0000000001309475
AUTHOR
Françoise Conan
Unprecedented reactivity of a Schiff base ligand in the co-ordination sphere of copper(I) complex towards β-diketones. Synthesis and X-ray characterisation of a new copper(I) complex
International audience; The reactions of the copper(I) derivative [CuL(THF)(CH3CN)]PF6 (1), in which L is the di-imine/pyridine ligand 2,6-bis[1-(2,6-diisopropylphenylimino)ethyl]pyridine, with different β-diketones (2,4-pentanedione (acacH), 1,3-diphenyl-1,3-propanedione (dbm)) yielded the new Cu(I) salt [CuL′2]PF6 (2) (L′: 2-[acetyl]-6-[1-(2,6-diisopropylphenylimino)ethyl]pyridine). These reactions of β-diketones with a di-imine/pyridine ligand co-ordinated to a Cu(I) centre constitute the first example of a partial hydrolysis of such a Schiff base within the inner sphere of a Cu centre. Compound 2·acaH has been characterised by X-ray crystallography. © 2002 Elsevier Science B.V. All righ…
Coordination polymers based on bridging cyanocarbanions and bis-tridentate p-phenylenediamine ligands
Two new Cu(II) coordination polymeric neutral chains of formula [Cu 2 (1,4-tpbd)(μ-A) 2 (H 2 O) 2 ](A) 2 with A = tcnoet − ( 1 ) and tcnopr − ( 2 ) (1,4-tpbd = N,N,N′N′ -tetrakis(2-pyridylmethyl)benzene-1,4-diamine, tcnoet − = 1,1,3,3-tetracyano-2-ethoxypropenide and tcnopr − = 1,1,3,3-tetracyano-2-propoxypropenide) have been synthesized and characterized by infrared spectroscopy, X-ray diffraction and magnetic measurements. 1 and 2 show alternating chains where the 1,4-tpbd and the cyanocarbanion units (tcnoet − for 1 and tcnopr − for 2 ) alternate as bridging ligands. The molecular structure can be viewed as [Cu 2 (μ-tpbd)] 4+ dinuclear units (with Cu⋯Cu distances of 8.2233(3) for 1 …
Quadruply-bonded dimolybdenum compounds: Reactivity towards TCNE. Structural evidences for the 1-D polymer [Mo2(O2 CCF3)4(TCNE)]∞
cited By 3; International audience; Reaction of [Mo2(O2CR)4] (R = CF 3, 1) with TCNE in toluene affords the new compound [Mo2(O2CCF3)4 (TCNE)·6H5CH3 (2). The structure of 2 is built on [Mo2(O2 CCF3)4] fragments having the usual paddlewheel structure of 1 (Mo-Mo 2.1117(8) Å) and TCNE units. Each polynitrile moiety acts as a bridging ligand between two Mo2 fragments (Mo-N 2.875(4) Å) affording 1-D polymeric chains crossing in the crystal; the toluene molecules occupy the cavities between the chains. 13C NMR, IR and electrochemical data clearly show that formation of 2 does not involve electron density transfer from dimolybdenum fragment to the TCNE unit, which remains in 2 in its neutral stat…
Polypyridyl-based Cu(II) coordination polymers: Synthesis, structural and magnetic characterizations
Abstract New Cu(II) coordination polymeric neutral chains of formula [Cu 2 (1,4-tpbd)Cl 2 L 2 ] (1,4-tpbd = N,N,N ′ N ′-tetrakis(2-pyridylmethyl)benzene-1,4-diamine, L = 1,1,3,3-tetracyano-2-ethoxypropenide (tcnoet) − ( 1) or 1,1,3,3-tetracyano-2-propoxypropenide (tcnopr) − ( 2 )) have been synthesized and characterized by infrared spectroscopy, X-ray diffraction and magnetic measurements. The crystal structure determinations of 1 and 2 reveal in both cases a one-dimensional structure in which the 1,4-tpbd acts as a bis-chelating ligand and the two chloride anions as asymmetrical bridging ligands. The Cu⋯Cu distances through the bis-chelating 1,4-tpbd ligand (8.194(1) and 8.245(3) A for 1 …
Organocyanide coordination chemistry: Syntheses, structural characterisations and magnetic properties of copper (II) complexes with a di-imine/pyridine ligand
Abstract The reactions between the copper (II) salts [CuXL]PF6 (L: 2,6-[1-(2,6-diisopropylphenylimino)ethyl]pyridine) (X = Cl 1, X = Br 2) and LiTCNQ, in a DMF/water mixture, or Et3NH(TCNQ)2, in acetone, produced the new complexes [CuXL(TCNQ)] (X = Cl 3, X = Br 4). For both compounds, crystallographic studies have clearly evidenced the existence of dimeric complexes [{CuClL}(TCNQ)]2 owing to π–π overlap between two adjacent TCNQ − radical anions. Compound 1 reacted with Et4N(C10N7) to afford the mononuclear derivative [CuClL(C10N7)] (5), while its reaction with K2C10N6 produced the dinuclear complex [(CuClL)2(C10N6)] (6). The crystal structures of complexes 5 and 6 have been determined by X…
