A β-cyclodextrin derivative, perbenzyl-β-cyclodextrin, was prepared and used as a chiral stationary phase for capillary gas chromatography. Using FID detector and the column temperature between 70 and 80℃, the chir...A β-cyclodextrin derivative, perbenzyl-β-cyclodextrin, was prepared and used as a chiral stationary phase for capillary gas chromatography. Using FID detector and the column temperature between 70 and 80℃, the chiral separations of racemic 3-phenyl-1, 2-epoxyethane and 1-phenyl-1-propanol on a 14m×0.23mm I. D. fused silica column with the β-cyclodextrin derivative were carried out and the optical purities of optically active 1-phenyl-1-propanol samples prepared by asymmetric synthesis were determined.展开更多
This work develops 2-Phenyl-1H-imidazole-1-sulfonate(PHIS)as a multi-functional electrolyte additive for H2O/HF scavenging and film formation to improve the high temperature performance of LiNi_(0.8)Co_(0.1)Mn_(0.1)O_...This work develops 2-Phenyl-1H-imidazole-1-sulfonate(PHIS)as a multi-functional electrolyte additive for H2O/HF scavenging and film formation to improve the high temperature performance of LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)/graphite batteries.After 450 cycles at room temperature(25℃),the discharge capacity retentions of batteries with blank and PHIS-containing electrolyte are 56.03%and 94.92%respectively.After 230 cycles at high temperatures(45℃),their values are 75.30%and 88.38%respectively.The enhanced electrochemical performance of the batteries with PHIS-containing electrolyte is supported by the spectroscopic characterization and theoretical calculations.It is demonstrated that this PHIS electrolyte additive can facilitate the construction of the electrode interface films,remove the H2O/HF in the electrolyte,and improve the electrochemical performance of the batteries.This work not only develops a sulfonate-based electrolyte but also can stimulate new ideas of functional additives to improve the battery performance.展开更多
New cobalt(II) complex, [Co(O<sub>2</sub>C<sub>15</sub>H<sub>11</sub>N<sub>2</sub>S)<sub>2</sub>(OH<sub>2</sub>)<sub>2</sub>]∙2H<s...New cobalt(II) complex, [Co(O<sub>2</sub>C<sub>15</sub>H<sub>11</sub>N<sub>2</sub>S)<sub>2</sub>(OH<sub>2</sub>)<sub>2</sub>]∙2H<sub>2</sub>O (1∙2H<sub>2</sub>O), has been synthesized upon reaction of cobalt chloride hexahydrate (Co(Cl)<sub>2</sub>∙6H<sub>2</sub>O) with 3-methyl-1-Phenyl-4-(2-thienoyl)-pyrazol-5-one (referred as HL) in ethanol at room temperature. Single crystal X-ray diffraction (XRD), spectroscopic methods, and microelemental analyses were used to characterize 1∙2H<sub>2</sub>O. Compound 1∙2H<sub>2</sub>O crystallizes in the orthorhombic crystal system with a Pbca space group and with the cobalt atom being pseudo-octahedral coordinated. The broth microdilution technique was used to screen the free ligand (HL) and the complex (1∙2H<sub>2</sub>O) for antimicrobial activities. HL has a low activity (MIC > 100 μg/mL) on all microorganisms, whereas compound 1∙2H<sub>2</sub>O displayed moderate activity (10 ∙2H<sub>2</sub>O exhibited bactericidal and fungicidal activity respectively on all the bacteria and yeasts tested. These findings reveal that the antimicrobial activity of HL was enhanced upon coordination to Co(II) ion against all microorganisms (bacteria and fungus).展开更多
New cobalt(II) complex, [Co(O<sub>2</sub>C<sub>15</sub>H<sub>11</sub>N<sub>2</sub>S)<sub>2</sub>(OH<sub>2</sub>)<sub>2</sub>]∙2H<s...New cobalt(II) complex, [Co(O<sub>2</sub>C<sub>15</sub>H<sub>11</sub>N<sub>2</sub>S)<sub>2</sub>(OH<sub>2</sub>)<sub>2</sub>]∙2H<sub>2</sub>O (1∙2H<sub>2</sub>O), has been synthesized upon reaction of cobalt chloride hexahydrate (Co(Cl)<sub>2</sub>∙6H<sub>2</sub>O) with 3-methyl-1-Phenyl-4-(2-thienoyl)-pyrazol-5-one (referred as HL) in ethanol at room temperature. Single crystal X-ray diffraction (XRD), spectroscopic methods, and microelemental analyses were used to characterize 1∙2H<sub>2</sub>O. Compound 1∙2H<sub>2</sub>O crystallizes in the orthorhombic crystal system with a Pbca space group and with the cobalt atom being pseudo-octahedral coordinated. The broth microdilution technique was used to screen the free ligand (HL) and the complex (1∙2H<sub>2</sub>O) for antimicrobial activities. HL has a low activity (MIC > 100 μg/mL) on all microorganisms, whereas compound 1∙2H<sub>2</sub>O displayed moderate activity (10 ∙2H<sub>2</sub>O exhibited bactericidal and fungicidal activity respectively on all the bacteria and yeasts tested. These findings reveal that the antimicrobial activity of HL was enhanced upon coordination to Co(II) ion against all microorganisms (bacteria and fungus).展开更多
Fourteen conformers of 3-amino-1-propanol as the minima on the potential energy surface are examined at the MP2/6-311++G** level. Their relative energies calculated at B3LYP, MP3 and MP4 levels of theory indicated...Fourteen conformers of 3-amino-1-propanol as the minima on the potential energy surface are examined at the MP2/6-311++G** level. Their relative energies calculated at B3LYP, MP3 and MP4 levels of theory indicated that two most stable conformers display the intramolecular OH - N hydrogen bonds. The vertical ionization energies of these conformers calculated with ab initio electron propagator theory in the P3/aug-cc-pVTZ approximation are in agreement with experimental data from photoelectron spectroscopy. Natural bond orbital analyses were used to explain the differences of IEs of the highest occupied molecular ortibal of conformers. Combined with statistical mechanics principles, conformational distributions at various temperatures are obtained and the temperature dependence of photoelectron spectra is interpreted.展开更多
