Synthesis and Characterization of 9,9-diethyl-1-phenyl-1,9-dihydrofluoreno[2,3-d]imidazole-ended Fluorophores

A series ofπ-conjugated compounds ending with 9,9-diethyl-1-phenyl-1,9-dihydrofluoreno[2,3-d]imidazole were conveniently synthesized by condensation of the key intermediate9,9-diethyl-N^(2)-phenyl-9H-fluorene-2,3-diamine with the corresponding symmetric aryl phthalaldehydes under very mild conditions.The structures of these compounds were confirmed by^(1)H NMR,^(13)C NMR,and HRMS.Their UV-Vis spectroscopy data,fluorescent spectroscopy data,and further details of the electronic properties from cyclic voltammetry measurements and theoretical calculations were studied.Most compounds possess good fluorescence-emitting ability with quantum yield of fluorescence values in the region of 0.36-0.92 and display emission within 449-513 nm depending on the molecular nature.

Multicomponent synthesis and designing of tetrasubstituted imidazole compounds catalyzed via ionic-liquid for acid steel corrosion protection:Experimental exploration and theoretical calculations

Five new tetrasubstituted imidazoles were designed with outstanding yields(83%-92%) in the occurrence of ionic liquid-based-pyridinium as a catalyst. The constructions of all synthesized derivatives were established by spectral tools and their purities were verified using thin-layer chromatography(TLC), displaying single-spot. The performance of corrosion protection of the prepared imidazole derivatives was examined theoretically and practically for acid steel corrosion. The experimental study was conducted by electrochemical(electrochemical impedance spectroscopy(EIS) and Tafel polarization(PPS)) tools.The findings from the used approaches concluded that the synthesized compounds were wellorganized inhibitors with an efficiency of 90.7%-98.5% at 50℃ and 0.7 mmol·L^(-1). The Tafel polarization results indicate the protective action of the additives was under mixed-monitoring. The additive adsorption on the electrode interface performed as a distinguished aspect for protection. The surface exploration on the blank and protected metal was completed by field emission scanning electron microscopy(FESEM). Computational studies by Monte Carlo(MC) simulation and quantum chemical calculation(DFT)were related to practical findings. The corrosion protection adsorption mechanism was reinforced by the preferable fitted Langmuir isotherm model. All findings from the applied-inspected approaches alternately confirm each other.

Bismuth (III) Triflate Catalyzed Multicomponent Synthesis of 2,4,5-Trisubstituted Imidazoles

Substituted imidazoles are of interest because of their useful biological activities. While several methods have been developed for the synthesis of such compounds, some of the reported methods utilize corrosive or toxic catalysts. We report a bismuth (III) triflate catalyzed multicomponent synthesis of 2,4,5-trisubstituted imidazoles. Bismuth (III) compounds are attractive from a green chemistry perspective because they are remarkably non-toxic and non-corrosive. Multicomponent syntheses save time and generate less waste.

Bismuth (III) Triflate Catalyzed Multicomponent Synthesis of 2,4,5-Trisubstituted Imidazoles

Substituted imidazoles are of interest because of their useful biological activities. While several methods have been developed for the synthesis of such compounds, some of the reported methods utilize corrosive or toxic catalysts. We report a bismuth (III) triflate catalyzed multicomponent synthesis of 2,4,5-trisubstituted imidazoles. Bismuth (III) compounds are attractive from a green chemistry perspective because they are remarkably non-toxic and non-corrosive. Multicomponent syntheses save time and generate less waste.

Synthesis,Crystal Structure,and Spectral Properties of a Novel Co(II) Complex Containing Imidazole Derivative

A novel imidazole derivative with functional group and π-conjugated system, 1- [trans-4-（4-diethylaminostyryl）phenyl]imidazole （abbreviated as L）, and its Con complex （COCl2L4）2 （Co2C168H184N24Cl4, Mr = 2799.05 ） have been synthesized and the crystal structure of the latter was determined by X-ray diffraction. The crystal is of triclinic, space group PI with a = 8.823（3）, b = 18.799（7）, c =23.065（9） A, α = 77.349（6）, β = 83.128（7）, ）, γ= 80.942（3）°, V = 3671.5（12） A^3, Z = 1, Dc = 1.266 g/cm^3,/z = 0.361 mm^-1 F（000） = 1482, the final R = 0.0587 and wR = 0.1284 for 6562 observed reflections with I 〉 2σ（I）. In the molecular structure of （COCl2L4）2, there are two crystallographically unique units. The Co^Ⅱ atoms are six-coordinated by four N atoms from four imidazole ligands （L） and two Cl atoms to form a distorted octahedral geometry. The optical properties of complex （COCl2L4）2 have been experimentally studied.

