0000000000033927

AUTHOR

Raúl Chiozzone

Unexpected magnetic topology in the heterobimetallic [ReIVBr4(μ-ox)CuII(bpy)2] compound

Abstract A novel oxalato-bridged rhenium(IV)-copper(II) compound, namely [ReIVBr4(μ-ox)CuII(bpy)2] (1), has been obtained by reacting (PPh4)2[ReBr4(ox)] with Cu(CF3SO3)2 and 2,2′-bpy in CH3CN, and its crystal structure determined by single-crystal X-ray diffraction. Intermolecular Br⋯Br interactions and nonbonding Cu⋯Br type contacts between the heterobimetallic dinuclear units lead to a two-dimensional supramolecular structure. Compound 1 behaves magnetically as a [ReIVCuII]2 tetranuclear species with weak antiferromagnetic interactions through the oxalato bridge and intermolecular Br⋯Br contacts.

research product

New family of thiocyanate-bridged Re(IV)-SCN-M(II) (M = Ni, Co, Fe, and Mn) heterobimetallic compounds: synthesis, crystal structure, and magnetic properties.

The heterobimetallic complexes of formula [(Me(2)phen)(2)M(μ-NCS)Re(NCS)(5)]·CH(3)CN [Me(2)phen = 2,9-dimethyl-1,10-phenanthroline and M = Ni (1), Co (2), Fe (3), and Mn (4)] have been prepared, and their crystal structures have been determined by X-ray diffraction on single crystals. Compounds 1-4 crystallize in the monoclinic C2/c space group, and their structure consists of neutral [(Me(2)phen)(2)M(μ-NCS)Re(NCS)(5)] heterodinuclear units with a Re-SCN-M bridge. Each Re(IV) ion in this series is six-coordinated with one sulfur and five nitrogen atoms from six thiocyanate groups building a somewhat distorted octahedral environment, whereas the M(II) metal ions are five-coordinated with fou…

research product

Structural and magnetic properties of polynuclear oximate copper complexes with different topologies

Abstract Two new copper(II) complexes containing the methyl(2-pyridyl)ketone oxime ligand (mpkoH) [Cu3(OH)(ClO4)2(mpko)3]·CH3OH (1) and [Cu(ClO4)(mpko)(mpkoH)]n (2) have been prepared from Cu(ClO4)2 and mpkoH in different metal-to-ligand molar ratios. In addition, the compound [Cu{(mpko)2BF2}(H2O)](BF4) (3) [(mpko)2BF2 is the fluoroboration product of the oxime] has been obtained when replacing Cu(ClO4)2 by Cu(BF4)2. Compound 1 is an isolated triangle with a {Cu3(µ3-OH)}5+ core, whereas 2 is a chain of CuII ions linked by anionic mpko− bridges. 1 exhibits strong antiferromagnetic competing interactions, as well as antisymmetric exchange. On the other hand, very weak ferromagnetic interactio…

research product

Synthesis, crystal structure and magnetic properties of a novel heterobimetallic rhenium(IV)-dysprosium(III) chain.

The use of the mononuclear rhenium(IV) precursor [ReBr5 (H2 pydc)](-) (H2 pydc=3,5-pyridinedicarboxylic acid) as a metalloligand towards dysprosium(III) afforded the first heterobimetallic Re(IV) -Dy(III) complex. Crystal structures and static and dynamic magnetic properties of both rhenium-containing species are reported herein. The 5d-4f compound shows an extended 1D structure and the AC magnetic measurements reveal frequency dependence at low temperature suggesting slow relaxation of the magnetization.

research product

Pentachloro(pyrazine)rhenate(iv) complex as precursor of heterobimetallic pyrazine-containing ReIV2MII (M = Ni, Cu) species: synthesis, crystal structures and magnetic properties

Three novel Re(IV) mononuclear complexes of formulae NBu4[ReC15(pyz)] (1), NH2Me2[ReCl5(pyz)] (2) and NH4[ReCl5(pyz)].0.75H2O (3), (pyz being pyrazine; NBu4+ = tetra-n-butylammonium cation, NH2Me2+ = dimethylammonium cation and NH4+ = ammonium cation), were synthesized by ligand substitution reaction from [ReCl6]2- anion and pyrazine in N,N-dimethylformamide (DMF). In addition, two new heterobimetallic compounds, the salt namely [ReCl5(pyz)]2[Ni(cyclam)](4) (cyclam = 1,4,8,11-tetraazacyclotetradecane) and the heterotrinuclear [{ReCl5(mu-pyz)}2Cu(DMF)4] (5) complex, were prepared by using as precursor 1 and 3, respectively. Compounds 1-5 were characterized by single-crystal X-ray diffraction…

research product

Synthesis, crystal structure, electrochemical and magnetic properties of (NBu4)[ReCl5(L)] with L=pyrimidine and pyridazine