To improve the efficiency of the carbon dioxide cycling process and to reduce the regeneration energy consumption, a sterically hindered amine of 2-amino-2-methyl-1- propranol (AMP) was investigated to determine its...To improve the efficiency of the carbon dioxide cycling process and to reduce the regeneration energy consumption, a sterically hindered amine of 2-amino-2-methyl-1- propranol (AMP) was investigated to determine its regeneration behavior as a CO2 absorbent. The CO2 absorption and amine regeneration characteristics were experimentally examined under various operating conditions. The regeneration efficiency increased from 86.2% to 98.3% during the temperature range of 358 to 403 K. The most suitable regeneration temperature for AMP was 383 K, in this experiment condition, and the regeneration efficiency of absorption/regeneration runs descended from 98.3% to 94.0%. A number of heat-stable salts (HSS) could cause a reduction in CO2 absorption capacity and regeneration efficiency. The results indicated that aqueous AMP was easier to regenerate with less loss of absorption capacity than other amines, such as, monoethanolamine (MEA), diethanolamine (DEA), diethylenetriamine (DETA), and N-methyldiethanolamine (MDEA).展开更多
1-Methy-4-phenyl-1,2,3,6-tetrahydropyridine(MPTP)is a neurotoxin that selectively damages dopaminergic neurons in the substantia nigra pars compacta and induces Parkinson's like symptoms in rodents.Quercetin(QC)i...1-Methy-4-phenyl-1,2,3,6-tetrahydropyridine(MPTP)is a neurotoxin that selectively damages dopaminergic neurons in the substantia nigra pars compacta and induces Parkinson's like symptoms in rodents.Quercetin(QC)is a natural polyphenolic bioflavonoid with potent antioxidant and anti-inflammatory properties but lacks of clinical attraction due to low oral bioavailability.Piperine is a well established bioavailability enhancer used pre-clinically to improve the bioavailability of antioxidants(e.g.,Quercetin).Therefore,the present study was designed to evaluate the neuroprotective potential of QC together with piperine against MPTP-induced neurotoxicity in rats.MPTP(100μg/μL/rat,bilaterally)was injected intranigrally on days 1,4 and 7 using a digital stereotaxic apparatus.QC(25 and 50 mg/kg,intragastrically)and QC(25 mg/kg,intragastrically)in combination with piperine(2.5 mg/kg,intragastrically)were administered daily for 14 days starting from day 8 after the 3^(rd) injection of MPTP.On day 22,animals were sacrificed and the striatum was isolated for oxidative stress parameter(thiobarbituric acid reactive substances,nitrite and glutathione),neuroinflammatory cytokine(interleukin-1β,interleukin-6,and tumor necrosis factor-α)and neurotransmitter(dopamine,norepinephrine,serotonin,gamma-aminobutyric acid,glutamate,3,4-dihydroxyphenylacetic acid,homovanillic acid,and 5-hydroxyindoleacetic acid)evaluations.Bilateral infusion of MPTP into substantia nigra pars compacta led to significant motor deficits as evidenced by impairments in locomotor activity and rotarod performance in open field test and grip strength and narrow beam walk performance.Both QC(25 and 50 mg/kg)and QC(25 mg/kg)in combination with piperine(2.5 mg/kg),in particular the combination therapy,significantly improved MPTP-induced behavioral abnormalities in rats,reversed the abnormal alterations of neurotransmitters in the striatum,and alleviated oxidative stress and inflammatory response in the striatum.These findings indicate that piperine can enhance the antioxidant and anti-inflammatory properties of QC,and QC in combination with piperine exhibits strong neuroprotective effects against MPTP-induced neurotoxicity.展开更多
The catalysis of ionic liquids (ILs) in the traditional stirred reactor suffers from insufficient mass and heat transfer, which always needs a long reaction time and results in a low reaction rate. In this work, highl...The catalysis of ionic liquids (ILs) in the traditional stirred reactor suffers from insufficient mass and heat transfer, which always needs a long reaction time and results in a low reaction rate. In this work, highly efficient synthesis of 1-methoxy-2-propanol via the alcoholysis reaction of propylene oxide (PO) with methanol was proposed and achieved by the combination of micro-tubular circulating reactor with the IL [N4444] [Buty] catalyst. Compared with the stirred reactor, the rate of alcoholysis reaction in a micro-tubular circulating reactor was found to be significantly improved. The reaction time was remarkably shortened to 20 min from 180 min as well as the yield of 1-methoxy-2-propanol reached 92%. Moreover, the kinetic study further demonstrated that the main reaction rate to 1-methoxy-2-propanol (K1) was about 20 times larger than the side reaction rate to byproduct 2-methoxy-1-propanol (K2) in the temperature range of 363–383 K. Such combination of micro-tubular circulating reactor with IL catalysts is believed to be a class of effective process intensification technique for highly efficient synthesis of 1-methoxy-2-propanol.展开更多
The title compound trans-4-[(5-(2,4-dichlorophenoxy)-3-methyl- 1-phenyl-1H-pyrazol-4-yl)methyleneamino]- 1,5-dimethyl-2-phenyl-1,2-dihydropyrazol-3-one 3 (C28H23Cl2N5O2, Mr = 532.41) has been synthesized and its...The title compound trans-4-[(5-(2,4-dichlorophenoxy)-3-methyl- 1-phenyl-1H-pyrazol-4-yl)methyleneamino]- 1,5-dimethyl-2-phenyl-1,2-dihydropyrazol-3-one 3 (C28H23Cl2N5O2, Mr = 532.41) has been synthesized and its crystal structure was determined by single-crystal X-ray diffraction analysis. It crystallizes in triclinic, space group P1- with a = 8.9438(4), b = 11.6065(5), c = 14.2215(6)A, α = 112.566(1), β = 92.324(2), γ = 102.91(1)°, V= 1315.65(10) A^3, Z = 2, Dc = 1.344 g/cm^3,μ(MoKa) = 0.282 mm^-1, λ = 0.71073 A, F(000) = 552, the final R = 0.0587 and wR = 0.1578 for 5071 observed reflections (I 〉 2σ(I)). X-ray analysis reveals that the product is a thermodynamically stable trans isomer. Intra- and intermolecular C( 12)-H(12)…O(1) and C(28)-H(28)...O(1)# 1 hydrogen bonds were observed in the title compound.展开更多