Interactions and Biological Activity of Rare Earth Perchlorate Complexes with Alanine and Imidazole

The interactions of nine rare earth perchlorate complexes with alanine and imidazole were studied in methanol. The general formulae of these compounds are RE(Ala) 2Im(ClO 4) 3· n H 2O(RE=Ce, Pr, Nd, Sm, Eu, Gd, Tb, Yb) and La(Ala) 3Im(ClO 4) 3·H 2O, respectively. The composition and structure of the prepared compounds were determined by the chemical analysis, elemental analysis, IR spectroscopy, UV, FS spectroscopy, X ray powder diffraction, 1H NMR and solubility. The thermal decomposition processes of these complexes were studied on the basis of TG DTG. The preliminary bioassay shows that the compounds have a remarkable bacteriostasis effect on nine varieties of microbe.

A Quantum Chemistry Study of Inhibition Properties of Imidazole and Its Derivatives on Iron Surface Corrosion

The geometries of imidazole and its derivatives were respectively optimized by using ab initio method, and the molecular orbital energy levels and the charge densities were obtained for their optimum geometries. The frontier orbital energy levels, and the net charges of N (1) atom and the imidazole ring of those molecules were obtained with ab initio and SCC-DV-Xα methods. It was found that the inhibition properties of those compounds change with the highest occupied molecular orbital energy levels, and the net charges of N (1) atom. We took four iron atoms on the crystal plane (100) of α-iron as the surface which was used to study the adsorption towards the inhibitors. The adsorption models of the inhibitor to be adsorbed on the Fe-cluster surface were optimized with SCC-DV-Xα method. It turns out that the most favorable model is that the inhibitor molecule is adsorbed on the Fe-cluster surface in an inclined state. The calculation shows that the stabilization energies of the systems are well correlated with the inhibition efficiencies.

Synthesis and antibacterial evaluation of 2-substituted-4,5-diphenyl-N-alkyl imidazole derivatives

Objective:To synthesis 2-substituted-4,5-diphenyl-N- alkyl imidazole derivatives,and evaluate their antibacterial activity.Methods:A mixture of benzil（10 mmol） and ammonium acetate（0.1 mol）（immediately fused） in glacial acetic acid（25 mL） was stirred at 80-100℃for 1 h under nitrogen atmosphere（to prevent incorporation of any atmospheric impurities and moisture）. Substituted aldehydes（10 mmol） in glacial acetic acid（5 mL） was added drop-wise over a period of 15-20 min at the same temperature and stirred for another 4 h,the progress of the reaction was monitored by TLC test using ethyl acetate as eluent.The newly synthesized compounds were characterized by IR,1HNMR,13CNMR and by mass spectroscopy.Results:All the synthesized compounds were confirmed by spectroscopical techniques and evaluated for antimicrobial activity against Staphylococcus aureus（S.aurius）,Bacilus subtilus（B.subtilus）,and Escheria coli （E.coli）.These compounds showed antibacterial activity（zone of inhibition） against S.aurius ranged from 3 mm to 9 mmin diameter,B.subtilus,4 -8 mm,and E.coli 5 -12 mm.Out of 2a-2e, only 2a and 2b showed some sort of activity but none of them had considerable activity compared with that of the standard.Conclusions:All the synthesized compounds show moderate activity against the tested bacteria S.aurius,B.subtilus,and E.coli.So,further structural modification is necessary to improve the antibacterial action of 2-substituted-4,5-diphenyl-N-alkyl imidazole derivatives.

