Login In
2004 Volume 15 Issue 11
2004, 15(11): 1261-1264
Abstract:
First cationic 6-quinolyl substituted dithiaporphyrin was synthesized using Skraup quinoline methodology from thiaporphyrin bearing 4-acetamidophenyl prepared by condensation reaction of aromatic aldehyde with pyrrole.
First cationic 6-quinolyl substituted dithiaporphyrin was synthesized using Skraup quinoline methodology from thiaporphyrin bearing 4-acetamidophenyl prepared by condensation reaction of aromatic aldehyde with pyrrole.
Solvent-free Mechanochemical and Liquid-phase Reaction of [60]Fullerene with Ethyl 2-Diazopropionate
2004, 15(11): 1265-1268
Abstract:
The solvent-free mechanochemical reaction and the liquid-phase reaction of C60 with ethyl 2-diazopropionate prepared in situ or preformed from alanine ethyl ester hydrochloride and sodium nitrite have been investigated. Methanofullerene 1 and fulleroids 2 and 3 from these reactions were obtained, meanwhile the pyrazoline intermediate was not observed. Fulleroids 2 and 3 can be converted to methanofullerene 1 in refluxing toluene.
The solvent-free mechanochemical reaction and the liquid-phase reaction of C60 with ethyl 2-diazopropionate prepared in situ or preformed from alanine ethyl ester hydrochloride and sodium nitrite have been investigated. Methanofullerene 1 and fulleroids 2 and 3 from these reactions were obtained, meanwhile the pyrazoline intermediate was not observed. Fulleroids 2 and 3 can be converted to methanofullerene 1 in refluxing toluene.
2004, 15(11): 1269-1272
Abstract:
The reaction of isocyanates with aliphatic and aromatic amines in the 1-n-butyl-3- methylimidazolium tetrafluoroborate (bmimBF4) ionic liquid in good to excellent yields is described. Due to its insolubility, the desired urea solids could be recovered by simple filtration from the ionic liquid after reaction.
The reaction of isocyanates with aliphatic and aromatic amines in the 1-n-butyl-3- methylimidazolium tetrafluoroborate (bmimBF4) ionic liquid in good to excellent yields is described. Due to its insolubility, the desired urea solids could be recovered by simple filtration from the ionic liquid after reaction.
2004, 15(11): 1273-1275
Abstract:
An alternative route for the synthesis of (-)-10-epi-α-cyperone 1 starting from (+)- dihydrocarvone 2 is described by using an asymmetric Michael addition as a key step. The route features more efficiently and can be performed in large scale.
An alternative route for the synthesis of (-)-10-epi-α-cyperone 1 starting from (+)- dihydrocarvone 2 is described by using an asymmetric Michael addition as a key step. The route features more efficiently and can be performed in large scale.
2004, 15(11): 1276-1278
Abstract:
2-Amino-1,1-diferrocenylethanol 2 was prepared by reduction of trimethylsilyl cyanohydrin ether of diferrocenyl ketone. The crystal structure of 2 was further defined by X-ray diffraction.
2-Amino-1,1-diferrocenylethanol 2 was prepared by reduction of trimethylsilyl cyanohydrin ether of diferrocenyl ketone. The crystal structure of 2 was further defined by X-ray diffraction.
2004, 15(11): 1279-1280
Abstract:
A mild, regioselective 1, 3-dipolar cycloaddition protocol for the preparation of phenylselenomethyl isoxazolines through substituted allyl phenyl selenides and nitrile oxides was reported.
A mild, regioselective 1, 3-dipolar cycloaddition protocol for the preparation of phenylselenomethyl isoxazolines through substituted allyl phenyl selenides and nitrile oxides was reported.
2004, 15(11): 1281-1284
Abstract:
Herein we reported a one-pot synthesis of arylsubstituted imidazolin-2-ones by the cyclization of α-aminoacetophenone hydrochloride analogues 2 with arylisocyanates 3. Compared with other known synthetic route, this method resulted in higher yield.
Herein we reported a one-pot synthesis of arylsubstituted imidazolin-2-ones by the cyclization of α-aminoacetophenone hydrochloride analogues 2 with arylisocyanates 3. Compared with other known synthetic route, this method resulted in higher yield.