While WCl_6-Ph_4Sn fails to polymerize 1-phenyl-1-propyne (PP) at room temperature, highmolecular weight (M_w up to 410× 10~3) polymers are obtained in high yields (up to 80%) when thepolymerizations of PP are ca...While WCl_6-Ph_4Sn fails to polymerize 1-phenyl-1-propyne (PP) at room temperature, highmolecular weight (M_w up to 410× 10~3) polymers are obtained in high yields (up to 80%) when thepolymerizations of PP are carried out in the presence of C_(60) using the W catalyst under the same conditions.The polymers are soluble in common organic solvents such as THF, chloroform, and toluene. Molecularstructures of the polymers are characterized by FT-IR, UV, NMR, GPC and XRD, and it is found that C_(60) iscopolymerized with PP. Thus C_(60) plays the dual roles of comonomer and cocatalyst in the polymerizationreaction. C_(60) contents of the copolymers can be easily changed by varying the C_(60) amounts in the feedmixtures. The copolymers effectively limit strong 532 nm laser pulses, whose limiting performance issuperior to that of parent C_(60).展开更多
The extraction behavior of rare earths was studied by using paraffin with ceresin as a diluent containing 1-phenyl-3-methyl-4-benzoyl-pyrazolone-5.In solid phase,the composition of complexes is REP_3.The equilib- rium...The extraction behavior of rare earths was studied by using paraffin with ceresin as a diluent containing 1-phenyl-3-methyl-4-benzoyl-pyrazolone-5.In solid phase,the composition of complexes is REP_3.The equilib- rium extraction constants and pH_(1/2) values of solid-liquid extraction are higher than those of normal liquid-liquid extraction.The extraction efficiency tends to maximum when the ratio of phases is 1:1.When the extraction temperature is higher than the melting point of paraffin and the extraction time is over 10 min,the extraction efficiency keeps constant.Moreover,the relationship among separation factor,equilibrium extrac- tion constant,pH_(1/2) value and atomic number was obtained.The mechanism of solid-liquid extraction is analogous to that of liquid-liquid extraction.展开更多
In this study, the LLE data of ternary system(water + 1,6-diaminohexane + 2-methyl-1-propanol) and(water +1,6-diaminohexane + 3-methyl-1-butanol) were measured at 293.15, 303.15 and 313.15 K under atmospheric pressure...In this study, the LLE data of ternary system(water + 1,6-diaminohexane + 2-methyl-1-propanol) and(water +1,6-diaminohexane + 3-methyl-1-butanol) were measured at 293.15, 303.15 and 313.15 K under atmospheric pressure. Reliability of the experimental tie-line data was checked by empirical Hand, Othmer-Tobias and Bachman equations. Distribution coefficient(D) and selectivity(S) were calculated in order to investigate capability of the studied organic solvents for 1,6-diaminohexane extraction. The high values of separation factors demonstrated that 2-methyl-1-propanol and 3-methyl-1-butanol were applicable for this purpose. The experimental data were correlated by nonrandom two-liquid(NRTL) and universal quasi-chemical(UNIQUAC) models.The percent-root-mean-square deviation(RMSD) values for NRTL and UNIQUAC models were less than 0.15,which indicated that the experimental data have been sufficiently correlated.展开更多
An efficient and environmental benign method is reported for the condensation of 3-methyl-1-phenyl-5-pyrazolone with carbonyl compounds in ionic liquids [Bmim]BF4 and [Bmim]PF6 catalyzed by ethylenediammonium diacetate.
This paper has studied the vapor-liquid equilibrium (VLE) for the salt-containing extractive distillation of the 1-propanol/water system. Binary VLE data were measured for the systems of 1-propanol (1)/KAc (4), ...This paper has studied the vapor-liquid equilibrium (VLE) for the salt-containing extractive distillation of the 1-propanol/water system. Binary VLE data were measured for the systems of 1-propanol (1)/KAc (4), ethanediol (3)/KAc (4), and 1-propanol (1)/ethanediol (3), with the VLE data correlated with the NRTL model in order to obtain the model parameters of these binary systems. The binary VLE data cited in technical literature were correlated to obtain the model parameters for other binary systems. VLE data of ternary and quaternary systems predicted by the NRTI.: model agreed well with the literature data. The influence of KAc, ethanediol, and the KAc/ethanediol mixture on volatility between 1-propanol and water was investigated respectively. Test results showed that the above-mentioned materials (KAc, ethanediol) and their mixture (KAc and ethanediol) have different influence on the volatility. When x3=0.5, and x4=0.05, the azeotropic point can be elimi- nated. The NRTL model method of salt-containing VLE is simple and effective for the prediction of the system's VLE data.展开更多
Using 2'-Hydroxyacetophenone and as the raw material, 1-( 2-Hydroxyphenyl )-3-Phenyl-1, 3- Propanedione (HPPPD) was synthesized by esterification reaction and Fries rearrangement reaction. And the complexes of HP...Using 2'-Hydroxyacetophenone and as the raw material, 1-( 2-Hydroxyphenyl )-3-Phenyl-1, 3- Propanedione (HPPPD) was synthesized by esterification reaction and Fries rearrangement reaction. And the complexes of HPPPD with europium were also synthesized. The compounds were characterized by IR, thermo-gravimetric analysis and ^1H-NMR. The effects of phenolic hydroxyl on the luminescence properties of complexes were studied. The results show that the complexes emit strong red fluorescence and the fluorescence intensity of the ternary complex is better than that of the duality. But the complexes of HPPPD with Sm( Ⅲ ), Tb ( Ⅲ ), Dy ( Ⅲ ) emit weak fluorescence. The phenomenon was interpreted by electron-effect and energy-matching mechanism. Energy transfer mechanism of the luminescence in the complex was discussed.展开更多
Density functional calculations have been used to study the mechanism of 1-phenyl-1-(3-pyridyl)ethene hydroformylation using rhodium catalyst.Our calculations reveal that the rate-determining step is the oxidative a...Density functional calculations have been used to study the mechanism of 1-phenyl-1-(3-pyridyl)ethene hydroformylation using rhodium catalyst.Our calculations reveal that the rate-determining step is the oxidative addition of hydrogen molecule and the preferred path is the one involving ts3ans for the lowest activation free-energy (ΔrGa),63.8 kJ/mol.This reaction is demonstrated to be strong exothermic by-96.6 kJ/mol of branched products and-98.2 kJ/mol of linear products.And the predominant product is the linear 3-phenyl-3-(3-pyridal)propanal (pr-ns) determined by both thermodynamics and kinetics.These results are in agreement with the practicality experimental studies.展开更多