Structure and Thermal Properties of Transition Metal Imidazole Chloride

The X-ray single-crystal structure analyses have been determined for two metal imidazole chlorides: [Fe(Im)6]Cl24H2O 1 and [CuCl(Im)4]Cl 2 (Im = imidazole). The red crystal of compound 1 is of triclinic, space group Pi with Mr = 607.31 (C18H32Cl2FeN12O4), a = 8.797(2), b = 9.068(2), c = 10.581(2) ? a = 75.35(3), ?= 83.20(3), ? = 61.85(3)o, V = 720.0(2) 3, Z = 1, Dc = 1.401 g/cm3, F(000) = 316, = 0.755 mm-1, R = 0.0353 and wR = 0.1227. The blue crystal of compound 2 belongs to monoclinic, space group P21/c with Mr = 406.77 (C12H16Cl2CuN8), a = 13.909(3), b = 8.8933(18), c = 15.086(7) ? ?= 118.32(2), V = 1642.7(9) 3, Z = 4, Dc = 1.645 g/cm3, F(000) = 828, = 1.666 mm-1, R = 0.0609 and wR = 0.1726. In solid state, both 1 and 2 form three-dimensional hydrogen bond networks to stabilize the structures which were also characterized by TG and elemental analyses. The thermal gravity (TG) data indicate that the residues are Fe and Cu for 1 and 2, respectively.

Synthesis, Crystal Structure and Properties of a New Zn(II) Coordination Polymer Constructed from 2,3-Pyridine Dicarboxylic Acid and 1,1′-(1,4-Butanediyl)bis(imidazole)

A new coordination polymer, namely [Zn（pdc）（bbi）]n {H2 pdc = 2,3-pyridine dicar- boxylic acid, bbi = 1,1-（1,4-butanediyl）bis（imidazole）}, has been prepared under hydrothermal conditions and characterized by elemental analysis, IR, and single-crystal X-ray diffraction. It crystallizes in monoclinic, space group P21 /n with a = 8.436（3）, b = 16.988（5）, c = 12.106（4）, β = 92.204（5）°, V = 1733.6（9）3, Z = 4, C17 H17 N5 O4 Zn, Mr = 420.73, Dc = 1.612 g/cm3, F（000） = 864, μ（MoKa） = 0.452 mm-1, the R = 0.0672 and wR = 0.1645. In the mononuclear complex, each Zn（II） is five-coordinated by one carboxylate O and one pyridyl N atoms from one pdc anion, one carboxylate O atom from another pdc anion, and two N atoms from two bib ligands. The Zn（II） ions are connected by pdc ligands to form skeleton chains, and bbi ligands further link them to construct a 2D framework. The thermal and luminescence properties of the complex were also investigated.

Synthesis,Crystal Structure and Antitumor Activity of a New 3H-Phenanthro-[2,1-d]imidazole Derivative of Dehydroabietic Acid

The title compound （CI9H24BrN302, 3） was synthesized from dehydroabietic acid and its crystal structure was determined by single-crystal X-ray diffraction. The compound is of monoclinic system, slSace group C2 with a = 24.830（5）, b = 7.1410（14）, c = 13.981（3） A, p = 107.68（3）°, Z = 4, V= 2361.9（8） A3, Mr = 482.42, Dc = 1.357 Mg/m3, S = 1.003,μ = 1.772 mm1, F（000） = 1008, the final R = 0.0660 and wR = 0.1402 for 2244 observed reflections （I 〉 2o（/））. The crystal structure is stabilized by four hydrogen bonds （O（W）-H（WA）...O（3）, O（W）-H（WB）...O（1）, N（2）-H（2A）...O（W） and N（3）-H（3A）...N（1）） formed among the title compound, the crystal water and acetone molecules. The preliminary antitumor assay showed the title compound exhibited considerable inhibitory activity against HepG2 and SMMC-7721 cell lines with the ICs0 values of 17.1 and 10.2 μM, respectively.

