The polynuclear manganese(II) complex of L-dihydroorotic acid has been synthesized and characteri... more The polynuclear manganese(II) complex of L-dihydroorotic acid has been synthesized and characterized by X-ray crystallography, UV-visible spectroscopy, and magnetic susceptibility measurements. Crystal data: triclinic, space group P1 bar , a = 4.7239(5) Å, b = 7.902(1) Å, c = 10.552(2) Å, α = 105.80(1)°, β = 98.864(7)°, γ = 104.69(1)°, V = 355.9(1) D 3, Z = 1, R = 0.035, Rw = 0.028. This complex consists of polymer chains of manganese atoms that are bound together via carboxylate bridges with a Mn . . .Mn distance in the chain of 4.724 D . The radical scavenging properties of the complex have been evaluated by ESR spectroscopy and cyclic voltammetry methods and compared to those of vitamin E and BHT (2,6-di-tert-butyl-4-methylphenol).Key words: orotic acid, L-dihydroorotic acid, manganese(II) complex, antioxidative properties.
Three new compounds of generalised formula [Cu(LIII)XY]·nH2O [LIII=pymep, terpy; X=I, N3; Y=I, NO... more Three new compounds of generalised formula [Cu(LIII)XY]·nH2O [LIII=pymep, terpy; X=I, N3; Y=I, NO3, PF6; n=0,1], pymep (C14H15N3)=N-(6methyl–2-pyridyl–methylene) -2-(2-pyridyl)-ethylamine and terpy (C15H11N3)=2,2′;6′,2″-terpyridine have been prepared by reaction in solution. Crystal data were determined by single-crystal methods. Powder diffraction data and densities determined by a flotation method are also presented.
Journal of the Chemical Society Dalton Transactions, 1993
... Crystal Structures of the Azidenitrate and Azidehexaf Iuoro-phosphate t Roberto Cortes,a M. K... more ... Crystal Structures of the Azidenitrate and Azidehexaf Iuoro-phosphate t Roberto Cortes,a M. Karmele Urtiaga,b Luis Lezama,a Jose lgnacio R. Larramendi,a M. Isabel Arriortuab and Teofilo Rojo"sa a Departamentos de Quimica lnorganica, Universidad de Pais Vasco, Aptdo. ...
Three tetrameric cobalt(II)-pseudohalide complexes have been structurally and magnetically charac... more Three tetrameric cobalt(II)-pseudohalide complexes have been structurally and magnetically characterized. Compounds 1 and 2 are isomorphous and exhibit the general formula [Co2(dpk-OH)(dpk-CH3O)(L)(H2O)]2A2-4H2O where dpk = di-2-pyridyl ketone, L = N3(-) and A = BF4(-) for 1, and L = NCO(-) and A = ClO4(-) for 2. The ligands dpk-OH(-) and dpk-CH3O(-) result from solvolysis and ulterior deprotonation of dpk in water and methanol, respectively. Both compounds exhibit cationic tetramers consisting of a dicubane-like core with two missing vertexes where the Co(II) ions are connected through end-on pseudohalide and oxo-bridges. A similar tetranuclear core has been found for 3 whose formula is [Co2(dpk-OH)(dpk-CH3O)(NCO)2]2. In this case, the tetramers are neutral and exhibit a terminal cyanate in place of the coordinated molecule of water for 1 and 2. The tetrameric units for 2 and 3 represent the first examples of any kind of cubanes exhibiting cyanate bridges as well as the first Co(II) compounds exhibiting intermetallic bridges through these pseudohalide groups. Measurements of the magnetic susceptibility indicated the presence of ferromagnetic Co(II)-Co(II) interactions in the three compounds.
Acta Crystallographica Section C Crystal Structure Communications, 1996
ABSTRACT The crystal structure of the title compound, di-mu-chlorobis{[N-(2-aminoethyl)-1,2-ethan... more ABSTRACT The crystal structure of the title compound, di-mu-chlorobis{[N-(2-aminoethyl)-1,2-ethanediamine-N,N',N'']-copper(II)} dinitrate, [Cu2Cl2(dien)(2)](NO3)(2) (dien is diethylenetriamine; C4H13N3), consists of chloride- bridged copper(II) dimers. Each copper ion is five-coordinate with geometry that is approximately square-pyramidal. Hydrogen bonding involving the three O atoms of the nitrate counteranions and the three H atoms of the amine groups of the organic ligand stabilizes the crystal packing.
