Marc Fourmigué

Publications (59)302.62 Total impact

• Article: Variable Magnetic Interactions between S = 1/2 Cation Radical Salts of Functionalizable Electron-Rich Dithiolene and Diselenolene Cp(2)Mo Complexes.

  Talia Bsaibess, Michel Guerro, Yann Le Gal, Daad Sarraf, Nathalie Bellec, Marc Fourmigué, Frédéric Barrière, Vincent Dorcet, Thierry Guizouarn, Thierry Roisnel, Dominique Lorcy
  [show abstract] [hide abstract]
  ABSTRACT: A series of Cp(2)Mo(dithiolene) and Cp(2)Mo(diselenolene) complexes containing N-alkyl-1,3-thiazoline-2-thione-4,5-dithiolate ligand (R-thiazdt, R = Me, Et, CH(2)CH(2)OH) and N-alkyl-1,3-thiazoline-2-thione-4,5-diselenolate ligand (R-thiazds, R = Me, Et) have been synthesized. These heteroleptic molybdenum complexes have been characterized by electrochemistry, spectroelectrochemistry, and single crystal X-ray diffraction. They act as very good electron donor complexes with a first oxidation potential 200 mV lower than in the prototypical Cp(2)Mo(dmit) complex and exhibit almost planar MoS(2)C(2) (or MoSe(2)C(2)) metallacycles. All five complexes formed charge transfer salts with a weak (TCNQ) and a strong acceptor (TCNQF(4)), affording ten different charge-transfer salts, all with 1:1 stoichiometry. Crystal structure determinations show that the S/Se substitution in the metallacycle systematically affords isostructural salts, while the Cp(2)Mo(R-thiazdt) complexes with R equals ethyl or CH(2)CH(2)OH can adopt different structures, depending on the involvement of the hydroxyl group into intra- or intermolecular hydrogen bonding interactions. Magnetic susceptibility data of the salts are correlated with their structural organization, demonstrating that a face-to-face organization of the Me-thiazdt (or Me-thiazds) ligand favors a strong antiferromagnetic interaction, while the bulkier R = Et or R = CH(2)CH(2)OH substituents can completely suppress such intermolecular interactions, with the added contribution of hydrogen bonding to the solid state organization.
  Inorganic Chemistry 01/2013; · 4.60 Impact Factor
• Source

  Available from: Kim R Dunbar

  Article: Crystal Structure of the Radical-Cation Salt (o-Me2TTF)I3 with Close Intermolecular Sulfur Contacts

  Eric W. Reinheimer, Marc Fourmigué, Kim R. Dunbar
  [show abstract] [hide abstract]
  ABSTRACT: AbstractThe synthesis and crystal structure of the organic radical-cation salt (o-Me2TTF)I3 is described. The salt crystallizes in the monoclinic space group P2 1 /n with a=10.927(2) Å, b=11.904(2) Å, c=12.660(2) Å, β=115.174(5)°. The bond length of the central C=C bond in o-Me2TTF is 1.401(1) Å, indicating an approximate oxidation state of +1 for the o-Me2TTF radical cation. Graphical AbstractThe X-ray crystallographic structure of the radical cation salt (o-Me2TTF)I3 has been determined and its structural properties and synthetic preparation are discussed.
  Journal of Chemical Crystallography 04/2012; 39(10):735-739. · 0.57 Impact Factor
• Article: Near-infrared chiro-optical effects in metallogels.

  Sisir Debnath, Jean-Francois Bergamini, Franck Artzner, Cristelle Mériadec, Franck Camerel, Marc Fourmigué
  [show abstract] [hide abstract]
  ABSTRACT: A series of novel metallogelators containing near-IR nickel-bis(dithiolene) absorbers were rationally designed and synthesized. Robust gel networks are formed by right handed helical 1D-nanofibers which generate strong and remarkable chiro-optical effects in the near-infrared region.
  Chemical Communications 12/2011; 48(17):2283-5. · 6.17 Impact Factor
• Article: Paramagnetic dithiolene complexes as metallo-ligands: ether/thioether coordination.