At present, pathogenesis and mechanism of Parkinson disease (PD) are still unclear. Animal models of PD are essential tools in studies on etiology and therapy and should mimic the chronic pathological process, histo...At present, pathogenesis and mechanism of Parkinson disease (PD) are still unclear. Animal models of PD are essential tools in studies on etiology and therapy and should mimic the chronic pathological process, histological characteristics and motor behavior dysfunction. In recent years, transgenic mice have been widely utilized to study the mechanism of PD, and it has become imperative that a PD mouse model of motor behavioral dysfunction be established. OBJECTIVE: To compare the behavioral and histochemical characters of two neurotoxic mice model induced with 6-hydroxydopamine (6-OHDA) or 1-methyl-4-phenyl-1, 2, 3, 6 -tetrahydropyridine (MPTP), and a better method to mimic Parkinson disease will be found out. DESIGN: Parallel experiment. SETTING: Laboratory of Molecular Genetics, Department of Medical Genetics, Shanghai Jiao Tohg University. MATERIALS: Sixty 129Sv/C57BL6J male wild mice, SPF grade, 8 - 12 weeks old, weighing 20 - 25 g, were provided by Experimental Animal Center, Shanghai Jiao Tong University. All the surgery operation was performed according to the rules of Shanghai Jiaotong University Animal Committee. METHODS: The experiment was carried out in the Laboratory of Molecular Genetics (National Key Laboratory), Department of Medical Genetics, Shanghai Jiao Ttong University from March to August 2006. ①Thirty-two male mice were randomly divided into control group and drug treatment group with 16 mice in each group. Surgery was carried out and 6-OHDA was administrated to substantia nigra pars compacta (SNpc) and nigra-striatum pathway according to the different parameters with intoxication apparatus. Saline was injected to the other 16 mice according to the same paradigm. 1 mg/kg apomorphine was injected intraperitoneally 2 weeks later after surgery to induce the imbalanced rotation behavior for 40 minutes. ②Twenty-eight mice were randomly divided into 4 groups with 7 in each group, including low-dose, moderate-dose, high-dose groups and negative control group. Then, mice in the drug treatment group were injected intraperitoneally with 5, 10 and 15 mg/kg MPTP for 9 successive days. In addition, mice in the control group were injected with the same volume of saline for 9 days. Pole test and stride length test were utilized to detect coordinative behavioral dysfunction. Mice were sacrificed 20 days after MPTP treatment, and histochemical staining of tyrosine hydroxynase (TH) was used to observe the loss of dopaminergic neuron in SNpc. MAIN OUTCOME MEASURES: ① Success ratio of each model establishment method; ② inducible asymmetric cycle behavior test 2 weeks after 6-OHDA injection; ③behavioral dysfunction in pole test and stride length, morphological changes in brain tissue. RESULTS: Totally sixty mice were used in this experiment and 3 mice were excluded because of the hypersensitivity or the clumsy reaction in motor behavioral detection before MPTP treatment, therefore, data was analyzed with the rest 57 mice. ① Lethal ratio: Three out of 16 mice died in striatum injection group and 5 out of 16 mice died in nigro-striatal pathway group. No mouse died in MPTP treatment groups. ② Locomotor behavior: No dysfunction of locomotor was found in 6-OHDA treatment groups. However, several motor behavioral dysfunction were start to present at the 4th day of MPTP injection. ③ Asymmetric cycle behavior: No asymmetric cycle was induced successfully two weeks after 6-OHDA surgery. Mice show hypersensitive behavior 10 minutes after apomorphine injection, which lasted for about 20 minutes. ④ Pole test: From the 4^th day of MPTP treatment, mice started to display coordinate dysfunction, such as climbing down along the pole in spiral, moving slowly with hesitation. Some mice could not grab the pole and slide down along the pole at 4th day post injection. Comparing with 0 dose control group, all the threedrug treatment groups show significant different dysfunction from the 4th day to the 20th day post injection (P 〈 0.01). ⑤ stride length test: Mice's stride length decreased, when treated with MPTP, and the mice in the high dose group displayed obviously. ⑥ Dopaminergic neuron stained with TH in nigra pars compacta: The results indicated that administrated MPTP (from low dose to high dose) by intraperitoneal cause chronic lesions on the dopaminergic neuron in the SNpc. CONCLUSION: PD mice models induced with 6-OHDA show high mortality ratio and no asymmetric cycle was found after apomorphine injection. However, injection of MPTP intraperitoneally can simulate the chronic pathway of PD, typical histological changes are found and stable motor behavioral dysfunctions are displayed.展开更多
Two new Schiff bases based on 5-chloro-3-methyl-1-phenyl-1 H-pyrazole-4-carbaldehyde, namely, N-((5-chloro-3-methyl-1-phenyl-1 H-pyrazol-4-yl)methylene)-4-morpholinoaniline(Ⅲa) and N-((5-chloro-3-methyl-1-phenyl-1 H-...Two new Schiff bases based on 5-chloro-3-methyl-1-phenyl-1 H-pyrazole-4-carbaldehyde, namely, N-((5-chloro-3-methyl-1-phenyl-1 H-pyrazol-4-yl)methylene)-4-morpholinoaniline(Ⅲa) and N-((5-chloro-3-methyl-1-phenyl-1 H-pyrazol-4-yl)methylene)-3-fluoro-4-morpholinoaniline(Ⅲb), were synthesized and characterized by IR, LC-MS, 1 H NMR and 13 C NMR spectroscopy. Meanwhile, the three-dimensional configurations of the two title compounds were further characterized by single-crystal X-ray diffraction analyses. Both the compounds are thermodynamically stable trans-isomers. Moreover, the fluorescence properties and antioxidant activities against DPPH of the two target compounds have been investigated, and the results showed that the title compounds both have fluorescence performance and certain antioxidant activities against DPPH radical.展开更多
