0000000000013775

AUTHOR

Luis Lezama

0000-0001-6183-2052

showing 13 related works from this author

X-ray crystal structure and electronic properties of chlorobis(mepirizole)copper(II) tetrafluoroborate (mepirizole = 4-methoxy-2-(5-methoxy-3-methyl-…

1997

Abstract The crystal structure of [Cu(mep)2Cl](BF4)[mep = 4-methoxy-2-(5-methoxy-3-methyl-1H-pyrazol-1-yl)-6-methylpyrimidine] has been determined by X-ray diffraction. The crystal structure is built up of [Cu(mep)2Cl]+ cations and BF4− anions. The structure of the cation involves a five-coordinated CuN4Cl chromophore, with a stereochemistry near to a compressed trigonal bypyramid (TBP) but with a significant degree of distortion towards the square pyramidal (SP) topology. The EPR spectrum is indicative of a mixed dz2/dx2 − y2 ground state for the copper(II) ions, in agreement with the structural data.

chemistry.chemical_elementCrystal structureChromophoreCopperSquare pyramidal molecular geometryIonlaw.inventionInorganic ChemistryCopper(II) tetrafluoroboratechemistry.chemical_compoundCrystallographychemistrylawMaterials ChemistryPhysical and Theoretical ChemistryGround stateElectron paramagnetic resonancePolyhedron
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A novel dinuclear manganese(II) compound incorporating two bis(imidazolyl) based ligands with single μ2-η1:η1-carboxylato bridges. Molecular and crys…

2014

Abstract This paper reports the synthesis, X-ray structure and magnetic characterization of [Mn 2 Cl(BIP) (HBIMAM)(H 2 O) 5 ]Cl 3 ·4H 2 O a novel dinuclear manganese(II) incorporating two related bis(imidazolyl)-based ligands, BIP (3,3-di(2-1 H -2-imidazolyl)propanoate) and BIMAM ( N -methyldi(1 H -2-imidazolyl)methanamine). The metal atoms in the dinuclear entity are bridged by a μ 2 -η 1 :η 1 carboxylate group (from the propionate arm of the BIP ligand) acting in an anti – anti coordination bridging mode, with an intramolecular Mn⋯Mn distance of 6.47 A. The coordination around the Mn(II) ions shows a distorted octahedral geometry for both MnClN 2 O 3 and MnN 2 O 4 chromophores. Between th…

LigandStereochemistryDimerCrystal structureMagnetic susceptibilityInorganic Chemistrychemistry.chemical_compoundCrystallographychemistryIntramolecular forceOctahedral molecular geometryMaterials ChemistryImidazoleCarboxylatePhysical and Theoretical ChemistryPolyhedron
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Exchange interactions through hydrogen-bond bridges. Crystal structure, spectroscopic characterisation and magnetic properties of the complex [{Cu(en…

1998

Abstract The structure and spectroscopic and magnetic properties of [{Cu(en)}2(μ-egta)]·4H2O (H4egta = 3,12-bis(carboxymethyl)-6–9-dio 3,12-diazatetradecanedioic acid) are described. The compound is built of centrosymmetric neutral dimeric {[Cu(en)}2(μ-egta)] entities linked through hydrogen bonds involving water molecules. -NH2 groups and -CO2 groups, affording a three-dimensional framework. The egta anion displays an opened-up structure acting as a bridging ligand between two copper atoms. The coordination geometry about the metal atoms can be viewed as 4 + 1 + 1 (CuN3OO′O″ chromophores). The EPR spectra are indicative of an essentially dv−v ground state for the copper(II) ions. Magnetic …

Hydrogen bondChemistryTriatomic moleculeInorganic chemistryBridging ligandCrystal structureMagnetic susceptibilitylaw.inventionInorganic ChemistryCrystallographylawMaterials ChemistryMoleculePhysical and Theoretical ChemistryElectron paramagnetic resonanceCoordination geometryInorganica Chimica Acta
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Structure, magnetic properties and nuclease activity of pyridine-2-carbaldehyde thiosemicarbazonecopper(II) complexes.