Syntheses, structural characterisation and magnetic properties of Fe(ii) and Mn(ii) compounds with the pentacyanopropenido ligand; structural characterisation of a substituted pyrazolo[1,5-a]pyrimidine
International audience; Reactions between the metal(II) salts [M(CH3CN)n](BF4)2 (M = Fe, n = 6; M = Mn, n = 4) and some organic anionic polynitriles were studied. With the pentacyanopropenide anion pcp− [pcp− = (NC)2CC(CN)C(CN)2−], were obtained, according to the experimental conditions, the new complexes [M(pcp)2(H2O)4] (1, M = Fe; 2, M = Mn) and [M(pcp)2] (3, M = Fe; 4 = Mn). Use of the hexacyano-3,4-diazahexadienediide anion [(NC)2CC(CN)NNC(CN)C(CN)22−] instead of pcp− did not afford polynitrile metal complexes but led to a new organic derivative 5, of formula C10N8H2. Crystallographic studies indicated that the isostructural compounds 1 and 2 involve discrete monomeric units with pcp li…
Aza and cyanobridged tripodal dinuclear copper(II) complexes: Electrochemical studies and structural evidence for an original azacyanocarbanion
International audience; The reactivity of the mononuclear [Cu(TMPA)(L)] n+ complex (TMPA: tris(2-methylpyridine) amine, L: CH3CN, H2O) towards two different bridging species (tetracyanoethylene, 4,40-bipyridine) was investigated. The dinuclear complex [(mu-4,40-bipy)Cu-II(TMPA)(2)](CF3SO3)(4) (1) was synthesised and analysed by Xray diffraction (XRD). Magnetic studies revealed that this derivative displays very weak antiferromagnetic interactions between the two metal centres (2J = -0.69 cm(-1)). Solution studies (EPR spectroscopy and voltammetry) evidenced the lability of the bridged neutral bipyridine ligand in acetonitrile. The reaction of TCNE (TCNE: tetracyanoethylene) with the copper(…
Pentacyanopropenide group as ligand in organometallic chemistry. Crystal structure and electrochemical studies of (Et4N)[W(CO)5{(C(CN)2C(CN)C(CN)2}]
Abstract The title complex has been obtained by reaction of the tetraethylammonium pentacyanopropenide with tungsten hexacarbonyl in acetone. Its crystal structure involves discrete [W(CO)5{C3(CN)5}]− anions in which the organic fragment is N-coordinated via one of the nitrogen atoms of a cyano group borne by one of the terminal carbon atoms of the allylic skeleton. The anion presents a distorted octahedral coordination with a W–N bond length [2.168(5) A] considerably longer than the W–C bond lengths [cis-W–C in the range 1.998(7)–2.068(4) A; trans-W–C 1.962(7) A]. Cyclic voltammograms of this complex, recorded in CH2Cl2 and CH3CN (Bu4NPF6 0.1 M), display a quasi-reversible reduction and ir…
Guidelines to design new spin crossover materials
International audience; This review focuses on new families of spin crossover (SCO) complexes based on polynitrile anions as new anionic ligands or on polyazamacrocycles as neutral macrocyclic ligands. We have shown that the structural and electronic characteristics (original coordination modes and high electronic delocalization) of the polynitrile anions can be tuned by slight chemical modifications such as substitution of functional groups or variation of the negative charge to design new discrete or polymeric SCO systems.In our ongoing work on the design of new molecular systems based on new ligands that can be fine-tuned via chemical modifications, another promising way which has been r…
Unexpected behaviour of copper(I) towards a tridentate Schiff base: Synthesis, structure and properties of new Cu(I)-Cu(II) and Cu(II) complexes
cited By 17; International audience; The reaction of CuBr with 2,6-bis[1-(2,6-diisopropylphenylimino)ethyl]pyridine L afforded a new Cu(I)-Cu(II) derivative [CuBrL]2[Cu2Br4] (1), while the reaction of [Cu(CH3CN)4]PF6 with L in THF yielded the new Cu(I) compound CuL(THF)(CH3CN)PF6 (2). Derivative 2 further reacted with halogenated solvents to yield halogeno-Cu(II) salts, [CuClL]PF6 (3) using CHCl3 and [CuBrL]Br3 (4) using CHBr3. Compounds 1, 3 and 4 have been fully characterised by X-ray crystallography; they contain essentially similar [CuXL]+ cations with a square planar copper(II) co-ordination. However, the structure of compound 1 must be viewed as built of tetranuclear units since two […
