bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis and Magnetic Studies of Copper (II)‐Manganese (II) Heterobinuclear Complexes with an Oxamido Bridge
Authors: Li Yan‐Tuan , Zhu Xue‐Dong , Yan Cui‐Wei , Liao Dai‐Zheng 
Published: September 2010

AbstractFour new copper (II)‐manganese (II) heterobinuclear complexes bridged byN, N'‐bis[2‐(dimethylamino)ethyl)]oxamido dianion (dmoxæ) and end‐capped with 1, 10‐phenanthroline (phen), 5‐methyl‐1, 10‐phenanthroline (Mephen), diaminoethane (en) or 1,3‐di‐aminopropane (pn). respectively, namely, [Cu(dmoxae)MnL2] (CIO4)2 (L=phen, Mephen, en, pn), have been synthesized and characterized by elemental analyses, IR, electronic spectral studies, and molar conductivity measurements. The electronic reflectance spectrum indicates the presence of spin exchange‐coupling interaction between bridged copper(II) and manganese (II) ions. The cryomagnetic measurements (4.2‐300 K) of [Cu(dmoxae)Mn(phen)2](CIO4)2 (1) and [Cu(dmoxae)Mn(Mephen)2](CIO4)2(2) complexes demonstrated an antiferromagnetic interaction between the adjacent manganese(II) and copper (II) ions through the oxamido‐bridge within each molecule. On the basis of spin Hamiltonian, H= ‐ 2JS1. S2. the magnetic analysis was carried out for the two complexes and the spin‐coupling constant (J) was evaluated as −35.9 cm−1 for 1 and ‐ 32.6 cm−1 for 2. The influence of methyl substitutions in the amine groups of the bridging ligand on magnetic interactions between the metal ions of this kind of complexes is also discussed.
Intermolecular Heterocoupling Reaction between N‐Sulfonylimines and Aliphatic Ketones Promoted by Samarium (II) Iodide
Authors: Liu Yun‐Kui , Zhang Yong‐Min , Liu Xi 
Published: September 2010

AbstractN‐sulfonylimines (1) were induced by samarium(II) iodide to produce radical anion intermediates (2) in situ, which were trapped by aliphatic ketones (4) to afford heterocoupling products β‐sulfonamido alcohols (5) in moderate to good yields under mild and neutral conditions.
Synthesis and Mesomorphic Properties of 4‐((4‐n‐Alkoxy‐2, 3, 5, 6‐tetrafluorophenyl)ethynyl)phenyl Methoxy‐substituted Benzoates
Authors: Li Heng‐Feng , Yu Hong‐Bin , Liu Ke‐Gang , Wen Jian‐Xun 
Published: September 2010

AbstractTwo series of 4‐methoxybenzoate liquid crystals were synthesized. Their phase transition temperatures were also measured by texture observation in a polarizing microscope and confirmed by DSC. Their mesomorphic properties and fluoro‐substitute effect were studied in detail.
Palladium‐Catalyzed Addition Reaction of 1‐Octene, Carbon Tetrachloride and Carbon Monooxide in Alcohols
Authors: Sun Jun‐Hua , Jiang Huan‐Feng 
Published: September 2010

AbstractIn the presence of pyridine, the Pd‐catalyzed addition reaction of CO and CCI4 to 1‐octene could be carried out smoothly under mild conditions. In this reaction, the satisfactory results were afforded when different alcohols and palladium catalysts were used.
Molecular Recognition Studies on Modified Cyclodextrins
Authors: Liu Yu , You Chang‐Cheng 
Published: September 2010

AbstractThis account describes our research progress in recent years in the areas of the molecular recognition studies on modified cyclodextrins, including positively charged cyclodextrins, cyclodextrin derivatives with hydrophobic substituent, and dimeric cyclodextrins. Calorimetric titration and various spectrometric techniques were employed to determine the complex stability constants, as well as the thermodynamic parameters, for their inclusion complexation with diverse guest molecules. The results obtained have been discussed from the viewpoint of size/shape‐matching, induced‐fit, geometric compensation, and multiple recognition. Thermodynamically, the compensatory relationship between ΔH and TΔS was found to be exhibited in the inclusion complexation of modified cyclodextrin.
Reductive Cyclodimerization of α, β‐ Unsaturated Ketones Promoted by AlCl3/Sm System: A Facile Synthesis of 2‐Aroyl‐1,3,4‐triaryl Cyclopentanol Derivatives
Authors: Fan Xue‐Sen , Zhang Yong‐Min 
Published: September 2010