ABSTRACT Designing new high-dimensional magnetic molecular systems built from coordination compou... more ABSTRACT Designing new high-dimensional magnetic molecular systems built from coordination compounds has recently been a point of attention for inorganic chemists. The variety of coordination chemistry provides the synthesizers with a useful tool to build magnetic molecular architectures interesting for their properties, which arise from the interaction among their subunits. Strategies based on the reaction of appropriate terminal and bridging ligands with paramagnetic metal ions allow the preparation of oligomeric species whose nuclearity and magnetic properties may, in any sense, be tailored (1). By using good superexchange bridging groups such as oxalate or cyanide, extended lattices of antiferromagnetic or ferrimagnetic systems which show magnetic order at low temperatures have been achieved (2,3). In this way, the azido ligand represents a good choice for the design of new magnetic systems. This ligand is able to give ferromagnetic exchange interactions (through its end-on (EO) coordination mode) and antiferromagnetic ones (through the end-to-end (EE)
ABSTRACT The combined use of bpm (2,2′-bipyrimidine) and dca (dicyanamide) has led to the prepara... more ABSTRACT The combined use of bpm (2,2′-bipyrimidine) and dca (dicyanamide) has led to the preparation of two compounds of general formula [M2bpm(dca)4]·nH2O. Compound 1 (M = Ni, n = 1) exhibits a 2D layered structure based on ladder-like moieties. These units, whose steps are bpm groups, extend through single dca bridges, the connection between distinct ladder-like units taking place through double dca bridges. Compound 2 (M = Zn, n = 0) consists of a 3D structure based on the same type of ladder-like moieties that are connected to another four on the plane perpendicular to the extension of the ladders.
The polynuclear manganese(II) complex of L-dihydroorotic acid has been synthesized and characteri... more The polynuclear manganese(II) complex of L-dihydroorotic acid has been synthesized and characterized by X-ray crystallography, UV-visible spectroscopy, and magnetic susceptibility measurements. Crystal data: triclinic, space group P1 bar , a = 4.7239(5) Å, b = 7.902(1) Å, c = 10.552(2) Å, α = 105.80(1)°, β = 98.864(7)°, γ = 104.69(1)°, V = 355.9(1) D 3, Z = 1, R = 0.035, Rw = 0.028. This complex consists of polymer chains of manganese atoms that are bound together via carboxylate bridges with a Mn . . .Mn distance in the chain of 4.724 D . The radical scavenging properties of the complex have been evaluated by ESR spectroscopy and cyclic voltammetry methods and compared to those of vitamin E and BHT (2,6-di-tert-butyl-4-methylphenol).Key words: orotic acid, L-dihydroorotic acid, manganese(II) complex, antioxidative properties.
Three new compounds of generalised formula [Cu(LIII)XY]·nH2O [LIII=pymep, terpy; X=I, N3; Y=I, NO... more Three new compounds of generalised formula [Cu(LIII)XY]·nH2O [LIII=pymep, terpy; X=I, N3; Y=I, NO3, PF6; n=0,1], pymep (C14H15N3)=N-(6methyl–2-pyridyl–methylene) -2-(2-pyridyl)-ethylamine and terpy (C15H11N3)=2,2′;6′,2″-terpyridine have been prepared by reaction in solution. Crystal data were determined by single-crystal methods. Powder diffraction data and densities determined by a flotation method are also presented.
Journal of the Chemical Society Dalton Transactions, 1993
... Crystal Structures of the Azidenitrate and Azidehexaf Iuoro-phosphate t Roberto Cortes,a M. K... more ... Crystal Structures of the Azidenitrate and Azidehexaf Iuoro-phosphate t Roberto Cortes,a M. Karmele Urtiaga,b Luis Lezama,a Jose lgnacio R. Larramendi,a M. Isabel Arriortuab and Teofilo Rojo"sa a Departamentos de Quimica lnorganica, Universidad de Pais Vasco, Aptdo. ...
