Jacques Bonvoisin | Université de Toulouse III Paul Sabatier (original) (raw)
Papers by Jacques Bonvoisin
We have performed measurements of the magnetic susceptibility of NaV2O5 between 2 and 400 K. The ... more We have performed measurements of the magnetic susceptibility of NaV2O5 between 2 and 400 K. The high temperature part is typical of spin 1/2 chains with a nearest–neighbour antiferromagnetic exchange integral of 530 K. We develop a model for the susceptibility of a system with finite chains to account for the low temperature part of the data, which cannot be fitted by a standard Curie-Weiss term. These results suggest that the next nearest–neighbour exchange integral J2 in CaV4O9 should be of the order of 500 K because, like J in NaV2O5, it corresponds to corner sharing VO5 pyramids. PACS Nos: 71.10.+x,75.10.-b,71.30.+h,72.15.Nj 1 The report by Taniguchi et al [1] of a spin gap behaviour in the quasi-two dimensional system CaV4O9 has triggered an intensive theoretical activity aimed at understanding the origin of this gap [2–8]. The emerging picture is that there is no spin gap in the model with only exchange integrals J1 between nearest neighbours [5,6,8], and that there is a spin...
Journal of Molecular Structure
The Journal of Physical Chemistry C
Two novel copper β-diketonato complexes with halogen atoms are synthesized. The length of complex... more Two novel copper β-diketonato complexes with halogen atoms are synthesized. The length of complex arms is slightly different. Scanning tunneling microscopy shows that the two complexes self-assemble into porous two-dimensional (2D) nanoarchitectures at the solid–liquid interface on graphite. These arrangements are however stabilized by the formation of two different halogen synthons between neighboring molecules. These synthons are composed of four or two type-II halogen bonds. These observations reveal that a tiny modification of complex design can drastically affect the structure of 2D halogen-bonded nanoarchitectures.
Chirality, May 1, 2018
The charged, electroactive bipyridine-helicene-ruthenium(III) complex [4] ,PF has been prepared f... more The charged, electroactive bipyridine-helicene-ruthenium(III) complex [4] ,PF has been prepared from 3-(2-pyridyl)-4-aza[6]helicene and a Ru-bis-(β-diketonato)-bis-acetonitrile precursor (β-diketonato: 2,2,6,6-tetramethyl-3,5-heptanedionato). Its chiroptical properties (electronic circular dichroism and optical rotation) were studied both experimentally and theoretically and suggest the presence of 2 diastereoisomers, namely (P,Δ)- and (P,Λ)-[4] ,PF (denoted jointly as (P,Δ*)-[4] ,PF ) and their mirror-images (M,Λ)- and (M,Δ)-[4] ,PF ((M,Δ*)-[4] ,PF ). The electrochemical reduction of (P,Δ*)-[4] ,PF to neutral complex (P,Δ*)-4 was performed and revealed strong changes in the UV-vis and electronic circular dichroism spectra. A reversible redox-triggered chiroptical switching process was then achieved.
Inorganic chemistry, Jan 17, 2017
Five tris(β-diketonato) complexes of ruthenium(III), chromium(III), and cobalt(III) [Ru(Buacac)3 ... more Five tris(β-diketonato) complexes of ruthenium(III), chromium(III), and cobalt(III) [Ru(Buacac)3 (1), Ru(Oacac)3 (2), Cr(Buacac)3 (3), Cr(Oacac)3 (4), and Co(Buacac)3 (5), where Buacac = 3-butylpentane-2,4-dionato and Oacac = 3-octylpentane-2,4-dionato] with a chiral propeller-like structure have been prepared. Ligands and complexes syntheses are presented together with characterization of the compounds by (1)H and (13)C NMR spectroscopy, mass spectrometry, IR, UV-vis, electronic circular dichroism (ECD) spectroscopy, electrochemistry studies, and first-principles calculations. The crystal structures of 1 and 5 have also been obtained and analyzed. A comparison of the (1)H NMR spectra of diamagnetic (ligands and 5) and paramagnetic (1 and 2) species is presented. Optical resolution of the five complexes has been achieved for the first time by supercritical fluid chromatography using a chiral column, giving rise to very high purity grades in all cases. ECD measurements and calculatio...
