bluuebunny/crossref_metadata_2025_split huggingface dataset:
Electrochemical Study on Decomposition of Hydrogen Peroxide with Fe(II)
Authors: Kao Jing Yi , Wang Chong Mou 
Published: May 2015

AbstractDecomposition of H2O2 with Fe2+ was studied with SnO2 electrodes. By chronoamperometric and voltammetric techniques, the diffusion coefficients of Fe3* and H 2O2 were estimated to be 5 × 10‐6 and 2 × 10−5 cm2/s, respectively; the rate of decomposition of H2O2 with Fe2+ was proportional to [H2O2]1/2·[Fe2+]2 at a smaller concentration of Fe2+, but to [H2O2]1/2·[Fe2+] when [Fe2+] was increased, indicating the formation of ferryl ion and the electron exchange between it and Fe2+ playing important roles. This catalytic decomposition. was dependent on pH; the maximum rate was observed to occur about pH = 1.5.
Reactions of Tris(acetonitrile)tricarbonylchromium with Trimethylsilylarenes
Authors: Lin See , Liu Lin‐Kang 
Published: May 2015

AbstractThe reactions of tris(acetonitrile)tricarbonylchromium 1 with trimethylsilyl derivatives 2–5 of phenalene, indene, 1,2‐dihydronaphthalene and trans‐β‐methylstyrene gave products 10‐13, respectively, containing no trimethylsilyl groups. The reactions of 1 with trimethylsilyl derivatives 6–8 of benzene, toluene and cycloheptatriene gave products 14–16, respectively, containing trimethylsilyl groups. The reaction of 1 with 1,2‐bis(trimethylsily‐1,2‐dihydro)naphthalene 9 gave product 17 in which only trimethylsilyl at the allylic position was cleaved. Compound 10 crystallizes in the orthorhombic system, space group Pbca, with a = 12.228(4), b = 14.288(1), c = 15.128(3) Å, Z = 8, RF= 0.046, and Rw = 0.047. X‐ray crystallographic data confirm that the Cr(CO)3 moiety is bonded to phenalene in a η6‐mold.
Fragmentation of α‐Acetoximino Ketoesters in Polyphosphoric Acid
Authors: Zee Sheng‐Hsu , Chou Shan‐Yen 
Published: May 2015

AbstractFragmentations of various α‐acetoximino ketoesters in neat polyphosphoric acid medium to form acylium ions were studied. The resulting acylium ions were trapped by benzene rings either intermolecularly or intramolecularly.
Acetals of Dehydro‐L‐Ascorbic Acid 2‐Hydrazones. Access to the Chiral Building Block (R)‐Glycerol Acetonide
Authors: El Ashry E. S. H. , Rashed N. , Mousaad A. 
Published: May 2015

Abstract5,6‐O‐Isopropylidene, cyclohexylidene and benzylidene derivatives of L‐threo‐2,3‐hexodiulosono‐1,4‐lactone 2‐phenylhydrazone were prepared. Reduction of the isopropylidcne derivative was followed by treatment with base, and then periodate oxidation and reduction to give (R)‐glycerol acetonide. Hydrogen bonding in the hydrazones has a role in forming geometrical isomers.
Pyrolytic Chemistry of Benzyl Benzoate
Authors: Chen Ping‐Shu , Chou Chin‐Hsing 
Published: May 2015

AbstractFlash vacuum pyrolysis of benzyl benzoate (3) at temperatures in the range 750–900 °C and at 102 torr gave diphcnylmethane (5) as the major product with toluene (6) and eight other trace products, namely bipbenyl (7), dibenzyl (8), 2‐, 3‐, 4‐phenyltoluenes (9,10,11, respectively), fluorcne (12), benzyl alcohol (4) and benzaldehyde (13). The mechanism of formation of these products is proposed to involve benzyl and phenyl radicals.
Bicyclo[3.2.1]octenones as Building Blocks in Natural Product Synthesis (IV): Formal Synthesis of (±)‐Hydroxyloganin Aglucone
Authors: Chang Chi‐Peng , Yin Wei‐Kung , Chang Nein‐Chen 
Published: May 2015

AbstractA formal synthesis of (±)‐hydroxyloganin aglucone from bicyclo[3.2.1]octenone 1 is described. Ring opening of syn‐8‐(methanesulfonyloxy)‐1‐phenylthiotricyclo[4.2.1.03,7]non‐4‐en‐2‐one 14 with potassium hydroxide is the key reaction.
Bridgehead Nitrogen Heterocycles: Facile Synthesis of Imidazo [2,1‐b]‐1,3,4‐Thiadiazoles Using Hypervalent Iodine
Authors: Mohan Jag , Singh Virender , Kataria Sangeeta 
Published: May 2015