Abstract Two novel rhenium(IV) compounds, namely (NBu4)[ReCl5(pym)] (1) and (NBu4)[ReCl5(pyd)] (2) (pym = pyrimidine, pyd = pyridazine and NBu4 = n-tetrabutylammonium cation), have been obtained by reaction of [ReCl6]2− and the diazine in dmf, and their crystal structures determined by single-crystal X-ray diffraction. The structures of 1 and 2 consist of [ReCl5(pym)]− or [ReCl5(pyd)]− anions and NBu 4 + cations held together by electrostatic forces and van der Waals interactions. Stacking interactions are present only in 1. The coordination sphere of the ReIV ion is defined by five chloride anions and one nitrogen atom of a monodentate diazine, resulting in a distorted octahedral environme…

research product

Synthesis, characterization and magnetic properties of mixed-valence iron complexes with 2-pyridyl oximes

Two new mixed-valence iron complexes with 2-pyridyl oximes, [Fe(mpko)3Fe(H2O)2(NO3)](NO3)·2H2O (1) (mpko− = methyl(2-pyridyl)ketone oximate) and [{Fe(dpko)3}2Fe](ClO4)·4H2O (2) (dpko− = bis(2-pyridyl)ketone oximate), have been prepared by reaction of FeIII with mpkoH in methanol (1) and FeII with dpkoH in methanol/water (2). Dinuclear FeII(low-spin)FeIII(high-spin) and trinuclear FeII(low-spin)FeIII(high-spin)FeII(low-spin) cations are present in the crystal structure of 1 and 2, respectively. Intermolecular hydrogen bonds in 1 lead to weak antiferromagnetic interactions between pairs of neighboring FeIII centers, which allows observation of single-ion zero-field splitting effects.

research product

Exchange coupling in a thiocyanato-bridged copper(II) chain: Computational approach to magnetostructural correlations

Abstract In this article we report the synthesis and magneto-structural characterization of two new copper(II) compounds with thiocyanato and methyl(2-pyridil) ketone oxime (mpkOH), namely [Cu(NCS)(mpkO)(mpkOH)] (1) and [Cu(µ-NCS)(NCS)(mpkOH)]n (2). Compound 1 is a mononuclear complex that crystallizes as discrete units. Conversely, compound 2 is a single equatorial-axial end-to-end thiocyanato bridged polymeric chain of Cu(II) with the oxime as a co-ligand. The coordination geometry around the Cu(II) centers is distorted square pyramidal for 1 and 2. The magnetic susceptibility data for 2 reveal weak intrachain antiferromagnetic coupling, with J value −0.74(3) cm−1 and g  = 2.10(1). The ap…

research product

Synthesis, Crystal Structure and Magnetic Properties of Heteropolynuclear Re IV M II Complexes Based on the Robust [ReCl 5 (pyzCOO)] 2– Unit (pyzCOO = 2‐pyrazinecarboxylate)

The syntheses, crystal structures and magnetic properties of four rhenium(IV) compounds of formulae NBu4[ReCl5(pyzCOOH)]·H2O (1), [ReCl5(µ-pyzCOO)M(dmphen)2]·2CH3CN [M = Ni (2) and Co (3)] and {[ReCl5(µ3-pyzCOO)]2Mn2(dmphen)3}n (4) (NBu4 = tetra-n-butylammonium cation, pyzCOOH = 2-pyrazinecarboxylic acid, dmphen = 2,9-dimethyl-1,10-phenanthroline) are reported herein. Compound 1 was obtained by the reaction of NBu4[ReCl5(dmf)] (dmf = dimethylformamide) with pyzCOOH in acetone, whereas the other complexes were obtained by the reaction of 1 with M(ClO4)2·6H2O [M = Ni (2), Co (3), Mn (4)] and dmphen in acetonitrile. Complex 1 is a mononuclear compound, 2 and 3 are neutral heterodinuclear compl…

research product

New hexanuclear FeIII clusters with the gem-diol hydrated form of di(2-pyridyl)ketone and carboxylato ligands: Crystal structures and magnetic properties

Abstract The hexanuclear compounds [Fe6O2Cl2{(py)2CO2}2(pyOH)2(pyCOO)2(ButCOO)6] (1) and [Fe6O2{(py)2CO2}2(pyCOO)4(ButCOO)6] (2) were obtained by condensation of the trinuclear μ3-oxo-centered iron(III) pivalate [Fe3O(ButCOO)6(H2O)3]+ in the presence of di(2-pyridyl)ketone [(py)2CO] in MeCN at ambient temperature. Both complexes contain an analogous core which can be described as two {Fe3O}7+ units joined by gem-diolato (py)2CO22− bridges. Variable-temperature magnetic susceptibility measurements in polycrystalline samples of 1 and 2 reveal strong antiferromagnetic couplings between the iron(III) ions leading to S = 0 ground states.