Three tetrameric cobalt(II)-pseudohalide complexes have been structurally and magnetically charac... more Three tetrameric cobalt(II)-pseudohalide complexes have been structurally and magnetically characterized. Compounds 1 and 2 are isomorphous and exhibit the general formula [Co2(dpk-OH)(dpk-CH3O)(L)(H2O)]2A2-4H2O where dpk = di-2-pyridyl ketone, L = N3(-) and A = BF4(-) for 1, and L = NCO(-) and A = ClO4(-) for 2. The ligands dpk-OH(-) and dpk-CH3O(-) result from solvolysis and ulterior deprotonation of dpk in water and methanol, respectively. Both compounds exhibit cationic tetramers consisting of a dicubane-like core with two missing vertexes where the Co(II) ions are connected through end-on pseudohalide and oxo-bridges. A similar tetranuclear core has been found for 3 whose formula is [Co2(dpk-OH)(dpk-CH3O)(NCO)2]2. In this case, the tetramers are neutral and exhibit a terminal cyanate in place of the coordinated molecule of water for 1 and 2. The tetrameric units for 2 and 3 represent the first examples of any kind of cubanes exhibiting cyanate bridges as well as the first Co(II) compounds exhibiting intermetallic bridges through these pseudohalide groups. Measurements of the magnetic susceptibility indicated the presence of ferromagnetic Co(II)-Co(II) interactions in the three compounds.
Acta Crystallographica Section C Crystal Structure Communications, 1996
ABSTRACT The crystal structure of the title compound, di-mu-chlorobis{[N-(2-aminoethyl)-1,2-ethan... more ABSTRACT The crystal structure of the title compound, di-mu-chlorobis{[N-(2-aminoethyl)-1,2-ethanediamine-N,N',N'']-copper(II)} dinitrate, [Cu2Cl2(dien)(2)](NO3)(2) (dien is diethylenetriamine; C4H13N3), consists of chloride- bridged copper(II) dimers. Each copper ion is five-coordinate with geometry that is approximately square-pyramidal. Hydrogen bonding involving the three O atoms of the nitrate counteranions and the three H atoms of the amine groups of the organic ligand stabilizes the crystal packing.
ABSTRACT Designing new high-dimensional magnetic molecular systems built from coordination compou... more ABSTRACT Designing new high-dimensional magnetic molecular systems built from coordination compounds has recently been a point of attention for inorganic chemists. The variety of coordination chemistry provides the synthesizers with a useful tool to build magnetic molecular architectures interesting for their properties, which arise from the interaction among their subunits. Strategies based on the reaction of appropriate terminal and bridging ligands with paramagnetic metal ions allow the preparation of oligomeric species whose nuclearity and magnetic properties may, in any sense, be tailored (1). By using good superexchange bridging groups such as oxalate or cyanide, extended lattices of antiferromagnetic or ferrimagnetic systems which show magnetic order at low temperatures have been achieved (2,3). In this way, the azido ligand represents a good choice for the design of new magnetic systems. This ligand is able to give ferromagnetic exchange interactions (through its end-on (EO) coordination mode) and antiferromagnetic ones (through the end-to-end (EE)
ABSTRACT The combined use of bpm (2,2′-bipyrimidine) and dca (dicyanamide) has led to the prepara... more ABSTRACT The combined use of bpm (2,2′-bipyrimidine) and dca (dicyanamide) has led to the preparation of two compounds of general formula [M2bpm(dca)4]·nH2O. Compound 1 (M = Ni, n = 1) exhibits a 2D layered structure based on ladder-like moieties. These units, whose steps are bpm groups, extend through single dca bridges, the connection between distinct ladder-like units taking place through double dca bridges. Compound 2 (M = Zn, n = 0) consists of a 3D structure based on the same type of ladder-like moieties that are connected to another four on the plane perpendicular to the extension of the ladders.
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