Synthèse de nouvelles 7 (5)-〚benzimidazol-2-yl〛méthyl-2 (7)-méthyl-1,2,4-triazolo〚1,5-a〛(〚4,3-a〛)pyrimidines

Condensation of 4-hydroxy-6-methyl pyran-2-one 2 with 3-amino-1,2,4-triazole 1 in refluxing alcohol afforded 5-alkoxycarbonylmethyl-7-methyl-1,2,4-triazolo〚1,5-a〛pyrimidines and their isomers 5-alkoxycarbonylmethyl-7-methyl-1,2,4-triazolo〚4,3,-a〛pyrimidines 4. Reaction of hydrazine hydrate with compounds 4 and 5 yielded the corresponding hydrazid acids 6 and 7. Condensation of o-phenylenediamines 8 with esters 3(4) in refluxing xylol or with hydrazid acid 6(7) by melting reagents afforded 7(5)-〚benzimidazol-2-yl〛methyl-5(7)methyl-1,2,4-triazolo〚1,5-a〛(〚4,3-a〛)pyrimidines 9(10). The structures of the annealed compounds have been elucidated by their ¹H, ¹³C NMR and Mass Spectroscopy data.     

Structures of Pd(CN)2 and Pt(CN)2: intrinsically nanocrystalline materials?

Analysis and modeling of X-ray and neutron Bragg and total diffraction data show that the compounds referred to in the literature as "Pd(CN)(2)" and "Pt(CN)(2)" are nanocrystalline materials containing small sheets of vertex-sharing square-planar M(CN)(4) units, layered in a disordered manner with an intersheet separation of ~3.44 ? at 300 K. The small size of the crystallites means that the sheets' edges form a significant fraction of each material. The Pd(CN)(2) nanocrystallites studied using total neutron diffraction are terminated by water and the Pt(CN)(2) nanocrystallites by ammonia, in place of half of the terminal cyanide groups, thus maintaining charge neutrality. The neutron samples contain sheets of approximate dimensions 30 ? × 30 ?. For sheets of the size we describe, our structural models predict compositions of Pd(CN)(2)·xH(2)O and Pt(CN)(2)·yNH(3) (x ≈ y ≈ 0.29). These values are in good agreement with those obtained from total neutron diffraction and thermal analysis, and are also supported by infrared and Raman spectroscopy measurements. It is also possible to prepare related compounds Pd(CN)(2)·pNH(3) and Pt(CN)(2)·qH(2)O, in which the terminating groups are exchanged. Additional samples showing sheet sizes in the range ~10 ? × 10 ? (y ~ 0.67) to ~80 ? × 80 ? (p = q ~ 0.12), as determined by X-ray diffraction, have been prepared. The related mixed-metal phase, Pd(1/2)Pt(1/2)(CN)(2)·qH(2)O (q ~ 0.50), is also nanocrystalline (sheet size ~15 ? × 15 ?). In all cases, the interiors of the sheets are isostructural with those found in Ni(CN)(2). Removal of the final traces of water or ammonia by heating results in decomposition of the compounds to Pd and Pt metal, or in the case of the mixed-metal cyanide, the alloy, Pd(1/2)Pt(1/2), making it impossible to prepare the simple cyanides, Pd(CN)(2), Pt(CN)(2), or Pd(1/2)Pt(1/2)(CN)(2), by this method.     

Synthesis and stereochemical study of a trioxaquine prepared from cis-bicyclo〚3.3.0〛octane-3,7-dione

The preparation of a modular antimalarial drug named trioxaquine containing a cis-bicyclo〚3.3.0〛octane-3,7-dione is reported. Two diastereomeric racemates have been separated and characterised by NMR.     

Synthèse des 2-hydroxy-7-〚benzimidazol-2-yl〛-méthyl-5-méthylpyrazolo〚1,5-a〛pyrimidines à partir de la 4-hydroxy-6-méthylpyran-2-one

Condensation of 3-amino-5-hydroxypyrazole 1 with triacetic acid lactone 2 in refluxed alcohols afforded 2-hydroxy-5,7-dimethylpyrazolo〚1,5-a〛pyrimidine 3 beside to 7-alkoxycarbonylmethyl-2-hydroxy-5- methylpyrazolo〚1,5-a〛pyrimidine 4. Action of hydrazine on compounds 4 yielded 7-hydrazinocarbonylmethyl-2-hydroxy-5-methylpyrazolo〚1,5-a〛pyrimidine 5. Condensation of o-phenylenediamines 6 with hydrazide 5 to melting reactants afforded 2-hydroxy-7-〚benzimidazol-2-yl〛methyl-5-methylpyrazolo〚1,5-a〛pyrimidines 7. Structures of the obtained products have been assigned by means of spectroscopic measurements.     

