bluuebunny/crossref_metadata_2025 huggingface dataset:
Bromination of 3‐Aryl‐4‐acetylsydnones with Potassium Bromide and Sulfuric Acid
Authors: Tien Hsien‐Ju , Lin Shaw‐Tao , Ong Geok Ton
Published: May 2015

Bromination of 3‐aryl‐4‐acetylsydnones with alkali bromide and sulfuric acid yielded 3‐aryl‐4‐dibromoacetylsydnones (R=H, Me, C1, NO2) and 3‐(3‐bromoaryl)‐4‐dibromoacetyIsydnones (R=OH, OMe, OEt) in good yields. The resultant dibromoacetylsydnones were converted to the corresponding 3‐arylsydnones with alcoholic NaOH solution.
Photopolymerization of Styrene and Methyl Methacrylate with Poiy(methylphenylsilane) as Photoinitiator
Authors: Chang T. C. , Chin Y. S. , Chen H. B. , Ho S. Y.
Published: May 2015

The rate of photochemical polymerization of styrenc (St) and methyl methacrylate (MMA) with polymcthylphenylsilane (PMPS) as initiator were measured. Polymethylphenylsilane is photodegraded to form silyl radicals that may initiate polymerization of St and MMA. The kinetic orders of polymerization reactions of initiator PMPS in St and in MMA systems are 0.49 and 0.29, respectively. The rate coefficients kp and kt are 38.1 and 0.71 × 107 Lmol‐−1s−1 in the St/PMPS system and 249.5 and 6.71 × 107 Lmol−1s−1 in the MMA/PMPS system. A polymerization reaction mechanism is proposed.
Stereoselective Hydroiodination of 3‐Substituted Derivatives of Propynoic Acid
Authors: Luo Fen‐Tair , Hsieh Li‐Chen
Published: May 2015

The hydroiodination of 3‐substituted propynoic acids and their derivatives with sodium iodide/trimethylsilyl chloride/water in acetonitrile at 25 °C gives stereoselectively (Z)‐3‐iodopropenoic acid derivatives in good yields.
Reactions with Naphthoylhydroxlmoyl Chlorides: Synthesis of Derivatives of Isoxazole, Pyrrolidino[3,4‐d]isoxazoiin‐4,6‐dione, lmidazo[1,2‐a]pyridine, lmidazo[1,2‐a]pyrimidine, Benzotriazine and Benzothiadiazine
Authors: Abdelhamid Abdou O. , Al‐Hamidi Abdulaziz A.
Published: May 2015

Hydroximoyl chlorides 3 react with acrylonitrile, N‐arylmaleimide and maleic anhydride to give isoxazolines 5, pyrrolidino[3,4‐d]isoxazolines 8, and furolidino[3,4‐d]isoxazolines 9, respectively. 3 reacted with 2‐aminopyridine, 2‐aminopyrimidine, o‐phenylenediamine and o‐aminothiophenol to yield 3‐ni‐trosoimidazo[1,2‐α]pyridines 20, 3‐nitrosopyrimidines 22, 3‐naphthoyl‐1,4‐dihydrobenzo‐1,2,4‐triazines 24, and 3‐naphthoyl‐4H‐1,3,4‐benzothiadiazine 27, respectively. Compound 3 reacted with benzoylacetonitrile, acetoacetanilide, thiophenol, benzencsulfinic acid in ethanolic sodium ethoxide solution to give the corresponding isoxazoles 12–13 and oximes 16–17, respectively. The structures of these products were confirmed by elemental analyses, spectral data and, wherever possible, alternative synthesis.
Chemical Components from Triumfetta bartramia
Authors: Ho Li‐Kang , Chang Chiann‐Rong , Chang Yuan‐Shiun
Published: May 2015

Triumfetta bartramia Linn. is a folk medicine used in Taiwan. From this plant we identified β‐sitosterol, friedelin, friedelinol, quercetin, 2,6‐dimethoxy‐1,4‐benzoquinone, and rosmarinic acid. The identification of these compounds was confirmed by spectral methods and comparison with authentic samples.
Chemical Constituents from Berchemia formosana
Authors: Lee Shoei‐Sheng , Tsai Fang‐Yen , Chen Ih‐Sheng
Published: May 2015

Centrifugal partition chromatography, Sephadex LH‐20 and flash chromatography were applied to separate flavonoids and coumarins from Berchemia formosana. This first chemical investigation led to the isolation of ten compounds. Based on spectral analysis, they were determined to be quercetin (1), rutin (2), (+)‐dihydroquercetin (3), (+)‐dihydrokaempferol (4), naringenin (5), 2‐hydroxy‐naringenin (6), 2‐hydroxy‐naringenin‐7‐O‐β‐glucoside (7), (‐)‐catechin (8), (‐)‐gallocatechin (9) and scopoletin (10). Among these 7 is a novel natural product and was found to be composed of two inseparable diastereoisomers. The presence of the rare 2‐hydroxyflavanones 6 and 7 in B. formosana is of interest for chemotaxonomy.
Inversionless Amplification in a Three‐Level System Driven by a Single Field
Authors: Fain Benjamin , Khidekel Vadim
Published: May 2015

The three‐level system subjected to electromagnetic fields is investigated. It is shown that when one of two fields is strong (the pumping field), the system can amplify the second (probe) field even if no population inversion is created, but some phase relations are satisfied. The conditions necessary for inversionless amplification to take place are discussed. The connection between this effect and stimulated Raman emission is shown. Numerical simulations for each one of the discussed cases were performed.
Dual Mechanism for CO(A1Π)‐CO(X1 ∑+) Rovibronic Energy Transfer: An OODR‐MP1 Spectroscopic Study
Authors: He Jinbao , Sha Cuohe , Jiang Bo , Zhang Cunhao
Published: May 2015

The highly versatile OODR‐MPI technique is used, mostly without resort to isotope tagging, to study the quantum state specific rovibronic energy transfer between molecules of the same species, specifically CO(A)‐CO(XJ. Two types of rovibronic energy transfer mechanisms are found to be prevailing and are differentiated experimentally, i.e., the long range near resonant dipole‐dipole interactions and the short range exciplex formation. The first type is characterized, at first unexpectedly, by its compliance to the selection rules of optical dipole transitions, ΔJ = 0, ±1 and parity + ⟷ −. Numerical computation procedures are presented for the calculation of rovibronic energy transfer cross‐sections when the two types of mechanism are operating concurrently. The computed results and their variation with J are in good accord with the experiments.
Vibrational Spectroscopy As a Probe of Surface Heterogeneity: CO on NaCl(100)
Authors: Chang Huan‐Cheng , Dai David J. , Ewing George E.
Published: May 2015

