SOLVENTLESS CYCLOCONDENSATIONS BETWEEN 1-NAPHTHOL AND BENZILS

In the absence of organic solvents,the Lewis acid catalyzed cyclocondensation reactions between 1-naphthol and benzils gave 3-aryl-3-aryl'naphtho[1,2-b]furan-2(3H)-ones(NFs) in good yields(62%～70%)An electrophilic substitution mechanism involving formation of n-EPD/v- EPA complexes and rearrangement of aryl group was proposed.

Synthesis and Characterization of Novel Schiff Base for Enhanced Dye-Sensitized Solar Cell Photo-Response Mechanism

The efficient photo-response mechanism is one of the key factors in the commercialization of dye-sensitized solar cells in a bid to satisfy renewable energy demands. Progress in green technology has put solar energy on the front burner as a provider of clean and affordable energy for a sustainable society. We report the synthesis of a novel Schiff base with optical transparency in the visible and near IR region of the solar spectrum that can find application in the DSSCs photo-response mechanism. The synthesized crystal exhibited features that could handle some of the shortcomings of dye-sensitized solar cells which include wide band solar spectrum absorption and capability for swift charge transfer within the photoelectrodes. The synthesized Schiff base was characterized using x-ray diffractometer, UV/Visible spectrometer, Frontier transmission infrared spectrometer and conductometer. XRD data revealed the grown crystal to have an average crystallite size of 2.08 nm with average microstrain value of about 269.43. The FT-IR recorded transmission wave ѵ (CO) at 1207.7 cm−1 while dominant wave occurred at ѵ1654.9 and ѵ1592.3 cm−1 relating to ѵ (CN) stretching and ѵ (NH) bending respectively were observed. The IR spectrum revealed the bonding species and a probable molecular structure of 2,6-bis(benzyloxy)pyridine. The UV/Visible spectra convoluted to maximum peak within the near IR region suggesting that 2,6-bis(benzyloxy)pyridine can absorb both the visible and near IR region while its electrical conductivity was determined to be 4.58 µS/cm. The obtained result of the present study revealed promising characteristics of a photosensitizer that can find application in the photo-response mechanism of DSSCs.

Synthesis and Crystal Structure of a Hexameric Organooxotin Cluster from Benzilic Acid

The title complex [^n BuSn（O）O2C（OH）CPh2]6.2H2O has been synthesized by the reaction of n-BuSn（O）OH with benzilic acid in 1：1 molar radio and characterized by IR, ^1H NMR spectra and elemental analysis. The crystal structure was determined by X-ray diffraction. It crystallizes in triclinic, space group PI with a = 1.3543（2）, b = 1.4593（2）, c = 1.5293（2） nm, α = 102.075 （2）,β = 115.571 （2）, γ = 93.308（3）°, Z = 1, V = 2.6282（7） nm^3, Mr = 2550.21, Dc = 1.611 g/cm^3,μ = 1.477 mm^-1, F（000） = 1280, R = 0.0309 and wR = 0.0729. The structure shows a distorted octahedral configuration with six-coordination for the central tin atom.

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.

Potassium dihydrogen phosphate catalyzed one-pot synthesis of 2,4,5-triaryl-1H-imidazoles

A simple and efficient method has been developed;benzil/benzoin undergoes smooth condensation with various substituted aldehyde and ammonium acetate in the presence of potassium dihydrogen phosphate（KH;PO;） under mild reaction conditions to afford the corresponding trisubstituted imidazole in excellent yields.The method for synthesis of product,the reaction mixture was reflux in ethanol for 40-90 min.The present method is simple,efficient,and cost-effective.

Excellent electrocatalytic activity of benzil for direct reduction of CO2 as well as indirect reduction of pyridine:A kinetic view of the electrocarboxylation process

Benzil,1,2-diphenylethane-1,2-dione, was used as an excellent electrocatalyst for reduction of carbon dioxide, CO. The reduction overpotential of COwas reduced about 900 m V in the presence of a benzil mediator. The chemical reaction of the product of the electrocatalytic reduction of CO,(activated CO,CO) with pyridine at a glassy carbon electrode, GCE, surface and in an acetonitrile-ButNClOsolution was investigated by cyclic voltammetry, chronoamperometry and controlled potential coulometry.By chronoamperometry, the catalytic rate constant, k, for the electron transfer between benzil and COwas obtained as 8.1 ± 0.4 Ms. The results indicate that pyridine has a strong interaction with the activated CO. The coulometry method was used to obtain the product of the pyridine chemical reaction with CO. The spectral characterizations of FTIR,H andC NMR of the coulometry experiment product proved that the pyridine anion radical, Py, was carboxylated by CO, and isonicotinic acid is the final major product.

PHOTOINITIATED CROSSLINKING OF EPDM/INORGANIC FILLER BLENDS AND CHARACTERIZATION OF RELATED PROPERTIES

Photoinitiated crosslinking of ethylene-propylene-diene terpolymer （EPDM） blends filled with calcium carbonate, talc and calcined kaolin （CK） in the presence of benzil dimethyl ketal as photoinitiator and trimethylolpropane triacrylate as crosslinker and their related properties have been studied by different analytical methods, The results from gel content and heat extension determination show that the efficiency ofphotocrosslinking of EPDM increases with increasing the content of diene and its molecular weight. The EPDM blends with 100 phr different inorganic fillers can be photocrosslinked to gel content of above 60% by 5 s UV-irradiation under optimum conditions. Under the same conditions of irradiation, the orders of photocrosslinking rate and final gel content are EPDM/CaCO3 〉 EPDM/talc 〉 EPDM/CK. The data from thermogravimetric analysis, dynamic mechanical thermal analysis, electrical properties, mechanical tests and scanning electron microscopy show that UV irradiation crosslinking apparently enhances the thermal stability, mechanical properties and electrical properties of the photocrosslinked EPDM/inorganic filler samples. Although the attenuated total-reflection FTIR data show that inorganic fillers can promote the surface photo-oxidation of EPDM/inorganic filler samples with increasing the irradiation time, the above related properties of the photocrosslinked EPDM blends irradiated within 5 s are enough to satisfy many applications in the cable industry.

