄ ]·2H₂0 Single Crystals

EPR studies of Cu(II) doped glycine lithium sulphate single crystals – a case of low hyperfine coupling constant

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Structural and magnetic properties of a copper–amino acid salt: Copper (II) bis (α-amino isobutyrato)

Abstract: ESR and ENDOR studies on the structure of primary oxidation products in irradiated αamino acids

Cited by 32 publications

References 26 publications

Electron paramagnetic resonance study of ternary CuII compounds with glycine and phenanthroline

Electron paramagnetic resonance study of ternary CuII compounds with glycine and phenanthroline

EPR Studies of Cu2+ Doped Zinc Saccharin, [Zn(sac)2·(H20)4 ]·2H20 Single Crystals

EPR studies of Cu(II) doped glycine lithium sulphate single crystals – a case of low hyperfine coupling constant

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EPR Studies of Cu²⁺ Doped Zinc Saccharin, [Zn(sac)₂·(H₂0)₄ ]·2H₂0 Single Crystals