The fundamental (Δv = 1 ← 0) and the first overtone (Δv = 2 ← 0) transitions of monolayer physisorbed CO on NaCl(100) single crystal surfaces at 5 K have been investigated using polarized Fourier transform infrared spectroscopy. Comparisons of the transition frequencies, bandwidths and absorbances for these two transitions together with those of dilute isotopes allow us to isolate the contribution of dynamic and static coupling effects of molecules within the monolayer. Homogeneous and heterogeneous effects can also be distinguished from band profiles of these various transitions. We conclude that the residual line broadening of 0.1 cm−1 at 5 K for the isolated CO isotopes arises from heterogeneous surface effects. We set an upper limit of 0.07 cm−1 for the linewidth of single CO molecules on NaCl(lOO) due to surface heterogeneity. A lower limit of × 10−8 cm−1 is provided by the vibrational lifetime of adsorbed CO molecules. Sharpness of the vibrational features shows that infrared spectroscopy of adsorbate is a sensitive method for probing surface and adlayer irregularities of adsorbed molecules on a single crystal.
TEA CO2‐Laser Induced SF6 + Ba Beam‐Surface Ionization
Authors: Castaño J. , Zapata V. , Makarov G. , Ureña A. González
Published: May 2015

A TEA CO2‐laser induced SF6 + Ba beam‐surface ionization process has been studied when vibrational excitation of SF6 molecules was carried out at (and near) the polished surface of the electrically heated up to 675 K polycristalline Ba. Electron emission and negative molecular ion signal were detected. The dependence of the molecular ion signal on laser fluence and frequency (on SF6 molecular absorption) as well as on the SF6 gas pressure in the nozzle were studied. The results reveal a nonlinear, probably multiphoton character of the molecular ion formation and a clear vibrational selectivity i.e. vibrational enhancement, of the SF6 + Ba beam‐surface ionization process. Possible mechanisms of the negative molecular ion formation in the IR laser induced SF6 + Ba beam‐surface ionization process are discussed.
A Study on the Reaction of O(1D) and N2O by Trajectory Calculation and Time‐Resolved FTIR Spectroscopy
Authors: Wang Xuebin , Li Hongzhi , Zhu Qihe , Kong Fanao , Yu Huagen
Published: May 2015

O(1D) atoms, generated via the laser photodissociation of N2O at 193 nm, reacting with N2O was studied by Time‐Resolved Fourier Transform Infrared (TR‐FTIR) Spectroscopy. The IR emission from NO(v1–11.) was collected at 30 μs after the laser was fired. Several instrumental corrections were made to obtain reliable experimental results. The vibrational temperature of the nearly‐nascent NO product was estimated to be Tv  9,000 K. A Quasi‐Classical Trajectory (QCT) calculation of the reaction was performed. The calculated results, corresponding to a head‐on attack mechanism, agree with the experimental data. Additional reaction channel with side‐on attack producing N2 and O2 was also studied by QCT, where vibrationally hot O2(a 1 Δg) and cold N2(X1∑g+) products are predicted.
Molecular Beam Studies on the Laser‐Enhanced Surface Reaction of GaAs(100) with Chlorine
Authors: Qin Qizong , Zhang Kangzhan , Lu Pinghe , Zheng Qike
Published: May 2015

A cw supersonic Cl2 molecular beam coupled with an angle‐resolved time‐of‐flight (TOF) technique has been used to investigate the laser‐enhanced surface reaction of GaAs(100) with chlorine. The mass and velocity distributions of the major reaction products under 1064 nm laser irradiation have been measured as a function of laser fluence, detection angle, surface temperature and normal component of the translational energy of the incident chlorine molecules. It has been found that increasing both laser fluence and the translational energy of incident chlorine molecules markedly enhance mis surface reaction. The measured flux angular distributions of major reaction products can be fit satisfactorily with a bi‐cosine function. Measurements of the mass and angular distributions of reaction products by a modulated molecular beam mass spectrometry show that the surface temperature effect is obvious for the Cl2/GaAs(100) “dark” thermal reaction. A direct activated dissociative chemisorption is proposed for the mechanism of Cl2 chemisorption on the GaAs(100) surface.
Formation and Photodissociation of Transition Metal‐Sulfur Binary Cluster Ions
Authors: Shi Yang , Yu Zhong‐De , Zhang Nan , Gao Zhen , Kong Fan‐Ao , Zhu Qi‐He
Published: May 2015

Transition metal‐sulfur binary cluster ions were produced by direct laser ablation and analyzed with the first stage time‐of‐flight mass spectrometer (TOF‐MS). It was found that the distribution of the strong peaks of the stable cluster ions in the TOF‐MS were not appreciably affected by the composition of the sample. The composition of the most stable metal‐sulfur cluster ions, MnSm are different for various transition metals: Cu, n = 2m + I and n = 2m; Zn, m = n; Mn, m = n; Fe, m = n, m = n −1 and m = n − 2; Co, m = n − 1, m = n − 2, m = n − 3, m = n − 4 and m = n − 5; Cr, m = n and m = n + 1; Ta, m = n + 1 and m = n + 2. Cluster ions can be selected by a mass gate, and photolyzed by an excimer laser. The photodissociation product ions were analyzed with the second stage TOF‐MS. These product ions were mainly the more stable cluster ions as those given in the first stage TOF‐MS.
Aggregation Behaviour of Some Reactive Dyes
Authors: Mostafa O. I. , Abd El‐Aal A. Y. , El Bayaa A. A. , Sallam H. B. , Mahmoud A. A.
Published: May 2015

The absorption spectra of aqueous solutions of monochlorotriazine reactive dyes, C.I. Reactive Red 9 and Reactive Orange 13 were measured in the presence of 5, 10, 25 and 50% (v/v) of ethanol, pyridine and dioxane‐water mixtures and in varied concentrations of KCl, NaCl and LiCl. The varying position, intensity and shape of absorption bands are interpreted in terms of aggregation and disaggregation of dyes in solutions. The aggregation behaviour of the reactive dyes in solutions and in the presence of additives is related to their apparent deviations from Beer's law and aggregation numbers (N). The aggregation constant (K.) of the monomer/dimer equilibrium is calculated.