Abstract2,6‐Diarylimidazo [2,1‐b]‐1,3,4‐thiadiazoles (3) were synthesized by reactions of either α‐haloketones with 2‐aminothiadiazoles (1) or directly with acetophenones in the presence of [hydroxy(p‐tosyloxy)iodo]benzene. The latter method is convenient and versatile.
Charge Density Studies of Thiathiophthene. 4 Theoretical Studies on 2,5‐Dimethyl Thiathiophthene and 2,4‐Diphenyl Thlathiophthene with Density Functional Method
Authors: Hwang Tsong Song , Chong Delano P. , Wang Yu 
Published: May 2015

AbstractThe distribution of deformation density of 2,5‐dimethyl thiathiophthene and 2,4‐diphenyl thiathiophthene are calculated via density functional method. The results are in good agreement with the corresponding experimental and theoretical distributions from an ab initio method. The ionization potentials obtained in this calculation on 2,5‐dimethyl thiathiophthene are in good agreement with those obtained experimentally from photoelectron spectroscopy, it is in better agreement than those VIPs based on ab initio calculations. Net atomic charges are compared with the experimental multipole refinement and with those calculated with ab initio and DFT methods for various atomic partitions.
A Theoretical Study of Aluminium Substitution in MFI Zeolites
Authors: Fêng Ming‐Hsiang , Chao Kuei‐Jung 
Published: May 2015

AbstractThe substitution of aluminium for silicon in sodium and proton forms of MFI zeolites has been studied by theoretical force field calculations. The parameters of the cff91_czeo force field developed by Hill and Sauer for zeolites were adopted in this calculation. The molecular structure was optimized according to an energy minimization algorithm with the Newton‐Raphson method. The results indicate that mere seems little energetic preference for aluminium location in Na‐MFI, and that the smaller is the Si‐O‐Al angle, the smaller is the proton‐aluminium substitution energy in H‐MFL The acidity is related to the framework structure and the strong acid sites are correlated with large Si‐O‐Al angles. These conclude that the electrostatic interaction plays a minor role in aluminium substitution and the locations of aluminium atoms and of Brönsted acid sites depend mainly on the framework geometry.
Impedance Analysis of Charge Transport and Redox Reactions of Polypyrrole at Polypyrrole‐coated Electrodes
Authors: Chang Cmur‐Min , Song Chi‐Shyang , Huang Hsuan‐Jung 
Published: May 2015

AbstractCharge transport accompanying the redox reactions of polypyrrole at a polypyrrole‐coated electrode was investigated with systems containing selected electrolytes. From cyclic voltammeiric and impedance data, we found transport of anions into and from the polymer film to be responsible for the charge‐transfer process accompanying the oxidation and reduction of polypyrrole. With parameters such as charge‐transfer resistance, Rel, low‐frequency polymer resistance, Rl limiting capacitance, Cl and diffusion coefficient, Del estimated, the electrochemical behaviour of polypyrrole as an electronic insulator and conductor is explicitly identified.
Synthesis and Application of Long‐Chain Carboxylate Crown‐Ether Ionophores for Transport of Metal Cations
Authors: Jane Yih‐Song , Shih Jeng‐Shong 
Published: May 2015

AbstractAlkyl‐substituted sym‐dibenzo‐16‐crown‐5‐oxyacetic acid and sym‐dibenzo‐16‐crown‐5‐oxydodecanic acid were synthesized and applied as ion transport carriers in liquid and film membranes. Increasing crown‐ether lipophilicity decreased acid dissociation constants and solubilities of crown‐ether carboxylic acids in water but enhanced the solubility and transport ability of the carboxylic anion‐K+ complex through a liquid organic (CH2Cl2) membrane. Transport phenomena of the cations alkali‐metal ions, alkaline‐earth metal ions and transition‐metal ions through liquid membranes based on these crown‐ether carriers were investigated, Effects of anions, crown‐ethers and pH on ion transport are discussed. A mechanism of ion transport through a crown‐ether membrane is proposed to include [OH] and [H+] in both source and target layers. Ion transport through a polymer/crown‐ether film membrane was more efficient than through a liquid membrane.
Synthesis and Crystal Structure of Metal Complexes of N‐phenyl‐o‐benzoquinonediimine (M = Ru2+, Co3+, Ni2+)
Authors: Cheng Hei‐Ying , Lin Cheng‐Chen , Tzeng Biing‐Chiau , Peng Shie‐Ming 
Published: May 2015