Nickel precursors based on diamagnetic and paramagnetic di(imine)pyridine ligands for magnetic materials: Synthesis, X-ray structures and magnetic studies
International audience; Structural characterization and spectroscopic studies of the (2-acetyl-6-(1-TEMPO-imino)ethyl)pyridine (pat) and the 2,6-bis(1-TEMPO-imino)ethyl)pyridine (pbtMe) ligands are presented. Their electrochemical properties are also discussed. Two new nickel complexes, [NiII(dip)(CH3CN)(H2O)2](BF4)2 (1) (dip = 2,6-(di-iminepyridine)) and [NiII(pbtMe)(CH3CN)3](BF4)2 (2) have been characterized by X-ray diffraction. The reaction of 1 with the tetraethyl ammonium pentacyanopropenide salt (Et4N)(pcp) affords the new compound [NiII(pcp)(dip)(CH3CN)](pcp) (3) for which X-ray diffraction studies evidence an usual bridging μ2 coordination mode for the pentacyanopropenide anion, le…
Carbonylmolybdenum complexes with di(imino)pyridine and related ligands: Reduction of a di(imino)pyridine to an aminoiminopyridine system under mild conditions
Abstract The reactions of [Mo(CO) 6 ] towards a 2,6-di(imino)pyridine L 1 and related ligands were studied. The reaction with L 1 afforded two new complexes, [Mo(CO) 4 L 1 ] ( 1 ) and [Mo(CO) 4 L 2 ] ( 2 ), where L 2 is the 2-amino-6-iminopyridine ligand arising from the hydrogenation of one imine function of L 1 ; similar reaction with a 2-acetyl-6-iminopyridine ligand L 3 afforded [Mo(CO) 4 L 3 ] ( 3 ). Compounds 1 , 2 and 3 have been fully characterised by IR, 1 H NMR and X-ray crystallography; they present a metal ion in a pseudo-octahedral environment, the three organic ligands acting with bidentate N 2 coordination modes. One of the imine functions in 1 , the amine function in 2 , and…
CCDC 1823715: Experimental Crystal Structure Determination
Related Article: Nathalie Cosquer, Emeric Lefebvre, Bénédicte Douziech, Sylvie Houille, François Michaud, Carlos J. Gómez-García, Françoise Conan|2018|Inorg.Chim.Acta|479|1|doi:10.1016/j.ica.2018.04.026
CCDC 1494661: Experimental Crystal Structure Determination
Related Article: Karine Déniel, Nathalie Cosquer, Françoise Conan, Smail Triki, Carlos J. Gómez-García|2017|Polyhedron|125|50|doi:10.1016/j.poly.2016.09.023
CCDC 1823714: Experimental Crystal Structure Determination
Related Article: Nathalie Cosquer, Emeric Lefebvre, Bénédicte Douziech, Sylvie Houille, François Michaud, Carlos J. Gómez-García, Françoise Conan|2018|Inorg.Chim.Acta|479|1|doi:10.1016/j.ica.2018.04.026
CCDC 1823713: Experimental Crystal Structure Determination
Related Article: Nathalie Cosquer, Emeric Lefebvre, Bénédicte Douziech, Sylvie Houille, François Michaud, Carlos J. Gómez-García, Françoise Conan|2018|Inorg.Chim.Acta|479|1|doi:10.1016/j.ica.2018.04.026
CCDC 1042475: Experimental Crystal Structure Determination
Related Article: Karine Déniel, Kahina Nebbali, Nathalie Cosquer, Françoise Conan, Carlos J. Gómez-García, Said Yefsah, Smail Triki|2015|Polyhedron|97|253|doi:10.1016/j.poly.2015.05.032
CCDC 1823712: Experimental Crystal Structure Determination
Related Article: Nathalie Cosquer, Emeric Lefebvre, Bénédicte Douziech, Sylvie Houille, François Michaud, Carlos J. Gómez-García, Françoise Conan|2018|Inorg.Chim.Acta|479|1|doi:10.1016/j.ica.2018.04.026
CCDC 1494660: Experimental Crystal Structure Determination
Related Article: Karine Déniel, Nathalie Cosquer, Françoise Conan, Smail Triki, Carlos J. Gómez-García|2017|Polyhedron|125|50|doi:10.1016/j.poly.2016.09.023
CCDC 1042474: Experimental Crystal Structure Determination
Related Article: Karine Déniel, Kahina Nebbali, Nathalie Cosquer, Françoise Conan, Carlos J. Gómez-García, Said Yefsah, Smail Triki|2015|Polyhedron|97|253|doi:10.1016/j.poly.2015.05.032