Molecular Properties of 9,10-Phenanthrenequinone and Benzil

9,10-Phenanthrenequinone（PQ） and benzil are important a-diketones. This manuscript explains the first comparison of PQ and benzil molecular properties. We have used 1H NMR, 13C NMR, 1H-IH COSY, HMBC, HMQC, UV-Vis absorption and emission, CV and TGA experiments to study PQ and benzil that provided the following novel results. （1） The 1H NMR（CDC13） of PQ show δ 8.19（H1）, 8.02（H4）, 7.72（H3）, 7.47（H2） instead of an earlier reported 8.25（H4）, 8.08（H1）, 7.80（H2）, 7.55（H3）; （2） in the 13C NMR（CDCl3）, the C9/C10（C=O） signal of PQ appears upfield（6 180.3） compared to C9/Cl0（C=O） signal of benzil（6 194.5）, which shows higher electrophilic character（more attractive for nucleophiles） of C9/C10（C=O） of benzil; （3） the first 2max for the UV-Vis absorption and emission of PQ are blue-shifted compared to benzil despite increased conjugation attributed to the different symmetries（C2v for PQ and C2h for Benzil） of the two molecules; （4） the emission spectrum of benzil is broader compared to that of PQ due to slower relaxation of the excited state; （5） The CV study shows that PQ and benzil are good electron acceptors and PQ shows a better reduction process than benzil due to an extra ring that provides stability for the reduced species（mono or diradical anions）; （6） TGA shows the higher thermal stability of PQ than benzil attributed to the presence of phenanthrene unit in PQ.

Direct Electrochemical Synthesis and Crystal Structure of a New Mononuclear Copper(Ⅱ) Complex: [(bipy)_2Cu(PhCOO)]ClO_4·(benzil) (benzil = 1,2-Diphenyl-ethane-1,2-dione)

A new mononuclear copper（Ⅱ） complex [（bipy）2Cu（PhCOO）]ClO4·（benzil） （bipy = 2,2＇-bipyridine, benzil = 1,2-diphenyl-ethane-1,2-dione） was synthesized by direct electrochemical oxidation of Cu electrode in an acetonitrile solution with benzoic acid, 2,2＇-bipyridine and benzoin. As soon as the current flowed in the cell, benzoin was oxidized to benzil quickly. The crystal structure was determined by X-ray diffraction. It belongs to monoclinic system, space group P21/c with a = 14.860（2）, b = 20.784（3）, c = 11.9150（17）A, β = 101.401（3）°, V= 3607.3（9）/k^3, Z = 4, M, = 806.69, D, = 1.485 g/cm^3, F（000） = 1660, μ = 0.742 mm^-1, R = 0.0788 and wR = 0.1519 for 6254 observed reflections （I 〉 2σ（I）. The complex contains a mononuclear [（bipy）2Cu（PhCOO）] cation, a solvate benzil molecule and a ClO4^- anion which locates around the cation outside acting as the counter ion. The Cu（ll） ion is coordinated by two 2,2＇-bipyridines and one benzoato ligand to form a distorted square-pyramid.

STEREOCHEMISTRY OF THE BENZILIC ACID-TYPE REARRANGEMENT IN BASE-CATALYZED AUTOXIDATION OF 3α,5-CYCLO-5α-CHOLESTANE-6-ONE

The configuration of the hydroxy acid 2, a product from base-catalyzed autoxidation of 3α,5-cyclo-5α-cholestane-6-one,was established on the basis of NMR techniques and the mechanism of the formation of 2 was discussed.

Solid State Synthesis and Crystal Structure of 3—Methly—1—phenyl—4—phe

The solid state thermal reaction of benzil with 3-methyl-1-phenyl-5-pyrazolone gave the title compound 1 (C_24H_18N_2O_2) and its isomer 2. The crystal structure of the title compound has been determined by X-ray analysis. The crystal belongs to monoclinic system, space group P2_1/n, with cell parameters a = 7. 479 ( 1 ), b =16. 992(1), c=15. 165(1) A , β= 100. 99(1)°, V= 1891. 9 A￣3, M_r=366. 42, Z=4, D_c= 1. 286 g/cm￣3, μ= 6. 236 cm￣-1, F(000) = 768. In the molecule of 1, benzoyl group and CO group of five-member ring are in cis-positions, the interaction of oxygen atoms leads to the noncoplanarity.

Synthesis of Asymmetrical Monobenzo-Substituted Cobalt Thioporphyrazines and Their Biomimetic Catalytic Property

Two novel monobenzo porphyrazines bearing nitro and methoxyl respectively on fused benzene ring were suc- cessfully synthesized. Also, an asymmetrical porphyrazine with one butylthio branch at the pyrrolic p-position sub- stituted by hydrogen atom was successfully isolated in the course of synthesis of symmetric octakis（butylthio） porphyrazine. Their corresponding cobalt complexes were subsequently obtained and characterized. Their catalytic ability was assessed by aerobic oxidation of benzoin, showing the highest benzil yield of 95.2% for 60 min. A pos- sible mechanism was also presented from the in-situ UV-Vis spectra, in which a novel and characteristic absorption peak of metal-oxo was observed. At the same time, similar results of the extended oxidation of benzyl alcohol also confirmed the reactive mechanism.