research product

Ligand substitution reactions of the [ReX6]2− (X=Cl, Br) anions. Synthesis and crystal structure of novel oxalato complexes of rhenium(IV)

Abstract The reaction of K2[ReX6] (X = Cl, Br) with oxalic acid and triethylamine in dimethylformamide solution yields the substituted complexes [ReX4(ox)]2− and cis-[ReX2(ox)2]2−, which can be obtained separately depending on the amount of added amine. The crystal structures of (PPh4)2[ReBr4(ox)], cis-(PPh4)2[ReBr2(ox)2] and cis-(AsPh4)2[ReCl2(ox)2] have been determined by single-crystal X-ray diffraction. The anionic complexes are octahedral with only slight distortions. The direct isolation of the pure complexes as well as the formation of only the cis isomers – without the presence of trans isomers and/or [Re(ox)3]2− – is probably due to the kinetic inertness of Re(IV)–X bonds, which in…

research product

Synthesis, structural and magnetic characterizations of new complexes of di-2,6-(2-pyridylcarbonyl)pyridine (pyCOpyCOpy) ligand

International audience; Using the di-2,6-(2-pyridylcarbonyl)pyridine ligand (L1) as starting framework, five new mononuclear complexes were obtained: [Cu(L1)(MeCN)(ClO4)2] (1) [Co(L1)(MeCN)(Br)2]*MeCN (2), [Fe(L1)2](BF4)2*MeOH*H2O (3), [Cr(L2a)Cl2]*2MeOH (where HL2a is (6-(hydroxyl(methoxy)(pyridin-2-yl)methyl)pyridin-2-yl)(pyridin-2-yl)methanone) (4) and one trinuclear [NiII3] complex, [Ni3(L2b)2(Bz)2(EtOH)2](ClO4)2*2EtOH (where HL2b is (6-(hydroxyl(ethoxy)(pyridin-2-yl)methyl)pyridin-2-yl)(pyridin-2-yl)methanone; Bz = benzoato) (5). Their structural and magnetic characterizations are herein reported. All the metal ions show octahedral coordination geometry, which is slightly unusual for t…

research product

Linkage isomerism in the metal complex hexa(thiocyanato)rhenate(IV): Synthesis and crystal structure of (NBu4)2[Re(NCS)6] and [Zn(NO3)(Me2phen)2]2[Re(NCS)5(SCN)]

Abstract The linkage isomers [Re(NCS)6]2− and [Re(NCS)5(SCN)]2− are obtained by the reaction of [ReBr6]2− with NCS− in dimethylformamide. Some differences in the chemical behavior allowed their separation and structural characterization in the form of (NBu4)2[Re(NCS)6] (1) and [Zn(NO3)(Me2phen)2]2[Re(NCS)5(SCN)] (2), respectively (Bu = n-C4H9 and Me2phen = 2,9-dimethyl-1,10-phenanthroline).

research product

A novel series of rhenium-bipyrimidine complexes: synthesis, crystal structure and electrochemical properties

Four novel rhenium complexes of formula [ReCl(4)(bpym)] (1), [ReBr(4)(bpym)] (2) PPh(4)[ReCl(4)(bpym)] (3) and NBu(4)[ReBr(4)(bpym)] (4) (bpym = 2,2'-bipyrimidine, PPh(4) = tetraphenylphosphonium cation and NBu(4) = tetrabutylammonium cation), have been synthesized and their crystal structures determined by single-crystal X-ray diffraction. The structures of 1 and 2 consist of [ReX(4)(bpym)] molecules held together by van der Waals forces. In both complexes the Re(iv) central atom is surrounded by four halide anions and two nitrogen atoms of a bpym bidentate ligand in a distorted octahedral environment. The structures of 3 and 4 consist of [ReX(4)(bpym)](-) anions and PPh(4)(+) () or NBu(4)…

research product

CCDC 1025298: Experimental Crystal Structure Determination

Related Article: Carolina Pejo, Guilherme P. Guedes, Miguel A. Novak, Nivaldo L. Speziali, Raúl Chiozzone, Miguel Julve, Francesc Lloret, Maria G. F. Vaz, Ricardo González|2015|Chem.-Eur.J.|21|8696|doi:10.1002/chem.201500168