Http Www Theses Fr, 1989
Ce travail comporte trois parties. La premiere concerne l'etude magnetique de sites actifs de... more Ce travail comporte trois parties. La premiere concerne l'etude magnetique de sites actifs de metallobiomolecules en utilisant un susceptometre a SQUID. De par sa haute sensibilite, cet instrument permet de mesurer le signal paramagnetique de metalloproteines en solution. Nous avons developpe une methodologie de ces mesures. Nous avons applique cette technique a des proteines fer-soufre comme la proteine Sulfite Reductase ou la proteine Ferredoxine II et des proteines au fer a pont oxo comme la proteine Uteroferrine. Nous confrontons nos resultats a ceux obtenus par d'autres methodes. Dans la deuxieme partie de ce travail, nous exposons les proprietes magnetiques de complexes homo et heterobinucleaires presentant le motif suivant [M(III)(μ - O)(μ -CH3CO2)2M'(III)]2+ avec M,M'=Fe,Fe; Fe,Mn ; Fe,Cr; Mn,Mn; V,V. Nous envisageons ensuite la relation entre les phenomenes d'echange et la liaison metal-metal en nous appuyant sur notre etude experimentale d'un compose dinucleaire du Mn(IV) ou les ions sont pontes par trois ligands μ-oxo. Enfin, dans la derniere partie, nous examinons la spectroscopie de systemes polynucleaires a valence mixte au Mn(III) et Mn(IV) et elaborons differents modeles pour interpreter le spectre RPE multiligne observe pour l'etat S2 du site de degagement d'oxygene des plantes.
Cheminform, 2010
ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was e... more ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
Cheminform, 2010
ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was e... more ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
Related Article: Justine Cousin de Puymarcel, Christine Viala, Nicolas Ratel-Ramond, Jacques Bonv... more Related Article: Justine Cousin de Puymarcel, Christine Viala, Nicolas Ratel-Ramond, Jacques Bonvoisin|2017|CSD Communication|||
Journal of Solid State Chemistry, 1996
ABSTRACT
![Research paper thumbnail of ‘Layered hydrogenselenites’ II. Synthesis, structure studies and magnetic properties of a novel series of bimetallic hydrogenselenites: [Cu(HSeO3)2MCl2(H2O)4], M(II) = Mn, Co, Ni, Cu, Zn](https://attachments.academia-assets.com/53083630/thumbnails/1.jpg)
](Inorganica Chimica Acta, 1995
A new family of bimetallic hydrogenselenites [Cu(HSeO3)2CUxM1-1C12(H20)4], with M(H) =Mn, Co, Ni,... more A new family of bimetallic hydrogenselenites [Cu(HSeO3)2CUxM1-1C12(H20)4], with M(H) =Mn, Co, Ni, Cu, Zn and x depending mainly on the nature of the second cation M, has been prepared. The crystal structure of [ Cu (HSeO3)2MnC12 (H20)4 ] has been determined. It crystallizes in the orthorhombic system, space group Pnma, with a=9.125(2), b= 18.178(3), c=7.187(2) /~ and V= 1192.4(4) /~3, Z=4. This structure is three-dimensional but it may be described as a bidimensional structure made of layers, parallel to the (010) plane, which contain copper atoms and HSeO3-anions. The sheets are similar to those obtained for the [ Cu (HSeO3)2 ] compound. In this family, the sheets are interconnected by [ (CuxM 1 -x ) C12 (H20) 4 ] entities. Magnetic measurements reveal the occurrence of weak ferromagnetism at low temperature (T= ~ 10-20 K) for almost all compounds except [Cu(HSeO3)2]. A tentative explanation will be offered for this peculiar property.
