bluuebunny/crossref_metadata_2025 huggingface dataset:
Dihydrofolate Reductase from E. coli Catalyzes the Oxygen‐Dependent Oxidation of NADPH in the Absense of Folates
Authors: Hsu Ming‐Ching , Ho Yuh , Huang Fu‐Yung
Published: May 2015

The intensity changes of proton NMR resonances of NADPH and NADP+ were employed to monitor the oxidation of NADPH in the presence of dihydrofolate reductase (DHFR) from Escherichia coli. It was found that in addition to the normal reductase activity E. coli dihydrofolate reductase (DHFR) also catalyzes oxygen‐dependent oxidation of NADPH to NADP+ in the absence of folate or dihydrofolate. Mutant‐type DHFR (Asp27→Asn) shows almost no activity at pH 7.0, while at pH 4.0 it regains its activity. This enzymatic activity is characterized by a fast initial rate followed by a gradual leveling‐off (slow phase), which appears to be due to the depletion of oxygen in the solution, under our experimental conditions. From the NADP concentration at the fast phase we estimated that four moles of NADPH were oxidized per mole of oxygen consumed. The specific activity, determined from the initial rate of NADPH oxidation, is highly pH dependent. It decreases from 9.6 × 10−3 units/mg protein at pD = 5.2 to 0.56 × 103 units/mg at pD = 8.0 at 21 °C. The pH dependence fits quite well to a titration curve of a single group with pKa = 6.5. DHFR inhibitors, trimethoprim (TMP) and methotrexate (MTX) completely inhibit this activity, whereas folate and H4F do not. NADP+ appears to partially inhibit this reaction. Thus this oxidative activity of DHFR shares several similar characteristics of the normal reductase activity and suggests some common structural requirements.
Electrochemistry of Hypervalent Compounds. 6. Selective α‐Fluorination of Sulfides Using Electrogenerated Hypervalent p‐Methoxyiodobenzene Difluoride1
Authors: Fuchigami Toshio , Fujita Toshiyasu , Higashiya Seiichiro , Konno Akinori
Published: May 2015

Anodically generated hypervalent p‐methoxyiodobenezene difluoride reacted with α‐(ary]thio)‐ and α‐(benzylthio)acetates, and α‐(phenylthio)acetophenone to provide the corresponding fluorinated compounds. In ail cases, a fluorine atom was introduced exclusively α to the ester or benzoyl group.
Synthesis of Carbon‐Chain Tethered Bistetraoxa‐Cage Compounds
Authors: Chem Jyh‐Haur , Wu Hsien‐Jen , Wang Sue‐Lein , Liao Fen‐Ling
Published: May 2015

Carbon‐chain tethered bistetraoxa‐cage compounds 7a‐c and 8a‐c were synthesized from 2‐methylfuran in a four‐step sequence. They were obtained from ozonolysis of the syn bisadducts 5a‐c and the anti bisadducts 6a‐c in dichloromethane at −78 °C followed by reduction with dimethyl sulfide. The structure of the anti bisadduct 6a was proven by X‐ray crystallographical analysis.
Solvolysis of 1‐Aryl‐1‐tert‐butylmethyl Chlorides. Solvent Effects on the Hammett‐type Correlation Analysis
Authors: Liu Kwang‐Ting , Duann Yeh‐Fang , Yu Der‐Gann
Published: May 2015

A series of 1‐aryl‐1‐tert‐butylmethyl chlorides were prepared, and their rates of solvolysis in a variety of solvents were measured. Correlation analyses using the single‐parameter Grunwald‐Winstein equation against YBnCl showed excellent linear relationships in every case. Hammett‐type analysis of rate data against Brown‐Okamoto's σ+ constants gave excellent linear correlations with ρ values dependent upon the range of substitutents and the type of solvents used. Similar results were observed when the Yukawa‐Tsuno equation was employed. The use of solvent‐dependent σ+ constants also yielded comparable results, although with smaller variation. The function of solvents on the solvolytic mechanism was discussed.
Thermal Reactions of N‐Acyl Phenylcyclobutylimines
Authors: Wu Pei‐Lin , Chen Chang‐Fu
Published: May 2015

Flash vacuum thermolysis of the parent and phenyl substituted N‐acyl cyclobutylimines 3 was under investigation. At 500 °C and 0.01 torr, 3d with phenyl group on C‐1 and 3e with phenyl group on C‐2 of cyclobutane ring underwent ring expansion processes to produce N‐acyl 1,2,3,4‐tetrahydropyridines 8d and 8e. Meanwhile the parent N‐acyl cyclobutylimines 3a together with the phenyl group on C‐3 (3c) and imine carbon (3b) proceeded a hydrogen shift reaction to afford N‐acylaminomethylenecyclobutanes 8a‐c. In addition, cycloreversion competed with ring expansion or hydrogen shift in all cases.
Reactions of 6‐Tricyanovinyldihydroquinolines
Authors: Lin Wen‐Chung , Lin Shaw‐Tao , Hsieh Mon‐Lin
Published: May 2015

Reactions of 6‐tricyanovinyldihydroquinoline with concentrated hydrochloric acid and methanolic sodium hydroxide yield chlorine substitution on the heterocyclic ring and methoxide substitution of the cyano group, respectively. The chlorine substitution via a radical process is initiated from the tricyanovinyl group by the irradiation of visible light.
Reaction Dynamics and Molecular Spectroscopy Via High Resolution Laser Techniques
Authors: Vetter R.
Published: May 2015

Laser techniques are used to enlarge the range of application of crossed‐beam experiments and to increase their resolution, via excitation of atomic/molecular reagents on well‐defined quantum states and characterization of reaction products by L.I.F. and R.E.M.P.I. Detailed applications are described in the case of the Cs + H2 → CsH + H photochemical reaction for which a complete set of experimental data was obtained and interpreted by quasi‐classical trajectories.