Synthesis and X-ray crystal structure of 〚VCl3((–)-sparteine)〛 and 〚FeCl2((–)-sparteine)〛

Novel complexes of vanadium(III), chromium(III) and iron(II) containing the alkaloid (–)-sparteine as a bidentate ligand have been prepared. Two of them, 〚VCl₃((–)-sparteine)〛 and 〚FeCl₂((–)-sparteine)〛, were characterised by X-ray diffraction. Known cobalt(III) and nickel(II) analogue complexes were prepared using the same procedure.     

Synthesis and Structure of Acetonitrile Solvates of Copper(II) Monofluoroacetate and Silver(I) Trifluoroacetate, [Cu2(CH2FCOO)4· 2CH3CN](CH3CN) and Ag3(CF3COO)3(CH3CN)2

Compounds [Cu₂(CH₂FCOO)₄· 2CH₃CN](CH₃CN) (I) and Ag₃(CF₃COO)₃(CH₃CN)₂(II) were synthesized and studied by X-ray structural analysis. Crystals Iare monoclinic, space group C2/c, a= 27.854(6), b= 8.286(2), c= 19.428(4) Å, = 106.82(3)°, V= 4292(2) ų, Z= 8, R ₁= 0.0426; crystals IIare triclinic, space group , a= 8.676(2), b= 9.819(2), c= 11.961(2) Å, = 95.27(3), = 109.59(3)°, = 104.60(3)°, V= 911.4(3) ų, Z= 2, R ₁= 0.0252. Structure Iis composed of the structural units (lanterns) typical of copper(II) carboxylates. The presence of an additional acetonitrile molecule noncoordinated by the copper atoms makes it possible to consider compound Ias a lattice clathrate. Structure IIhas no analogs among the silver carboxylates. It simultaneously contains silver atoms with coordination numbers varying from 2 to 4.     

An infrared and Raman spectroscopic study of Td-type 4,4′-bipyridylcadmium(II) tetracyanometallate (II) benzene (1/2) clathrates: Cd(C10H8N2)Cd(CN)4 · 2C6H6 and Cd(C10H8N2)Hg(CN)4 · 2C6H6

Two new benzene clathrates of the form Cd(4,4-bipyridyl)M(CN)₄ · 2C₆H₆, (M=Cd or Hg) have been prepared in powder form. Their spectral data were compared with those of the corresponding host complexes and found to be consistent with the host structure found in Td-type clathrates.     

Crystal Structure of (γ-CH_3C_5H_4N)_2Zn(S_2C_2(CN)_2)and the Second Harmonic Effect

1mrnODUCTIONMetallorganiccompoundisconsideredtobehighlyprospectiveasnonlinearoptical(NLO)materials.NLOpropertiesofmanymetallorganiccompoundshavebeenstudiedsince1986[h,clearlyshowingthepracticalmeaningofthiskindofresearch,especiallyforapplicationsinthevisiblefield.ForametallorganicNLOcrystaltobetransparentinthevisibleregion,generally,atleastthefollowingprerequisites"'mustbesatisfiedwithmolecularandcrystalstructurerespects.Firstly,theelectronconfigurationofcentricionsoftransitionmetalmustb…     

Differentiation of planar chiral enantiomers of 〚Cp*M(2-alkyl-Phenoxo)〛 〚BF4〛 {M = Rh,Ir} by the trisphat anion

Precursor oxo-dienyl rhodium and iridium complexes 〚(η⁵-Cp*)M(η⁵-2-alkyl-oxodienyl)〛 〚BF₄〛 (2a–c) were prepared according to literature procedure. Addition of 〚n-Bu₄N〛 〚Δ-trisphat〛 (6) to a CD₂Cl₂ solution of these chiral derivatives has led to the NMR differentiation of the enantiomers. These results pave the way towards the preparation of enantiomerically pure o-quinone methide complexes.     