![Research paper thumbnail of Synthesis, structure and magnetic measurement of a new layered copper hydrogenselenite: [Cu(HSeO3)2]·(NH4)Cl](https://attachments.academia-assets.com/53083631/thumbnails/1.jpg)
](Inorganica Chimica Acta, 1997
The crystal structure of a new compound of copper layered hydrogenselenite [Cu(HSeO 3 ) 2 ]P(NH 4... more The crystal structure of a new compound of copper layered hydrogenselenite [Cu(HSeO 3 ) 2 ]P(NH 4 )Cl has been determined. This compound crystallizes in the orthorhombic system, space group Pnma, with as8.975(2), bs12.118(2), cs7.265(1) Å , Zs4 and Vs790.1(2) Å 3 . This structure is mainly two-dimensional; copper atoms bridged by HSeO anions build layers parallel to (010). The sheets are similar to y 3 those obtained for Cu(HSeO 3 ) 2 . The copper atom presents a classical environment, elongated tetragonal bipyramid, with four oxygen atoms belonging to four HSeO groups and two chloride ions. The chloride ions bridge two copper atoms belonging to neighboring layers. The y 3 ammonium ions, localized into the interlayer space, are related to the lattice by hydrogen bonds. Magnetic measurements of this compound reveal the occurrence of weak ferromagnetism at low temperature.
![Research paper thumbnail of UHV-STM Investigations and Numerical Calculations of a Ruthenium β-Diketonato Complex with Protected Ethynyl Ligand: [Ru(dbm) 2 (acac-TIPSA)]](https://attachments.academia-assets.com/39752169/thumbnails/1.jpg)
](The Journal of Physical Chemistry C, 2012
The quest of molecular electronic devices necessitates addressing model molecular systems as star... more The quest of molecular electronic devices necessitates addressing model molecular systems as starting points. Among the targeted functions, electron transfer between specific moieties inside a molecule is expected to play a fundamental role for ultimate logical gates. Here we propose a coordination complex exhibiting two inorganic centers (Ru and Si) that constitutes a step toward a more complex architecture. Starting from the complex 1 [Ru(dbm) 2 (acac-I)] (dbm = dibenzoylmethanate ion, acac-I = 3-iodo-2,4-pentanedionate ion), the complex 2 [Ru(dbm) 2 (acac-TIPSA)] (acac-TIPSA = 3-(triisopropylsilyl)acetylene-2,4-pentanedionate ion) was obtained through Sonogashira cross coupling reaction under classical conditions. This complex 2 was characterized by elemental analysis, IR, 1 H NMR, 13 C NMR, UV−vis, cyclic voltammetry, mass spectroscopy as well as X-ray single-crystal diffraction. It crystallized with empirical formula of C 46 H 49 O 6 Ru 1 Si 1 in a monoclinic crystal system and space group P2 1 /c with a = 21.077(3) Å, b = 9.5130(7) Å, c = 21.8790(12) Å, β = 94.125(7)°, V = 4375.5(7) Å 3 and Z = 4. Additionally, scanning tunneling microscopy measurements at liquid He temperature and in an ultrahigh vacuum (UHV-STM) were conducted on complex 2 on a Ag(111) surface. The STM images, supported by adsorption and STM image calculations, demonstrate that the molecules exist in two stable forms when adsorbed on the metallic surface.
European Journal of Inorganic Chemistry, 2011
A series of ruthenium tris(β-diketonate) complexes was investigated by using electrochemistry, UV... more A series of ruthenium tris(β-diketonate) complexes was investigated by using electrochemistry, UV/Vis spectroscopy, 1 H NMR and 13 C NMR spectroscopy and FAB mass spectroscopy. Several new mononuclear mixed-ligand ruthenium(III) complexes were prepared: with three dibenzoylmethanate ions {[Ru(dbm) 3 ] (1)}, one or two acetylacetonate ions (2,4-pentanedionate, acac) {[Ru(dbm) 2 (acac)] (2), [Ru(dbm)(acac) 2 ] (3)}, two acetonitrile ligands {[Ru(dbm) 2 -(CH 3 CN) 2 ][CF 3 SO 3 ] (4)} or a functionalized acetylacetonate ion {[Ru(dbm) 2 (acac-I)] (5) (acac-I = 3-iodo-2,4-pentanedionate ion), [Ru(dbm) 2 (acac-Br)] (6) (acac-Br = 3-bromo-2,4-pent-Eur.