2008

New complexes of formulae [Cu(HL 2 )(H 2 O)(NO 3 )](NO 3 ) ( 1 ), [{Cu(L 1 )(tfa)} 2 ] ( 2 ), [{Cu(L 1 )} 2 (pz)](ClO 4 ) 2 ( 3 ) and {[{Cu(L 1 )} 2 (dca)](ClO 4 )} n ( 4 ), where HL 1  = pyridine-2-carbaldehyde thiosemicarbazone, HL 2  = pyridine-2-carbaldehyde 4 N -methylthiosemicarbazone, Htfa = trifluoroacetic acid (CF 3 COOH), pz = pyrazine (C 4 H 4 N 2 ) and dca = dicyanamide [N(CN) 2 ] − , have been synthesized and characterized. The crystal structures of these compounds are built up of monomers ( 1 ), dinuclear entities with the metal centers bridged through the non-thiosemicarbazone coligand ( 2 and 3 ) and 1D chains of dimers ( 4 ). In all the cases, square–pyramidal copper(II) io…

ThiosemicarbazonesNucleasebiologyChemistryPyridineschemistry.chemical_elementCrystal structureDNACrystallography X-RayBiochemistryMagnetic susceptibilityCopperInorganic ChemistryMetalCrystallographychemistry.chemical_compoundMagneticsMonomervisual_artbiology.proteinvisual_art.visual_art_mediumOrganometallic CompoundsAntiferromagnetismSemicarbazoneCopperJournal of inorganic biochemistry
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Revisiting the thiosemicarbazonecopper(II) reaction with glutathione. Activity against colorectal carcinoma cell lines.

2018

Thiosemicarbazones (TSCs), and their copper derivatives, have been extensively studied mainly due to the potential applications as antitumor compounds. A part of the biological activity of the TSC-CuII complexes rests on their reactivity against cell reductants, as glutathione (GSH). The present paper describes the structure of the [Cu(PTSC)(ONO2)]n compound (1) (HPTSC =pyridine-2-carbaldehyde thiosemicarbazone) and its spectroscopic and magnetic properties. ESI studies performed on the reaction of GSH with 1 and the analogous [{Cu (PTSC*)(ONO2)}2] derivative (2, HPTSC* =pyridine-2-carbaldehyde 4N-methylthiosemicarbazone) show the absence of peaks related with TSC-Cu-GSH species. However GS…

Aparato digestivo-EnfermedadesThiosemicarbazonesSpectrometry Mass Electrospray IonizationColorectal cancerColon carcinoma010402 general chemistryCrystallography X-RayThiosemicarbazone01 natural sciencesBiochemistryInorganic Chemistrychemistry.chemical_compoundColon carcinomaCell Line TumorSpectroscopy Fourier Transform InfraredmedicineHumansMolecular magnetismDigestive organs-DiseasesMolecular Structure010405 organic chemistryChemistryMyoglobinCytochromes cGlutathioneChemistry Inorganicmedicine.diseaseMolecular biologyGlutathioneQuímica inorgánica0104 chemical sciencesCell cultureDrug Screening Assays AntitumorColorectal NeoplasmsCopperJournal of inorganic biochemistry
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Networks based on hydrogen-bonds containing phosphorus anions and tris(3,5-dimethylpyrazolyl)borate nickel(II) moieties

2012

Abstract Five structural kinds of nickel hydrogen-bonded networks containing hydrotris(3,5-dimethylpyrazolyl)borate ligands (Tp∗) have been elucidated by X-ray diffraction, [Tp∗Ni(OH2)3][(p-NO2C6H4O)2PO2] (4), [Tp∗Ni(OH2)3][Me2PO2]·Me2P(O)OH (5), [Tp∗Ni(OH2)3][(nBuO)2PO2]·0.5H2O (6), [(Hpz)Tp∗Ni(OH2)2][(Ph)PO2OH] (7) and [Tp∗Ni(OH2)2(Me2PO2)] (8). The most relevant supramolecular feature of complexes 4–8 is all of them form coordination networks based on hydrogen bonds between water molecules and phosphate, phosphonate or phosphinate anions. These hydrogen bonds are formed within the monomer units in addition to connect monomers along the chains. Their behaviors in solution were investigate…