AbstractPromoted by AlCl3/Sm bimetallic system, α, β‐unsaturated ketones underwent reductive cyclodimerization to afford cyclopentanol derivatives under mild conditions. The reaction is stereocontrolled and regioselective over the competitive carbon‐carbon double bond reduction.
Characterization and Activity of MnO/γ‐Al2O3 for Hydrogenation of Methyl Benzoate to Benzaldehyde
Authors: Xu Hua‐Long , Shen Wei , Yang Yong‐Tai 
Published: September 2010

AbstractThe activities of a MnO/γ‐Al2O3 catalyst for the selective reduction of methyl benzoate to benzaldehyde have been studied in a continuous flow reactor. Characterization of the catalyst has been conducted by XRD, XPS, NH3‐TPD and TPD‐IR. XRD and XPS results revealed that the steady state catalyst is mainly MnO2/γ‐AlO3 before reduction and MnO/γ‐Al2O3 after reduction. Monolayer dispersion capacity obtained by XPS method is about w (Mn)11.3% TPD‐IR results revealed that there are only L acidic centers on the catalytic surface. NH3‐TPD determinations have verified that the catalyst with a certain number of moderate strength acidic sites is advantageous to hydrogenation of methyl benzoate to benzaldehyde.
Evaluation of a Combined Quantum Chemical Method Used in Calculating OH Bond Dissociation Enthalpy
Authors: Sun You‐Min , Zhang Hong‐Yu , Chen De‐Zhan 
Published: September 2010

AbstractOH bond dissociation enthalpies (BDE) for a variety of substituted phenols were calculated using a combined quantum chemical method. It is found that the calculated OH BDE correlated well with the recommended values, except for ortho‐tert‐butyl substituted phenols. For the electron‐donating group substituted phenols the calculated OH BDE are slightly higher than the recommended values, however, for the electron‐withdrawing group substituted phenols the calculated OH BDE are slightly lower than the recommended values.
Oscillations Produced From Acidity Hydrolysis of Triglyceride in Emulsion
Authors: He Zhan‐Bo , Qi Gang 
Published: September 2010

AbstractA new type of oscillating reaction was found from the systematic design of the chemical oscillator in water in oil (W/O) emulsions. It is an acidity hydrolysis reaction of long chain triglyceride in W/O emulsion at 25.0 ± 0.1°C in a bath stirring reactor. During the process of reaction, there were periodic and semi‐periodic changes lasting more than 10 hours both in electrolytic conductivity and electric potential. Microscope also revealed that the emulsion structure changed regularly and quickly. Because of the large difference in the solubility of the hydrolyzed products, it could be thought, that the different redistribution in the two phases of water and oil induces the regular changes. Marangoni effect of interface membrane made oscillation to form. The oscillating reaction can be used to explain the periodic change in the living system produced from coupling between reaction and diffusion.
Solid‐state Asymmetric Reduction of ( S )‐1, 1′‐Bi‐2‐naphthol‐Acetylferrocene Molecular Compound with Sodium Borohydride
Authors: Du Hai‐Feng , Ding Kui‐Ling , Meng Ji‐Ben 
Published: September 2010

AbstractA novel molecular crystal formed between enantiopure 1,1′‐bi‐2‐naphthol and acetylferrocene has been prepared and characterized in this communication. The examination on its reduction with sodium borohydride showed that the asymmetric induction was observed in the solid state but not in the solution phase. The asymmetric induction in the solid‐state reduction may be attributed to the chiral microenvironment of molecular crystal.
Characterization of the Kinetic Phase Transition of Phospholipids Using Avrami and Tobin Models
Authors: Chen Lin , Yu Zh‐Wu , Xue Fang‐Yu , Hong Xiao‐Yin 
Published: September 2010