  Alessia Famengo, Dalice Pinero, Olivier Jeannin, Thierry Guizouarn, Marc Fourmigué
  [show abstract] [hide abstract]
  ABSTRACT: The secondary coordination ability of a paramagnetic nickel dithiolene complex, bearing an ether coordinating function within a nine-membered flexible ring, has been demonstrated in its [NiCl(DMF)(2)](+) complex, through coordination by both ether and thioether functions, allowing for a ferromagnetic interaction between both paramagnetic entities.
  Dalton Transactions 12/2011; 41(5):1441-3. · 3.84 Impact Factor
• Article: Syntheses, crystal structures, transport properties and first-principles electronic structure study of the (tTTF)2X (X=Br, I) low-dimensional antiferromagnets.

  Marc Fourmigué, Eric W Reinheimer, Ali Assaf, Olivier Jeannin, Ali Saad, Pascale Auban-Senzier, Pere Alemany, Antonio Rodríguez-Fortea, Enric Canadell
  [show abstract] [hide abstract]
  ABSTRACT: An efficient synthetic procedure for the preparation of unsymmetrically substituted tetrathiafulvalene (TTF) donors has been used to obtain the trimethylene-tetrathiafulvalene (tTTF) donor with high purity. Good quality crystals of the two (tTTF)(2)X (X = Br, I) salts have been obtained by electrocrystallization. The two salts are isomorphous and contain tTTF layers which are built from (tTTF)(2) dimeric units. Both systems are low-dimensional antiferromagnets with the highest Néel temperatures for TTF based radical cation salts: ≈ 35 K (Br salt) and ≈43 K (I salt). The resistivity is found to substantially decrease with pressure although both salts still have activated conductivity at 25 kbar. First-principles Density Functional Theory (DFT) calculations have been used to investigate the relative strength of the three different types of magnetic interactions in the tTTF layers as well as the potential magnetic ground states. These calculations successfully predict the nature of the ground state and suggest a possible correlation between structural details and Néel temperatures for the bromine and iodine salts. Remarkably, the calculated antiferromagnetic ground state can be predicted from the nesting properties of the Fermi surface for the hypothetical Pauli paramagnetic metallic state.
  Inorganic Chemistry 03/2011; 50(9):4171-81. · 4.60 Impact Factor
• Article: Involvement of weak CH···X hydrogen bonds in metal‐to‐semiconductor regime change in one‐dimensional organic conductors (o‐DMTTF)2X (X = Cl, Br, and I): combined IR and Raman studies

  Damian Jankowski, Roman Świetlik, Eric W. Reinheimer, Marc Fourmigué
  Journal of Raman Spectroscopy 02/2011; 42(7):1518 - 1527. · 3.09 Impact Factor
• Article: Structural distortions upon oxidation in heteroleptic [Cp(2)W(dmit)] tungsten dithiolene complex: combined structural, spectroscopic, and magnetic studies.