Advances in Atom and Single Molecule Machines, 2012
A monomolecular four center low spin paramagnetic organometallic complex is proposed and theoreti... more A monomolecular four center low spin paramagnetic organometallic complex is proposed and theoretically studied to work as a controlled quantum swap molecule logic gate. The magnetic super-exchange interaction between the 2 intramolecular qubits depends on the oxydation state of a third intermediate center itself controlled by an intervalence electron transfer process. A model system is build up using entangled spin qubits in the framework of an Heisenberg-Dirac-Van Vleck like spin Hamiltonian demonstrating the effective swapping operation of this complex.
Physical Review Letters, 2011
Scanning tunneling microscopy and dynamic force microscopy in the noncontact mode are used in com... more Scanning tunneling microscopy and dynamic force microscopy in the noncontact mode are used in combination to investigate the reversible switching between two stable states of a copper complex adsorbed on a NaCl bilayer grown on Cu(111). The molecular conformation in these two states is deduced from scanning tunneling microscopy imaging, while their charge is characterized by the direct measurement of the tip-molecule electrostatic force. These measurements demonstrate that the molecular bistability is achieved through a charge-induced rearrangement of the coordination sphere of the metal complex, qualifying this system as a new electromechanical single-molecular switch.
Journal of the American Chemical Society, 2007
Four new phenylcyanamido-bridge dinuclear ruthenium complexes [{Ru(tpy)(thd)}2(mu-L)] with tpy = ... more Four new phenylcyanamido-bridge dinuclear ruthenium complexes [{Ru(tpy)(thd)}2(mu-L)] with tpy = 2,2':6',2' '-terpyridine, thd = 2,2,6,6-tetramethyl-3,5-heptanedione and L = dcbp = 4,4'-dicyanamidobiphenyl; bcpa = bis(4-cyanamidophenyl)acetylene; bcpda = bis(4-cyanamidophenyl)diacetylene; bcpea = 9,10,-bis(4-cyanamidophenylethynyl)anthracene have been prepared and fully characterized. The mixed valent Ru(II)Ru(III) and homovalent paramagnetic Ru(III)Ru(III) forms of all the complexes were electrochemically generated and studied by UV-vis-NIR and EPR spectroscopy. Electronic communication was quantified by the electronic coupling parameter V(ab) extracted from intervalence measurements in the near IR area, and magnetic communication was quantified in terms of the exchange coupling constant J, accessible from the intensity of the EPR signal when varying the temperature. Exponential decays for both electronic and magnetic coupling versus intermetallic distance were obtained and discussed.
Inorganic Chemistry, 2006
The dicyanamidobenzene-bridge diruthenium complex [{Ru(tpy)(thd)}(2)(mu-dicyd)][PF(6)] ([3][PF(6)... more The dicyanamidobenzene-bridge diruthenium complex [{Ru(tpy)(thd)}(2)(mu-dicyd)][PF(6)] ([3][PF(6)]) (dicyd = 1,4-dicyanamidobenzene, tpy = 2,2':6',2' '-terpyridine, thd = 2,2,6,6-tetramethyl-3,5-heptanedione) and its mononuclear counterpart [Ru(tpy)(thd)(Ipcyd)] (2) [Ipcyd = 4-iodophenylcyanamide anion (Ipcyd(-))] were synthesized and fully characterized. Cyclic voltammetry of 3 showed the presence of four reversible one-electron redox couples. UV-vis-NIR spectroelectrochemistry and EPR spectroscopy of the electrogenerated paramagnetic intermediates were used to ascertain the oxidation-state distribution. The stable starting dinuclear complex 3(+) is found to be a ligand-centered anion radical as shown by EPR spectroscopy, magnetic susceptibility measurements, and DFT calculations. Oxidation of 3(+) to 3(2+) led to an EPR silent system due to substantial intramolecular antiferromagnetic interaction of the electron spins carried by the low spin ruthenium(III) atom and the bridging anion radical dicyanamido (dicyd(*)(-)), an observation which was supported by UV-vis-NIR, X-ray structure, and DFT calculations. Complex 3(3+) presented an EPR spectra consistent with a total effective spin S = (1)/(2) issued from an antiferromagnetic interaction of electron spins carried by two low spin ruthenium(III) atoms and the bridging anion radical dicyd(*)(-) in accordance with UV-vis-NIR. This study shows that the dicyanamidobenzene bridging ligand has indubitably a noninnocent behavior.