AbstractMechanism of the lamellar crystalline phase formation of distearoyl‐phosphatidylethanolamine (DSPE) dispersed in excess glycerol has been examined by differential scanning calorimetry. It was found that transformation of liquid‐crystal phase to a crystalline phase must be mediated by a lamellar‐gel phase. Further examination of the kinetic phase behavior using Avrami and Tobin models suggested a single dimensional growing pattern and a three‐step mechanism of the crystallization, consisting of nucleation, normal growth, and restricted growth.
Preparation of Dy‐ferrite Ferrofluids and Magnetochemical Studies on the Superparamagnetism
Authors: Hu Xian‐Luo , Xu Chao , Shen Qin , Chen Yi‐Wei , Zhao Hong , Zhu Chuan‐Zheng 
Published: September 2010

AbstractThis paper reports unprecedented preparation of Dy‐ferrite water‐based ferrofluids stabilized by polymeric surfactant PMAA. The stability of ferrofluids was characterized in terms of the equation of criterion for the stability of ferrofluids. Magnetic susceptibility was measured with a Faraday‐type magnetic balance at different temperature and with different magnetic field intensity. According to the Langevin function, superparamagnetism of Dy‐ferrite ferrofluids has been confirmed by the curves of saturation magnetization σ versus H/ T, and the blocking temperature is between 160 and 200 K. In terms of the simplified Langevin function in the low magnetic field, the average particle size is 20 nm that coincides with the result evaluated by FHMW. In addition, chemical analysis, infrared spectra and Mossbauer spectroscopy were utilized to analyze the main components of the ferrofluids.
Structure of Bischloro tris (1, 10‐phenanthroline) copper (II) Dichloromethane Solvate Nonahydrate: [Cu(phen)3]Cl2CH2Cl2·9H2O
Authors: Jian Fang‐Fang , Lin Jie‐Hua , Zhang Shu‐Sheng 
Published: September 2010

AbstractThe crystal and molecular structures of [Cu(phen)3] Cl2 · CH2Cl2.9H2O (PHEN= 1, 10‐pbenanthroline) have been determined by X‐ray crystallography. The complex crystallizes in triclinic system, space group P1, with lattice parameters a = 1.26000(3), b = 1.37525(4), c = 1.42750(3)nm, α = 85.2970(1),β = 66.8400(1), γ= 83.09(1)°, and Z = 2. The coordinated cations contain a six‐coordinated copper atom chelated by three PHEN ligands, and the Jahn‐Teller effect of the Cu(II) ion results in a distorted octahedral arrangement with the six CuN distances ranging from 0.2112(6) to 0.2265(7) nm. In addition to the copper coordinated cation, there are two chloride ions, one dichloromethane solvate and nine water molecules in its asymmetric unit. In the solid state, the title compound forms three dimensional network structures through hydrogen bonds. The intermolecular hydrogen bonds connect the [Cu(phen)3]2+, chloride ion, dichloromethane solvate and H2O moieties altogether.
Novel Synthesis of α‐Diketones from Bisbenzimidazolium Salt and Grignard Reagents
Authors: Shi Zhen , Lu Lin‐Gang , Yang Bing‐Qin , Guo Yuan 
Published: September 2010

AbstractThe reaction of bisbenzimidazolium salt with Grignard reagents and a new synthetic method of a‐diketones from bis‐benzimidazolium salt and Grignard reagents are reported. The structures of all a‐diketones are characterized by elemental analyses, infrared spectroscopy and 1H NMR spectroscopy. The influences of the various Grignard reagents on the yield of a‐diketones and the mechanism are discussed, and a new convenient synthetic method for a‐diketones is provided.
Physico‐chemical Properties and Bioactivities of a Glycoconjugate LbGp5B from Lycium barbarum L
Authors: Peng Xue‐Mei , Qi Chun‐Hui , Tian Geng‐Yuan , Zhang Yong‐Xiang 
Published: September 2010

AbstractA glycoconjugate designated as LbGp5B was isolated from the fruit of Lycium barbarian L. and purified to homogeneity by gel filtration. LbGpSB is composed of rhamnose (Una), arabinose (Ara), galactose (Gal), glucose (Glc), galacturonic add (GalA) and seventeen amino adds. The molecular weight of LbGpSB was determined by sodium dodecyl sulfate‐polyacrylamide gel electrophoresis (SDS‐PAGE) and by matrix‐assisted laser desorption/ionization (MALDI) time of fight (TOF) mass spectrometry (MS). The preliminary experiments showed that LbGpSB promoted splenocyte proliferation in mice and inhibited the peroxidation of low density lipoprotein (LDL).
Ethylene Oligomerization Catalyzed by MCl2(PPh3)2 Complex‐es/Ethylaluminoxane
Authors: Qian Ming‐Xing , Zhang Yu‐Liang , He Ren 
Published: September 2010