Dyes in ethanol‐water mixtures record a larger aggregation number and aggregation constant than in the presence of pyridine. Dioxane is classified as anon‐polar solvent and hence has a more disaggregating influence. The value of the aggregation number and constant are increased with increasing salt conentration and the order of degree of aggregation is KCl > NaCl > LiCl related to the order of ionic radii of K+, Na+ and Li+ ions.
Reactivity of Iminophosphoranes. Formation of the Piperazine Ring
Authors: Lin Tu‐Chen , Cheng Ming‐Chu , Peng Shie Ming , Liu Shiuh‐Tzung , Kiang Fu‐Mei
Published: May 2015

Reaction of 3‐azidopropyl methanesulfonate with triphenylphosphine produced the 1,4‐bis(triphenyl‐phosphino)piperazine 5 by intermolecular cyclization, instead of formation azidine derivatives by an intramolecular pathway. Structural formulation of 5 was achieved by both spectral and X‐ray crystal analysis. Hydrolysis of 5 under basic condition gives piperazine, whereas reaction of lithium diphenylphosphide with 5 produced 1,2‐bis(diphenyl‐phosphino)ethane (dppe) exclusively.
Synthesis of α‐Methyldopa Prodrugs Containing Dipeptide Moieties as Tools for Intestinal Delivery
Authors: Wang Hui‐Po , Cheng Chih‐Yuan , Ma Jin‐Ran , Lee Jia‐Shuai
Published: May 2015

Dipeptides containing D‐phenylglycine or D‐p‐hydroxyphenylglycine were attached onto the antihypertensive agent α‐methyldopa to form prodrugs 1a, 1b and 1c. The nonessential amino acids were introduced into the prodrug molecules as tools of chemical delivery to improve the intestinal absorption of the parent drug. Preliminary tests revealed that the prodrugs were stable in phosphate buffer solutions at pH 7.4 (t1/2 > 10 h). These compounds also demonstrated satisfactory stability toward enzymatic degradation in a mucosa preparation isolated from rat intestine, indicating that they might be feasibly formulated as an oral prodrug of α‐methyldopa.
Mechanistic Studies of the Biosynthesis of 3,6‐Dideoxysugars in Bacteria: Exploration of a Novel C‐O Bond Cleavage Event
Authors: Liu Hung‐Wen , Thorson Jon S. , Miller Vaughn P. , Kelley Theresa M. , Lei Yenyoung , Ploux Olivier , He Xuemei , Yang Ding‐Yah
Published: May 2015

Deoxy sugars are ubiquitous in nature and contribute to diverse biological activities. Attempts to design systems to control or to mimic their functions are hampered, however, by the lack of biosynthetic knowledge of these unique sugars. To elucidate the mechanism by which the sugar deoxygenation is effected, we have initiated a study to explore the biosynthesis of CDP‐ascarylose, a 3,6‐dideoxyhexose found in the lipopolysaccharides of Yersinia pseudotuberculosis, and our initial focus centered on C‐3 deoxygenation catalyzed by E1 and E3. We have now purified the wild‐type enzymes, cloned the corresponding genes (ascC for E1 and ascD for E3), and overexpressed the gene products in Escherichia coli. The purified E3 is a flavoprotein comprising an iron‐sulfur center and E1 is an iron‐sulfur containing, pyridoxamine 5′‐phosphate‐de‐pendent enzyme. Since these iron‐sulfur clusters are well known one‐electron carriers, reactions mediated by E1 and E3 must proceed via a radical mechanism. Recently, EPR analysis of E1/E3 catalysis indicated a potential new redox role for pyridoxamine as a cofactor. These findings make this system unique from two perspectives: E1 is the only coenzyme B6‐dependent catalyst that interacts with a sugar and not with an amino acid, and it is the first example in which coenzyme B6 may facilitate one‐electron redox chemistry. Thus, the unprecedented mechanisms of E1 and E3 distinguish this system as a novel radical deoxygenation with potentially interesting future developments.
Enantioselective Aldol Type Reactions of Acetate Titanium Enolate with α,β‐Unsaturated Aldehyde‐TiCl4 Complex
Authors: Yan Tu‐Hsin , Hung An‐Wei , Lee Hui‐Chun , Liu Wen‐Hung , Chang Chii‐Shin
Published: May 2015

The camphor‐derived N‐acetyloxazolidinethione has been used to effect enantioselective aldol type reaction of the derived thioimide titanium enolate with unsaturated aldehyde‐TiCl4 complex. The observed facial selectivity is best explained by an open transition state model.
P‐C Bond Cleavage in Platinum Complexes Containing bis (Diphenylphosphino) Methane Promoted with a Phase‐Transfer Catalyst
Authors: Lin Ivan J. B. , Shen H. I. , Feng And Da‐Fa
Published: May 2015

With a phase‐transfer catalyst, Pt‐dppm (dppm = Ph2PCH2PPh2) complexes undergo basic hydrolysis, in which a dppm ligand is hydrolyzed to produce PPh2Me and PPh2OH (or PPh2O). The ease of this hydrolysis reaction depends partly on the molecular charges of the metal complexes. Hydrolysis of neutral [Pt(dppm)(L‐L)] (L‐L = S2CO2, S2P(O)(OEt)2− and mnt = S2C2(CN)22−) is slower than that of monocationic [Pt(dppm)(L′‐L′)]Cl (L′‐V = S2CNEt2‐, (CH2)2S(O)Me and acetylacetonate) compounds. Among the neutral compounds, hydrolysis of [Pt(dppm)(mnt)] is more rapid than that of the other two. These results are rationalized according to the ease with which partial positive charges are induced on the dppm phosphorus atoms. The steric effect due to ligands trans to dppm also influences the rate of hydrolysis of Pt‐dppm compounds. When trans ligands are Ph2P(CH)2PPh2, Ph2P(CH2)3PPh2 and (Ph2PO2)H, no hydrolysis of dppm occurs. Hydrolysis of Pt‐dppm compounds depends further on the concentrations of both the phase‐transfer catalyst and OH− ions. All these results are consistent with nucleophilic attack of OH− on dppm phosphorus atoms to release strain in the Pt‐dppm ring.
Oxidation of Alkenes and Sulfides with Transition Metal Catalysts
Authors: Liao Jen‐Hai , Cheng Kuang‐Yuan , Fang Jim‐Min , Cheng Ming‐Chu , Wang Yu
Published: May 2015

Alkenes and sulfides were oxidized with transition‐metal catalysts. The oxidant sources include molecular dioxygen, air and iodosylbenzene. The metal ions Mn(III), Fe(III), Co(II) and Ni(II) were used. The Catalysts 1‐18 of 1,3‐dioxo‐, β‐ketoimine‐ or salen‐types were prepared and their efficacy was examined. 1,2‐Dihydronaphthalene is most efficiently epoxidized with O2/Me2CHCHO or PhIO in the presence of Mn(III)‐salen catalysts. The Ni(II)‐, Co(II)‐ and Fe(III)‐catalysts of either β‐ketoimine‐ or salen‐types are useful for epoxidation of styrene, (E)‐stilbene and (E)‐benzalacetone in the O2/Me2HCHO system; these epoxidations are stereospecific without formation of corresponding diastereomeric epoxides. Oxidation of methyl p‐tolyl sulfide with O2/Me2CHCHO is facilitated by the 1,3‐dioxo‐catalyst Co(II)‐1. Monooxidation is achieved with Me2CHCHO in equimolar proportions to give the corresponding sulfoxide, whereas overoxidation is realized with excess Me2CHCHO to give the sulfone. These epoxidation and sulfide oxidations all occur at 25 °C and are complete in less than a day.
Cyanation of the Seven‐Membered Ring of Diethyl Azulene‐1,3‐Dicarboxylate
Authors: Morita Tadayoshi , Sasaki Kazuo , Lin Bing Bing , Lin Yuan‐Shan
Published: May 2015

