Facile and efficient one-pot multicomponent synthesis of a new class of substituted pyrimidine containing imidazoles catalyzed by ceric ammonium nitrate: Screening in vitro microbiological evaluation with various microorganisms

An effective and simple method for the one-pot synthesis of 4,6-diaryl-2-(2-aryl-4,5-diphenyl-1H-imidazol-1-yl)pyrimidines 13-24 from substituted 2-amino pyrimidine 1-12, benzil, substituted aromatic aldehyde and ammonium acetate in methanol by using ceric ammonium nitrate (CAN) as catalyst has been described. This CAN catalyzed reactions are carried out at a temperature of 70-75°C and give very high yields in a lesser reaction time. All the synthesized compounds have been characterized by elemental analysis, FT-IR, 1H NMR 13C NMR and MS spectral data. All the newly synthesized compounds are tested for their in vitro antimicrobial activity against selected clinically isolated bacterial and fungal strains by disc diffusion and minimum inhibitory concentration method

Implementation of slow magnetic relaxation in a SIM-MOF through a structural rearrangement

Here we report the structural flexibility of a Dy-based Single-Ion Magnet MOF in which its magnetic properties can be modified through a ligand substitution process involving an increase of the charge density of the coordination environment

A [Mn-32] Double-Decker Wheel

International audienc

Fluorescence emission in schiff bases of 2,6-diformyl-4-methylphenol: Effect of chelation on the emission

696-701The absorption and emission spectra of the schiff base (I) derived from 2,6-diformyl-4-methylphenol and o-aminobenzoic acid have been investigated in various solvents like N,N- dimethylformamide, acetonitrile, methanol and chloroform. Only in N,N-dimethylformamide, formation of phenoxide and cleavage of the imine bond is observed accompanied by changes in absorption and emission spectra. Results on the metal complexes of schiff base (I) indicate that the generation of phenoxide and cleavage of -CH=N-bond are retarded by chelation with metal ions like Cd2+ or Z2+ without quenching the emission, whereas chelation with Cu2+ or Fe2+ ions results in complete quenching of emission

A nickel(II)-sulfur-based radical-ligand complex as a functional model of hydrogenase

A nickel(II) dithiolene complex [Ni<SUP>II</SUP>(L<SUP>2−</SUP>)(L<SUP>−</SUP>.)][PPh<SUB>4</SUB>] (1; see figure; L=1,2-dicarbomethoxyethylene dithiolate) electrocatalyzes hydrogen evolution at the lowest achievable reduction potential (−0.69 V) in CH3CN and also in aqueous medium (−0.71 V) to date. Compound 1 shows strikingly similar EPR and reduction potential values to those observed with native Ni-containing hydrogenases

Dangling thiyl radical: stabilized in [PPh<SUB>4</SUB><SUB>]2</SUB>[(bdt)W<SUP>VI</SUP>(O)(&#956; -S)<SUB>2</SUB>CuI(SC<SUB>6</SUB>H<SUB>4</SUB>S&#x2022;)]

The synthesis, crystal structure, and spectroscopic characterization of [PPh4]2[(bdt)W(O)(S2)Cu(SC6H4S&#183; )] (3; bdt= benzenedithiolate) relevant to the active site of carbon monoxide dehydrogenase are presented. Curiously, in 3, the copper(I) benzenemonothiolate subcenter possesses a dangling thiyl radical that is stabilized by a disulfido-bridged oxo tungsten dithiolene core. The benzenedithiolate ligand, which is generally bidentate in nature, acts as a bidentate and also as a monodentate in 3. The formation of an unusual dangling thiyl radical has been magnetically and spectroscopically identified and has been supported by the density functional theory level of calculation

From molecular to micro structure via nanostructure of a nickel(II) dithiolene complex

1257-1262The nanocrystal structure of a hetero-polyatomic metal-ligand complex, [PPh4][NiII(L2−)(L1−·)], (1) (L = 1,2-dicarbomethoxyethylene dithiolate) has been arrived at from its molecular structure obtained by X-ray crystallography. The complex (1) exhibits dimorphism, existing in two crystal habits at the micro level, viz., rectangular prismatic and hexagonal. Rectangular or hexagonal repeating motifs manifest in the lattice packing of the two crystal structures of (1) in two different solvents which extend up to nano dimension and result in nano sized rectangular and hexagonal prismatic crystals. This provides major clues to understand the shapes of hetero-poly atomic nanocrystals at the molecular level

From the {Cu(μ2-S)N}4 butterfly architecture to the {Cu(μ3-S)N}12 double wheel

Copper(I) complexes with {Cu(μ2-S)N}4 and {Cu(μ3-S)N}12 core portions of butterfly-shaped or double wheel architectures have been isolated in the reaction of Cu(I) with the Schiff base ligand C6H4(CHNC6H4S)2, aiso-abtâ, under different conditions. View the MathML source containing the tetranuclear electroneutral complex View the MathML source is formed by the reaction of CuI in acetonitrilic solution and recrystallization from DMF, whereas View the MathML source containing dodecanuclear View the MathML source wheels is accessible starting from CuBF4. Complexes 2 and 4 represent the first examples of cyclic complexes with the same overall stoichiometry but different ring sizes. The ligand induces two different coordination environments around copper(I) by switching between μ2- and μ3-sulfur bridging modes