To apply these techniques precise spectroscopic data are required, which are obtained from high resolution, Doppler‐free beam experiments. In turn, reaction dynamics experiments provide out‐of‐equilibrium light sources which can be used to extend spectroscopic analyses. It is shown how the high resolution study of the TiO molecule leads to a new description of its electronic structure.
Integration of Separation Capillary with a Au Film Electrode and an Etched Decoupler in Amperometric Capillary Electrophoresis
Authors: Chen Der‐Chang , Hsieh Re‐Ming Ray , Chen Chun‐Hsien
Published: May 2015

Introduced in this article is fabrication of an integrated capillary for the applications of electrochemical detection in capillary electrophoresis. The separation section, voltage decoupler, and working electrode were composed into a single section of capillary. The porous decoupler was constructed by HF etching till the thickness of the capillary wall less than 20 μm. The working electrode was prepared by sputtering Au‐films on the outlet of the capillary. The integration of the separation capillary with a complete detection assembly improves the convenience for the routine application of electrochemical measurements in capillary electrophoresis. For a 100‐μm‐i.d. capillary, the theoretical plate number of catechol and the migration time reproducibility can reach 120,000 and 1.9% RSD, respectively. The linear range exceeds 3 order of magnitude and the detection limit is lower than 0.65 μM.
Syntheses, Structures and Spectroscopic Studies of Quadruply Bonded Complexes Containing Bridging Acetate and η3‐etp Ligands (etp = Ph2PCH2CH2P(Ph)CH2CH2PPh2)
Authors: Suen Maw‐Cherng , Chiang Shih‐Fu , Chen Jhy‐Der , Chern Shuenn‐Shing , Hsiao Chwan‐Deng
Published: May 2015

The quadruply bonded complexes containing bridging acetate and polydentate phosphine ligands of the type Mo2(O2CCR3)XJ(η3‐etp) (R = H, X = Br, 1; R = F, X = CI, 2; R = F, X = Br, 3; etp = Ph2PCH2CH2P(Ph)CH2CH2PPh2) were prepared by reactions of Mo2(O2CCR3)X2(PPh3)2 with etp in CH2X2. Their UV‐vis and 31P{1H}‐NMR spectra have been recorded, and the structure of 1 has been determined by X‐ray crystallography. Crystal data for 1·2CH2Br2: space group P21/c, a = 13.924(7) Å, b = 21.157(4) Å, c = 14.427(5) Å, β = 101.82(3)°, V = 4159(2) Å3, Z = 4, with final residuals R = 0.0797 and Rw = 0.0793. The absorption wavelengths of the δ → δ* transitions and the chemical shifts and the coupling constants of the 31P{1H}‐NMR spectra of these complexes are dependent on the natures of the halogen atoms and the acetate ligands.
New Cantharidinimides from Cantharidin and 2‐Arylethylamines: Efficient Synthesis under High Pressure
Authors: Lin Pen‐Yuan , Shi Sheng‐Jie , Hsu Feng‐Lin , Chen Chieh‐Fu
Published: May 2015

The new cantharidinimides 3a‐j were prepared, in good to excellent yield, by heating the reactents 1 and 2a‐j to 200 °C with toluene and triethylamine in a high pressure tube. The mixture was evaporated to dryness and furthermore heated to 180 °C‐200 °C for 1 h.
Studies on the Synthesis of Ethylene Copolymers and Their Properties
Authors: Jiang George J. , Wang Ta‐Yong
Published: May 2015

The copolymerization of ethylene and 5‐ethylidene‐2‐norbornene (ENB) catalyzed by metallocene catalysts system is reported in this paper. The catalysts include Et(Ind)2 ZrCl2/MAO and Cp2ZrCl2/MAO. The resulting copolymer contains an ethylidene group which can be readily converted to a hydroxyl group by hydrogen borane. Then the hydroxyl group in turn can be utilized for grafting with ϵ‐caprolactone. The dependence of the graft weight percentage on the reaction time was also studied. The graft copolymer is a compatibilizer for various polyethylene blends with engineering plastics.

A functional polyethylene can be easily synthesized by the copolymerization of ethylene and 9‐decen‐l‐ol using a homogeneous catalytic system of El(Ind)2ZrCl2/MAO. The resulting functional polyethylene was characterized by NMR, DSC, IR and TGA; and can also be utilized for grafting with ϵ‐caprolactone. The grafted copolymer is also an effective compatibilizer.
Syntheses and Characterization of Organoimido Complexes of Niobium(V); Potential CVD Precursors
Authors: Chiu Hsin‐Tien , Lin Jyh‐Cherng , Chuang Shiow‐Huey , Lee Gene‐Hsiang , Peng Shie‐Ming
Published: May 2015

New niobium imido complexes (RN)Nb(NEt2)3 (R = Prn, Pri and But), potential precursors to grow niobium containing thin films by chemical vapor deposition (CVD), were prepared by reacting the corresponding (RN)NbCl3py2 complexes (R = Prn, Pri and But; py = pyridine) with LiNEt2 in hydrocarbon solvents. The structures of (RN)NbCl3py2 (R = Pri and But), determined by X‐ray crystallography, are mononuclear with distorted octahedral geometries, For each complex, three chloride ligands are cis to the imido ligand and occupy meridional positions. One of two py ligands is cis to and the other is trans to the imido ligand. For (PriN)NbCl3py2, the Nb=NPri bond distance (Å) is 1.733(3) and the ∠Nb=N‐Pri angle (°) is 178.0(3). Crystal data: monoclinic, space group P21/n, a = 8.805(2), b = 14.930(4), c = 13, 407(3) Å, β = 93.37(2)°, V = 1759.5(7) Å3, Z = 4, Dc = 1.565 g cm3. For (ButN)NbCl3py2, the Nb=NBut bond distance (Å) is 1.734(4) and the ∠Nb=N‐Bul angle (°) is 174.8(4). Crystal data: monoclinic, space group P21/c, a = 9.609(1), b = 13.591(6), c = 14.615(2) Å, β = 90.05(1)°, V = 1908.5(9) Å3, Z = 4, Dc = 1.492 g cm−3.
A Stereoselective Preparation of 1,2,7‐Triazabicyclo[3.3.0]oct‐2‐enes
Authors: Teng Ju‐Tsen , Yang Chia‐Hsi
Published: May 2015

5‐(Alkylamino)methyl‐2‐pyrazolines react with ketones or aldehydes to give 1,2,7‐triazabicyclo‐[3.3.0]oct‐2‐enes in high yields. The reaction gives only one diastereomer with various aldehydes, except for CH3CHO.
Spectrophotometric Determination of Rhenium(IV) with Thiocyanate, TX‐100 and N,N′‐Diphenylbenzamidine
Authors: Agnihotri P. K. , Deb M. K. , Thakur Manisha , Mishra R. K.
Published: May 2015