We have performed measurements of the magnetic susceptibility of NaV2O5 between 2 and 400 K. The ... more We have performed measurements of the magnetic susceptibility of NaV2O5 between 2 and 400 K. The high temperature part is typical of spin 1/2 chains with a nearest–neighbour antiferromagnetic exchange integral of 530 K. We develop a model for the susceptibility of a system with finite chains to account for the low temperature part of the data, which cannot be fitted by a standard Curie-Weiss term. These results suggest that the next nearest–neighbour exchange integral J2 in CaV4O9 should be of the order of 500 K because, like J in NaV2O5, it corresponds to corner sharing VO5 pyramids. PACS Nos: 71.10.+x,75.10.-b,71.30.+h,72.15.Nj 1 The report by Taniguchi et al [1] of a spin gap behaviour in the quasi-two dimensional system CaV4O9 has triggered an intensive theoretical activity aimed at understanding the origin of this gap [2–8]. The emerging picture is that there is no spin gap in the model with only exchange integrals J1 between nearest neighbours [5,6,8], and that there is a spin...
Journal of Molecular Structure
The Journal of Physical Chemistry C
Two novel copper β-diketonato complexes with halogen atoms are synthesized. The length of complex... more Two novel copper β-diketonato complexes with halogen atoms are synthesized. The length of complex arms is slightly different. Scanning tunneling microscopy shows that the two complexes self-assemble into porous two-dimensional (2D) nanoarchitectures at the solid–liquid interface on graphite. These arrangements are however stabilized by the formation of two different halogen synthons between neighboring molecules. These synthons are composed of four or two type-II halogen bonds. These observations reveal that a tiny modification of complex design can drastically affect the structure of 2D halogen-bonded nanoarchitectures.
Chirality, May 1, 2018
The charged, electroactive bipyridine-helicene-ruthenium(III) complex [4] ,PF has been prepared f... more The charged, electroactive bipyridine-helicene-ruthenium(III) complex [4] ,PF has been prepared from 3-(2-pyridyl)-4-aza[6]helicene and a Ru-bis-(β-diketonato)-bis-acetonitrile precursor (β-diketonato: 2,2,6,6-tetramethyl-3,5-heptanedionato). Its chiroptical properties (electronic circular dichroism and optical rotation) were studied both experimentally and theoretically and suggest the presence of 2 diastereoisomers, namely (P,Δ)- and (P,Λ)-[4] ,PF (denoted jointly as (P,Δ*)-[4] ,PF ) and their mirror-images (M,Λ)- and (M,Δ)-[4] ,PF ((M,Δ*)-[4] ,PF ). The electrochemical reduction of (P,Δ*)-[4] ,PF to neutral complex (P,Δ*)-4 was performed and revealed strong changes in the UV-vis and electronic circular dichroism spectra. A reversible redox-triggered chiroptical switching process was then achieved.
Inorganic chemistry, Jan 17, 2017
Five tris(β-diketonato) complexes of ruthenium(III), chromium(III), and cobalt(III) [Ru(Buacac)3 ... more Five tris(β-diketonato) complexes of ruthenium(III), chromium(III), and cobalt(III) [Ru(Buacac)3 (1), Ru(Oacac)3 (2), Cr(Buacac)3 (3), Cr(Oacac)3 (4), and Co(Buacac)3 (5), where Buacac = 3-butylpentane-2,4-dionato and Oacac = 3-octylpentane-2,4-dionato] with a chiral propeller-like structure have been prepared. Ligands and complexes syntheses are presented together with characterization of the compounds by (1)H and (13)C NMR spectroscopy, mass spectrometry, IR, UV-vis, electronic circular dichroism (ECD) spectroscopy, electrochemistry studies, and first-principles calculations. The crystal structures of 1 and 5 have also been obtained and analyzed. A comparison of the (1)H NMR spectra of diamagnetic (ligands and 5) and paramagnetic (1 and 2) species is presented. Optical resolution of the five complexes has been achieved for the first time by supercritical fluid chromatography using a chiral column, giving rise to very high purity grades in all cases. ECD measurements and calculatio...