Catalytic performance of imidazole modified HZSM-5 for methanol to aromatics reaction

A facile approach was developed for the preparation of nano-sized HZSM-5 with a hierarchical mesoporous structure by adding imidazole into conventional zeolite synthesis precursor solution. The physicochemical properties of modified HZSM-5 were characterized by X-ray diffraction（XRD）, N;adsorption–desorption isotherms, scanning electron microscopy（SEM）, NH;-temperature-programmed desorption（NH;-TPD） and pyridine adsorption infrared spectroscopy（Py-IR）. The coke in spent catalysts was characterized by thermogravimetry（TG）. The results showed that hierarchical HZSM-5 zeolites with excellent textural properties, such as abundant porous structure, uniform particle size and suitable acidity, could be synthesized by the recipe of one-pot synthesis routes. Moreover, the obtained HZSM-5 exhibited higher selectivity of total aromatics as well as longer lifetime in the catalytic conversion of methanol to aromatics, comparing with conventional HZSM-5. It is expected that the synthesis approach demonstrated here will be applicable to other zeolites with particular textural properties and controllable particle sizes, facilitating the emergence of new-type porous materials and their related applications in catalysis and separation.

Synthesis of organosoluble polyamides with bulky triaryl imidazole pendent group

New unsymmetrical diamine monomer containing triaryl imidazole pendent group, 4-[4-（4,5-diphenyl-1H-imidazol-2-y1）phe- noxy]-1,3-benzenediamine, was synthesized via aromatic substitution reaction of 1-chloro-2,4-dinitrobenzene with 4-（4,5- diphenyl-1H-imidazol-2-y1）pbenol, followed by palladium-catalyzed hydrazine reduction. This new monomer was further confirmed by FT-IR, IH NMR and ^13C NMR. Novel polyamides having pendant triaryl imidazole group were prepared by the phosphorylation polycondensation of four commercially aromatic dicarboxylic acids with the prepared diamine. Inherent viscosities of polyamides were in the range 0.42-0.53 dL/g indicating formation of medium molecular weight polymers. Polyamides exhibited glass-transition temperature （Tg） in the range 236-265 ℃. These polymers are essentially amorphous and were soluble in polar aprotic solvents such as DMF, NMP, DMAc. The 10% weight loss temperatures in air atmosphere, measured by TGA were in the range 350-373 ℃ indicating their good thermal stabilities. ？2009 Mousa Ghaemy. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.

Hydrothermal Synthesis and Structure of a Novel 1-D Mn(II) Compound with Carboxlyto and Imidazole Ligands

A novel manganiferous polymeric complex [(imid)2(ta)Mn0.5]n (imid = imidazole, ta = terephthalato) was synthesized by the hydrothermal reaction of MnO2, terephthalic acid, imidazole, and H2O. Structure analysis indicates that the compound crystallizes in the triclinic system, space group P1, with a = 8.1500(16), b = 8.5100(17), c = 9.0500(18) ?, α = 72.77(3), β = 65.50(3), γ = 77.22(3)o, V = 542.02(19) ?3, Z = 2, Dc = 1.505 g/cm3, F(000) = 253, Mr = 245.69, μ(MoKα) = 0.655 mm-1, R = 0.0733 and wR = 0.1703 for 1673 observed reflections (I > 2σ(I)). The compound is characteristic of a zigzag chain-like framework built up of ta bridge and (Imid)4Mn group. The 1-D frameworks are held together by H-bonds between the dangling N–H donors from imid and O acceptors from ta.

One-pot synthesis of tri- and tetra-substituted imidazoles using sodium dihydrogen phosphate under solvent-free conditions

Sodium dihydrogen phosphate （NaH2PO4） efficiently catalyzes the condensation reaction of benzil, aldehydes, amines and ammonium acetate in a four-component reaction under solvent-free conditions. The reaction proceeds rapidly and affords the corresponding tetra-substituted imidazoles in high yields. Also an efficient route was developed for the synthesis of tri-substituted imidazoles from condensation of benzil, aldehydes and ammonium acetate using NaH2PO4.

Solvent Free One-Pot Synthesis of 1,2,4,5-Tetrasubstituted Imidazoles Catalyzed by Secondary Amine Based Ionic Liquid and Defective Keggin Heteropoly Acid

Secondary amine based ionic liquid and defective Keggin type heteropoly acid (HPA) are separately used for efficient one-pot four-component synthesis of 1,2,4,5-tetrasubstituted imidazoles assisted by microwave (MW). Eco-friendly solvent free procedure, short reaction time, high yield of products and reusability of catalysts are important features of the synthesis. A comparative study on the efficiency of the two catalysts is reported. This work further demonstrates the alternate use of urea, instead of often used ammonium acetate, as source of nitrogen.