A spectrophotometric method to determine rhenium(IV) at trace level is based on the extraction of Re(IV)‐SCN− complex in sulphuric acid media with N,N′‐diphenylbenzamidine(DPBA) in presence of a non‐ionic surfactant triton X‐100 (TX‐100) in chloroform. The complex shows maximum absorbance at 435 nm with amolar absorptivity value of 4.24 × 104 L mol−1 cm−1 at an acidity range 3.5‐6.5 M H2SO4. The method followed Beer's Law for the system Re(IV)‐SCN−(TX‐100)‐DPBA upto 4.0 μg Re(IV) mL−1. The detection limit of the method is 5 ppb. None of the tested foreign ions, except molybdenum(VI), interfere with the determination of rhenium. The interference due to molybdenum could effectively be removed by prior precipitation with oxine. The effect of various analytical parameters on the extraction of the metal are discussed.
Molecular Mechanics Modeling of the Interactions between the Active Domain of CAP18106–137 and Lipid A
Authors: Lee Kuei‐Jen
Published: May 2015

In this work, a computer search with molecular mechanics calculations is applied to determine the possible low‐energy configurations of two adjacent molecules, CAP18106–137 and lipid A. This computer search is performed by systematically searching the five degrees of freedom that define the relative orientations of the two adjacent molecules. Hydrophilic and hydrophobic units are separated into several small domains along the CAP18106–137 molecule so that it can interact with the lipid A either through the Coulombic interactions with the diphosphoryl head group or through the hydrophobic interactions with the fatty acyl chains. The intermolecular interactions are calculated through the van der Waals and Coulombic interactions. The Coulombic interactions are calculated by using a dielectric constant either with a value of unity ϵ = 1 or with a distance‐dependent dielectric function ϵ(r) = rij. Based on the 400 lowest searched configurations, the intermolecular interactions calculated with ϵ = 1 are found to be about sevenfold lower than those calculated with ϵ(r) = rij. Based on the inspection of the sixteen snapshots of molecular associations, the hydrophobic interactions calculated with ϵ(r) = rij are more favorable than those calculated with ϵ = 1. The high population of the lipid A binding to the CAP 18106–137 molecule is located within the first 19 residues near the N‐terminus of the peptide, as calculated either with e = 1 or with ϵ(r) = rij, by observing the diphosphoryl groups of the lipid A. The orientations of the lipid A with respect to the CAP18106–137 molecule complete an angle of 260°, which appose to the positively charged residues in the N‐terminal half by using the helical wheel projection of the peptide.
Synthesis and Structures of [Mo12E16(PEt3)10] (E = S, Se)
Authors: Amari Shingo , Imoto Hideo , Saito Taro
Published: May 2015

Dodecanuclcar cluster complexes [Mo12S16(PEt3)10] 1 and [Mo12Se16(PEt3)10] 2 have been prepared by the reactions of [Mo6S8(PEt3)6] with sulfur or [Mo6Se8(PEt3)6] with Cp2TiSe5, respectively, in toluene at refluxing temperature. The structures have been determined at 173 K by X‐ray crystallography. The compound 1·3CHCl3 crystallizes in the triclinic space group \documentclass{article}\pagestyle{empty}\begin{document}$ {\rm P}\bar 1 $\end{document}, with a = 14.859(5) Å, b = 15.868(4) Å, c = 14.200(7) Å, α = 100.58(3)°, β = 117.58(3)°, γ = 79.53(2)°, V = 2899(1) Å3, and Z = 1. Full‐matrix least‐squares refinement using 9016 observed reflections (Io > 2σ(Io)) gave R = 0.056, and Rw = 0.045. The data for 2·2CHCl3 are: triclinic, \documentclass{article}\pagestyle{empty}\begin{document}$ {\rm P}\bar 1 $\end{document}, a = 15.737(4) Å, b = 18.763(9) Å, c = 13.062(4) Å, α = 102.45(3)°, β = 128.54(2)°, γ = 69.49(3)°, V = 2825 Å3, Z = 1, R = 0.096, and Rw = 0.120 for 5922 reflections (Io > 2σ(Io)). The cluster complexes 1 and 2 have two octahedral molybdenum cluster units linked by the rhomboidal intercluster Mo2(μ4‐E)2 bonding. The intercluster Mo—Mo distances in 1 are 3.419 Å and 2 3.551 Å. The cyclic voltammetry of 1 and 2 shows two oxidation and two reduction steps separated as large as 380–490 mV. The UV‐Vis spectra of the dodecanuclear cluster complexes 1 and 2 have an extra weak band at around 744 nm which is absent in the starting octahedral cluster complexes.
Isomerization of n‐Hexane over Chlorinated Pt/γ‐Al2O3 Catalysts
Authors: Chu Hon Yue , Rosynek Michael P. , Lunsford Jack H.
Published: May 2015

Chlorided 0.57 wt. % Pt/γ‐Al2O3 is a moderately active and highly selective catalyst for the isomerization of n‐hexane at 300 °C when an excess of H2 is present. Chlorine, which is continuously lost from the catalyst, may be replaced by adding a small amount of chloroform to the reactant stream. The catalyst exhibits activity and high isomerization selectivity even at 150 °C. Under the conditions of these lower temperature experiments, the equilibrium concentration of C6 alkenes would be only 8 × 10−7 Torr. This suggests that the classical mechanism, which involves the formation of n‐hexene on the Pt, is not applicable. Rather, it is proposed that isomerization of the alkane occurs at acid sites on the catalyst, and the role of Pt is to catalyze the hydrogenation of any alkenes that might be formed as a result of cracking reactions. At temperatures ≤ 300 °C Brönsted acid sites are present in the catalyst, and presumably are responsible for the isomerization and cracking activity, but at higher temperatures Lewis acid sites play a dominant role.
Room‐Temperature Near‐Infrared Metastable Species Measured by Phase‐Sensitive Lock‐in and Fourier Transform Techniques
Authors: Chou Pi‐Tai , Chen Youn‐Chan , Chen Shu‐Juan , Lee Min‐Zen , Wei Ching‐Yen , Wen Tsai‐Chuan
Published: May 2015