  Eric W Reinheimer, Iwona Olejniczak, Andrzej Łapiński, Roman Swietlik, Olivier Jeannin, Marc Fourmigué
  [show abstract] [hide abstract]
  ABSTRACT: Four different cation radical salts are obtained upon electrocrystallization of [Cp(2)W(dmit)] (dmit = 1,3-dithiole-2-thione-4,5-dithiolato) in the presence of the BF(4)(-), PF(6)(-), Br(-), and [Au(CN)(2)](-) anions. In these formally d(1) cations, the WS(2)C(2) metallacycle is folded along the S···S hinge to different extents in the four salts, an illustration of the noninnocent character of the dithiolate ligand. Structural characteristics and the charge distribution on atoms, for neutral and ionized complexes with various folding angles, were calculated using DFT methods, together with the normal vibrational modes and theoretical Raman spectra. Raman spectra of neutral complex [Cp(2)W(dmit)] and its salts formed with BF(4)(-), AsF(6)(-), PF(6)(-), Br(-), and [Au(CN)(2)](-) anions were measured using the red excitation (λ = 632.8 nm). A correlation between the folding angle of the metallacycle and the Raman spectroscopic properties is analyzed. The bands attributed to the C═C and C-S stretching modes shift toward higher and lower frequencies by about 0.3-0.4 cm(-1) deg(-1), respectively. The solid state structural and magnetic properties of the three salts are analyzed and compared with those of the corresponding molybdenum complexes. Temperature dependence of the magnetic susceptibility shows the presence of one-dimensional antiferromagnetic interactions in the BF(4)(-), PF(6)(-), and [Au(CN)(2)](-) salts, while an antiferromagnetic ground state is identified in the Br(-) salt below T(Néel) = 7 K. Interactions are systematically weaker in the tungsten salts than in the isostructural molybdenum analogs, a consequence of the decreased spin density on the dithiolene ligand in the tungsten complexes.
  Inorganic Chemistry 09/2010; 49(21):9777-87. · 4.60 Impact Factor
• Article: Persistent mixed-valence [(TTF)2]+* dyad of a chiral bis(binaphthol)-tetrathiafulvalene (TTF) derivative.

  Ali Saad, Frédéric Barrière, Eric Levillain, Nicolas Vanthuyne, Olivier Jeannin, Marc Fourmigué
  [show abstract] [hide abstract]
  ABSTRACT: Mixed-valence dyadic [(TTF)(2)](+*) (TTF=tetrathiafulvalene) species--the elementary building blocks of organic conductors--are usually too weakly associated to be observed in solution, unless covalently bound in dimers or physically constrained into a cage structure. We demonstrate here that a novel chiral tetrathiafulvalene functionalised with two 1,1'-binaphthol units (1) is able to associate in solution into persistent mixed-valence [(TTF)(2)](+*) dyadic moieties through a stereospecific recognition pattern. This redox active molecule exhibits different electrochemical and spectroscopic responses, as enantiopure RR, SS or meso isomers, a rare example of a chiral system in which different diastereoisomers do not exhibit the same electrochemical features, with a selective formation of the mixed-valence species in the enantiopure (RR)-1 or (SS)-1 isomers only, whereas the meso form does not show this association ability. A rationale for the selective self-association of the RR and SS enantiomers upon oxidation is provided, based on the different molecular geometries and accessibility of the TTF core toward the formation of the mixed-valence species.
  Chemistry 07/2010; 16(27):8020-8. · 5.93 Impact Factor
• Article: Combining halogen bonding and chirality in a two-dimensional organic metal (EDT-TTF-I2)2(D-camphorsulfonate).H2O.

  Mariya Brezgunova, Kyung-Soon Shin, Pascale Auban-Senzier, Olivier Jeannin, Marc Fourmigué
  [show abstract] [hide abstract]
  ABSTRACT: A chiral organic conductor with metallic conductivity has been obtained by electrocrystallisation of a diiodotetrathiafulvalene derivative and enantiopure D-camphorsulfonate anion, associated in the solid state by halogen bonding interactions.
  Chemical Communications 06/2010; 46(22):3926-8. · 6.17 Impact Factor
• Article: Redox multifunctionality in a series of Pt(II) dithiolene complexes of a tetrathiafulvalene-based diphosphine ligand.