The microcosmic reaction mechanism of K2CO3-catalyzed 1-chlo-2-propanol and carbon dioxide has been investigated by density functional theory(DFT) at the GGA/PW91/DNP level.We optimize the geometric configurations o...The microcosmic reaction mechanism of K2CO3-catalyzed 1-chlo-2-propanol and carbon dioxide has been investigated by density functional theory(DFT) at the GGA/PW91/DNP level.We optimize the geometric configurations of reactants,intermediates,transition states,and products.The energy analysis calculation approves the authenticity of intermediates and transition states.According to our calculations,four feasible reaction pathways are found.The main pathway of the reaction is ReA → IMA1 → TSA1 → IMA2 → IMA5 → TSA5 → P.Besides,we also in-vestigate the reaction mechanism of 1-chlo-2-propanol and carbon dioxide without K2CO3-catalyzation by the same theory and level.The computational results indicate that the activation barrier with K2CO3-catalyzed is smaller than the activation barrier without K2CO3-catalyzed.That is to say,K2CO3 can promote the reaction to give the product in a high yield,which is in agreement with the experimental results.展开更多
Density functional theory (DFT) has been applied to study the enantioselective reduction of 3-morpholin-4-yl-1-phenyl-1-propanone with borane catalyzed by (S)-4-benzyl-5,5- diphenyl-1,3,2-oxazaborolidine at the B3LY...Density functional theory (DFT) has been applied to study the enantioselective reduction of 3-morpholin-4-yl-1-phenyl-1-propanone with borane catalyzed by (S)-4-benzyl-5,5- diphenyl-1,3,2-oxazaborolidine at the B3LYP/6-31G* level. All molecular species involved in the four reaction steps have been fully optimized and the structural parameters are provided, and the micro process of reaction was also investigated. The catalyst-alkoxyborane adduct formed in step III exhibits a B-O-B-N tetra-atomic ring. Reaction coordination calculations show that BH3 can react with 3-morpholin-4-yl-1-phenyl-1-propanone spontaneously, resulting in the need of 2 mol BH3 in the reaction.展开更多
文摘A β-cyclodextrin derivative, perbenzyl-β-cyclodextrin, was prepared and used as a chiral stationary phase for capillary gas chromatography. Using FID detector and the column temperature between 70 and 80℃, the chiral separations of racemic 3-phenyl-1, 2-epoxyethane and 1-phenyl-1-propanol on a 14m×0.23mm I. D. fused silica column with the β-cyclodextrin derivative were carried out and the optical purities of optically active 1-phenyl-1-propanol samples prepared by asymmetric synthesis were determined.
基金financially supported by the Scientific and Technological Plan Projects of Guangzhou City(202103040001)。
文摘This work develops 2-Phenyl-1H-imidazole-1-sulfonate(PHIS)as a multi-functional electrolyte additive for H2O/HF scavenging and film formation to improve the high temperature performance of LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)/graphite batteries.After 450 cycles at room temperature(25℃),the discharge capacity retentions of batteries with blank and PHIS-containing electrolyte are 56.03%and 94.92%respectively.After 230 cycles at high temperatures(45℃),their values are 75.30%and 88.38%respectively.The enhanced electrochemical performance of the batteries with PHIS-containing electrolyte is supported by the spectroscopic characterization and theoretical calculations.It is demonstrated that this PHIS electrolyte additive can facilitate the construction of the electrode interface films,remove the H2O/HF in the electrolyte,and improve the electrochemical performance of the batteries.This work not only develops a sulfonate-based electrolyte but also can stimulate new ideas of functional additives to improve the battery performance.
文摘New cobalt(II) complex, [Co(O<sub>2</sub>C<sub>15</sub>H<sub>11</sub>N<sub>2</sub>S)<sub>2</sub>(OH<sub>2</sub>)<sub>2</sub>]∙2H<sub>2</sub>O (1∙2H<sub>2</sub>O), has been synthesized upon reaction of cobalt chloride hexahydrate (Co(Cl)<sub>2</sub>∙6H<sub>2</sub>O) with 3-methyl-1-Phenyl-4-(2-thienoyl)-pyrazol-5-one (referred as HL) in ethanol at room temperature. Single crystal X-ray diffraction (XRD), spectroscopic methods, and microelemental analyses were used to characterize 1∙2H<sub>2</sub>O. Compound 1∙2H<sub>2</sub>O crystallizes in the orthorhombic crystal system with a Pbca space group and with the cobalt atom being pseudo-octahedral coordinated. The broth microdilution technique was used to screen the free ligand (HL) and the complex (1∙2H<sub>2</sub>O) for antimicrobial activities. HL has a low activity (MIC > 100 μg/mL) on all microorganisms, whereas compound 1∙2H<sub>2</sub>O displayed moderate activity (10 ∙2H<sub>2</sub>O exhibited bactericidal and fungicidal activity respectively on all the bacteria and yeasts tested. These findings reveal that the antimicrobial activity of HL was enhanced upon coordination to Co(II) ion against all microorganisms (bacteria and fungus).
文摘New cobalt(II) complex, [Co(O<sub>2</sub>C<sub>15</sub>H<sub>11</sub>N<sub>2</sub>S)<sub>2</sub>(OH<sub>2</sub>)<sub>2</sub>]∙2H<sub>2</sub>O (1∙2H<sub>2</sub>O), has been synthesized upon reaction of cobalt chloride hexahydrate (Co(Cl)<sub>2</sub>∙6H<sub>2</sub>O) with 3-methyl-1-Phenyl-4-(2-thienoyl)-pyrazol-5-one (referred as HL) in ethanol at room temperature. Single crystal X-ray diffraction (XRD), spectroscopic methods, and microelemental analyses were used to characterize 1∙2H<sub>2</sub>O. Compound 1∙2H<sub>2</sub>O crystallizes in the orthorhombic crystal system with a Pbca space group and with the cobalt atom being pseudo-octahedral coordinated. The broth microdilution technique was used to screen the free ligand (HL) and the complex (1∙2H<sub>2</sub>O) for antimicrobial activities. HL has a low activity (MIC > 100 μg/mL) on all microorganisms, whereas compound 1∙2H<sub>2</sub>O displayed moderate activity (10 ∙2H<sub>2</sub>O exhibited bactericidal and fungicidal activity respectively on all the bacteria and yeasts tested. These findings reveal that the antimicrobial activity of HL was enhanced upon coordination to Co(II) ion against all microorganisms (bacteria and fungus).
基金This work was supported by the Province Natural Science Foundation of Henan (No.082300410030), the Foundation of Henan Educational Committee (No.2011A140015), and the Doctoral Research Pund of Henan Normal University (No.525449).