Reaction of diethyl azulene‐1,3‐dicarboxylate with potassium cyanide in dimethoxyethane gave diethyl 4‐cyano‐, 6‐cyano‐, and 4,6‐dicyanoazulene‐1,3‐dicarboxylates. This cyanation involved addition of acyanide ion to the seven‐membered ring of azulene to form a cyclopentadienide ion, followed by oxidation.
Thermophysical Properties of Cholesteryl Oleyl Carbonate Determined with Microscopic Ftir/Dsc System
Authors: Lin Yih‐Yih , Chen Ko‐Shao , Lin Shan‐Yang
Published: May 2015

A microscopic Fourier transform infrared spectrometer (Micro FTIR) equipped for differential scanning calorimetry (DSC) was used to measure simultaneously the chemical structural variation and the thermal response of phase transition of cholesteryl oleyl carbonate (COC). The differential scanning calorimeter served also to determine the phase transitions of COC during heating or cooling. Two endothermic features due to phase transition were found in the thermogram: 18. 3 °C for a smectic‐cholesteric transition and 37.5 °C for a cholesteric‐isotropic transition during heating; 35.1 °C for an isotropic‐cholesteric transition and 15.8 °C for a cholesteric‐smectic transition during cooling. The breadth of the feature indicated sluggish phase transitions. The three‐dimensional plot indicated that the intensities of lines due to the C‐H stretching and scissoring deformation modes and C=O stretching mode of COC decreased suddenly near the temperature of phase transition during heating but the intensity of the line dues to the C‐O stretching mode of carbonate ester of COC increased. Lattice vibrations or coupling of vibrational modes might be responsible for the result. These intensities in the cooling process varied inversely to those in heating process.
An Efficient and Highly Chemoselective Method to Desilylate Silyl Ethers
Authors: Lee Adam Shih‐Yuan , Yeh Hsiu‐Chih , Yeh Ming‐Kuo , Tsai Ming‐Hung
Published: May 2015

An efficient and highly chemoselective desilylating method is described. Trimethylsilyl ethers (0.25 M) in a CH3OH/CCl4 (1:1) solvent mixture are deprotected to their corresponding alcohols with ultrasound in a commercial ultrasonic cleaning bath. Selective deprotection of tert‐butyldimethylsilyl ethers of benzyl alcohols and phenols is achieved under ultrasonic conditions. We deprotected also tert‐butyldimethylsilyl ethers of primary alcohols, whereas tert‐butyldimethylsilyl ethers of secondary and tertiary alcohols are stable under these conditions.
Methylation of Aniline Over SAPO‐11
Authors: Yang Sze‐Ming , Pan Tzuu‐Wanq
Published: May 2015

Methylation of aniline over a mildly acidic siliconaluminium phosphate catalyst (SAPO‐11) with medium pores is reported. The selectivity of N‐methylates products is about 90%. By comparison with results obtained from SAPO‐5 with large pores and with amorphous aluminium phosphate, molecular sieves with medium pores prevent the formation of bulky isomers and better resist formation of coke. The ortho isomer is most abundant among toluidine isomers. Some ortho isomers may result from the rearrangement of N‐methylaniline.
Azeotropic Distillation‐ and Ultrasound‐Promoted Lipase‐Catalyzed Reactions
Authors: Lin Gialih , Liu Hsiao‐Chien , Liu Shih‐Huang
Published: May 2015

Lipase from porcine pancreas was demonstrated to catalyze reactions under azeotropic and ultrasonic conditions. Reaction rates were significantly enhanced 3 to 60‐fold by applying azeotropic distillation and 7 to 83‐fold by applying ultrasonication. For both conditions, enantioselectivities were retained.
Roripanoside, a New Kaempferol Rhamnoside from Rorippa Indica (L.) Hiern
Authors: Lin Yun‐Lian , Kuo Yueh‐Hsiung
Published: May 2015

Extracts of the whole herb of Rorippa indica contain benzoic acid, ferulic acid, vanillic acid, gallic acid, glucosyl sinapinate, β‐sitosteroyl‐3‐O‐β‐glucoside, quercetin‐7‐O‐rhamnoside, kaempferol, kaempferol‐3‐O‐β‐glucoside, −7‐O‐β‐glucoside, −7‐O‐rhamnoside, −3‐O‐arabinoside, and −3‐O‐glucosyl‐7‐O‐rhamnoside together with a new compound, roripanoside. The new compound was elucidated as kampferol‐7‐O‐(6″′‐O‐caffeoyl)glucosyl (1 → 4) rhamnoside on the basis of spectral and chemical evidence.
Reduction of Acetylsydnones with Borohydride Anion: Preparation of 4‐(1‐Hydroxyethyl) Sydnones
Authors: Tien Hsien‐Ju , Cherng Jye‐Yu , Lin Shaw‐Tao
Published: May 2015

Acetyl group on the sydnone ring can be reduced by using NaBH4 in MeOH solution in good yields. Acetyl group on the sydnone ring is less reactive for reduction than that on a phenyl ring when both rings are present.
Oxidations of 4‐ and 3‐Aminopyridinepentaammineruthenium(ii) Complexes by Ethylenediaminetetraacetatocobaltate(III)
Authors: Chien Chiu Feng , Chen Chang‐Nan , Yang Wen Yi , Yeh Andrew
Published: May 2015

Redox reactions of Co(edta)− with Ru(NH3)5L2+ (L = 3‐ and 4‐aminopyridine (AmPy)) were found to follow an outer‐sphere electron transfer mechanism. The specific rate constants are (3.26 ± 0.03) × 102 and (3.07 ± 0.04) × 103 M−1S−1, for L = 3‐ and 4‐AmPy, respectively, at μ, = 0.10 M LiClO4, pH = 8.0 (tris) and T = 25 °C. The rate constants of oxidations for a series of Ru(NH3)5L2+ complexes are higher than those of the corresponding Fe(CN)5L3‐ complexes by factors of 4 to 15 even after corrections for differences in reduction potentials and in charges of the complexes. Nonadiabaticity in the reactions of Fe(CN)5L3 complexes may account for the difference in the relative reactivities.
Secoiridoid Glycosides from Jasminum Polyanthum
Authors: Shen Ya‐Ching , Lin Shao‐Ling , Hsieh Pei‐Wen , Chein Chyh‐Cbung
Published: May 2015