  Su-Kyung Lee, Kyong-Soon Shin, Dong-Youn Noh, Olivier Jeannin, Frédéric Barrière, Jean-François Bergamini, Marc Fourmigué
  [show abstract] [hide abstract]
  ABSTRACT: The redox-active and chelating diphosphine, 3,4-dimethyl-3',4'-bis(diphenylphosphino)-tetrathiafulvalene, denoted as P2, is engaged in a series of platinum complexes, [(P2)Pt(dithiolene)], with different dithiolate ligands, such as 1,2-benzenedithiolate (bdt), 1,3-dithiole-2-thione-4,5-dithiolate (dmit), and 5,6-dihydro-1,4-dithiin-2,3-dithiolate (dddt). The complexes are structurally characterized by X-ray diffraction, together with a model compound derived from bis(diphenylphosphino)ethane, namely, [(dppe)Pt(dddt)]. Four successive reversible electron-transfer processes are found for the [(P2)Pt(dddt)] complex, associated with the two covalently linked but electronically uncoupled electrophores, that is, the TTF core and the platinum dithiolene moiety. The assignments of the different redox processes to either one or the other electrophore is made thanks to the electrochemical properties of the model compound [(dppe)Pt(dddt)] lacking the TTF redox core, and with the help of theoretical calculations (DFT) to understand the nature and energy of the frontier orbitals of the [(P2)Pt(dithiolene)] complexes in their different oxidation states. The first oxidation of the highly electron-rich [(P2)Pt(dddt)] complex can be unambiguously assigned to the redox process affecting the Pt(dddt) moiety rather than the TTF core, a rare example in the coordination chemistry of tetrathiafulvalenes acting as ligands.
  Chemistry - An Asian Journal 12/2009; 5(1):169-76. · 4.50 Impact Factor
• Article: Order versus disorder in chiral tetrathiafulvalene-oxazoline radical-cation salts: structural and theoretical investigations and physical properties.

  Augustin M Madalan, Céline Réthoré, Marc Fourmigué, Enric Canadell, Elsa B Lopes, Manuel Almeida, Pascale Auban-Senzier, Narcis Avarvari
  [show abstract] [hide abstract]
  ABSTRACT: Electrocrystallization experiments with the chiral ethylenedithio-tetrathiafulvalene-methyl-oxazoline (EDT-TTF-OX) donors (R)-, (S)-, and (rac)-1 have provided two series of mixed-valence salts with the PF(6) (-) and [Au(CN)(2)](-) anions. Within each series the cell parameters are the same for the three R, S, and rac compounds, except for the space group, which is centrosymmetric triclinic P$\bar 1$ for the racemic forms and noncentrosymmetric P1 for the enantiopure salts. In the racemic salt [(rac)-1](2)PF(6) the two enantiomers crystallize disordered on the same crystallographic site with a site occupational factor of 0.6:0.4, whereas this type of disorder is not possible in the enantiopure salts. Both s-cis and s-trans conformations, when taking into account the mutual orientation of the TTF and oxazoline moieties, are present in this first series. In sharp contrast, in the series of salts [1](2)[Au(CN)(2)], only the s-trans conformation is observed with no structural disorder. Theoretical calculations at the DFT level of theory revealed a very small energy difference between the two stable planar s-cis and s-trans conformations, which are both energy minima in either neutral or oxidized states. Single-crystal conductivity measurements showed metallic-like behavior for all the salts down to 220-250 K with a smooth increase in resistivity at lower temperatures. The conductivity at room temperature is 5 S cm(-1) for [(rac)-1](2)PF(6), in which disorder was observed, whereas for [(R)-1](2)PF(6) and [(S)-1](2)PF(6) the average value is around 100 S cm(-1). In the second series of salts the conductivity at room temperature is 125-130 S cm(-1) for [(rac)-1](2)[Au(CN)(2)] and [(R)-1](2)[Au(CN)(2)]. Extended Hückel band structure calculations revealed identical features for the three salts of the [1](2)[Au(CN)(2)] series and are consistent with the electronic structures of quasi-one-dimensional conductors.
  Chemistry 11/2009; 16(2):528-37. · 5.93 Impact Factor
• Article: Chiral, Neutral, and Paramagnetic Gold Dithiolene Complexes Derived from Camphorquinone

  Romain Perochon, Cyril Poriel, Olivier Jeannin, Lidia Piekara-Sady, Marc Fourmigué
  Berichte der deutschen chemischen Gesellschaft 10/2009; 2009(35):5413 - 5421. · 2.94 Impact Factor
• Article: Flexibility of paramagnetic (d1) organometallic dithiolene complex [Cp2Mo(dmit)]+• studied by Raman spectroscopy

  Roman Świetlik, Andrzej Łapiński, Marc Fourmigué, Kyuya Yakushi
  Journal of Raman Spectroscopy 08/2009; 40(12):2092 - 2098. · 3.09 Impact Factor
• Article: Amphiphilic paramagnetic neutral gold dithiolene complexes.