An infrared and raman spectroscopic study of pyrazinecadmium (II) tetracyanometalate (II) Benzene (1/1) clathrates: Cd(C4H4N2)Cd(CN)4⁗C6H6 and Cd(C4H4N2)Hg(CN)4⁗C6H6

Two new benzene clathrates of the form Cd(Pyrazine)M(CN)₄C₆H₆, where M = Cd or Hg, have been prepared and their infrared and Raman spectra are reported.     

A new one-dimensional coordination polymer containing a μ-[N(CN)2]− bridging ligand. Synthesis,crystal structure and magnetic properties of Mn[N(CN)2]2-(2,4′-bpy)2 (2,4′-bpy = 2,4′-bipyridine)

The new one-dimensional (1D) coordination complex Mn[N(CN)₂]₂(2,4-bpy)₂ (1) (2,4-bpy = 2,4-bipyridine) has been synthesized. X-ray crystallography analysis reveals that the structure of (1) consists of linear chains of manganese atoms bridged by end-to-end dicyanamide ligands and coordinated by 2,4-bipyridine ligands. Weak – interactions between pyridine planes of adjacent chains force 1D Mn[N(CN)₂]₂(2,4-bpy)₂ chains into interesting 2D supramolecular arrays. Variable temperature magnetic susceptibility measurement for complex (1) shows that antiferromagnetic exchange interactions exist between manganese(II) centres of the linear chain.     

Synthesis of 2-(hydroxyphenylamino)- and 2-(aminophenylamino)-4-methylquinolines and N,N′-bis(4-methylquinolin-2-yl)benzenediamines

2-(Hydroxyphenylamino)- and 2-(aminophenylamino)-4-methylquinolines and N,N′-bis(4-methylquinolin-2-yl)benzenediamines were synthesized by reactions of 2-chloro-4-methylquinolines with o-, m-, and p-aminophenols and o-, m-, and p-phenylenediamines.     

Copper(II) and palladium(II) complexes of N,N′-bis(2-hydroxyethyl)stilbenediamine

A new 1,2-diamine ligand, N,N-bis(2-hydroxyethyl)stilbenediamine (L), has been prepared by reduction of the condensation product of benzaldehyde with 2-aminoethanol with Al amalgam. Mononuclear complexes of the [CuL(H₂O)]X₂ type where X=Cl^– or AcO^– with Cu^II and PdLCl₂ with palladium(II) have been prepared and characterized by elemental analysis and i.r., u.v.–vis. or ¹H-n.m.r. spectroscopy.     

New multicomponent organic semiconductors based on ET with polymeric Anions: α″-(ET)2N(CN)2·2H2O and α‴-(ET)6(NO3)3·2C2H5O2N3

New multicomponent radical cation salts derived from bis(ethylenedithio)tetrathiafulvalene (ET) were prepared: bis(ethylenedithio)tetrathiafulvalene dicyanamide dihydrate α″-(ET)₂N(CN)₂·2H₂O and bis-(ethylenedithio)tetrathiafulvalene nitrate α?-(ET)₆(NO₃)₃·2C₂H₅O₂N₃ containing two biuret molecules (C₂H₅O₂N₃). The crystal structures of the compounds were determined, and their conducting properties were examined. Both salts have layered structures in which radical cation layers alternate with nonconducting anionic layers. The radical cation layers in the salts α″-(ET)₂N(CN)₂·2H₂O and α?-(ET)₆(NO₃)₃·2C₂H₅O₂N₃ are packed in the α″ and α? fashion, respectively. Anionic layers consist of polymeric chains formed by hydrogen bonding between [N(CN)₂]? anions and water molecules in α″-(ET)₂N(CN)₂·2H₂O or between NO?₃ anions and biuret molecules in α?-(ET)₆(NO₃)₃·2C₂H₅O₂N₃. Both salts show semiconductor conductivity.     