AbstractThe catalytic properties of MCl2 (PPh3)2 (M = Fe, A; Co, B; Ni, C) in combination with ethylaluminoxane (EAO) as cocatalyst for ethylene oligomerization have been investigated. Treatment of the MCl2 (PPh3)2 complexes with EAO in toluene generated active catalysts in situ that are capable of oligomerizating ethylene to low‐carbon olefins. The catalytic activity and product distribution were affected by reaction condition, such as reaction temperature, the ratios of Al/M and the reaction time. The activity of 1.70 × 105 g oligomers/ (mol Co. h) for the catalytic system of CoCl2(PPh3)2 with EAO at 200°C was observed, with the selectivity of 91.1% to C4–10 olefins and 70.7% to C4–10 linear α‐olefins.
Study of 2‐Iodo‐3‐(phenylsulfinyl)‐2‐propen‐1‐ol and its Analogues by Self‐chemical Ionization Mass Spectrometry
Authors: Zhang Fang , Guo Yin‐Long , Wei Qi , Ma Sheng‐Ming 
Published: September 2010

AbstractThe self‐chemical ionization (SCI) in quadrupole mass spectrometry was developed to determine the structure of (E)‐2‐iod‐3‐(phenylsulfinyl)‐2‐propen‐1‐ol and its 6 analogues. Some techniques that increase the sample quantity and heating speed and shorten vaporization time to obtain high pressure in the ion source were applied to increase the chance of ionmolecule reactions. The structures of these compounds were identified by mass spectral data of MH+ and some characteristic fragment ions. Compared with the mass spectra for 2‐iodo‐3‐(phenylsulfinyl)‐2‐propen‐l‐ols obtained in electron impact ionization (EI), SCI showed more information, in particular, an improvement in amount of information at the high mass area. The absence of reagent gas makes the spectrum clean and simple.
Structural and Spectral Studies on the Ni(II) Complexes of 1,5‐Diazacyclooctane (DACO) Bearing Heterocyclic Pendants: Formation of a Two‐dimensional Network via Hydrogen Bonds and π‐π Stacking Interactions
Authors: Du Miao , Xu Qiang , Guo Ya‐Mei , Weng Lin‐Hong , Bu Xian‐He 
Published: September 2010

AbstractA penta‐coordinated Ni(II) complex with a 1,5‐diazacyclooctane (DACO) ligand functionalized by two imidazole donor pendants, [NiL1Cl] (ClO4) H2O (1) (where L1 = 1,5‐bis (imidazol‐4‐ylmethyl)‐l,5‐diazacyclooctane) has been synthesized and characterized by X‐ray diffraction, infrared spectra, elemental analyses, conductance, thermal analyses and UV‐Vis techniques. Complex 1 crystallizes in triclinic crystal system, P‐l space group with a = 0.74782(7), b = 1.15082 (10), c = 1.23781(11) nm, α = 82.090(2), β = 73.011(2), γ = 83.462(2)°, V = 1.00603(16) nm3, M, = 486.00, Z = 2, Dc = 1.604 g/cm3, final R = 0.0435, and wR = 0.1244. The structures of 1 and its related complexes show that in all the three mononuclear complexes, each Ni(II) center is penta‐coordinated with a near regular square pyramid (RSP) to distorted square‐pyramidal (DSP) coordination environment due to the boat/chair configuration of DACO ring in these complexes, and the degree of distortion increases with the augment of the size of the heterocyclic pendants. In addition, the most striking feature of complex 1 resides in the formation of a two‐dimensional network structure through hydrogen bonds and stabilized by π‐π stacking. The solution behaviors of the Ni(II) complexes are also discussed in detail.
New Tolan‐type Liquid Crystals with 1, 3‐Dithiane Ring
Authors: Li Heng‐Feng , Liu Ke‐Gang , Wang Kan , Wen Jian‐Xun 
Published: September 2010