An ultrasensitive detecting system coupled with either a lock‐in or Fourier transform technique has been used to detect near‐infrared (1000‐2500 nm) metastable species in room temperature solutions. These species include O2(1Δg), O2(1σ+g), the solvent induced satellite peak of molecular singlet oxygen (1Δg) emission, and the triplet state of bis(triisobutylsiloxy)silicon‐2,‐3‐naphthalocyanine (SilNC). Using the O2(1Δg) emission in benzene as a standard, the quantum yield and radiative decay rate of SiINC triplet state have been determined. Depending on types of spectral acquisition, special techniques such as phase‐distinguishing and step scan capabilities were utilized. Their advantages and disadvantages are discussed.
Kinetic Study of the Substitution Reactions of Triphenylphosphine with Chlorobenzyl Chlorides, Dimethylbenzyl Chloride, and Methylbenzyl Bromides in Various Two‐Phase Organic Solvent/Water Media
Authors: Shieh Ruey‐Lone , Lin Ruey‐Lih , Hwang Jiann‐Jyh , Jwo Jing‐Jer
Published: May 2015

The kinetics of the substitution reactions of triphenylphosphine (TP) with chlorobenzyl chlorides (CBC), 2,5‐dimethylbenzyl chloride (DMBC), and methylbenzyl bromides (MBB) in aprotic organic solvent was studied under the extraction by water. The effects of water, agitation, organic solvent, reactant, and temperature were investigated. These reactions take place via the SN2 mechanism and exhibit large and negative entropy of activation. The order of relative activity of solvents is CHCl3 > CH2Cl2 ≫ C6H6. In CHCl3, the order of relative reactivity of benzyl chloride (BC), benzyl bromide (BB), CBC, DMBC, and MBB toward reaction with TP is 2‐MBB > 4‐MBB > 3‐MBB > BB > DMBC > BC > 2‐CBC > 4‐CBC > 3‐CBC. These reactions produce quantitatively benzyltriphenylphosphonium salts, which are useful for synthesizing Z‐form isomers of stilbenes via the two‐phase Wittig reaction.
Studies on Condensed Heterocyclic Compounds XVII. Synthesis of 6‐(1‐Aryl‐5‐methyl‐1,2,3‐triazol‐4‐yl)‐3‐phenyl‐s‐triazolo[3,4‐b]‐1,3,4‐thiadiazoles
Authors: Sun Xiao‐Wen , Zhang Yan , Zhang Zi‐Yi
Published: May 2015

Treatment of 4‐amino‐5‐mercapto‐3‐phenyl‐1,2,4‐triazole 2 with 1‐aryl‐4‐carboxy‐5‐methyl‐1,2,3‐triazoles 1a‐1j in a one‐step reaction yielded several 6‐(1‐aryl‐5‐methyl‐1,2,3‐triazol‐4‐yl)‐3‐phenyl‐s‐triazolo[3,4‐b]‐1,3,4‐thiadiazoles 3a‐3j. The structures of all the products were established on the basis of elemental analyses and spectral data. The fragmentation of the mass spectra of 3a‐3j under electron impact was discussed.
Isolation and Characterization of intermediate in the Synthesis of α‐Fluorodiesters
Authors: Tsai Hou‐Jen
Published: May 2015

The anion [(EtO)2P(O)CFCO2Et]−Li+, pregenerated from its precursor diethyl (carboethoxyfluoromethyl)phosphonate (EtO)2P(O)CFHCO2Et and n‐butyllithium, was added via syringe to a THF solution of ethyl oxaiyl chloride to yield an acylated phosphonate (EtO)2P(O)CF(COCO2Et)CO2Et. In situ reaction with Grignard reagents RMgX produces the α‐fluorodiesters (E,Z)‐R(CO2Et)C=CFCO2Et in good yields. In contrast, addition of ethyl oxalyl chloride to a THF solution of diethyl (carboethoxyfluoromethyl)phosphonate anion gives an isolated intermediate (EtO)2P(O)CFCO2Et(CO2Et)C=CFCO2Et. Subsequent reaction of this isolated intermediate with Grignard reagents also affords a one‐pot synthesis of the α‐fluorodiesters with high E‐stereoselectivity. The E‐stereoselectivity increases when HMPT or DMPU is used as a cosolvent in the preparation of diethyl 2‐fluoro‐3‐phenylfumarate (E,Z)‐Ph(CO2Et)C=CFCO2Et.
Metal‐Support interaction in Silica‐Supported Cobalt Catalyst
Authors: Ho Sui‐Wen
Published: May 2015

The variations in catalytic properties for CO hydrogenation and adsorptive properties for H2 and CO of silica‐supported cobalt catalyst as a function of reduction temperature (400 to 700 °C) were investigated. A mild sintering of cobalt metal from 130 Å to 145 Å occurred only when the reduction temperature was further increased from 600 to 700 °C. However, a monotone decrease in the activity (per gram Co) for CO hydrogenation was observed with increasing reduction temperature. This is accompanied with a decrease in methane and an increase in olefin formation. The decrease in activity can not be accounted for by the variation of crystallite size of cobalt metal. A concurrent suppression in the amount of hydrogen and CO adsorptions was observed after reduction temperature was raised to 700 °C. The turnover frequencies, based on cobalt dispersion estimated from H2 and CO chemisorption, remained, more or less, similar with increasing reduction temperature from 400 to 600 °C, but increased ca. 3 and 1.5 times, respectively, at 700 °C. The relative amount of subcarbonyl species (2062 cm−1) with respect to the linear adsorbed CO (2010 cm−1) was found to increase as well. Furthermore, reduction of silica surface at 700 °C was indicated by the presence of ˜Si‐H, which was detected by infrared spectroscopy at 2294 cm−1. This shows the presence of metal‐support interaction for silica‐supported cobalt systems after reduction treatment at 700 °C.
A Novel Convenient Method to Synthesize Unsymmetrical 1,1′‐Disubstituted Ferrocenes Consisting of Various Phosphino, Thiolato and Pyridyl Substituents
Authors: Dong Teng‐Yuan , Chang Chung‐Kay
Published: May 2015

A novel convenient method for preparing unsymmetrical 1,1′‐disubstituted ferrocenyl phosphine ligands by using the readily accessible 1,1′‐dibromoferrocene as a precursor is described. The method is of interest for modifying the chelating ferrocenyl phosphine ligands in view of the growing influence of homogeneous catalysis in organic synthesis, manipulation of materials and production of high optical yield.
The Evolution of Chiral Stationary Phases for Liquid Chromatography
Authors: Armstrong Daniel W.
Published: May 2015