research product

CCDC 1036871: Experimental Crystal Structure Determination

Related Article: Livia Arizaga, Ricardo González, Donatella Armentano, Giovanni De Munno, Miguel A. Novak, Francesc Lloret, Miguel Julve, Carlos Kremer and Raúl Chiozzone|2016|Eur.J.Inorg.Chem.||1835|doi:10.1002/ejic.201501487

research product

CCDC 1901540: Experimental Crystal Structure Determination

Related Article: Livia Arizaga, Walter Cañon-Mancisidor, Jorge S. Gancheff, Robert A. Burrow, Donatella Armentano, Francesc Lloret, Ricardo González, Carlos Kremer, Raúl Chiozzone|2019|Polyhedron|174|114165|doi:10.1016/j.poly.2019.114165

research product

CCDC 1025299: Experimental Crystal Structure Determination

Related Article: Carolina Pejo, Guilherme P. Guedes, Miguel A. Novak, Nivaldo L. Speziali, Raúl Chiozzone, Miguel Julve, Francesc Lloret, Maria G. F. Vaz, Ricardo González|2015|Chem.-Eur.J.|21|8696|doi:10.1002/chem.201500168

research product

CCDC 864757: Experimental Crystal Structure Determination

Related Article: Lorena Martínez, Carla Bazzicalupi, Antonio Bianchi, Francesc Lloret, Ricardo González, Carlos Kremer, Raúl Chiozzone|2017|Polyhedron|138|125|doi:10.1016/j.poly.2017.09.017

research product

CCDC 1538260: Experimental Crystal Structure Determination

Related Article: Lorena Martínez, Carla Bazzicalupi, Antonio Bianchi, Francesc Lloret, Ricardo González, Carlos Kremer, Raúl Chiozzone|2017|Polyhedron|138|125|doi:10.1016/j.poly.2017.09.017

research product

CCDC 1901541: Experimental Crystal Structure Determination

Related Article: Livia Arizaga, Walter Cañon-Mancisidor, Jorge S. Gancheff, Robert A. Burrow, Donatella Armentano, Francesc Lloret, Ricardo González, Carlos Kremer, Raúl Chiozzone|2019|Polyhedron|174|114165|doi:10.1016/j.poly.2019.114165

research product

CCDC 864758: Experimental Crystal Structure Determination

Related Article: Lorena Martínez, Nicolás Veiga, Carla Bazzicalupi, Antonio Bianchi, Francesc Lloret, Carlos Kremer, Raúl Chiozzone|2021|Polyhedron|208|115406|doi:10.1016/j.poly.2021.115406

research product

CCDC 1579781: Experimental Crystal Structure Determination

Related Article: Lorena Martínez, Livia Arizaga, Donatella Armentano, Francesc Lloret, Ricardo González, Carlos Kremer, Raúl Chiozzone|2018|J.Coord.Chem.|71|748|doi:10.1080/00958972.2018.1441405

research product

CCDC 1036873: Experimental Crystal Structure Determination

Related Article: Livia Arizaga, Ricardo González, Donatella Armentano, Giovanni De Munno, Miguel A. Novak, Francesc Lloret, Miguel Julve, Carlos Kremer and Raúl Chiozzone|2016|Eur.J.Inorg.Chem.||1835|doi:10.1002/ejic.201501487

research product

CCDC 1579780: Experimental Crystal Structure Determination

Related Article: Lorena Martínez, Livia Arizaga, Donatella Armentano, Francesc Lloret, Ricardo González, Carlos Kremer, Raúl Chiozzone|2018|J.Coord.Chem.|71|748|doi:10.1080/00958972.2018.1441405

research product

CCDC 1036872: Experimental Crystal Structure Determination

Related Article: Livia Arizaga, Ricardo González, Donatella Armentano, Giovanni De Munno, Miguel A. Novak, Francesc Lloret, Miguel Julve, Carlos Kremer and Raúl Chiozzone|2016|Eur.J.Inorg.Chem.||1835|doi:10.1002/ejic.201501487

research product

CCDC 1443218: Experimental Crystal Structure Determination

Related Article: Livia Arizaga, Ricardo González, Donatella Armentano, Giovanni De Munno, Miguel A. Novak, Francesc Lloret, Miguel Julve, Carlos Kremer and Raúl Chiozzone|2016|Eur.J.Inorg.Chem.||1835|doi:10.1002/ejic.201501487

research product

CCDC 2073463: Experimental Crystal Structure Determination

Related Article: Lorena Martínez, Nicolás Veiga, Carla Bazzicalupi, Antonio Bianchi, Francesc Lloret, Carlos Kremer, Raúl Chiozzone|2021|Polyhedron|208|115406|doi:10.1016/j.poly.2021.115406

research product