文摘Fourteen conformers of 3-amino-1-propanol as the minima on the potential energy surface are examined at the MP2/6-311++G** level. Their relative energies calculated at B3LYP, MP3 and MP4 levels of theory indicated that two most stable conformers display the intramolecular OH - N hydrogen bonds. The vertical ionization energies of these conformers calculated with ab initio electron propagator theory in the P3/aug-cc-pVTZ approximation are in agreement with experimental data from photoelectron spectroscopy. Natural bond orbital analyses were used to explain the differences of IEs of the highest occupied molecular ortibal of conformers. Combined with statistical mechanics principles, conformational distributions at various temperatures are obtained and the temperature dependence of photoelectron spectra is interpreted.
文摘To improve the efficiency of the carbon dioxide cycling process and to reduce the regeneration energy consumption, a sterically hindered amine of 2-amino-2-methyl-1- propranol (AMP) was investigated to determine its regeneration behavior as a CO2 absorbent. The CO2 absorption and amine regeneration characteristics were experimentally examined under various operating conditions. The regeneration efficiency increased from 86.2% to 98.3% during the temperature range of 358 to 403 K. The most suitable regeneration temperature for AMP was 383 K, in this experiment condition, and the regeneration efficiency of absorption/regeneration runs descended from 98.3% to 94.0%. A number of heat-stable salts (HSS) could cause a reduction in CO2 absorption capacity and regeneration efficiency. The results indicated that aqueous AMP was easier to regenerate with less loss of absorption capacity than other amines, such as, monoethanolamine (MEA), diethanolamine (DEA), diethylenetriamine (DETA), and N-methyldiethanolamine (MDEA).
基金Science and Engineering Board(SERB),Department of Science and Technology,Government of India,New Delhi for providing financial assistance under Fast Track Scheme(DST-SERB-FTYS)(SB/FT/LS-139/2012) to Dr.PK
文摘1-Methy-4-phenyl-1,2,3,6-tetrahydropyridine(MPTP)is a neurotoxin that selectively damages dopaminergic neurons in the substantia nigra pars compacta and induces Parkinson's like symptoms in rodents.Quercetin(QC)is a natural polyphenolic bioflavonoid with potent antioxidant and anti-inflammatory properties but lacks of clinical attraction due to low oral bioavailability.Piperine is a well established bioavailability enhancer used pre-clinically to improve the bioavailability of antioxidants(e.g.,Quercetin).Therefore,the present study was designed to evaluate the neuroprotective potential of QC together with piperine against MPTP-induced neurotoxicity in rats.MPTP(100μg/μL/rat,bilaterally)was injected intranigrally on days 1,4 and 7 using a digital stereotaxic apparatus.QC(25 and 50 mg/kg,intragastrically)and QC(25 mg/kg,intragastrically)in combination with piperine(2.5 mg/kg,intragastrically)were administered daily for 14 days starting from day 8 after the 3^(rd) injection of MPTP.On day 22,animals were sacrificed and the striatum was isolated for oxidative stress parameter(thiobarbituric acid reactive substances,nitrite and glutathione),neuroinflammatory cytokine(interleukin-1β,interleukin-6,and tumor necrosis factor-α)and neurotransmitter(dopamine,norepinephrine,serotonin,gamma-aminobutyric acid,glutamate,3,4-dihydroxyphenylacetic acid,homovanillic acid,and 5-hydroxyindoleacetic acid)evaluations.Bilateral infusion of MPTP into substantia nigra pars compacta led to significant motor deficits as evidenced by impairments in locomotor activity and rotarod performance in open field test and grip strength and narrow beam walk performance.Both QC(25 and 50 mg/kg)and QC(25 mg/kg)in combination with piperine(2.5 mg/kg),in particular the combination therapy,significantly improved MPTP-induced behavioral abnormalities in rats,reversed the abnormal alterations of neurotransmitters in the striatum,and alleviated oxidative stress and inflammatory response in the striatum.These findings indicate that piperine can enhance the antioxidant and anti-inflammatory properties of QC,and QC in combination with piperine exhibits strong neuroprotective effects against MPTP-induced neurotoxicity.
基金We thank the National Natural Science Foundations of China(Nos.21566011,31570560)the Jiangxi Province Sponsored Programs for Distinguished Young Scholars(No.20162BCB23026)and the Science&Technology Programs of Jiangxi Province Department of Education(No.GJJ160272)for financial support.
文摘The catalysis of ionic liquids (ILs) in the traditional stirred reactor suffers from insufficient mass and heat transfer, which always needs a long reaction time and results in a low reaction rate. In this work, highly efficient synthesis of 1-methoxy-2-propanol via the alcoholysis reaction of propylene oxide (PO) with methanol was proposed and achieved by the combination of micro-tubular circulating reactor with the IL [N4444] [Buty] catalyst. Compared with the stirred reactor, the rate of alcoholysis reaction in a micro-tubular circulating reactor was found to be significantly improved. The reaction time was remarkably shortened to 20 min from 180 min as well as the yield of 1-methoxy-2-propanol reached 92%. Moreover, the kinetic study further demonstrated that the main reaction rate to 1-methoxy-2-propanol (K1) was about 20 times larger than the side reaction rate to byproduct 2-methoxy-1-propanol (K2) in the temperature range of 363–383 K. Such combination of micro-tubular circulating reactor with IL catalysts is believed to be a class of effective process intensification technique for highly efficient synthesis of 1-methoxy-2-propanol.
基金the Science Research Foundation of Henan Institute of Science and Technology (No. 06036)
文摘The title compound trans-4-[(5-(2,4-dichlorophenoxy)-3-methyl- 1-phenyl-1H-pyrazol-4-yl)methyleneamino]- 1,5-dimethyl-2-phenyl-1,2-dihydropyrazol-3-one 3 (C28H23Cl2N5O2, Mr = 532.41) has been synthesized and its crystal structure was determined by single-crystal X-ray diffraction analysis. It crystallizes in triclinic, space group P1- with a = 8.9438(4), b = 11.6065(5), c = 14.2215(6)A, α = 112.566(1), β = 92.324(2), γ = 102.91(1)°, V= 1315.65(10) A^3, Z = 2, Dc = 1.344 g/cm^3,μ(MoKa) = 0.282 mm^-1, λ = 0.71073 A, F(000) = 552, the final R = 0.0587 and wR = 0.1578 for 5071 observed reflections (I 〉 2σ(I)). X-ray analysis reveals that the product is a thermodynamically stable trans isomer. Intra- and intermolecular C( 12)-H(12)…O(1) and C(28)-H(28)...O(1)# 1 hydrogen bonds were observed in the title compound.