The development of effective chiral stationary phases (CSPs) and separation strategies for the liquid chromatographic (LC) resolution of enantiomers has been beneficial to many scientific disciplines. Over the last decade the number and type of CSPs has expanded tremendously. Not only have new classes of chiral selectors been introduced, but also many of the first CSPs have been changed and/or improved. The second or third generation of a CSP often can be different from the original. This can be confusing and intimidating to someone just entering the area of LC enantiomeric separations. Fortunately, all CSPs can be categorized in one or another of a few classes. There are generally one or two columns that can accomplish the majority of separations in each class. In this work we look at the different classes of CSPs and how they have expanded and changed over the last decade.
Recent Advances in Solid Acid‐Base Catalysis and Future Problems
Authors: Tanabe Kozo
Published: May 2015

Recent advances in acid‐base catalysis are summarized. Several examples of solid acid, base, and acid‐base bifunctional catalysis which have brought significant progress of the field or are considered to give strong impacts to industrial application are presented. Selected commercialized processes developed by using solid acid‐base catalysts are demonstrated, their significance being discussed. The future problems in this field are speculated and important fundamental research subjects are pointed out.
Reactions of 7‐Chloro‐1,3‐dihydro‐1‐methyl‐5‐phenyl‐2H‐1,4‐benzodiazepin‐2,2‐dioxide in Various pH Solutions
Authors: Yang Shen K.
Published: May 2015

Diazepam (1) is a frequently prescribed hypnotic/anxiolytic drug worldwide. 7‐Chloro‐1,3‐dihydro‐l‐methyl‐5‐phenyl‐2H‐1,4‐benzodiazepin‐2,2‐dioxide (2) is an initial alkaline hydrolysis product of 1. The mechanisms in the conversion of 2 to 2‐methylamino‐5‐chloro‐α‐(phenylbenzylidene)glycinate (3), 2‐methylamino‐5‐chlorobenzophenone (4), and 1 in aqueous solutions with pH ranging from 0 to 12.2 is the subject of this report. Results of temperature‐dependent hydrolysis kinetics and product identification indicated that: (1) in solutions with pH between 7 and 12.2, 2 underwent a ring‐opening reaction to form 3; the rate decreased with increasing pH. (2) In solutions with pH between 2 and 7, 2 was rapidly converted to 3, followed by a pH‐dependent conversion to 4; the rate increased with decreasing pH and became less sentitive to pH at pH ≤ 4.5. (3) In solutions with pH between 0 and 2, 2 was rapidly converted to 4 and 1; the percentage of 1 increased with decreasing pH. (4) A 2 containing one oxygen‐18 atom lost 50% of its oxygen‐18 following conversion to 1 in 1 M HCl. In addition to understanding the mechanism in the transformations of 2 in various pH solutions, this study established a simple and efficient method in the quantitative conversion of 1 to 4 and in the preparation of an oxygen‐18‐containing 1 at C2 position.
Alkoxide‐Accelerated [1,3] Sigmatropic Shift of Bicyclo[3.2.1]oct‐6‐en‐2‐ols to 8‐endo‐Hydroxybicyclo[3.3.0]oct‐2‐en‐4‐ones
Authors: Chen Yeh‐Long , Chang Chi‐Kang , Chang Nein‐Chen
Published: May 2015

Bicyclo[3.2.1]oct‐6‐en‐2‐ols 6 are shown to undergo [1,3] sigmatropic shift to afford 8‐endo‐hydroxy‐bicyclo[3.3.0]oct‐2‐en‐4‐ones 8 under the influence of potassium hydride.
The Effects of M2O3 on Stabilizing Monocopper over the Surface of Cu‐ZnO‐M2O3 Catalysts for Mathanol Synthesis
Authors: Chen Hong‐Bo , Liao Dai‐Wei , Yu La‐Jia , Yi Jun , Zhang Hong‐Bin , Tsai Khi‐Rui
Published: May 2015

The effects of M3O3 (M = Al, Sc etc.) in Cu‐ZnO‐M2O3 catalysts on methanol synthesis at low pressure were studied with ESR, XPS and TPR spectroscopy. The results of ESR showed that the generation of monovalent cationic defects was because the valence state and electronic charge on the ZnO lattice lost their balance as M3+ doped into ZnO. The induced effect by Sc3+ is stronger than that by Al3+. The results of XPS and TPR indicated that the amount and stabilization of Cu+ on the surface of reduced copper‐based catalyst and its catalytic activity were affected by the monovalent cationic defects on the surface of ZnO.
Synthesis, Crystal Structure, Cryomagnetic Properties and Catalytic Activity for H2O2 Disproportionation of New Dinuclear and Polynuclear Bis(2,4‐pentanedionate)manganese(II) Complexes with Diazine Ligands
Authors: Hong D. M. , Wei H. H. , Chang K. H. , Lee G. H. , Wang Yu
Published: May 2015

The structures, magnetic properties, and catalytic activity for H2O2 disproportionation are reported for three new complexes [Mn2(acac),(pydz)] (1), [Mn(acac)2(pym)] (2), and (Mn(acac)2(pyz)] (3) (acac = 2,4‐pentanedionate, pydz = pyridazine, pym = pyrimidine, pyz = pyrazine). The X‐ray crystal structures of 1 and 3 have been determined. Complex 1 crystallizes as a binuclear complex with η2‐pyridazine and acac bridging ligands 3 crystallizes as a linear polymeric chain with bridging pyrazine molecule. Cryomagnetic investigations (4‐300 K) reveal a weak intramolecular antiferromagnetic spin exchange with J = −2.05, −0.04, and −0.05 cm−1 for the complexes of 1, 2, and 3, respectively. The complexes 1–3 showed two‐step catalytic activity for H2O2 disproportionation in pyridine solution at 0 °C.
Thermal Stability of Robust Unsymmetrical Copperporphyrins with Multiple Diphenylamino and Nitro Substituents
Authors: Chen Chin‐Ti , Cha I , Hsieh Shih Jung
Published: May 2015

The syntheses and thermal stability properties of a series of amino and nitro substituted copperporphyrins are described. The thermal decomposition temperatures of the porphyrins were determined by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and differential thermal analysis (DTA). The on‐set thermal decomposition temperatures of the unsymmetrical porphyrins were found to be high in the range of 350 – 405 °C (DSC), 374 – 441 (TGA in air), 395 – 411 °C (TGA under nitrogen atmosphere), and 410 – 424 °C (DTA in air). Substituent dependent thermal stability trends were also studied. The trend is variable depending on the thermal analysis technique utilized. Possible reasons for such variation are discussed. These porphyrins are thermally robust even in the melamine‐based sol‐gel matrix. Containing 20% by weight of the substituted unsymmetrical copperporphyrin, melamine‐based sol‐gel showed no indication of decomposition until −400 °C.
Thermal and Photofragmentation of N‐Benzoylhydrazone Derivatives
Authors: Gaber Abd El‐Aal M. , Mohamed Shaaban K.
Published: May 2015