AbstractTwo new tolan‐type liquid crystalline (LC) materials, 2‐[4‐(4‐pentoxyphenyl)ethynylphenyl]‐5‐pentyl‐l,3‐dithiane (A) and 2‐[4‐(4‐pentoxy‐2, 3, 5, 6‐tetrafluorophenyl) ethynylphenyl]‐5‐pentyl‐1, 3‐dithiane (B) were synthesized and their mesomorphic behavior was determined. The 1, 3‐dithiane‐type compound A exhibits only nematic phase. The compound B, fluorosubstituted in the LC core, shows the same nematic phase range.
Study on the Reaction of Electron‐deficient Cyclopropane Derivatives with Amines
Authors: Chen Ya‐Li , Ding Wei‐Yu , Cao Wei‐Guo , Lu Cheng 
Published: September 2010

AbstractReaction of electron deficient cyclopropane derivatives cis‐1‐methoxycarbonyl‐2‐aryl‐6, 6‐dimethyl‐5, 7‐dioxa‐spiro‐[2,5]‐4,8‐octadiones (1a‐d) (X = CH3, H, Cl, NO2) with anilines (2a‐e) (Y = p‐CH3, H, p‐Br, p‐NO2, o‐CH3) at room temperature gives N‐aryl‐trans, trans‐α‐carboxyl‐β‐methoxycarbonyl‐γ‐aryl‐γ‐butyrolactams (3a‐p) in high yields with high stereoselectivity. For example, 1a (X= CH3) reacts with ammonia 4 or benzyl amine 5 at room temperature to give inner ammonium salt 6 or 7 in the yield of 83% or 97% respectively. The reaction mechanisms for formation of the products are proposed.
Novel intramolecular coordination chemistry of some new metallocene complexes
Authors: Qian Yan‐Long , Deng Feng‐Jiao , Li Feng‐Jun , Liu Yi , Liu Yu‐Wen , Wang Cun‐Xin , Liu Si‐Yang , Cao Ai‐Hua , Qu Song‐Sheng 
Published: September 2010

AbstractThe metabolic thermogenic curves of liver mitochondria isolated from the livers of Cyprinus Carpio vol and its parents were determined at 28°C by using an LKB‐2277 Bioactivity Monitor. The results indicated that their thermogenic curves are different The total heat output and total time of the metabolism of the liver mitochondria of the hybrid F1 (Cyprinus Carpio val) are more than those of its parents, and its maximum heat power is between that of the female parent and male parent. The relationship between their metabolic thermogenic curves and character of mitochondrial metabolism, and thermokinetics and the heterosis were analyzed and discussed. The character of the mitochondrial thermogenic curves reflected the physiologic character of heterosis. The microcalorimetric method proved to be a probable and sensitive tool for the assessment of heterosis.
Microcalorimetric studies on the mitochondria metabolism of Cyprinus Carpio val and its parents
Authors: Deng Feng‐Jiao , Li Feng‐Jun , Liu Yi , Liu Yu‐Wen , Wang Cun‐Xin , Liu Si‐Yang , Cao Ai‐Hua , Qu Song‐Sheng 
Published: September 2010

AbstractThe metabolic thermogenic curves of liver mitochondria isolated from the livers of Cyprinus Carpio vol and its parents were determined at 28°C by using an LKB‐2277 Bioactivity Monitor. The results indicated that their thermogenic curves are different The total heat output and total time of the metabolism of the liver mitochondria of the hybrid F1 (Cyprinus Carpio val) are more than those of its parents, and its maximum heat power is between that of the female parent and male parent. The relationship between their metabolic thermogenic curves and character of mitochondrial metabolism, and thermokinetics and the heterosis were analyzed and discussed. The character of the mitochondrial thermogenic curves reflected the physiologic character of heterosis. The microcalorimetric method proved to be a probable and sensitive tool for the assessment of heterosis.
Interaction of water‐soluble tetrakis‐(1‐methyl‐4‐pyridiniyl)‐porphyrin and CdS naonoparticles
Authors: Tian Chun‐Hong , He Xue‐Zhong , Shen Tao 
Published: September 2010