Chemical investigation of the ethanolic extract of Jasminum polyanthum Franch has resulted in the isolation of verbascoside (10) and 9 secoiridoid glycosides including oleoside dimethyl ester (1), 10‐hydroxy oleoside dimethyl ester (2), oleoside 11 methyl ester (3), methyl‐glucooleoside (4), 8‐epikingiside (5), ligustroside (6), angustifolioside B (7), oleuropein (8), and oleoacetoside (9). The structures of 1‐10 were established primarily on the basis of NMR analysis.
Structure and Synthesis of Simulansamide, a Platelet Aggregation Inhibitor from Zanthoxylum Simulans
Authors: Wu Shwn‐Jen , Chen Ih‐Sheng , Chem Ching‐Yuh , Teng Che‐Ming , Wu Tian‐Shung
Published: May 2015

Simulansamide, isolated from the root bark of Zanthoxylum simulans, shows strong inhibition of platelet aggregation. The structure of this compound was deduced from spectral data and verified by synthesis.
Specific Uphill Transport of Zinc as Zn(SCN)42− Ion using Na+‐Dicyclohexyl‐18‐Crown‐6 as Carrier
Authors: Akhond Morteza , Shamsipur Mojtaba
Published: May 2015

Sodium‐dicyclohexyl‐ 18‐crown‐6 complex cation was used as carrier for the uphill transport of zinc as Zn(SCN)42− complex anion. By using L‐cysteine as a metal ion acceptor in the receiving phase at the optimized pH of 7.6, the amount of zinc transport through the liquid membrane after 90 min was 97.2 ± 1.0%. The selectivity and efficiency of zinc transport from aqueous solutions containing equimolar mixtures of Ag+, Cd2+ Co2+, Cu2+, Fe2+, Ni2+, Pb2+, Pd2+, Sr2+, Bi3+, Cr3+ and Fe3+ ions was investigated. In the presence of NH2OH.HCl as a suitable masking agent in the source phase, the interfering effect of Cu2+ and Pb2+ ions was diminished drastically.
Chemical Transformations of (2,3,9,10‐Tetramethyl‐1,4,5,7,8,11,12,14‐Octa‐Azacyclotetradeca‐1,3,8,10‐Tetraenato)Cobalt(II)Perchlorate
Authors: You Yuan‐Shyane , Lee Gene‐Hsiang , Peng Shie‐Ming
Published: May 2015

The monomeric octa‐aza bis‐α‐diimine macrocyclic complex [CoII(C10H20N8)(H2O)](ClO4)2 I, undergoes various reactions on the macrocyclic ligand. Reaction of complex I with triethylamine in double molar proportions, followed by slow aerial oxidation, produces a molecular dimeric complex [CoII(C10H14N8)]2, III, and a novel Co(I) complex [CoI(C10H19N8)], IV. Complex III is a staggered cofacial dimer with a cobalt‐cobalt bond length 2.86(1) Å. The macrocyclic ligand of the complex contains an a‐diimine function in each five‐membered chelate ring, and a three‐atom N‐C‐N− delocalized system in each six‐membered chelate ring. Complex IV has the 5‐5‐6‐6 chelate arrangement because one α‐diimine moiety is rearranged to a syn‐anti configuration. In the structure, the two fused six‐membered chelate rings are fully conjugated and the two fused five‐membered rings are saturated. However, when complex I reacts with excess triethylamine under the similar conditions, a dimeric complex of another type, [CoII(C10Hl6N8)]2, II, was generated, in which one N‐N bond of the macrocyclic ligand is broken. Complex IV can be isolated also from the reaction of complex I with excess hydrazine, followed by slow aerial oxidation. When hydrazine in double molar proportions was used, complex [CoI(C10H17N8)(NHNH)] V, which contains a coordinated diazene ligand, was obtained. Only one six‐membered chelate ring of complex V is deprotonated and oxidized to form a three‐atom N‐C‐N− delocalized system. The structures of octa‐aza complexes I‐V are determined by X‐ray crystallography: I, orthorhombic, C mca, a = 11.646(4), b = 17.049(3), c = 10.706(3) Å, Z = 4, R = 0.045, Rw = 0.047, based on 1024 reflections with I > 2σ(I); II, monoclinic, P 21/c, a = 9.814(3), b = 22.583(6). c = 14.632(9) Å, β = 98.90(5)°, Z = 4, R = 0.085, Rw = 0.101, based on 2033 reflections with I > 2σ(I); III, tetragonal, P 4/nmm, a = 15.614(3), c = 6.498(2) Å, Z = 4, R = 0.081, Rw = 0.115, based on 340 reflections with I > 2σ(I); IV, orthorhombic, P bca, a = 8.484(1), b = 16.662(3), c = 18.760(2) Å, Z = 8, R = 0.029, Rw = 0.024, based on 1441 reflections with I > 2σ(I); V, monoclinic, P 21/m, a = 7.892(3), b = 11.713(6), c = 9.326(4) Å, β = 108.03(3), Z = 2, R = 0.047, Rw = 0.056, based on 948 reflections with I > 2σ(I).
Formation of 3‐Bromo‐1,5‐ and −1,7‐Azulenequinones from 1‐Alkyl‐and 1‐Phenylazulenes by Substituent Extrusion on the Bromine‐ Oxidation in Aqueous THF. Remarkable Substituent Effects on the Product Distribution
Authors: Wakabayashi Hidetsugu , Takano Akifumi , Shindo Kimio , Yasunami Masafumi , Chen Jhy‐An , Yang Paw‐Wang , Nozoe (The Late) Tetsuo
Published: May 2015

Oxidation of 1‐ethyl‐, 1‐propylazulenes, and their 5‐isopropyl derivatives with bromine gave 3‐bromo‐1,5‐ and 3‐bromo‐l,7‐azulenequinones (Type A) together with 3‐bromo‐l‐hydroxy‐5‐isopropyl‐l‐alkylazulen‐7‐one and its isomeric products (Type B), while the same reaction of 1‐methylazulenes afforded Type B products along with many unidentified products. On the other hand, 1‐phenylazulene gave 3‐phenyl‐1,5‐ and 3‐phenyl‐l,7‐azulenequinones (Type C) and Type B products in high yie]ds. 1,2‐Polymethyleneazulenes afforded a considerable amount of 3‐bromo‐2‐(ω‐formylalkyl)azulenequinones together with Type B products. Possible pathways for the extrusion of the alkyl substituent at C‐l are discussed.
Coking and Deactivation of H‐ZSM‐5 Zeolites during Ethylbenzene Disproportionation: I. Formation and Location of Coke
Authors: Chen Wen‐Hua , Jong Sung‐Jeng , Pradhan Ajit , Lee Ting‐Yueh , Wang Ikai , Tsai Tseng‐Chang , Liu Shang‐Bin
Published: May 2015