Two selected benzoylhydrazones I and II were subjected to thermolysis by reflux at 200 °C. Benzil, benzoic acid, biphenyl, benzanilide together with the corresponding ketones, nitriles and imines were isolated. Similar treatment of the third hydrazone III at 250 °C afforded, in addition to the previous products, bibenzyl, stilbene, and 2‐phenylindole. Photolysis of the same hydrazones I‐III in acetonitrile gave the previously reported products but in different ratios along with azine derivatives and substituted methanes. A free radical mechanism involving homolysis of the N‐N and C‐N bonds is suggested, substantiated by trapping of phenyl radical with isoquinoline, to account for the formation of the identified products.
The Synthesis of 5, 6, 7, 7a‐Tetrahydro‐1‐methyl‐3H‐pyrrolizin‐3‐one by the Palladium‐Catalyzed Cyclization of N‐Bromoacetyl‐2‐vinylpyrrolidine
Authors: Yang Sbyh‐Chyun , Shea Fang‐Rong , Hung Chung‐Wei
Published: May 2015

N‐Bromoacetyl‐2‐vinylpyrrolidine underwent cyclization to give a pyrrolizidine derivative in the presence of a base and a catalytic amount of palladium catalyst.
Synthesis and Biological Activities of Aryl Propargyl Sulfone
Authors: Wu Ming‐Jung , Lin Chi‐Fong , Chang Li‐Juan , Jing Pao‐Tzu , Duh Tsai‐Hui , Tseng Wuan‐Ting , Lee Fang‐Chen , Wang Shan‐Shue , Chang Hsueh‐O
Published: May 2015

A series of molecules containing monopropargyl sulfone or 1, 2‐bis‐propargyl sulfone were synthesized. The cytotoxicity of these compounds against human carcinoma cells was also examined. This study indicated that the formation of a biradical intermediate is important to the potency of cytotoxicity.
Rate Study for Electron Transfer of Sml2 to the Carbonyl Compounds and the Sulfoxides
Authors: Lin Tzuen‐Yeuan , Fun Ming‐Ren S. , Chang Shih‐Chun , Lin Yu‐Sheng
Published: May 2015

The rate constants for the electron transfer of samarium diiodide to 2‐heptanal, 2‐methyl valeraldehyde and diphenyl sulfoxide were obtained for the first time. The reaction is first order in these substrates and there are hints that the reaction rate has a strong steric dependence. HMPA exhibited a profound catalytic effect but t‐BuOH did not. The effect of temperature on reaction rates was also obtained.
Acceleration Effect of Fe(II), Co(II), Ni(II) and Cu(II) on the Hydrolysis Rate of Ortho‐ or Para‐Hydroxy Schiff Bases
Authors: El‐Taher M. A.
Published: May 2015

The kinetics of hydrolysis of ortho‐ or para‐hydroxybenzylidene‐4‐benzidine Schiff bases have been examined in the pH range 1.70–11.90, in aqueous media containing 20wt% dioxane, at 20 °C. In basic media, pH > 8.47, a slight increase in the hydrolysis reaction rate of the Schiff bases is observed. In such basic media, the rate‐controlling step is the attack of hydroxide ion on the ionized Schiff base. Below pH 6.82, the rate‐determining step is ascribed to be the attack of water molecules on the protonated substrate. The effects of Fe(II), Co(II), Ni(II) and Cu(II) ions on the hydrolysis reaction rate of the Schiff bases have been studied and discussed on the basis of formation of a monocyclic chelate rings. The various thermodynamic parameters have also been evaluated and discussed.
Preliminary Study on Reverse Pulse Amperometric Detection in Capillary Electrophoresis for Simultaneous Determination of Cysteine and Cystine
Authors: Hsi Tai‐Sung , Chuang May‐Yin
Published: May 2015

Simultaneous determination of cysteine (RSH) and cystine (RSSR), two important sulfur‐containing amino acids, in capillary electrophoresis (CE) has been an analytical task. Dual‐microelectrode amperometric detection seems to be a good scheme, but significant difficulty in electrode construction and poor detection limit for RSSR determination remain major short‐comings. In reverse pulse amperometric (RPA) detection, the applied potentials are repeatedly pulsed back and forth between the reducing initial potential (e.g., Ei = −1.4 V) and the oxidizing final potential (e.g., Ef = 0.0 V) at a single, gold‐mercury amalgam (Au/Hg) microelectrode. At Ei, RSSR is reduced to RSH which causes catalytical oxidation of the Au/Hg amalgam microelectrode when the potential is pulsed to Ef. The resulting anodic current is then recorded. Therefore, by using RPA detection after CE separation, RSH and RSSR can be simultaneously determined.
Electrochemical Methoxylation of 1,2,3‐Trisubstituted Azulenes
Authors: Chen Arh‐Hwang
Published: May 2015

1,2,3‐Trisubstituted azulene analogs 6a and 6b easily underwent methoxylation in position 4 or 6 of an azulene ring via an electrochemical oxidation. It is a simple, convenient and selective method for introducing a methoxy group into a 7‐membered ring of azulene analogs when compared with traditional chemical methods. It could be useful in preparing 2,4‐ and 2,6‐azuloquinone analogs.
The Syntheses of Triazinone and Pyrimidinone Biphenyltetrazoles as Angiotensin II Receptor Antagonists
Authors: Choir Shan‐Yen , Yang Paw‐Hwa , Wang Chia‐Lin J. , Lu Hsiao‐Hwa , Chen Yin , Kao Jen‐Mann
Published: May 2015

A series of biphenylyltetrazole substituted triazinones and structure‐related pyrimidinones are systhesized, and their binding affinities for angiotensin II receptor are reported.
Reactions of 4‐Hydrazinocarbonylmethylene 3‐Arylsydnones and 3‐(4‐Hydrazinocarbonylphenyl)sydnones
Authors: Lin Shaw‐Tao , Yang Mein‐Lin , Tien Hsien‐Ju
Published: May 2015