  Romain Perochon, Lydia Piekara-Sady, Witold Jurga, Rodolphe Clérac, Marc Fourmigué
  [show abstract] [hide abstract]
  ABSTRACT: The sulfiding of benzils with P(4)S(10) in 1,3-dimethyl-2-imidazolidinone (DMI) as solvent allows for a direct synthesis of neutral radical, gold dithiolene complexes based on 1,2-bis-(4-alkoxy-phenyl)ethylene-1,2-dithiolate ligands with n-butyl, n-octyl and n-dodecyl chains. The three neutral and soluble complexes Au-OC(4), Au-OC(8) and Au-OC(12) exhibit a near infrared (NIR) absorption band around 1.5 mum and EPR characteristics which confirm a strong delocalization of the spin density on the electron-rich dithiolene ligands. X-Ray crystal structures of Au-OC(4) and Au-OC(12) are compared with those of the corresponding nickel complexes. They are characterised by segregation of the alkyl chains into layered structures with a stacking of the radical complexes into alternated spin chains, confirmed by the temperature dependence of the magnetic susceptibility which attests for antiferromagnetic interactions and a singlet ground state. Observations under polarising microscope and DSC experiments do not reveal a thermotropic behaviour for Au-OC(12).
  Dalton Transactions 05/2009; · 3.84 Impact Factor
• Article: [M(III)(dmit)2](-)-coordinated Mn(III) salen-type dimers (M(III) = Ni(III), Au(III); dmit2- = 1,3-dithiol-2-thione-4,5-dithiolate): design of single-component conducting single-molecule magnet-based materials.

  Hiroki Hiraga, Hitoshi Miyasaka, Rodolphe Clérac, Marc Fourmigué, Masahiro Yamashita
  [show abstract] [hide abstract]
  ABSTRACT: Four linear-type tetranuclear complexes, [Mn(5-Rsaltmen){M(dmit)(2)}](2) (R = MeO, M = Ni, 1a; M = Au, 1b; R = Me, M = Ni, 2a; M = Au, 2b), were synthesized and structurally characterized (5-Rsaltmen(2-) = N,N '-(1,1,2,2-tetramethylethylene)-bis(5-Rsalicylideneiminate), dmit(2-) = 1,3-dithiol-2-thione-4,5-dithiolate). These compounds crystallize in the same triclinic P1 space group (Z = 1) and have a similar molecular structure with a bridging array of [M-(dmit)-Mn-(O(Ph))(2)-Mn-(dmit)-M] and a packing feature where the respective sets of 1a/1b and 2a/2b are isomorphous. Intermolecular pi-pi/S...S contacts are observed between the coordinating [M(dmit)(2)](-) moieties to form zigzag stair-like columns along the a axis direction. Huckel calculations revealed a strong intermolecular dimerization within the [Ni(dmit)(2)](-) column that makes them magnetically silent even at room temperature. Nevertheless, 1a and 2a with M = Ni behave as semiconductors with sigma(r.t.) = 7 x 10(-4) S x cm(-1) and E(a) = 182 meV for 1a and sigma(r.t.) = 1 x 10(-4) S x cm(-1) and E(a) = 292 meV for 2a, while 1b and 2b with M = Au are insulators. As a result of the strong dimerization of the [Ni(dmit)(2)](-) anions, the magnetic properties of 1a are essentially identical to those of 1b and 2b, which can be described as isolated Mn(III) dimers, acting as single-molecule magnets (SMM). Meanwhile, the magnetic properties of 2a are dominated by the intermolecular Mn...Mn antiferromagnetic interactions via the singlet [Ni(dmit)(2)](2)(2-) dimer (J(Mn...Mn)/k(B) = -2.85 K), inducing a long-range antiferromagnetic order at T(N) = 6.4 K. The present systems are unique materials made of neutral single-component complexes that exhibit two major solid-state properties, that is, electrical conductivity and magnetism, varied as semiconductor/SMM for 1a, insulator/SMM for 1b and 2b, and semiconductor/antiferromagnet for 2a by tuning metal center and partial structural modification.
  Inorganic Chemistry 05/2009; 48(7):2887-98. · 4.60 Impact Factor
• Article: Redox bifunctionality in a Pt(ii) dithiolene complex of a tetrathiafulvalene diphosphine ligand.