AbstractThe interaction between positively charged porphyrin TMPyP(4) (tetrakis‐(1‐methyl‐4‐pyridiniyl) porphyrin) and negatively charged surface of colloidal CdS nanoparticles has been studied by absorption spectrum, fluorescence spectroscopy, and time‐correlated single‐photon‐counting methods. Addition of CdS colloid to a TMPyP(4) solution leads to TMPyP(4) adsorption onto the surface of CdS colloid with an apparent association constant of 4643 L/mol. This adsorption results in distinct changes in absorption spectrum of TMPyP (4) and the quenching of its′ fluorescence, but the biexponential fluorescence decay changes hardly. Nearly 90% of the fluorescence of 5 × 10−6 mol/L TMPyP(4) can be quenched with 1.5 × 10−4 mol/L CdS colloid. These spectral changes are attributed to the formation of a certain form complex TMPyP(4)‐CdS.
Determination of constant‐volume combustion energy for the complexes of zinc nitrate with three amino acids
Authors: Gao Sheng‐Li , Chen San‐Ping , Hu Rong‐Zu 
Published: September 2010

AbstractFive solid complexes of zinc with L‐α‐methionine, L‐α‐phenylalanine and L‐α‐histidine were prepared. The constant‐volume combustion energies of the complexes, ΔEc (coordination), were determined by a precise rotating bomb calorimeter at 298.15 K. They were ‐ 2969.03 ± 0.34, ‐2929.46 ± 1.59, ‐9597.13 ± 6.12, ‐4378.98 ± 3.27 and ‐14047 ± 6.75 kJ/mol, respectively. Their standard enthalpies of combustion, ΔHθm,c(coordination, s, 298.15 K), and standard enthalpies of formation, ΔHθm,f (coordination, s, 298.15 K), were calculated. They were ‐2959.73 ± 0.34, ‐2923.88 ± 1.59, ‐9649.18 ± 6.12, ‐4373.40 ± 3.27, ‐14048.53 ± 6.75 kj/mol and ‐1180.94 ± 0.92, ‐1401.26 ± 1.77, ‐2501.69 ± 6.50, ‐1381.47 ± 3.49, ‐1950.19 ± 7.65 kJ/mol, respectively.
Study on new typical ionic clusters K+ (KNO3)n and NO3‐(KNO3)m
Authors: Shi Lei , Liu Zhi‐Qiang , Song Feng‐Ri , Liu Shu‐Ying 
Published: September 2010

AbstractThe sample solution of KNO3 is ejected into the gas phase and the ionic dusters of K+(KNO3)n and NO3 (KNO3)m are formed and observed by electrospray ionization mass spectrometry (ESIMS). Hie full mass spectra of both the positive ion and the negative ion show that the differences between each peak nearby are all about 101 (m/z), which correspond to the molecular weight of KNO3. The general formula of the ionic clusters can be assigned as K+(KNO3)n and NO3′‐(KNO3)m..
Theoretical study on the mechanism of the cycloaddition reaction between stannylene and ethylene or formaldehyde
Authors: Lu Xiu‐Hui , Zhai Li‐Min , Wang Ayi‐Xnan 
Published: September 2010

AbstractThe mechanism of the cycloaddition reaction of singlet stannylene and ethylene or formaldehyde has been studied by using density functional theory. The geometrical parameters, harmonic vibrational frequencies and energies of stationary points for potential energy surface are calculated by RB3LYP/3–21G* method. The results show that the two reaction processes are both two steps: (1) stannylene and ethylene or formaldehyde form an energy‐rich intermediate complex respectively, which is an exothermal reaction with no barrier; (2) two intermediate complexes isomerize to the product, respectively, with the barriers of these two reactions being 52.97 and 45.15 kJ/mol at RB3LYP/3–21G* level.
Catalysis of heteropoly acidic salts for synthesis of diethylene glycol ethyl ether with diethylene glycol and ethanol
Authors: Liu Jun‐Feng , Yi Ping‐Gui , Qi Yun‐Shi 
Published: September 2010

AbstractAg3PW12O40 and Ag4SiW12O40 showed high activity and stability in the synthesis of diethylene glycol ethyl ether with diethylene glycol and ethanol, on which the conversion is 80.2% and 78.4%, respectively, and the selectivity of diethylene glycol ether is 75.4% and 80.6%, respectively. After the third reaction cycle, Ag3PW12O40 and Ag4SiW12O40) still showed higher activity and selectivity, on which the conversion is 72. 6% and 77.5% respectively. But the activity of Ag3PMo12O40 is lower, the conversion is only 21.0%. IR, XRD, TG and n‐butylamine titrimetry showed that the catalysis may be connected with two kinds of acidic centers owned by heteropoly acidic salt.