The phenyl ring of 3‐(4‐hydrazinocarbonylphenyl)sydnone activates a hydrazinocarbonyl group to undergo a series of reactions for preparing heterocyclic compounds including oxadiazoles, dihydropyrroles, and pyrroles. However, the hydrazinocarbonyl group on the C(4)‐CH2 resists a cyclization under the same reaction conditions.
Preliminary Study on Cataractous Human Lenses Using Near‐Infrared Fourier Transform Raman Spectroscopy
Authors: Huang Fu‐Yung , Ho Yuh , Hsu Ming‐Ching , Wong Fong‐Zo
Published: May 2015

Raman vibrations of the fingerprint of aromatic amino acid residues were analyzed to study the changes of cataractous lens protein in the cortex and nucleus at various ages. Tryptophan content, analyzed by the quantification of I758/I1448 ratio, shows the damage (modification) of tryptophan residue in the nucleus is caused primarily by the formation of cataracts, not by the aging process. Microenvironmental changes of tryptophan and tyrosine were analyzed by the intensity ratios of I879/I758 and I829/I853, respectively. The decrease of the ratio of I879/I758, from 0.9 to 0.6 in the nucleus and from 0.7 to 0.6 for the cortex, reveal that more buried tryptophan residues become exposed in the cortex than in the nucleus during cataractogenesis, especially for non‐senile cataractous lenses. The ratio of I829/I853 is around 1.0 for both cortical and nuclear proteins at various ages, indicating some tyrosine residues have undergone a change in their hydrogen bonding environment. When compared to previous studies, we found that a normal (clear) lens has a higher peak at 1617 cm−1 than at 1604 cm−1, while a dense opaque or brunescent lens shows stronger intensity at 1604 cm−1 than at 1617 cm−1, suggesting the ratio of I1617/I1604 can be used to evaluate the human lens morphology.
Alcalase‐catalyzed Synthesis of Novel 2,6‐Dimethoxyhydroquinone‐3‐mercaptoacetyl‐peptide Conjugates
Authors: Chen Wen‐Fu , Jong Ming‐Chu , Chen Shui‐Tein , Sheh Leung
Published: May 2015

Seven dipeptide and one tripeptide conjugates of the cytotoxic drug 2,6‐dimethoxyhydroquinone‐3‐mercaptoacetic acid (DMQ‐MA) conjugates were prepared successfully by an alcalase‐catalyzed reaction in alcohols, using DMQ‐MA‐X‐OMe as the acyl donor and H2N‐Y‐CONH2 as the nucleophile (where X and Y are amino acids, and amino acid/dipeptides, respectively).
Some New Radical Reactions of Xanthates
Authors: Quiclet‐Sire Béatrice , Zard Samir Z.
Published: May 2015

Xanthates are convenient precursors of a variety of radicals that can be captured in an inter‐ or intramolecular fashion. Overall, the process involves rupture of the sulfide C‐S bond and addition of the elements of the xanthate to the olefinic trap. The xanthate in the product can be used in another radical sequence or ionically modified in a great variety of ways. S‐Propargyl xanthates exhibit a special but interesting behaviour which involves a sigmatropic rearrangement to the corresponding allene and ring closure to a novel betaine.
Bisabolane Sesquiterpenes from Ligularia thyrsoidea
Authors: Liao Jian‐Chun , Zhu Qi‐Xiu , Yang Hua , Jia Zhong‐Jian
Published: May 2015

Phytochemistry investigation of the whole plants of Ligularia thyrsoidea, has led to the isolation of five new bisabolane sesquiterpenes along with three known compounds. The structures of these new compounds were elucidated by spectroscopic methods and 2D NMR techniques.
Total Synthesis of (±)‐Boschnialactone and (±)‐Tetrahydroanhydrodesoxyaucubigenin
Authors: Chang Meng‐Yang , Lin Ching‐Han , Lee An‐Yang , Tai Huo‐Mu , Chang Nein‐Chen
Published: May 2015

A total synthesis of (±)‐boschnialactone (1) and (±)‐tertahydroanhydrodesoxyaucubigenin (2) is described and trisubstitued cyclopentenoid 3 is a key intermediate.
Axial Ligand Effects on the Redox Reactions of Manganese Porphyrins
Authors: Chang Chi‐Hong , Cheng Shu‐Hua , Oliver Su Y.
Published: May 2015

A systematic study for the effect of axially coordinated monovalent anions on the electrode reactions of several manganese porphyrins in acetonitrile is presented. Potential shifts of the metal‐centered reduction with changes in counterion were related to the degree of Mn(III)‐counterion interaction. In the electrochemically induced ligand exchange, perchlorate anion replaces the other anions as axial ligand coordinated to Mn(III) at oxidation potential less than the first oxidation of manganese porphyrins. Formation constants for axial ligation of OH− are calculated. One‐electron oxidation of dihydroxide coordinated manganese porphyrins generate oxomanganese(IV) porphyrin complexes electrochemically. O=MnIVOEP(OH) is more thermodynamically stable than O=MnIVTPP(OH), while O=MnIVTpFPP(OH) cannot be generated electrochemically. In the presence of styrene or cyclohexene, the absorption spectra of oxomanganese(IV) porphyrins are changed to form manganese(III) porphyrins gradually, which indicates the oxygen atom transfer from oxomanganese(IV) porphyrins to the substrates.
An Efficient Total Synthesis of (2E,4E,7R)‐Farnesa‐2,4,10‐triene from (R)‐(+)‐Citronellal
Authors: Li Jing , Liu Zuosheng , Lan Jiong , Li Yulin
Published: May 2015

(2E,4E,7R)‐farnesa‐2,4,10‐triene(Caparratriene) (1), a novel sesquiterpene hydrocarbon with significant growth inhibitory activity against CEM leukemia cells, was first synthesized from (R)‐(+)‐citronellal (2) by employing titanium‐induced intermolecular carbonyl‐coupling as the key step. The absolute configuration of (+)‐Caparratriene was determined to be 7R.
Human and Limulus Blood: Opportunity for Development of A Medical Biotechnology Project in Taiwan
Authors: Liu Teh‐Yung , Chen Yih‐Wen , Chiou Shean‐Tai
Published: May 2015

The function of blood is to deliver nourishments to and remove wastes from all parts of the body. It is made up of different kinds of cells bathed in a fluid called plasma. The major cellular components of blood include (1) red blood cells for carrying oxygen to the various tissues, (2) white blood cells for providing defense against infectious agents and cancer, and (3) platelets for inducing a cascade of events leading to blood clot formation that stops bleeding. The plasma also contains numerous proteins for maintaining normal balance in our body, and include (1) clotting factors such as factor VIII, factor IX, fibrinogen, and thrombin, (2) protease inhibitors and anticoagulants that regulate the coagulation pathway, the complement system, or the fibrinolytic system, (3) immunoglobulin which are antibodies directed against different infectious agents, and (4) albumin which functions as a volume expander to maintain our blood volume and is essential when threatened with severe blood loss.