  Kyong-Soon Shin, Younjung Jung, Su-Kyung Lee, Marc Fourmigué, Frédéric Barrière, Jean-François Bergamini, Dong-Youn Noh
  [show abstract] [hide abstract]
  ABSTRACT: The Pt(ii) dithiolene complex of a tetrathiafulvalene diphosphine ligand exhibits two reversible redox systems at close potentials, localized on the weakly interacting TTF (tetrathiafulvalene) and Pt(dmit) moieties.
  Dalton Transactions 12/2008; · 3.84 Impact Factor
• Source

  Available from: itn.pt

  Article: Ferromagnetic interactions in heterobimetallic chains formed through the secondary coordination of dithiolene complexes.

  Olivier Jeannin, Rodolphe Clérac, Thomas Cauchy, Marc Fourmigué
  [show abstract] [hide abstract]
  ABSTRACT: A novel paramagnetic ( S = 1/2) copper dithiolene complex based on the tfadt ligand (tfadt: 3-trifluoromethyl-acrylonitrile-2,3-dithiolate) is prepared as its n-Bu 4N (+) salt and crystallized with [Ni(cyclam)] (2+) into infinite, one-dimensional chains through CN...Ni interactions, avoiding any direct (antiferromagnetic) overlap between the dithiolene complexes. An unprecedented ferromagnetic interaction within the heterobimetallic chains between the S = 1/2 [Cu(tfadt) 2] (2-) and the S = 1 [Ni(cyclam)] (2+) tectons is observed, despite the fact that the SOMOs of both [Cu(tfadt) 2] (2-) (with d x (2) - y (2) symmetry) and [Ni(cyclam)] (2+) (with d x (2) - y (2) and d z (2) symmetry) have the same e g symmetry. The experimental exchange interaction deduced from the fit of the magnetic susceptibility ( J exp/ k B = +5.0 K) was confirmed by theoretical calculations ( J calc/ k B = +7.3 K), and a rationale is given for the presence of an intrachain ferromagnetic interaction.
  Inorganic Chemistry 11/2008; 47(22):10656-61. · 4.60 Impact Factor
• Article: Anionic layered networks reconstructed from [Cd(SCN)3]infinity(-) chains in pseudo one-dimensional conducting salts of halogenated tetrathiafulvalenes.

  Marc Fourmigué, Pascale Auban-Senzier
  [show abstract] [hide abstract]
  ABSTRACT: The electrocrystallization of diiodo- and dibromo-ethylenedithiotetrathiafuvalene (EDT-TTFI2 and EDT-TTFBr2) in the presence of the polymeric 1D [Et4N][Cd(SCN)3] as an electrolyte affords two different salts, formulated as [EDT-TTF-I2]4[Cd3(NCS)8] x CH3CN x H2O (1) and [EDT-TTF-Br2]10[Cd5(SCN)14] x 2 TCE (2), characterized by a two-dimensional segregation of the partially oxidized donor molecules and the polymeric anionic network incorporating embedded solvent molecules. Both salts exhibit a partial charge transfer, that is, rho = 0.5 in 1 and an unconventional rho = 0.4 in 2. They behave as semiconductors with sigma RT = 0.67 and 33 S cm(-1) and activation energies of 330 and 370 K for 1 and 2, respectively. Compared with a 1:3 Cd/SCN ratio of the starting electrolyte, the reconstructed, thiocyanate (SCN)-deficient motifs [Cd3(NCS)8](2-) and [Cd5(SCN)14](4-) organize into layered hollow structures with cavities filled by solvent molecules, halogen-bonded to the halogenated TTF molecules, through a C(TTF)-I...N[triple bond]C-CH3 interaction in 1, through a type II C(TTF)-Br...Cl-C(TCE) halogen/halogen interaction in 2. Band structure and Fermi surface calculations for the two salts indicate a two-dimensional character, while the semiconducting properties of the salts are attributed to an efficient nesting of the hidden 1D Fermi surfaces.
  Inorganic Chemistry 11/2008; 47(21):9979-86. · 4.60 Impact Factor
• Source