基金This work was in part supported by the Hong Kong Research Grants Council(HKUST6062/98P and DAG96/97 SC11).
文摘While WCl_6-Ph_4Sn fails to polymerize 1-phenyl-1-propyne (PP) at room temperature, highmolecular weight (M_w up to 410× 10~3) polymers are obtained in high yields (up to 80%) when thepolymerizations of PP are carried out in the presence of C_(60) using the W catalyst under the same conditions.The polymers are soluble in common organic solvents such as THF, chloroform, and toluene. Molecularstructures of the polymers are characterized by FT-IR, UV, NMR, GPC and XRD, and it is found that C_(60) iscopolymerized with PP. Thus C_(60) plays the dual roles of comonomer and cocatalyst in the polymerizationreaction. C_(60) contents of the copolymers can be easily changed by varying the C_(60) amounts in the feedmixtures. The copolymers effectively limit strong 532 nm laser pulses, whose limiting performance issuperior to that of parent C_(60).
文摘The extraction behavior of rare earths was studied by using paraffin with ceresin as a diluent containing 1-phenyl-3-methyl-4-benzoyl-pyrazolone-5.In solid phase,the composition of complexes is REP_3.The equilib- rium extraction constants and pH_(1/2) values of solid-liquid extraction are higher than those of normal liquid-liquid extraction.The extraction efficiency tends to maximum when the ratio of phases is 1:1.When the extraction temperature is higher than the melting point of paraffin and the extraction time is over 10 min,the extraction efficiency keeps constant.Moreover,the relationship among separation factor,equilibrium extrac- tion constant,pH_(1/2) value and atomic number was obtained.The mechanism of solid-liquid extraction is analogous to that of liquid-liquid extraction.
文摘In this study, the LLE data of ternary system(water + 1,6-diaminohexane + 2-methyl-1-propanol) and(water +1,6-diaminohexane + 3-methyl-1-butanol) were measured at 293.15, 303.15 and 313.15 K under atmospheric pressure. Reliability of the experimental tie-line data was checked by empirical Hand, Othmer-Tobias and Bachman equations. Distribution coefficient(D) and selectivity(S) were calculated in order to investigate capability of the studied organic solvents for 1,6-diaminohexane extraction. The high values of separation factors demonstrated that 2-methyl-1-propanol and 3-methyl-1-butanol were applicable for this purpose. The experimental data were correlated by nonrandom two-liquid(NRTL) and universal quasi-chemical(UNIQUAC) models.The percent-root-mean-square deviation(RMSD) values for NRTL and UNIQUAC models were less than 0.15,which indicated that the experimental data have been sufficiently correlated.
文摘An efficient and environmental benign method is reported for the condensation of 3-methyl-1-phenyl-5-pyrazolone with carbonyl compounds in ionic liquids [Bmim]BF4 and [Bmim]PF6 catalyzed by ethylenediammonium diacetate.
文摘This paper has studied the vapor-liquid equilibrium (VLE) for the salt-containing extractive distillation of the 1-propanol/water system. Binary VLE data were measured for the systems of 1-propanol (1)/KAc (4), ethanediol (3)/KAc (4), and 1-propanol (1)/ethanediol (3), with the VLE data correlated with the NRTL model in order to obtain the model parameters of these binary systems. The binary VLE data cited in technical literature were correlated to obtain the model parameters for other binary systems. VLE data of ternary and quaternary systems predicted by the NRTI.: model agreed well with the literature data. The influence of KAc, ethanediol, and the KAc/ethanediol mixture on volatility between 1-propanol and water was investigated respectively. Test results showed that the above-mentioned materials (KAc, ethanediol) and their mixture (KAc and ethanediol) have different influence on the volatility. When x3=0.5, and x4=0.05, the azeotropic point can be elimi- nated. The NRTL model method of salt-containing VLE is simple and effective for the prediction of the system's VLE data.
文摘Using 2'-Hydroxyacetophenone and as the raw material, 1-( 2-Hydroxyphenyl )-3-Phenyl-1, 3- Propanedione (HPPPD) was synthesized by esterification reaction and Fries rearrangement reaction. And the complexes of HPPPD with europium were also synthesized. The compounds were characterized by IR, thermo-gravimetric analysis and ^1H-NMR. The effects of phenolic hydroxyl on the luminescence properties of complexes were studied. The results show that the complexes emit strong red fluorescence and the fluorescence intensity of the ternary complex is better than that of the duality. But the complexes of HPPPD with Sm( Ⅲ ), Tb ( Ⅲ ), Dy ( Ⅲ ) emit weak fluorescence. The phenomenon was interpreted by electron-effect and energy-matching mechanism. Energy transfer mechanism of the luminescence in the complex was discussed.
基金Supported by the Education Commission of Chongqing (kj070809)Chongqing Normal University (06XLY018)crosswise project of Sichuan Normal University
文摘Density functional calculations have been used to study the mechanism of 1-phenyl-1-(3-pyridyl)ethene hydroformylation using rhodium catalyst.Our calculations reveal that the rate-determining step is the oxidative addition of hydrogen molecule and the preferred path is the one involving ts3ans for the lowest activation free-energy (ΔrGa),63.8 kJ/mol.This reaction is demonstrated to be strong exothermic by-96.6 kJ/mol of branched products and-98.2 kJ/mol of linear products.And the predominant product is the linear 3-phenyl-3-(3-pyridal)propanal (pr-ns) determined by both thermodynamics and kinetics.These results are in agreement with the practicality experimental studies.