Http Www Theses Fr, 1989
Ce travail comporte trois parties. La premiere concerne l'etude magnetique de sites actifs de... more Ce travail comporte trois parties. La premiere concerne l'etude magnetique de sites actifs de metallobiomolecules en utilisant un susceptometre a SQUID. De par sa haute sensibilite, cet instrument permet de mesurer le signal paramagnetique de metalloproteines en solution. Nous avons developpe une methodologie de ces mesures. Nous avons applique cette technique a des proteines fer-soufre comme la proteine Sulfite Reductase ou la proteine Ferredoxine II et des proteines au fer a pont oxo comme la proteine Uteroferrine. Nous confrontons nos resultats a ceux obtenus par d'autres methodes. Dans la deuxieme partie de ce travail, nous exposons les proprietes magnetiques de complexes homo et heterobinucleaires presentant le motif suivant [M(III)(μ - O)(μ -CH3CO2)2M'(III)]2+ avec M,M'=Fe,Fe; Fe,Mn ; Fe,Cr; Mn,Mn; V,V. Nous envisageons ensuite la relation entre les phenomenes d'echange et la liaison metal-metal en nous appuyant sur notre etude experimentale d'un compose dinucleaire du Mn(IV) ou les ions sont pontes par trois ligands μ-oxo. Enfin, dans la derniere partie, nous examinons la spectroscopie de systemes polynucleaires a valence mixte au Mn(III) et Mn(IV) et elaborons differents modeles pour interpreter le spectre RPE multiligne observe pour l'etat S2 du site de degagement d'oxygene des plantes.
Cheminform, 2010
ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was e... more ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
Cheminform, 2010
ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was e... more ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
Related Article: Justine Cousin de Puymarcel, Christine Viala, Nicolas Ratel-Ramond, Jacques Bonv... more Related Article: Justine Cousin de Puymarcel, Christine Viala, Nicolas Ratel-Ramond, Jacques Bonvoisin|2017|CSD Communication|||
Journal of Solid State Chemistry, 1996
ABSTRACT
Inorganica Chimica Acta, 1995
A new family of bimetallic hydrogenselenites [Cu(HSeO3)2CUxM1-1C12(H20)4], with M(H) =Mn, Co, Ni,... more A new family of bimetallic hydrogenselenites [Cu(HSeO3)2CUxM1-1C12(H20)4], with M(H) =Mn, Co, Ni, Cu, Zn and x depending mainly on the nature of the second cation M, has been prepared. The crystal structure of [ Cu (HSeO3)2MnC12 (H20)4 ] has been determined. It crystallizes in the orthorhombic system, space group Pnma, with a=9.125(2), b= 18.178(3), c=7.187(2) /~ and V= 1192.4(4) /~3, Z=4. This structure is three-dimensional but it may be described as a bidimensional structure made of layers, parallel to the (010) plane, which contain copper atoms and HSeO3-anions. The sheets are similar to those obtained for the [ Cu (HSeO3)2 ] compound. In this family, the sheets are interconnected by [ (CuxM 1 -x ) C12 (H20) 4 ] entities. Magnetic measurements reveal the occurrence of weak ferromagnetism at low temperature (T= ~ 10-20 K) for almost all compounds except [Cu(HSeO3)2]. A tentative explanation will be offered for this peculiar property.