AbstractElectron‐delocalized quinoid‐like complexes — [RuII(bipy)2(N‐ph‐bqdi)]2+, cw‐[CoIII(N‐ph‐s‐bqdi)2(py)]+ and trans‐[NiII(N‐ph‐s‐bqdi)2] (N‐ph‐bqdi = N‐phenyl‐o‐benzoquinonediimine, N‐ph‐s‐bqdi = N‐phenyl‐o‐semi‐benzoquinonediimine) were synthesized that display reversible multi‐electron redox couples. The respective cis‐ and trans‐ conformation of the Co and Ni complexes are controlled by the steric effect of the substituent phenyl group. The Ni complex forms one‐dimensional stacks in crystals. The crystal and molecular structures of three compounds are reported. [Ru(bipy)2(N‐ph‐bqdi)](PF6)2: space group P2l/c, a = 13.292(2), b = 18.785(4), c = 13.959(2) Å; β = 97.42(1)°, V = 3456(1) Å3, Z = 4, Rf = 0.047, Rw = 0.044; cis‐[Co(N‐ph‐s‐bqdi)2(py)](OAc)(H2O): space group P21/n, a = 12.752(4), b = 13.303(2), c = 16.683(3) Å; β = 102.27(2)°, V = 2765(1)Å3 Z = 4, Rf = 0.035, Rw = 0.035; and trans‐[Ni(N‐ph‐s‐bqdi)2]: space group P‐1, a = 9.771(2), b = 10.417(1), c = 11.541(2) Å; α = 92.24(1), β = 104.04(1), γ = 117.94(1)°, V = 990.6(3) Å3, Z = 2, Rf = 0.030, Rw = 0.031. Infrared, 1H NMR, 15N NMR and electronic absorption spectra, elemental analyses, magnetic and cyclic voltammetric data are presented.
Syntheses of α‐Haloformylarylhydrazines and Their Self‐dimerizations
Authors: Kuo C. N. , Wu M. H. , Chen S. P. , Li T. P. , Huang C. Y. , Yeh M. Y. 
Published: May 2015

Abstractα‐Haloformylarylhydrazine hydrohalides 1 were prepared through ring opening of 3‐aryl‐4‐halosydnones 7 with hydrohalic acids in EtOAc in moderate yields. Reactions between compounds 1 and primary alcohols gave alkyl 1‐arylhydrazinecarboxylates 12 and 14, important intermediates in syntheses of antiinflammatory drugs. Compounds 16,4‐aryl‐2‐(arylhydrazin‐1‐y1)‐1,3,4‐oxadiazolin‐5‐ones, and compounds 18, 1,4‐diaryl‐1,4‐dihydro‐1,2,4,5‐tetrazine‐3,6(2H,5H)‐diones, were synthesized by self‐dimerization of compounds 1. Compounds 18 were also converted to compounds 17 via intramolecular rearrangement. Structural elucidation and verification of the reaction mechanisms are presented.
Triplex Formation of Oligonucleotides Containing 2′‐O‐Methylurldine, 5‐Bromo‐2′‐OMethyluridine and 2′‐0‐Methycytidine
Authors: Ono Akira , Kan Lou‐Sing 
Published: May 2015

AbstractThe influence of 5‐bromo and 2′‐O‐methyl substitution of pyrimidine bases on nucleic acid triplex formation was examined by thermal denaturation and circular dichroism spectra with the following oligomers: 5′‐(Um) (I, Um = 2′‐O‐methyluridine), 5′‐(BUm)15T (II, BUm = 5‐bromo2′‐O‐metnyluridine), 5′‐(CmUm)6Cm‐T (III, Cm = 2′‐O‐methylcytidine), and 5′‐(CmUm)6Cm T (IV). Both I and II form triplexes with dA16 (A) or 5′‐d(C2A16C2)‐5′‐d(G2T16G2) (D), but III and IV form triplexes with 5′‐d(AG)8 (G). Triplex formation involving two unmodified oligomers, dT16 (T) and 5′‐d(CT)7 (C), was used for comparison. The orders of melting temperatures (Tm) of triplexes were II A II (Tm = 48 °C) > I A I (34 °C) > T A T (22 °C); II D (Tm= 30 °C) > I D (22 °) > T D (12 °C); and IV G IV (Tm= 82 °C) > III G III (72 °C) > C G C (55 °C). The pKa of IVG IV, III G III, and C G C were determined by CD to be 6.5,6.3, and 6.2, respectively. Triplexes formed by oligonucleotides containing both 2′‐O‐methyl and 5‐bromo substitutions are more stable and have a greater pKa than those formed by oligonucleotides with 2′‐O‐methyl substitution only; which in turn are more stable and have a greater pKa than those formed by unmodified oligonucleotides.
Photolysis of (7R)‐7‐Methoxycarbonyl‐1,5‐di‐f‐butylbicyclo[2.2.2]oct‐5‐ene‐2,3‐dione at Various Temperatures
Authors: Lin Yu‐Min , Ueng Yin‐Gang , Wu Sean‐Nan 
Published: May 2015