基金the grants from Shanghai Educational Committee, No. 03BZ03Department of Education for Doctor Foundation, No. 20040266014Shanghai Jiao Tong University Medical School for Doctor Foundation, No. BXJ0304
文摘At present, pathogenesis and mechanism of Parkinson disease (PD) are still unclear. Animal models of PD are essential tools in studies on etiology and therapy and should mimic the chronic pathological process, histological characteristics and motor behavior dysfunction. In recent years, transgenic mice have been widely utilized to study the mechanism of PD, and it has become imperative that a PD mouse model of motor behavioral dysfunction be established. OBJECTIVE: To compare the behavioral and histochemical characters of two neurotoxic mice model induced with 6-hydroxydopamine (6-OHDA) or 1-methyl-4-phenyl-1, 2, 3, 6 -tetrahydropyridine (MPTP), and a better method to mimic Parkinson disease will be found out. DESIGN: Parallel experiment. SETTING: Laboratory of Molecular Genetics, Department of Medical Genetics, Shanghai Jiao Tohg University. MATERIALS: Sixty 129Sv/C57BL6J male wild mice, SPF grade, 8 - 12 weeks old, weighing 20 - 25 g, were provided by Experimental Animal Center, Shanghai Jiao Tong University. All the surgery operation was performed according to the rules of Shanghai Jiaotong University Animal Committee. METHODS: The experiment was carried out in the Laboratory of Molecular Genetics (National Key Laboratory), Department of Medical Genetics, Shanghai Jiao Ttong University from March to August 2006. ①Thirty-two male mice were randomly divided into control group and drug treatment group with 16 mice in each group. Surgery was carried out and 6-OHDA was administrated to substantia nigra pars compacta (SNpc) and nigra-striatum pathway according to the different parameters with intoxication apparatus. Saline was injected to the other 16 mice according to the same paradigm. 1 mg/kg apomorphine was injected intraperitoneally 2 weeks later after surgery to induce the imbalanced rotation behavior for 40 minutes. ②Twenty-eight mice were randomly divided into 4 groups with 7 in each group, including low-dose, moderate-dose, high-dose groups and negative control group. Then, mice in the drug treatment group were injected intraperitoneally with 5, 10 and 15 mg/kg MPTP for 9 successive days. In addition, mice in the control group were injected with the same volume of saline for 9 days. Pole test and stride length test were utilized to detect coordinative behavioral dysfunction. Mice were sacrificed 20 days after MPTP treatment, and histochemical staining of tyrosine hydroxynase (TH) was used to observe the loss of dopaminergic neuron in SNpc. MAIN OUTCOME MEASURES: ① Success ratio of each model establishment method; ② inducible asymmetric cycle behavior test 2 weeks after 6-OHDA injection; ③behavioral dysfunction in pole test and stride length, morphological changes in brain tissue. RESULTS: Totally sixty mice were used in this experiment and 3 mice were excluded because of the hypersensitivity or the clumsy reaction in motor behavioral detection before MPTP treatment, therefore, data was analyzed with the rest 57 mice. ① Lethal ratio: Three out of 16 mice died in striatum injection group and 5 out of 16 mice died in nigro-striatal pathway group. No mouse died in MPTP treatment groups. ② Locomotor behavior: No dysfunction of locomotor was found in 6-OHDA treatment groups. However, several motor behavioral dysfunction were start to present at the 4th day of MPTP injection. ③ Asymmetric cycle behavior: No asymmetric cycle was induced successfully two weeks after 6-OHDA surgery. Mice show hypersensitive behavior 10 minutes after apomorphine injection, which lasted for about 20 minutes. ④ Pole test: From the 4^th day of MPTP treatment, mice started to display coordinate dysfunction, such as climbing down along the pole in spiral, moving slowly with hesitation. Some mice could not grab the pole and slide down along the pole at 4th day post injection. Comparing with 0 dose control group, all the threedrug treatment groups show significant different dysfunction from the 4th day to the 20th day post injection (P 〈 0.01). ⑤ stride length test: Mice's stride length decreased, when treated with MPTP, and the mice in the high dose group displayed obviously. ⑥ Dopaminergic neuron stained with TH in nigra pars compacta: The results indicated that administrated MPTP (from low dose to high dose) by intraperitoneal cause chronic lesions on the dopaminergic neuron in the SNpc. CONCLUSION: PD mice models induced with 6-OHDA show high mortality ratio and no asymmetric cycle was found after apomorphine injection. However, injection of MPTP intraperitoneally can simulate the chronic pathway of PD, typical histological changes are found and stable motor behavioral dysfunctions are displayed.
基金supported by the Jiangsu Province College Students’ Practice and Innovation Training Program(No.201810323007Z)
文摘Two new Schiff bases based on 5-chloro-3-methyl-1-phenyl-1 H-pyrazole-4-carbaldehyde, namely, N-((5-chloro-3-methyl-1-phenyl-1 H-pyrazol-4-yl)methylene)-4-morpholinoaniline(Ⅲa) and N-((5-chloro-3-methyl-1-phenyl-1 H-pyrazol-4-yl)methylene)-3-fluoro-4-morpholinoaniline(Ⅲb), were synthesized and characterized by IR, LC-MS, 1 H NMR and 13 C NMR spectroscopy. Meanwhile, the three-dimensional configurations of the two title compounds were further characterized by single-crystal X-ray diffraction analyses. Both the compounds are thermodynamically stable trans-isomers. Moreover, the fluorescence properties and antioxidant activities against DPPH of the two target compounds have been investigated, and the results showed that the title compounds both have fluorescence performance and certain antioxidant activities against DPPH radical.
基金Project supported by the Natural Science Foundation of Education Committee of Chongqing (No. KJ091311)
文摘The microcosmic reaction mechanism of K2CO3-catalyzed 1-chlo-2-propanol and carbon dioxide has been investigated by density functional theory(DFT) at the GGA/PW91/DNP level.We optimize the geometric configurations of reactants,intermediates,transition states,and products.The energy analysis calculation approves the authenticity of intermediates and transition states.According to our calculations,four feasible reaction pathways are found.The main pathway of the reaction is ReA → IMA1 → TSA1 → IMA2 → IMA5 → TSA5 → P.Besides,we also in-vestigate the reaction mechanism of 1-chlo-2-propanol and carbon dioxide without K2CO3-catalyzation by the same theory and level.The computational results indicate that the activation barrier with K2CO3-catalyzed is smaller than the activation barrier without K2CO3-catalyzed.That is to say,K2CO3 can promote the reaction to give the product in a high yield,which is in agreement with the experimental results.
基金Project supported by the Research Foundation of Suzhou University (Q3109306)
文摘Density functional theory (DFT) has been applied to study the enantioselective reduction of 3-morpholin-4-yl-1-phenyl-1-propanone with borane catalyzed by (S)-4-benzyl-5,5- diphenyl-1,3,2-oxazaborolidine at the B3LYP/6-31G* level. All molecular species involved in the four reaction steps have been fully optimized and the structural parameters are provided, and the micro process of reaction was also investigated. The catalyst-alkoxyborane adduct formed in step III exhibits a B-O-B-N tetra-atomic ring. Reaction coordination calculations show that BH3 can react with 3-morpholin-4-yl-1-phenyl-1-propanone spontaneously, resulting in the need of 2 mol BH3 in the reaction.