Hydrogen bondInorganic chemistrySupramolecular chemistrychemistry.chemical_elementNuclear magnetic resonance spectroscopyPhosphinatePhosphonateInorganic Chemistrychemistry.chemical_compoundNickelMonomerchemistryPolymer chemistryMaterials ChemistryMoleculePhysical and Theoretical ChemistryPolyhedron
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Dimetallic complexes derived from a novel dinucleating chelating symmetric triazole ligand; crystal structure, magnetic properties and ESR study of b…

1999

Reaction of 3,5-diacetylamino-1,2,4-triazole (Hdaat) with copper(II), nickel(II) and cobalt(II) salts yields dinuclear co-ordination compounds, which were spectroscopically characterized. The crystal and molecular structure of one of the compounds, bis[µ-3,5-diacetylamino-1,2,4-triazolato-O′,N 1,N 2,O″]bis[(nitrato)(aqua)copper(II)] 1, was determined by single-crystal X-ray diffraction. Complex 1 consists of dinuclear units with an inversion center at the midpoint of the Cu–Cu vector. The most remarkable feature of this structure is that the daat ligand forms a six-membered chelate ring [Cu–N3–C3–N1–C2–O1; Cua–N4–C4–N5–C5–O2], in contrast with the five-membered chelate rings always found in…

StereochemistryTriazolechemistry.chemical_elementGeneral ChemistryCrystal structureCopperMagnetic susceptibilitychemistry.chemical_compoundNickelCrystallographychemistryMoleculeAntiferromagnetismIsostructuralJournal of the Chemical Society, Dalton Transactions
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Copper(II) complexes of 1,4,5,8,9,12-hexaazatriphenylene with oxalate, squarate, perchlorate as auxiliary ligands or counter ion

2002

Abstract The crystal structures of [Cu(hat)(H2O)(ox)]·H2O (I), [Cu(hat)(H2O)3(sq)]·3H2O (II) and [Cu(hat)(H2O)2](ClO4)2·4H2O (III) have been determined from X-ray single crystal diffraction data (hat=1,4,5,8,9,12-hexaazatriphenylene, ox=oxalate, sq=squarate=dianion of 3,4-dihydroxy-cyclobut-3-ene-1,2-dione). Compound I crystallises in the triclinic system, space group P 1 with a=6.6626(10), b=9.2001(14), c=12.9954(19) A , α=103.301(15), β=91.414(21), γ=105.523(13)°, Z=2; compound II in the orthorhombic system, space group P212121 with a=6.9274(2), b=8.4327(3), c=34.0577(14) A , Z=4; and compound III in the monoclinic system, space group C2/c with a=22.6652(10), b=9.2220(10), c=16.1400(10) A…

Coordination sphereChemistryOrganic Chemistrychemistry.chemical_elementCrystal structureTriclinic crystal systemCopperOxalateSquare pyramidal molecular geometryAnalytical ChemistryInorganic Chemistrychemistry.chemical_compoundCrystallographyOctahedral molecular geometrySpectroscopyCoordination geometryJournal of Molecular Structure
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(1,3,4‐Oxadiazole)copper(II) Compounds: Dimensionality, Magnetism and Nuclease Activity

2009

The work presented here describes the synthesis of new copper(II) complexes derived from 2-amino-5-(pyridin-2-yl)-1,3,4-oxadiazole (L1) and 2-methylamino-5-(pyridin-2-yl)-1,3,4-oxadiazole (L2) which also incorporate azido (N3 -), thiocyanato (NCS-), cyanato (NCO-), dicyanamido [N(CN)2 -, dca] and malonato (C3H2O4 2-, mal) coligands. Structures of the [Cu(L2)(mal)(H2O)]·2H 2O(1), [{Cu(L2)(mal)}2] (2), [Cu(L 2)2-(NCS)2] (3), [Cu(L1)(NCS) 2]n (4) and [{Cu(L2)}2(dca) 2](ClO4)2·2H2O (5) compounds show the dependence of the dimensionality on parameters such as the type of oxadiazole and coligand utilised, solvents or reaction times. In this sense, 1 and 3 are mononuclear complexes, 2 contains cen…

NucleasebiologyChemistryMagnetismOxadiazoleMineralogychemistry.chemical_elementReflectivityCopperInorganic Chemistrychemistry.chemical_compoundCrystallographyDna cleavagebiology.proteinEuropean Journal of Inorganic Chemistry
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Chains and channels in polynuclear copper(II) complexes with 2,3-bis(2-pyridyl)pyrazine (dpp) as bridging ligand; syntheses, crystal structures and m…