Inorganica Chimica Acta, 1997
The crystal structure of a new compound of copper layered hydrogenselenite [Cu(HSeO 3 ) 2 ]P(NH 4... more The crystal structure of a new compound of copper layered hydrogenselenite [Cu(HSeO 3 ) 2 ]P(NH 4 )Cl has been determined. This compound crystallizes in the orthorhombic system, space group Pnma, with as8.975(2), bs12.118(2), cs7.265(1) Å , Zs4 and Vs790.1(2) Å 3 . This structure is mainly two-dimensional; copper atoms bridged by HSeO anions build layers parallel to (010). The sheets are similar to y 3 those obtained for Cu(HSeO 3 ) 2 . The copper atom presents a classical environment, elongated tetragonal bipyramid, with four oxygen atoms belonging to four HSeO groups and two chloride ions. The chloride ions bridge two copper atoms belonging to neighboring layers. The y 3 ammonium ions, localized into the interlayer space, are related to the lattice by hydrogen bonds. Magnetic measurements of this compound reveal the occurrence of weak ferromagnetism at low temperature.
The Journal of Physical Chemistry C, 2012
The quest of molecular electronic devices necessitates addressing model molecular systems as star... more The quest of molecular electronic devices necessitates addressing model molecular systems as starting points. Among the targeted functions, electron transfer between specific moieties inside a molecule is expected to play a fundamental role for ultimate logical gates. Here we propose a coordination complex exhibiting two inorganic centers (Ru and Si) that constitutes a step toward a more complex architecture. Starting from the complex 1 [Ru(dbm) 2 (acac-I)] (dbm = dibenzoylmethanate ion, acac-I = 3-iodo-2,4-pentanedionate ion), the complex 2 [Ru(dbm) 2 (acac-TIPSA)] (acac-TIPSA = 3-(triisopropylsilyl)acetylene-2,4-pentanedionate ion) was obtained through Sonogashira cross coupling reaction under classical conditions. This complex 2 was characterized by elemental analysis, IR, 1 H NMR, 13 C NMR, UV−vis, cyclic voltammetry, mass spectroscopy as well as X-ray single-crystal diffraction. It crystallized with empirical formula of C 46 H 49 O 6 Ru 1 Si 1 in a monoclinic crystal system and space group P2 1 /c with a = 21.077(3) Å, b = 9.5130(7) Å, c = 21.8790(12) Å, β = 94.125(7)°, V = 4375.5(7) Å 3 and Z = 4. Additionally, scanning tunneling microscopy measurements at liquid He temperature and in an ultrahigh vacuum (UHV-STM) were conducted on complex 2 on a Ag(111) surface. The STM images, supported by adsorption and STM image calculations, demonstrate that the molecules exist in two stable forms when adsorbed on the metallic surface.
European Journal of Inorganic Chemistry, 2011
A series of ruthenium tris(β-diketonate) complexes was investigated by using electrochemistry, UV... more A series of ruthenium tris(β-diketonate) complexes was investigated by using electrochemistry, UV/Vis spectroscopy, 1 H NMR and 13 C NMR spectroscopy and FAB mass spectroscopy. Several new mononuclear mixed-ligand ruthenium(III) complexes were prepared: with three dibenzoylmethanate ions {[Ru(dbm) 3 ] (1)}, one or two acetylacetonate ions (2,4-pentanedionate, acac) {[Ru(dbm) 2 (acac)] (2), [Ru(dbm)(acac) 2 ] (3)}, two acetonitrile ligands {[Ru(dbm) 2 -(CH 3 CN) 2 ][CF 3 SO 3 ] (4)} or a functionalized acetylacetonate ion {[Ru(dbm) 2 (acac-I)] (5) (acac-I = 3-iodo-2,4-pentanedionate ion), [Ru(dbm) 2 (acac-Br)] (6) (acac-Br = 3-bromo-2,4-pent-Eur.
Advances in Atom and Single Molecule Machines, 2012
A monomolecular four center low spin paramagnetic organometallic complex is proposed and theoreti... more A monomolecular four center low spin paramagnetic organometallic complex is proposed and theoretically studied to work as a controlled quantum swap molecule logic gate. The magnetic super-exchange interaction between the 2 intramolecular qubits depends on the oxydation state of a third intermediate center itself controlled by an intervalence electron transfer process. A model system is build up using entangled spin qubits in the framework of an Heisenberg-Dirac-Van Vleck like spin Hamiltonian demonstrating the effective swapping operation of this complex.