Effect of imidazole based polymer blend electrolytes for dye-sensitized solar cells in energy harvesting window glass applications

The exploration of polymer electrolyte in the field of dye sensitized solar cell(DSSC) can contribute to increase the invention of renewable energy applications. In the present work, the influence of imidazole on the poly(vinylidene fluoride)(PVDF)–poly(methyl methacrylate)(PMMA)–Ethylene carbonate(EC)–KI–I2 polymer blend electrolytes has been evaluated. The different weight percentages of imidazole added into polymer blend electrolytes have been prepared by solution casting. The prepared films were characterized by Fourier transform infrared spectroscopy(FTIR), X-ray diffraction(XRD), thermogravimetric analysis(TGA), UV–visible spectra, photoluminescence spectra and impedance spectroscopy. The surface roughness texture of the film was analyzed by atomic force microscopy(AFM). The ionic conductivity of the optimized polymer blend electrolyte was determined by impedance measurement, which is 1.95 × 10-3 S·cm-1 at room temperature. The polymer electrolyte containing 40 wt% of imidazole content exhibits the highest photo-conversion efficiency of 3.04%under the illumination of 100 m W·cm-2. Moreover, a considerable enhancement in the stability of the DSSC device was demonstrated.

A New Efficient Synthesis of Bisphenol A Diether Bis-imidazoles and Bis-benzimidazoles

A new efficient synthesis of bisphenol A diether bis-imidazoles and bis-benzimidazoles by bromoalkylation and imidazolylation or benzimidazolylation two-step reactions from commercial bisphenol A, imidazole, 2-methylimidazole and benzimidazole is reported.

Hydrothermal Synthesis,Structure and Characterization of a New 2D Co(Ⅱ) Coordination Polymer Based on Flexible Double Imidazole Derivative and Oxalate

A 1D supramolecular compound [dmbbbi]（1） and a 2D cobalt coordination polymer [Co（dmbbbi）（ox）] 2（2） [dmbbbi=1,1-（1,4-butanediyl）bis（5,6-dimethylbenzimidazole）,ox=oxalate],C48H52Co2N8O8,were obtained under hydrothermal conditions by tuning the molar ratio of the reactants.The crystal structure analysis reveals that in compound 1,the adjacent dmbbbi molecules connect with each other via hydrogen bonds to form a 1D supramolecular chain.In compound 2,two crystallographically independent Co2＋ ions show the same six-coordination mode.Each Co2＋ ion is coordinated by four oxygen atoms from two ox anions and two nitrogen atoms from two cis-dmbbbi ligands.The adjacent Co2＋ ions are bridged by ox anions to generate an infinite 1D zigzag chain,which is extended by pairs of dmbbbi ligands to form a 2D honeycomb-like（6,3） network.Moreover,the thermal stability and the electrochemical property of compound 2 were studied.

Interactions between Bioactive Diperoxovanadate Complexes and Imidazole: Insights into Their Solution Structures by NMR and ESI-MS

The interactions between four high bioactive diperoxovanadate complexes Kn[OV(O2)2L]mH2O (n = 1~3, m = 1~5, L = oxalate (abbr. oxa), picolinate (abbr. pic), bipyridine (abbr. bipy) and 1,10-phenanthroline (abbr. phen); their corresponding complexes abbreviated as bpV(oxa), bpV(pic), bpV(bipy) and bpV(phen), respectively) and imidazole (abbr. imi) in solution were studied by several NMR techniques: multinuclear (1H, 13C and 51V) and variable temperature 51V NMR. Competitive coordination interactions were observed and the order of the interaction strength of the four complexes with imidazole is as follows: bpV(oxa) > bpV(pic) > bpV(bipy) > bpV(phen), which is deeply affected by the identity of the ligands and has the same order as their inhibition effect toward bovine heart phosphotyrosyl protein phosphatase. The species [OV- (O2)2(imi)]- was formed in all cases. Both of the NMR data and equilibrium constants of the interaction systems were reported. The experimental results indicate that the species of bpV(oxa) and [OV(O2)2(imi)]- are six-coordinated, while bpV(pic), bpV(bipy) and bpV(phen) are seven- coordinated in solution. ESI-MS results support the conclusions obtained by NMR.