2000

Abstract The preparation and crystal structures for three Cu(II) polynuclear, chain complexes with 2,3-bis(2-pyridyl)pyrazine (dpp) as bridging ligand are reported, [Cu(dpp)(H2O)2]n(NO3)2n·2n/3H2O (1), [Cu(dpp)(H2O)2]n(CF3SO3)2n (2), and [Cu(dpp)(H2O)2]n(BF4)2n·2nH2O (3). For the latter compound the crystal structure at four different temperatures have been studied. Variable-temperature magnetic susceptibility data and ESR measurements of 1–3 and of the related copper(II) chain [Cu(dpp)(H2O)2]n(ClO4)2n·2nH2O (4) (whose structure was previously reported) have been performed. Compounds 1 and 2 crystallize in the same trigonal space group, R 3 c; 3 is orthorhombic, space group Pbca. Complexes …

PyrazineBridging ligandCrystal structureMagnetic susceptibilityInorganic ChemistryCrystallographychemistry.chemical_compoundchemistryOctahedronOctahedral molecular geometryMaterials ChemistryOrthorhombic crystal systemPhysical and Theoretical ChemistryCoordination geometryInorganica Chimica Acta
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Defective dicubane-like tetranuclear nickel(II) cyanate and azide nanoscale magnets.

2010

Four tetrameric nickel(II) pseudohalide complexes have been synthesized and structurally, spectroscopically, and magnetically characterized. Compounds 1-3 are isostructural and exhibit the general formula [Ni(2)(dpk·OH)(dpk·CH(3)O)(L)(H(2)O)](2)A(2)·2H(2)O, where dpk = di-2-pyridylketone; L = N(3)(-), and A = ClO(4)(-) for 1, L = NCO(-) and A = ClO(4)(-) for 2, and L = NCO(-) and A = NO(3)(-) for 3. The formula for 4 is [Ni(4)(dpk·OH)(3) (dpk·CH(3)O)(2)(NCO)](BF(4))(2)·3H(2)O. The ligands dpk·OH(-) and dpk·CH(3)O(-) result from solvolysis and ulterior deprotonation of dpk in water and methanol, respectively. The four tetramers exhibit a dicubane-like core with two missing vertexes where the…

Stereochemistrychemistry.chemical_elementCyanateIonInorganic Chemistrychemistry.chemical_compoundCrystallographyNickelDeprotonationchemistryFerromagnetismSolvolysisAzidePhysical and Theoretical ChemistryIsostructuralInorganic chemistry
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CCDC 1424631: Experimental Crystal Structure Determination

2017

Related Article: Javier García-Tojal, Rubén Gil-García, Víctor Ivo Fouz, Gotzon Madariaga, Luis Lezama, María S. Galletero, Joaquín Borrás, Friederike I. Nollmann, Carlos García-Girón, Raquel Alcaraz, Mónica Cavia-Saiz, Pilar Muñiz, Òscar Palacios, Katia G. Samper, Teófilo Rojo|2018|J.Inorg.Biochem.|180|69|doi:10.1016/j.jinorgbio.2017.12.005

Space GroupCrystallographyCrystal Systemcatena-(bis(mu-N'-[(pyridin-2-yl)methylidene]carbamohydrazonothioiato)-bis(nitrato)-di-copper)Crystal StructureCell ParametersExperimental 3D Coordinates
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CCDC 946082: Experimental Crystal Structure Determination

2013

Related Article: Emilio Escriva, Luis Lezama, Lucia Soto, Amparo Sancho, Jose-Vicente Folgado and Carmen Ramirez de Arellano|2014|Polyhedron|68|319|doi:10.1016/j.poly.2013.11.008

Space GroupCrystallographyCrystal System(mu2-(33-bis(1H-Imidazol-2-yl)propanoato))-penta-aqua-chloro-(bis(1H-imidazol-2-yl)-N-methylmethanaminium)-di-manganese(ii) trichloride tetrahydrateCrystal StructureCell ParametersExperimental 3D Coordinates
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