The mode of deactivation and coke formation in a H‐ZSM‐5 zeolite during ethylbenzene disproportionate has been investigated by TGA, adsorption, IR, and 129Xe NMR techniques. The initial rate of deactivation and the total coke content are found to increase with increasing conversion level. Within the range of conversion (54‐63%) covered in the present study, the location and extent of coke deposition can be divided into three distinct regions. At low coke content, coke is found to deposit on the Brønsted acid sites and resulted in a notable decrease in catalytic activity. As the amount of coke increases (≤ 7 wt%), while the catalytic activity decreases slightly, most of coke still tends to deposit within the zeolite channels. The slight decrease in catalytic activity is ascribed to steric hindrance by coke residues. When the coke content exceeds 7 wt%, while the activity remains almost constant, the deposition of coke on the external surface of the zeolite crystallites is evident. It is found that neither the pore opening nor the acid site were completely blocked off by coke residues even at the highest coke loading.
The Versatile Synthesis of Azulenothiazole Derivatives
Authors: Huang Tian‐Chyuan , Lin Yun‐Shan
Published: May 2015

6‐Methoxy‐2‐methylazuleno[6,5‐d]thiazole 5, 2‐benzamidoazuleno[6,5‐d]thiazole 13 and its 6‐methoxy derivative 10 were obtained by the decarbethoxylation of the diethyl 6‐methoxy‐2‐methylazuleno[6,5‐d]thiazole‐5,7‐dicarboxytate 4, diethyl 2‐benzamidoazuleno[6,5‐d]thiazole‐5,7‐dicarboxylate 12 and ite 6‐methoxy derivative 9, respectively. The latter compounds were synthesized from diethyl 6‐amino‐2‐hydroxyazulene‐l,3‐dicarboxylate 1, diethyl 5‐bromo‐6‐amino‐2‐acetylaminoazulene‐l,3‐dicarboxylate 6b and diethyl 5‐bromo‐6‐amino‐2‐hydroxyazulene‐l,3‐dicarboxylate 6a in a few steps, by previous methods.
Synthesis, Characterization, and Thermotropic Properties of Liquid Crystals with an Oligo (Ethylene Oxide) Monomethyl Substituent I: Biphenyl‐Based Systems
Authors: Chang‐Chien Guo‐Ping
Published: May 2015

New alkene liquid crystals 4‐[oligo(ethylene oxide)o, monomethylether)carbonyl]phenyl 4‐[4(allyloxy) phenyl]benzoate(MBPBEn, n = 1‐3), 4′‐[oligo(ethylene oxide)o, monomethylether)carbonyl]biphenyl‐4‐yl 4‐[4‐(al1yloxy)phenyl]benzoate(MBPBPEn, n = 1‐3), (S)‐4‐[(2‐methyl‐I‐butoxy)carbonyl]phenyl 4[4‐(allyloxy)phenyl]benzoate(MBPBKA), and (S)‐4′‐[(2‐methyl‐l‐butoxy)carbonyl]biphenyl‐4‐yl 4‐[4(allyloxy)phenyl]benzoate(MBPBPKA) were synthesized and characterized using 1H‐NMR and elemental analysis methods. The thermal transition temperatures, mesomorphic properties, and mesophase textures of these compounds have been determined by differential scanning calorimetry (DSC), by polarizing optical microscopy, and by X‐ray diffraction analysis. The effect of changes in chemical structure on the mesophase properties, mesophase and isotropic transition temperatures, and mesophase textures are discussed.
Oxidative Addition of Diphenyl Disulfide/Thiophenol to [Mn(CO)5]−: Crystal Structure of cis‐[Mn(CO)4(SPh)2]−
Authors: Liaw Wen‐Feng , Ching Chao‐Yi , Lee Chen‐Kang , Lee Gene‐Hsiang , Peng Shie‐Ming
Published: May 2015

Oxidative addition of diphenyl disulfide to the coordinatively unsaturated [Mn(CO)5]− led to the formation of low‐spin, six‐coordinate cis‐[Mn(CO)4(SPh)2]−. The complex cis‐[PPN][Mn(CO)4(SPh)2] crystallized in monoclinic space group P21/c with a = 9.965(2) Å, b = 24.604(5) Å, c = 19.291(4) Å, β = 100.05(2)°, V = 4657(2)Å3, and Z = 4; final R = 0.036 and Rw = 0.039. Thermal transformation of cis‐[Mn(CO)4(SPh)2]− to [(CO)3Mn(μ‐SPh)3Mn(CO)3]− was completed overnight in THF at room temperature. Additionally, reaction of [Mn(CO)5]− and PhSH in 1:2 mole ratio also led to cis‐[PPN](Mn(CO)4(SPh)2]. Presumably, oxidative addition of PhSH to [Mn(CO)4]− was followed by a Lewis acid‐base reaction to form cis‐[Mn(CO)4(SPh)2]− with evolution of H2.
Synthesis and Biological Evaluation of New Fused Thiazolo[4,5‐d] Pyridazine Derivatives
Authors: Makki Mohamad S. I. , Faidallah Hassan M.
Published: May 2015

The synthesis of thiazolo[4,5‐d]pyridazines and the unknown ring systems, thiazolo[4,5‐d]‐1,2,4‐triazolo‐ and tetrazolo[4,3‐b]pyridazines as well as thiazolo(4,5‐d]pyridazino[2,3‐c]2H triazines, has been achieved according to different pathways. Biological testing of the new tricyclic heterocycles revealed that some of these compounds possess remarkable antibacterial activity.
Acute Toxicity of Cresols to Pseudomonas — An Initial Oxygen Uptake Method
Authors: Huang Ded‐Shih , Tseng I‐Cheng , Liou Huie‐Yun , Huang Chi‐Ming
Published: May 2015

Acute toxicity of cresols to both Pseudomonas I and II was estimated by an initial oxygen uptake method. Inhibition studies of toluene and cresols on the oxidation of either benzoate by Pseudomnas I or phenol by Pseudomonas II were analyzed and expressed as oxygen uptake rates. Double reciprocal plots for the inhibiton by cresols of oxygen uptake in Pseudomonas, two physical constants, Vmaxi and Ki, were obtained. The Vmaxi of o−, m− and p‐cresol were 80%, 81% and 57% of Vmax in Pseudomnas I, and 10%, 25% and 36% in Pseudomonas II, respectively. Thus, the toxicity to Pseudomonas I decreases in the order p‐ > o‐ ≥ m‐cresol, whereas to Pseudomonas II, the order is changed to o‐ > m‐ > p‐cresol. This difference in the toxicity order is probably due to the allosteric effect of p‐cresol towards Pseudomonas II.