  Available from: Kim R Dunbar

  Article: A series of strongly one-dimensional organic metals with strictly uniform stacks: (o-DMTTF)2X (X = Cl, Br, I).

  Marc Fourmigué, Eric W Reinheimer, Kim R Dunbar, Pascale Auban-Senzier, Claude Pasquier, Claude Coulon
  [show abstract] [hide abstract]
  ABSTRACT: The electrocrystallization of o-dimethyl-tetrathiafulvalene in the presence of halide anions affords 2:1 salts formulated as [o-DMTTF]2 X, (X = Cl, Br, I). The three salts are isomorphous, crystallizing in the tetragonal system, space group I42d, with the halide anion on the -4 site and the o-DMTTF molecule along a two-fold axis, forming strictly uniform stacks along c, and is further stabilized by C-H...X hydrogen bonds. Detailed physical investigations were performed on the bromide salt. It exhibits a metallic behaviour down to T(MI) = 50 K, while application of pressure moves the metal insulator transition to 39 K at 7.9 kbar. Band-structure calculations indicate a strong one-dimensional character, also confirmed by the anisotropy ratio of the conductivity, sigma / sigma = 500, as determined by two independent methods (four-contact, low-frequency transport measurements and analysis of the anisotropy of the Dysonian EPR line). The singular temperature dependence of the g tensor and the EPR line width at the phase transition suggests charge ordering.
  Dalton Transactions 10/2008; · 3.84 Impact Factor
• Article: Trinuclear Mo3S7 clusters coordinated to dithiolate or diselenolate ligands and their use in the preparation of magnetic single component molecular conductors.

  Rosa Llusar, Sonia Triguero, Victor Polo, Cristian Vicent, Carlos J Gómez-García, Olivier Jeannin, Marc Fourmigué
  [show abstract] [hide abstract]
  ABSTRACT: A general route for the preparation of a series of dianionic Mo3S7 cluster complexes bearing dithiolate or diselenolate ligands, namely, [Mo3S7L3](2-) (where L = tfd (bis(trifluoromethyl)-1,2-dithiolate) (4(2-)), bdt (1,2-benzenedithiolate) (5(2-)), dmid (1,3-dithia-2-one-4,5-dithiolate) (6(2-)), and dsit (1,3-dithia-2-thione-4,5-diselenolate) (7(2-))) is reported by direct reaction of [Mo3S7Br6](2-) and (n-Bu)2Sn(dithiolate). The redox properties, molecular structure, and electronic structure (BP86/VTZP) of the 4(2-) to 7(2-) clusters have also been investigated. The HOMO orbital in all complexes is delocalized over the ligand and the Mo3S7 cluster core. Ligand contributions to the HOMO range from 61.67% for 4(2-) to 82.07% for 7(2-), which would allow fine-tuning of the electronic and magnetic properties. These dianionic clusters present small energy gaps between the HOMO and HOMO-1 orbitals (0.277-0.104 eV). Complexes 6(2-) and 7(2-) are oxidized to the neutral state to afford microcrystalline or amorphous fine powders that exhibit semiconducting behavior and present antiferromagnetic exchange interactions. These compounds are new examples of the still rare single-component conductors based on cluster magnetic units.
  Inorganic Chemistry 10/2008; 47(20):9400-9. · 4.60 Impact Factor