AbstractUpon irradiation at room temperature, the title compound 1 isomerized selectively and quantitatively into a cyclobutanedione 2 which underwent quantitatively bisdecarbonylation to afford a cyclohexadiene 3. Thermolysis of 2 produced 1 and a bicyclo[2.2.1]heptenone 4. Compound 4 was prepared in 70% yield by irradiation of 1 in refluxing dry toluene.
Transfer Chemical Potentials, Solubility and Reactivity of Psoralen and 8‐Hydroxypsoralen in Binary Aqueous Methanol Mixtures
Authors: Alsehaibani Hamad A. , Abu‐Gharib Ezz‐Eldin A. 
Published: May 2015

AbstractSolubilities are reported for psoralen and 8‐hydroxypsoralen in binary aqueous mixtures at ambient pressure and 298 K, with organic cosolvent methanol. Gibb's energies of transfer of there two compounds are calculated from their solubilities. Transfer chemical potentials of both compounds are stabilised by increasing prapartion of organic cosolvent because of their markedly hydrophobic character.Basic hydrolysis of psoralen and 8‐hydroxypsoralen in aqueous methanol mixtures was examines kinetically, yielding Gibb's energies of activation. Derived transfer parameters are used in analysis of kinetic data to describe the influence of solvent composition on initial and transition states. Derived transfer chemical potentials for a single ion such as hydroxide ion lead to an interesting comparison of the effects of extrathermodynamic assumptions, Wells estimates and TATB assumption, on the initial and transition states. The analysis comfirm the important role played by the choice of extrathermodynamic assumption in determining the overall kinetic pattern. We describe misgivings concerning procedures used by wells to derive transfer chemical potential for single ions.
Simultaneous Determination of Nickel(II) and Cobalt(II) by Second‐Derivative Spectrophotometry
Authors: Ho Wu‐Hsiung , Chen Chien‐Lung , Chen Huey‐ru 
Published: May 2015

Abstract4‐(2‐Pyridylazo) resorcinol, PAR, is shown to be useful for simultaneous determination of cobalt(II) and nickel(II) using second‐derivative spectrophotometric method with controlled experimental parameters. This method allows the determination of 0.20‐1.25 ppm of nickel(II) and 0.25‐1.50 ppm of cobalt(II) in mixtures with good precision and accuracy. This method has advantages of simplicity, speed and requires no prior separations.
Cyclopentylidene Ketals of C‐Glycerolyl Heterocycles
Authors: Abdel Hamid H. , El Habrouk M. , El Ashry E. S. H. 
Published: May 2015

AbstractCyclopentylidene ketals of 3‐(D‐erythro and L‐threo‐glycerol‐1‐yl) of l‐phenyl‐2‐pyrazoline‐4,5‐dione‐4‐phenylhydrazone and 1 ‐phenylflavazole were prepared. The location of the ketal ring on the glycerolyl residues was determined by NMR spectral analyses.
Pulsed, Crossed, Supersonic Molecular Beam Studies of Refractory Atom Reactions
Authors: Naulin Christian , Costes Michel 
Published: May 2015

AbstractDynamics of refractory atom reactions have been studied with a crossed beam apparatus combining two pulsed, supersonic molecular beam sources, a pulsed UV laser for creating the refractory atoms in the gas phase by laser ablation, and a pulsed dye laser to probe the reaction products by laser‐induced fluorescence. Examples of the A1(2Pj) + O2(X3∑g)→ A10(X2∑+) + O(3Pj), Mg(1So) + N2O(X1∑+) → MgO(X1∑+,a3Π) + N2(X1∑g+) andC(3Pj) + NO(X2Πr) → CN(X2∑+) + 0(3Pj) systems are given. Comparisons with the studies performed using the conventional steady‐state beam approach are made.
Magnetic Analysis of Atomic and Molecular Beams. Recent Applications
Authors: Aquilanti Vincenzo , Ascenzi Daniela , Cappelletti David , Pirani Fernando 
Published: May 2015