The plasma of the invertebrate horseshoe crab, contains three major proteins: hemocyanin, C‐reactive protein (CRP), and α2‐macroglobulin. Hemocyanin functions as an oxygen‐carrying protein. CRP is a lectin that binds to phosphocholine of the pneumococcus C‐polysaccharide, to the chromatins of damaged cells, and to the galactose moiety of desialylated glycoprotein as a membrane‐associated protein on liver marcrophages. CRP exists, however, as a normal component of the invertebrate hemolymph. α2‐macroglobulin exhibits proteinase inhibitory activity with a broad specificity that can block the activities of protease secreted from invading microorganisms. The Limulus CRP, along with the C3 homologue α2‐macroglobulin, participates in a complement ‐ like hemolytic activity in horseshoe crab hemolymph.

Whereas the vertebrate evolved to use both the innate and the adaptive immunity, the invertebrate only uses the innate immunity. The innate immunity uses germ‐line encoded receptors to recognize conserved molecular constituents of infectious microorganisms, is phylogenetically older, with some of its form presumably presents in all multicellular organisms. The adaptive immunity is mediated by highly specific antigen receptors that are distributed clonally on the two types of lymphocytes, the T‐cells and the B‐cells. Evidence has accumulated in recent years to suggest that the innate immune system provides signals that are essential for the adaptive immune response to generate information on the origin of the antigen and the type of response to be induced. This linkage invites renewed interest in the study of the innate immune system of the horseshoe crab.
On the Assignment of Anomeric Configuration
Authors: Lee Yuan C. , Lee Reiko T.
Published: May 2015

One of the diversities of carbohydrate structure lies in their ability to form different anomers from the monosaccharide unit. Unfortunately, the question of assignment of anomers has not been dealt with properly or accurately in most organic and biochemical textbooks and reference books. In this article, the question of assignment of anomers is examined from several different standpoints and an easy solution for this tricky problem is suggested.
Multifunctional Antiviral Poly‐DNP‐Oligonucleotides
Authors: Wang Jui Hsin , Wang Aihong , Kang Insug , Li Chih‐Chien , Silbermann Benjamin Wang
Published: May 2015

Monofunctional, bifunctional and trifunctional poly‐2′‐(2,4‐dinitrophenyl)‐oligoribonucleotides have been designed and synthesized as inhibitors of retroviruses. These compounds are membrane‐permeable, ribonuclease‐resistant, and apparently mutation‐insensitive inhibitors of reverse transcriptases. These inhibitors have been tested for the treatment of murine leukemia as an animal model related to AIDS. Although the monofunctional inhibitor is already 100% effective for the treatment of murine leukemia, its efficacy can be increased by two orders of magnitude by introducing antisense sequences in the nucleotide backbone so that the resulting multifunctional inhibitor can also disrupt the synthesis of specific viral proteins. The entropy advantage of multifunctionality in the design of antiviral agents is discussed.
Extended Hückel Orbital Forces and the Jahn‐Teller Distortions in Molecules
Authors: Letelier Jorge Ricardo , Toro‐Labbé Alejandro , Chiu Ying‐Nan
Published: May 2015

Linear orbital vibronic constants are calculated within the Extended Hückel formalism and used to evaluate the forces acting on the atoms along the symmetry coordinates, in a planar arrangement of four identical atoms. It is shown, from the magnitude and direction of the forces, that the high‐symmetry square planar arrangement is unstable and distorts to lower symmetry.
Chemical Characterization of Single Cells and Single Molecules
Authors: Yeung Edward S.
Published: May 2015

Advances in sensitive optical measurement schemes have led to the detection and the physical and chemical characterization of single biological cells and individual molecules. These technological achievements are much more than the ultimate milestone in low‐level monitoring. Potential applications include DNA sequencing at high speeds, probing microscale environments, monitoring environmental pollution, studying the variability of molecular conformations, detecting disease infection at an early stage, and devising molecular‐scale imaging probes.
Laser Detection of Reaction Products: Slicing versus Projection Techniques
Authors: Chen Kuo‐Mei
Published: May 2015

Combining laser spectroscopy and two‐dimensional imaging technologies, researchers can execute sophisticated experiments to measure time‐resolved spatial profiles of state‐selected reactants and products of elementary chemical reactions. Besides the scalar observables, there are issues of vector correlations of reaction products which are best studied by imaging techniques. Advantages and drawbacks of various projection and slicing detection techniques are elucidated. The problem of vector correlations in concerted three‐body dissociations can be tackled by the slicing techniques and a new analysis algorithm.
On Theoretical Study of a Molecular Dimer System
Authors: Hayashi M. , Shiu Y. J. , Chang C. H. , Liang K. K. , Chang R. , Yang T. S. , Islampour R. , Yu J. , Lin S. H.
Published: May 2015

In this paper, the vibronic structure of a dimer system is studied both theoretically and numerically. To construct adiabatic potential surfaces and electronic and vibrational wave functions for a dimer system, the adiabatic approximation is applied to two identical molecules, each of which has two electronic states with one vibrational mode. In this scheme, the excitonic splitting results not only from the electronic coupling of two molecules, but also from the vibronic coupling in each molecule. By using the resulting wavefunctions and the corresponding energies, the absorption and fluorescence spectra are studied. The effect of temperature on these spectra is also studied.
Molecular Vibronic Structures of HDITC in Solutions Studied by Femtosecond Wavelength‐Resolved Pump‐Probe Spectroscopy
Authors: Yang T.‐S. , Vöhringer P. , Dietz W. , Scherer N. F. , Lin S. H.
Published: May 2015

Wavelength‐resolved pump‐probe measurements using 11 fs duration pulses were performed to study the vibronic structures of HDITC, a cyanine dye, in ethylene glycol. Ten vibrational modes were observed in the forms of quantum beats. The frequencies of these ten vibrational modes ranged from 135 cm−1 to 1300 cm−1. The relative potential displacements along these ten vibrational coordinates were estimated by comparison with theoretical calculations.