Physical Review Letters, 2011
Scanning tunneling microscopy and dynamic force microscopy in the noncontact mode are used in com... more Scanning tunneling microscopy and dynamic force microscopy in the noncontact mode are used in combination to investigate the reversible switching between two stable states of a copper complex adsorbed on a NaCl bilayer grown on Cu(111). The molecular conformation in these two states is deduced from scanning tunneling microscopy imaging, while their charge is characterized by the direct measurement of the tip-molecule electrostatic force. These measurements demonstrate that the molecular bistability is achieved through a charge-induced rearrangement of the coordination sphere of the metal complex, qualifying this system as a new electromechanical single-molecular switch.
Journal of the American Chemical Society, 2007
Four new phenylcyanamido-bridge dinuclear ruthenium complexes [{Ru(tpy)(thd)}2(mu-L)] with tpy = ... more Four new phenylcyanamido-bridge dinuclear ruthenium complexes [{Ru(tpy)(thd)}2(mu-L)] with tpy = 2,2':6',2' '-terpyridine, thd = 2,2,6,6-tetramethyl-3,5-heptanedione and L = dcbp = 4,4'-dicyanamidobiphenyl; bcpa = bis(4-cyanamidophenyl)acetylene; bcpda = bis(4-cyanamidophenyl)diacetylene; bcpea = 9,10,-bis(4-cyanamidophenylethynyl)anthracene have been prepared and fully characterized. The mixed valent Ru(II)Ru(III) and homovalent paramagnetic Ru(III)Ru(III) forms of all the complexes were electrochemically generated and studied by UV-vis-NIR and EPR spectroscopy. Electronic communication was quantified by the electronic coupling parameter V(ab) extracted from intervalence measurements in the near IR area, and magnetic communication was quantified in terms of the exchange coupling constant J, accessible from the intensity of the EPR signal when varying the temperature. Exponential decays for both electronic and magnetic coupling versus intermetallic distance were obtained and discussed.
Inorganic Chemistry, 2006
The dicyanamidobenzene-bridge diruthenium complex [{Ru(tpy)(thd)}(2)(mu-dicyd)][PF(6)] ([3][PF(6)... more The dicyanamidobenzene-bridge diruthenium complex [{Ru(tpy)(thd)}(2)(mu-dicyd)][PF(6)] ([3][PF(6)]) (dicyd = 1,4-dicyanamidobenzene, tpy = 2,2':6',2' '-terpyridine, thd = 2,2,6,6-tetramethyl-3,5-heptanedione) and its mononuclear counterpart [Ru(tpy)(thd)(Ipcyd)] (2) [Ipcyd = 4-iodophenylcyanamide anion (Ipcyd(-))] were synthesized and fully characterized. Cyclic voltammetry of 3 showed the presence of four reversible one-electron redox couples. UV-vis-NIR spectroelectrochemistry and EPR spectroscopy of the electrogenerated paramagnetic intermediates were used to ascertain the oxidation-state distribution. The stable starting dinuclear complex 3(+) is found to be a ligand-centered anion radical as shown by EPR spectroscopy, magnetic susceptibility measurements, and DFT calculations. Oxidation of 3(+) to 3(2+) led to an EPR silent system due to substantial intramolecular antiferromagnetic interaction of the electron spins carried by the low spin ruthenium(III) atom and the bridging anion radical dicyanamido (dicyd(*)(-)), an observation which was supported by UV-vis-NIR, X-ray structure, and DFT calculations. Complex 3(3+) presented an EPR spectra consistent with a total effective spin S = (1)/(2) issued from an antiferromagnetic interaction of electron spins carried by two low spin ruthenium(III) atoms and the bridging anion radical dicyd(*)(-) in accordance with UV-vis-NIR. This study shows that the dicyanamidobenzene bridging ligand has indubitably a noninnocent behavior.