Inasmuch as most compounds inhibit noncompetively, the relative toxicity of different compounds can be estimated by a new toxicity parameter RI (relative inhibition) which is defined as 100/Ki. By comparing the RI value of each compound, the toxicity to Pseudomonas I decreases in the order m‐chlorophenol > p‐cresol > p‐chlorophenol > o‐cresol ≥ m‐cresol > o‐chlorophenol > toluene > phenol.
Bicyclo[3.2.1]octenones as Building Blocks in Natural Product Synthesis (V): Formal Synthesis of (±)‐Specionin
Authors: Chang Meng‐Yang , Chang Chi‐Peng , Chang Nein‐Chen
Published: May 2015

A formal synthesis (±)‐specionin (1) is described. The key intermediate is tricyclic ketone 4.
Excited‐State Double Proton Transfer in 1‐Azacarbazole Hydrogen Bonded Complexes
Authors: Chang Chen‐Pin , Yen Fu‐Hsiang , Chou Pi‐Tai , Wei Ching‐Yen
Published: May 2015

Excited‐state double proton transfer (ESDPT) has been studied in a variety of 1‐azacarbazole (1AC) hosted hydrogen‐bonded complexes. In 1 AC/carboxylic acids hydrogen bonded complexes, large association constants of > 1.0 × 104 M−1 are measured in the ground state and the rate of ESDPT is » 5.0 × 109 s−1, resulting in a dominant proton‐transfer tautomer emission. In several 1 AC/lactam hydrogen bonded complexes, however, spectral and dynamic results show the existence of a fast excited‐state equilibrium between normal and proton‐transfer tautomer states. The result can be tentatively rationalized by a non‐catalytic ESDPT mechanism incorporating tautomerization energy of the guest molecule.
Chelating Properties of γ‐Aminobutyrohydroxamate Resin toward Lanthanides
Authors: Lee N‐Ming , Liu Chuen‐Ying
Published: May 2015

γ‐Aminobutyrohydroxamate resin that simulate siderophore analogues was prepared. The structure and conversion of functional groups of the resin were confirmed with IR spectra and elemental analysis. The influence of pH on adsorption of metal ions to the resin was examined. Uptake of metal ions increased with pH and was quantitative in the pH range of 4 to 6 for most of the lanthanides. These metal ions showed high exchange rates towards the resin. The complexation behavior of the resin was also investigated by means of IR and potentiometry. The dissociation constant, pKa of the hydroxamic hydroxyl group is 9.36. Stability constants of the insoluble lanthanide complexes on the resins were measured potentiometrically at 25 ± 0.1 °C and ionic strength of 0.1 M KCl. The results were compared with those of the corresponding soluble lanthanide complexes. It was found that a higher stability of the resin resulted in an increase of the stability constants. The phenomena might be due to the length of the spacer in providing the proper geometry of the resin ligand for intramolecular metal complexation.
Reactions with Hydrazidoyl Halides XII Synthesis of Pyrazolo[5,1‐c]‐1,2,4‐triazine, Selenadiazolo[3,2‐a]quinazolones, Selenadiazoline, Thiadiazoline and Thiazole Derivatives
Authors: Hassan Nabil M. , Fahmi Abdelgawad A. , Abd‐El‐Mageid Fouad F. , Abdelhamid Abdou O.
Published: May 2015

Several new pyrazolo[5,I‐c]triazine, selenadiazoline, thiadiazoline, selenadiazolo[3,2‐a]quitiazolone, and arylazothiazole derivatives were synthesised by the reaction of hydrazonoyl halides with different reagents. The structure of new heterocycles were assigned on the basis of their elemental analysis, spectral data, and alternate synthesis whenever possible.
Preparation and Characterization of a Heteronuclear μ‐Alkyne Complex; X‐Ray Crystal Structure of MoCo(CO)4(PPh3){μ‐HCCSiMe3)(η5‐C5H5)
Authors: Hong Fung‐E , Hung Chang‐Ku , Lin Chu‐Chieh
Published: May 2015

Reaction of MoCo(CO)5(PPh3)2(η5‐C5H5) (1a) with trimethylsilylacetylene in tetrahydrofuran at 58° C yielded two acetylene bridged heterobimetallic compounds, MoCo(CO)4(PPh3){μ‐HCCSiMe3}(η5‐C5H5) (4) and MoCo (CO)5{μ‐HCCSiMe3}(η5‐C5H5)(5). (4) was characterized by mass, infrared, 1H, 13C and 31P NMR spectra. The X‐ray crystal structure of (4) was determined:triclinic, P‐1, a=8.821(1) Å, b=11.315(3) Å, c=17.029(2) Å, α=70.73(1)°, β=78 .72(1)°, γ=86.10(2)°,V =1573.4(6) Å3, Z=2, R = 3.92%,Rw = 6.06% for 4285 (F > 4σ (F)) observed reflections. The core of this molecule is a quasi‐tetrahedron containing Mo, Co and two carbons of acetylene. The triphenylphosphine ligand is attached to cobalt rather than molybdenum center.
A Facile Synthesis of Aldehyde and Ketone via Senochemical Barbier Reaction and Oxidation
Authors: Lee Adam Shih‐Yuan , Kung Chih‐Chun
Published: May 2015

Methyl ketone is prepared by a sonochemical Barbier reaction of methyl iodide, magnesium powder and aldehyde in Benzene/THF (9/1) solvent in a commercial ultrasonic cleaning bath (39 kHz), followed by the addition of N‐chlorosuccinimide (NCS) as an oxidizing agent.
Simultaneous Determination of Carbohydrates and Amino Acids by Capillary Zone Electrophoresis with Constant Potential Amperometric Detection at a Copper Electrode
Authors: Hsi Tai‐Sung , Lin Jia‐Neng , Kuo Keng‐Yu
Published: May 2015

Capillary zone electrophoresis with end‐column amperometric detection at a copper microdisk electrode (100 μm in diameter) was successfully applied for simultaneous determination of carbohydrates and amino acids. Under the separation voltage of 27 kV and the separation electrolyte of 80 mM NaOH in a 75 cm fused silica capillary (10 μm i.d. × 375 μmU o.d.), complete separation of a standard mixture containing 9 carbohydrates and 12 amino acids was achieved in less than 25 min. With the electrokinetical injection of 5.4 s at 27 kV and the detection potential of 0.62 V vs. Ag/AgCl, the detection limits (S/N = 3) were 0.22–0.65 ppm (1.2–1.9 μM) for carbohydrates and 0.31–6.5 ppm (2.3–39 μM) for amino acids, respectively. The calculated numbers of theoretical plates were between 41,000 and 190,000. The use of this method for analysis of carbohydrates and amino acids in a urine sample was demonstrated.
An Investigation on the Effect of Arsenic Poisoning on Humans, Agriculture, and Fisheries
Authors: Chen Syhi‐Hwan
Published: May 2015

The purpose of this investigation is to try and understand the degree of arsenic poisoning in the waste water from agricultural chemical factories which release effluents into the waterways in their vicinity. The method of determination is to use the water samples, soil, fish, clams, shell‐fish, etc. found in the areas along the canals and aqueducts and those which lie upstream, midstream, and downstream and also the hair samples of people living in the contiguous areas, to check for the levels of arsenic in them by emission spectroscopy.