AbstractA progress report is given on recent advances in the magnetic analysis techniques for atomic and molecular beams. The cases of halogen atoms and of oxygen molecules are considered in detail. Applications are outlined to discharge plasma diagnostics, to the measurements of molecular alignment in seeded beams and to scattering studies of the interaction of open shell atoms.
Chemical Reconstruction of Pt‐Rh(100) Alloy and Pt/Rh(100), Rh/Pt(100) Bimetallic Surfaces
Authors: Tanaka Ken‐Ichi , Nieuwenhuys B. E. , Tamura Hiroyuki 
Published: May 2015

AbstractWhen Cu(110), Ni(l 10), Ag(110) surfaces are exposed to O2 at room temperature, one dimensional metal‐oxygen strings grow in the < 001 > direction of the (110) surfaces. A similar phenomenon occurs in the adsorption of H2 on Ni( 110) surface at room temperature, where the one dimensional strings grow along the < 110 > direction. These phenomena are undoubtedly different from the adsorption induced reconstruction but are explained by the chemical reconstruction involving the formation of quasi‐compounds and their self‐ordering on the metal surfaces. The chemical reconstruction is indispensablly important to understand the structure and catalysis of alloy and bimetallic surfaces.Pt0.25Rh0.75(100) alloy surface being active for the reaction of NO with H2 is an interesting example. When the Pt‐Rh(100) alloy surface is exposed to NO or O2 at arround 500 K, a p(3 × 1) ordered Rh‐O over‐layer is obtained on a Pt‐enriched 2nd layer by the chemical reconstruction. Ordering of Rh‐0 in the p(3 × 1) structure on the Pt(100) surface was reproduced by heating a Rh/Pt(100) bimetallic surface in O2, and the chemical reconstruction making the p(3 × 1) Rh‐O overlayer on a Pt enriched 2nd layer was also proved by heating a Pt/Rh(100) bimetallic surface in O2 or NO. The activation mechanism of the Pt‐Rh alloy and the Pt/Rh bimetallic surfaces by the chemical reconstruction was evidently shown by using a Pt deposited Rh(100), Pt/Rh(100), surface. That is, the Pt/Rh(100) is not so active for the reaction of NO with H2, but the reconstructed p(3 × 1)Rh‐O/Pt‐layer/Rh(100) surface is very active for the reaction. Therefore, it was concluded that the chemical reconstruction of the Pt‐Rh catalyst makes the active surface which is composed of Rh‐O and a Pt layer.
Internal Rotation of the Methyl Group in Cations of Toluene Derivatives
Authors: Fujii Masaaki , Takazawa Ken , Ito Mitsuo 
Published: May 2015

AbstractThe potential of the internal rotation of the methyl group was determined for o‐, m‐, and p‐fluorotoluene cations by pulsed field ionization spectroscopy. The potential of the internal rotational motion was also surveyed for other toluene derivative cations. It was found that the barrier height generally increases by ionization. The increase in the barrier height has been discussed in connection with the reduction of the internal rotational constant B by ionization. The geometrical distortion of the methyl group during the internal rotation has been suggested.
Characteristics and Dynamics of Superexcited States of Molecules
Authors: Nakamura Hiroki 
Published: May 2015

AbstractCharacteristics and dynamics of superexcited states of molecules are interpreted by emphasizing their significant roles in various molecular dynamic processes. The states are expected to open a new field of physics and chemistry; but because of their complexity, they should be investigated by using the possible multifarious means from the various view points. The interplays between theory and experiment and also between the two theories, dynamics theory and quantum chemistry, are crucial to reveal this world. More systematic studies are required for the superexcited states of polyatomic molecules.
Ejection of Cluster Ions from a Liquid Beam of an Aniline‐Propanol Solution Following Laser Photoionization
Authors: Mafuné Fumitaka , Kobno Jun‐Ya , Kondow Tamotsu 
Published: May 2015