Electronic state dependence of the ion-molecule reaction CH(3)CN(+) + CH(3)CN → CH(4)CN(+) + CH(2)CN: threshold electron-secondary ion coincidence (TESICO) and direct ab initio molecular dynamics study

The ion-molecule reaction, CH(3)CN(+) + CH(3)CN → CH(3)CNH(+) + CH(2)CN, has been investigated using the threshold electron-secondary ion coincidence (TESICO) technique. Relative reaction cross sections for two microscopic reaction mechanisms, i.e., proton transfer (PT) from the acetonitrile ion CH(3)CN(+) to neutral acetonitrile CH(3)CN and hydrogen atom abstraction (HA) by CH(3)CN(+) from CH(3)CN, have been determined for two low-lying electronic states, (2)E and (2)A(1) of the CH(3)CN(+) primary ion. The cross section for PT of the (2)A(1) state was smaller than that of the (2)E state, whereas that of HA are almost the same in the two states. Ab initio calculations showed that the dissociation of the C-H(+) bond of CH(3)CN(+) is easier in the (2)E state than that in the (2)A(1) state. The direct ab initio molecular dynamics (MD) calculations showed that two mechanisms, direct proton transfer and complex formation, contribute the reaction dynamics.     

Insulator-metal transitions induced by electric field and photoirradiation in organic Mott insulator deuterated κ-(BEDT-TTF)2Cu[N(CN)2]Br

The Mott insulator-metal transition induced by an external stimulus such as electric field, pressure, chemical doping, or photoirradiation has received considerable attention because of the potential use in new optoelectronic functional devices. Here we report an abrupt Mott insulator-metal transition observed as a current jump in a molecular-based Mott insulator, namely, deuterated κ-(BEDT-TTF)(2)Cu[N(CN)(2)]Br, where BEDT-TTF = bis(ethylenedithio)tetrathiafulvalene, upon application of a pulsed voltage of certain magnitude (threshold voltage). Furthermore, the threshold voltage needed for the transition is shown to be reduced by photoirradiation. Thus, the Mott insulator-metal transition can be controlled by a combination of an external electric field and photoirradiation.     

Iron salts with the tetracyanidoborate anion: [Fe(III)(H2O)6][B(CN)4]3, coordination polymer [Fe(II)(H2O)2{κ2N[B(CN)4]}2], and [Fe(II)(DMF)6][B(CN)4]2

The reaction of Fe(OH)(3) with tetracyanidoboronic acid, H[B(CN)(4)]·xH(2)O, in water leads to the first examples of tetracyanidoborates with a triply charged metal cation, [Fe(III)(H(2)O)(6)][B(CN)(4)](3) (1). Using elemental iron powder as starting material, [Fe(II)(H(2)O)(2){κ(2)ΝB(CN)(4)]}(2)] (2) is obtained. Anhydrous iron(II) tetracyanidoborate, which is synthesized by heating of 2, is soluble in dry dimethylformamide. After evaporation of the DMF solvent, single crystals of the third title compound, [Fe(II)(DMF)(6)][B(CN)(4)](2) (3), are obtained. Compound 3 is the first metal tetracyanidoborate soluble in nonpolar solvents. The title compounds have been characterized by single-crystal X-ray diffraction (1 rhombohedral, R3c (no. 167), a = 14.9017(7) ?, c = 20.486(1) ?, Z = 6; 2 tetragonal, I42d (no. 122), a = 12.3662(3) ?, c = 9.2066(4) ?, Z = 4; 3 triclinic, P1 (no. 2), a = 8.6255(3) ?, b = 11.0544(4) ?, c = 12.2377(5) ?, Z = 1). The metal ions in all three compounds are octahedrally coordinated. Whereas 1 and 3 are built up from isolated complex ions, 2 comprises a coordination polymer, in which the Fe(II) ion is coordinated by two oxygen atoms of two water molecules in a trans orientation and four nitrogen donor atoms of the [B(CN)(4)](-) groups, which bridge between neighboring iron ions. The iron(III) ion in 3 is in a perfect octahedral environment, which is formed by the O atoms of 6 molecules of water. The single-crystal X-ray structures, vibrational spectra, thermal properties, solubilities, and electrochemical characteristics are reported and compared with those of other known tetracyanidoborates.     

Generation and characterization of C60(CN)2n−(n=1,2,3)

The mono-anion, di-anion and tri-anion of dicyanodihydrofullerene [C₆₀(CN)₂] have been generated and monitored with a thin-layer spectro-electrochemical cell. The characteristic NIR absorption bands are found to be at 1019, 875 as well as at 744, and 691 nm for C₆₀(CN)₂⁻, C₆₀(CN)₂²⁻ and C₆₀(CN)₂³⁻, respectively. Density functional theory calculations indicate that these anions exhibit no Jahn–Teller effect and possess charge distributions and shape distortions that are different from C₆₀ⁿ⁻(n=1,2,3) upon negative charge addition.