From the analysis during a one year investigation, we find that the level of As in the water creatures of Chungkang Stream and Lu‐Er‐Men Stream is much higher than in the other water areas of Taiwan such as along beaches and the other rivers; the levels in the hair of the people who live nearby these water courses have a certain degree of correspondence with their eating habits and the quantity of food eaten; however, even those people who eat relatively little have almost 3% As, beyond the 2 mg/kg limit allowed for human beings. We are fully aware of the high level of food contamination on Taiwan, and this fact has been taken into consideration. The effect of As contamination in the soil on agricultural produce does not seem to have any apparent relationship. By the way, the influence of the monthly average rainfall on As contamination in the soil is not obvious.
Relaxivity Study and X‐ray Structure of Gd(III)‐diethylenetriamine‐N,N′,N′‐triacetic‐N,N″‐bis(benzylamide). A Potential MRI Contrast Agent
Authors: Wang Yun‐Ming , Cheng Tsann‐Hwang , Sheu Reu‐Sheng , Chen I‐Ting , Chiang Michael Y.
Published: May 2015

The new bis(amide) derivatives of DTPA (diethylenetriamine‐N,N,N′,N″,N″‐pentaacetic acid), diethylenetriamine‐N,N′,N″‐triacetic‐N,N″‐bis(benzylamide) (DTPA‐BBA) have been synthesized. The crystal structure of gadolinium(III) complex of DTPA‐BBA ([Gd(DTPA‐BBA)]) has been determined by X‐ray crystallography: C28H52GdN5O17, Mw = 889 g mol−1, space group \documentclass{article}\pagestyle{empty}\begin{document}$ {\rm P}\bar 1 $\end{document} (#2) (triclinic), a = 12.645(4), b=14.125(8), c = 12.623(4) Å, α = 111.60(3), β = 114.79(3), γ = 88.39(4)°, V = 1881(1) Å3, Z = 2, Dx = 1.569 g/cm3, λ(Mo Kα) =0.71069 Å, μ = 18.44 cm−1, final R = 0.047, Rw = 0.046 for 3755 independent observed reflections at 23 °C. The coordination sphere of Gd(III) comprises three amine nitrogens, two amide oxygens, three carboxylic acid oxygens, and one water. The relaxivity of Gd(III) complex was determined to be R1 = 4.08(4) and R2 = 6.06(5) dm3 mmol−1 s−1 at pH = 7.0, 20 MHz, and 37(1) °C. Additionally, the R1 relaxivity for Gd(III) chelate was found to be invariant with respect to pH changes over the range of 2‐10. This indicates that a constant inner‐sphere hydration number is associated with the [Gd(DTPA‐BBA)] complex. Hence the high stability of the complex is demonstrated.
Platelet Aggregation Inhibitor from Ganoderma lucidum
Authors: Wu Tian‐Shung , Shi Li‐Shian , Kuo Sheng‐Chu , Cherng Ching‐Yuh , Tung Shu‐Fang , Teng Che‐Ming
Published: May 2015

Lucidenic acid A (1) and a new lactone, lucidenolactone (2) were isolated from the fruiting bodies of Ganoderma lucidum. Their structures were elucidated by spectroscopic method and single‐crystal X‐ray analysis. Lucidenolactone (2) showed significant antiplatelet aggregation activity. The NMR spectral data of lucidenic acid A were also reassigned.
Preparation of Aluminum Alkoxides and Crystal Structures of [Al{(S)‐(‐)‐μ‐OC(H)(CH3)C(Ph)2OH}Cl2]2·2Et2O and [(μ‐O(CH2)2OPh)AlMe2]2
Authors: Ko Bao‐Tsan , Lee Ming‐Der , Lin Chu‐Chieh
Published: May 2015

The reaction of (S)‐(‐)‐1, l‐diphenyl‐propane‐1,2‐diol with AlCl3 in diethyl ether furnishes the product [Al((S)‐(‐)‐μ2‐OC(H)(Me)C(Ph)2OH)Cl2]2 1, which decomposes slowly above 25 °C. Complex 1·2Et2O Crystallizes in the non‐centrosymmetric monoclinic space group P21 with a=10.591(1) Å, b=16.718(1) Å, c = 12.156(2) Å, β=99.30(2)°, V = 2124.1(3) Å3, z = 4, R = 4.67%, Rw=4.84%, GoF=1.14. The structure of 1 shows a dimer feature, which is hydrogen bonded to two diethyl ether molecules. In the reaction of 2‐phenoxyethanol with AlMe3, the dimeric [(μ‐O(CH2)2OPh)AlMe2]2 is obtained in high yield. 2 crystallizes in the monoclinic space group P21/c with a = 7.398(2) Å, b = 7.376(2) Å, c = 20.710(2) Å, β = 90.56(2)°, v = 1129.9(4) Å3, z=4, R=5.70%, Rw=7.15%, GoF=1.59.
The Studies of Microwave Effects on the Chemical Reactions
Authors: Chen Shui‐Tein , Tseng Ping‐Hui , Yu Hui‐Ming , Wu Chi‐Yue , Hsiao Kwo‐Feng , Wu Shih‐Hsiung , Wang Kung‐Tsung
Published: May 2015

Microwave heating involves direct absorption of energy by functional groups that bear ionic conductivity or a dipole rotational‐effect, and this energy is then released into the surrounding solution. This absorption of energy causes the functional groups involved to have higher reactivity to other surrounding reactants than when they are simply incubated with the reactants at the same temperature. In other word the enhanced rate of the reaction can be due to the reactant stirred by the molecular dipole rotation and molecules themselves acting as a stirring bar. In contrast to conventional heating, the salient feature of “dipole rotation” constitutes one efficient form of “molecular agitation” or “molecular stirring” many aspects of which can be explore in chemical reactions. We will discuss some of the useful applications of this “molecular agitation” by means of microwave irradiation. Using this unique technology, we have developed: 1) a method to control the cleavage sites of peptide bonds, especially those bonds connected to aspartic acid residues inside the native peptides and proteins, 2) a method to increase coupling efficiency in solid‐phase peptide synthesis using a common microwave oven, 3) a novel procedure that increases the rate of alcalase‐catalyzed reactions using microwave irradiation in peptide‐bond formation with proline as a nucleophile and selective benzoylation of a pyranoside derivative, 4) a procedure to solubilize and hydrolyze retrograded starch, 5) a novel procedure to enhance the rate of saponification in a serum sample for very long chain fatty acid analysis.
Effect of A Magnetic Field on Photophysical Processes of Molecules
Authors: Lin S. H. , Hayashi M. , Kono H. , Hayashi H. , Abe H. , Ikeda S.
Published: May 2015

A main purpose of this paper is to present a density matrix treatment of the magnetic quenching of molecular luminescence. Unlike the previous theories, which only consider the magnetic effect on the nonradiative rate constant, the present theory describes the time‐evolution of the system under the action of a magnetic field. Our theory can treat both the steady state and transient molecular luminescence affected by a magnetic field.