AbstractA simple technique of preparing a continuous laminar liquid flow in vacuum (liquid beam) was developed and combined with multiphoton ionization and a time‐of‐flight mass spectrometer. This technique was applied to the study on resonance photoionization of an aniline (AN)‐propanol (PrOH) solution (0.1 – 0.3 M). Binary cluster ions of aniline and propanol, AN+(PrOH)n (n ≤ 1), and protonated propanol cluster ions, H+(PrOH)n (n ≤ 1), were observed as product ions in the gas phase. The relative intensities of AN+PrOH and those of H+(PrOH)2 were measured as functions of the excitation laser power and the concentration of aniline in the propanol solution. The dependences of the ion intensities on the laser power and the AN concentration are explained in terms of a Coulomb ejection model, where the ions are ejected from the surface by Coulomb repulsion exerted from neighboring ions. It is also concluded that H+(PrOH)n is produced by a proton transfer reaction from an aniline ion to solvent molecules in the solution.
Parahydrogen Induced Polarization: A New Magnifying Glass for Examining Reactions with Hydrogen
Authors: Eisenberg Richard 
Published: May 2015

AbstractParahydrogen‐included polarization (PHIP), its occurrence and mechanistic implications in homogeneous hydrogenation chemistry, and its appearance in the oxidative addition of H2 to transition metal centers are described and analyzed. The PHIP phenomenon, which is characterized by unusual NMR absorptions and emissions in product spectra, arises when para‐enriched H2 is employed in hydrogenation of unsaturated organic substrates with a homogeneous metal catalyst or when para‐enriched H2 is added to a metal complex to form a metal dihydride. Examples of PHIP are found in ruthenium phosphine‐catalyzed hydrogenations, catalysis by binuclear rhodium complexes, and in H2 oxidative addition to Ir(I) complexes. The decay of polarization has been shown in the case of asymmetric hydrogenation catalyzed by Rh(chiraphos)+ to correlate well with the measured rate of reaction. For asymmetric hydrogenation of aprotic substrates using Noyori's Ru(BINAP)(OAc)2 catalyst (1), PHIP is observed indicating a pairwise hydrogen transfer mechanism. Through the signal enhancement of PHIP, it has been possible to observe Rh hydride species never previously detected including binuclear complexes in the reaction of H2 with RhCl(CO)(PR3)2 (R = Ph, Me) and in hydrogenation catalysis promoted by RhCl(PPh3)3. Also observed in the hydrogenation catalysis is the putative olefin dihydride catalytic intermediate.
1H NMR Study on the pH‐Dependent Polymorphism of a DNA Triplex with Oligonucleoside Methylphosphonate Analogues
Authors: Lin Leh‐Jame , Lin Shwu‐Bin , Wu Cheng‐Wen , Kan Lou‐Sing 
Published: May 2015

AbstractTriplex formation in various stoichiometric mixtures of oligonucleoside methylphosphonates d‐Ap(GpAp)7G (A) and d‐Cp(TpCp)7 (B) (p = methylphosphonate) was studied by measuring the NH‐N hydrogen bonded NMR resonance in relation to temperature and pH. Only a duplex or a triplex was observed for the mixture at pH 6.8 or 3.83 respectively, but both duplex and triplex coexist at pH 4.75. Thus the polymorphism of the mixture is close related to the pKa (4.30) for protonation of B. The triplex starts to dissociate when pH < 2. All data indicate that the duplex and triplex formed by A and B are less stable than those formed by d‐A‐(G‐A‐)7G (C) and d‐C‐(T‐C‐)7T (D) (‐ = phosphodiester). The conformation of the triplex A·B2 is the same at pH 3.83 as that of the corresponding triplex C·D2 at pH 4.50, but different at pH 4.75. Thus, the A·B2 triplex must be able to exist in various conformations, depending on the acidity of the solution. Furthermore, no diastereoisomeric effect was observable on duplex and triplex formation as similar chemical shifts of all NH resonances from C+, G, and T bases were recorded from a mixture of myriad steric isomers.
Circular Dichroism Measurements on C‐Terminal Fragment of Heat Shock Protein from Rat
Authors: Tsay L. M. , Hu S.‐M. , Wang C. , Lee W. S. , Lin L. J. , Kan Lou‐Sing 
Published: May 2015

AbstractThe secondary structure of the C‐terminal fragment (10 kDa) of rat hsc70 (a. a. #546–646) was analyzed according to circular dichroism spectra. In the pH range 5–9 and at concentrations of Na+ up to 0.18 M, the protein is estimated to contain 32‐34% a helix, 18–16% of β sheet, approximately 25% for both turns and disordered structures. This protein is most stable at pH between 6 and 7 in solution with 0.055 M Na+ concentration. However, all Tm are relatively large (57–73 °C) and alterations from one condition to another are small. Thus, the C‐fragment (10 kDa) of hsc70 is a stably folded protein under physiological conditions.