İbrahim Kani

1-Pentamethylbenzyl-3-(n)buthylbenzimidazolesilver(I)bromide complex: synthesis, characterization and DFT calculations.

A novel NHC complex of silver(I) ion, 1-pentamethylbenzyl-3-(n)buthylbenzimidazolesilver(I)bromide, was prepared and fully characterized by single crystal X-ray structure determination. FT-IR, NMR and UV-vis spectroscopies were employed to investigate the electronic transition behaviors of the complex. Additionally, the molecular geometry, vibrational frequencies, gauge including atomic orbital (GIAO) (1)H and (13)C chemical shift and electronic transition values of silver(I) complex were calculated by using density functional theory levels (B3LYP and PBE1PBE) with LANL2DZ basis set. Also, the vibrational frequencies were supported on the basis of the potential energy distribution (PED) analysis calculated for PBE1PBE level. We were also investigated total static dipole moment (μ), the mean polarizability (〈α〉), the anisotropy of the polarizability (Δα), the mean first-order hyperpolarizability (〈β〉) of the title complex. Natural bond orbital (NBO) analysis was performed to determine the presence of hyperconjugative interactions, and charge distributions.

A New Application Area for Ag‐NHCs: CO2 Fixation Catalyst

The first example of the silver‐NHC catalyzed cycloaddition of CO2 to terminal epoxides is reported. The choice of NHC substituents, halides and the nature of additives were determined to be important. Ionic [(Cnmim)2Ag]2[Ag2Br4] (Cnmim=1‐(CnH2n+1)‐3‐methylimidazol‐2‐ylidene; n=4–18) catalysts exhibited a high yield of styrene carbonate (77–92 %) in the presence of 4‐dimethylaminopyridine (DMAP) as a cocatalyst without needing any solvent. The catalytic activity improved as the length of the alkyl groups (n) increased, although substituents longer than C14 did not produce any further beneficial effect. For the protocol performed at 1.5 MPa pressure and 100 °C the TOF was calculated to be 440 h−1. A prolonged reaction time and increased pressure of CO2 increased the yield. Used without any additive, compound C14 was able to fix CO2 with PO (propylene oxide) quantitatively at 120 °C, 2.0 MPa and could be used at least seven times without loss of activity and selectivity. The nucleophilic nature of the anion is decisive for the formation of the product.

Synthesis, crystal structure, optical and electrochemical properties of novel diphenylether-based formazan derivatives

In this study, formazans 5a–5h were synthesized by coupling the reactions of substituted phenylhydrazone compounds 3a–3h with diazonium salt of 4-chloro-2-phenoxybenzenamine (4). The substituted phenylhydrazones 3a–3h were obtained from the condensation of substituted phenylhydrazines 1a–1h with 4-methoxybenzaldehyde (2). The structures of the formazans were characterized by using elemental analysis, FTIR, 1H NMR, 13C NMR, LC-MS and the crystal structure of compound 5e was determined by X-ray crystallography. The absorption spectra of all compounds were investigated in various solvents. Although their absorption bands are only slightly dependent on the polarities of solvents, the significant change was observed by altering the electronic characteristics of the substituents. The fluorescence quantum yield properties and Stokes shifts of compounds 5a–5h in DMSO were also explored. Electrochemical properties of the new products were studied by CV measurements. In addition, computational studies were conducted at the PBE1PBE/6-311g (2d,2p) level to shed light on the structures of possible tautomers and intramolecular H-bonds.

Synthesis, spectroscopic and theoretical studies of ethyl (2E)-3-amino-2-({[(4-benzoyl-1,5-diphenyl-1H-pyrazol-3-yl)carbonyl]amino}carbonothioyl)but-2-enoate butanol solvate.

We have synthesized ethyl (2E)-3-amino-2-({[(4-benzoyl-1,5-diphenyl-1H-pyrazol-3-yl)carbonyl]amino}carbonothioyl)but-2-enoate (2) by the reaction of 4-benzoyl-1,5-diphenyl-1H-pyrazole-3-carbonyl chloride (1), ammonium thiocyanate and ethyl 3-aminobut-2-enoate and then characterized by elemental analyses, IR, Raman, (1)H NMR, (13)C NMR and X-ray diffraction methods. The experimental and theoretical vibrational spectra of 2 were investigated. The experimental FT-IR (4000-400 cm(-1)) and Laser-Raman spectra (4000-100 cm(-1)) of the molecule in the solid phase were recorded. Theoretical vibrational frequencies and geometric parameters (bond lengths, bond angles) were calculated using Ab Initio Hartree Fock (HF), Density Functional Theory (B3LYP) methods with 6-311++G(d,p) basis set by Gaussian 09W program. The computed values of frequencies are scaled using a suitable scale factor to yield good coherence with the observed values. The assignments of the vibrational frequencies were performed by potential energy distribution (PED) analysis by using VEDA 4 program. The theoretical optimized geometric parameters and vibrational frequencies were compared with the corresponding experimental X-ray diffraction data, and they were seen to be in a good agreement with each other. Also, the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) energies were calculated.

Homogeneous oxidation of alcohol and alkene with copper (II) complex in water

A new water-soluble copper(II) complex bearing 4-bromobenzoate/2,2’-dipyridylamine ligands was successfully synthesized and characterized by using single crystal X-ray diffraction and spectroscopic techniques. The catalytic activity of the compound was investigated as a homogeneous catalyst in the oxidation of several alcohols (benzyl alcohol, cinnamyl alcohol, 1-phenylethanol, cyclohexanol, 1-heptanol) and alkenes (styrene, ethylbenzene, cyclohexene) in aqueous medium. The copper(II) catalyst was found to be active for the studied alcohols and alkenes.

A carboxylate-bridged Mn(II) compound with 6-methylanthranilate/bipy: oxidation of alcohols/alkenes and catalase-like activity

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Crystal structure of aqua­bis­(hepta­fluoro­butano­ato-κO)(1,10′-phenanthroline-κ2N,N′)copper(II)

H2O2 was used as an active oxidant for alcohol oxidation, while t-BuOOH (TBHP) was used for alkenes. The compound exhibited high selectivity toward benzaldehyde (88%) in cinnamyl alcohol oxidation under mild conditions (70