2004, 15(11): 1285-1288
Abstract:
A novel type of chiral molecular tweezers has been designed and synthesized by using chenodeoxy cholic acid as spacer and the aromatic compounds as arm. Their structures were characterized by 1HNMR, IR, MS spectra and elemental analysis. These chiral molecular tweezers showed good enantioselectivity for D-amino acid methyl esters.
A novel type of chiral molecular tweezers has been designed and synthesized by using chenodeoxy cholic acid as spacer and the aromatic compounds as arm. Their structures were characterized by 1HNMR, IR, MS spectra and elemental analysis. These chiral molecular tweezers showed good enantioselectivity for D-amino acid methyl esters.
2004, 15(11): 1289-1291
Abstract:
A novel intermolecular phosphoryl transfer from O-trimethylsilyl-N-(O, O-diisopropyl) phosphoryl serine trimethylsilyl ester to N, N'-bis(trimethylsilyl) histidine trimethylsilyl ester was studied through electrospray ionization mass spectrometry (ESI-MS). It was proposed that the transfer reaction went through penta-coordinated phosphorus intermediate.
A novel intermolecular phosphoryl transfer from O-trimethylsilyl-N-(O, O-diisopropyl) phosphoryl serine trimethylsilyl ester to N, N'-bis(trimethylsilyl) histidine trimethylsilyl ester was studied through electrospray ionization mass spectrometry (ESI-MS). It was proposed that the transfer reaction went through penta-coordinated phosphorus intermediate.
2004, 15(11): 1292-1294
Abstract:
Aryl selenoamides react smoothly with α-haloacetic acid in various alcohol to give corresponding bis(carboxyalkylmethyl) diselenides in good yields.
Aryl selenoamides react smoothly with α-haloacetic acid in various alcohol to give corresponding bis(carboxyalkylmethyl) diselenides in good yields.
2004, 15(11): 1295-1298
Abstract:
A Glaser coupling reaction of terminal alkynes in the presence of nickel chloride without any organics and bases in hot water has been developed, which produces the corresponding homo-coupling products in good yields.
A Glaser coupling reaction of terminal alkynes in the presence of nickel chloride without any organics and bases in hot water has been developed, which produces the corresponding homo-coupling products in good yields.
2004, 15(11): 1299-1302
Abstract:
Pyruvate was produced from DL-lactate by a kind of green-chemical biocatalyst-cell-free extract from bacterial strain Pseudomonas sp. SM-6. Catalase in cell-free extract, which could stabilize the pyruvate formed by lactate oxidase, played an important role in pyruvate preparation. The effect of catalase in conversion process was evaluated.
Pyruvate was produced from DL-lactate by a kind of green-chemical biocatalyst-cell-free extract from bacterial strain Pseudomonas sp. SM-6. Catalase in cell-free extract, which could stabilize the pyruvate formed by lactate oxidase, played an important role in pyruvate preparation. The effect of catalase in conversion process was evaluated.
2004, 15(11): 1303-1305
Abstract:
A new oleanane-type triterpene was isolated from the roots of Doellingeria scaber. Its structure was identified as 3-oxo-16α-hydroxy-olean-12-en-28-oic acid based on 1D and 2D NMR spectroscopy and X-ray analysis.
A new oleanane-type triterpene was isolated from the roots of Doellingeria scaber. Its structure was identified as 3-oxo-16α-hydroxy-olean-12-en-28-oic acid based on 1D and 2D NMR spectroscopy and X-ray analysis.
2004, 15(11): 1306-1308
Abstract:
Two new diaryheptanoids, (5S)-5-acetoxy-1,7-bis(4-hydroxy-3-methoxyphenyl)-3- heptanone (1) and (3S,5S)-3,5-diacetoxy-1,7-bis(4-hydroxy-3-methoxyphenyl)heptane (2) were isolated from the rhizomes of Zingiber officinale. Their structures were elucidated by spectral methods.
Two new diaryheptanoids, (5S)-5-acetoxy-1,7-bis(4-hydroxy-3-methoxyphenyl)-3- heptanone (1) and (3S,5S)-3,5-diacetoxy-1,7-bis(4-hydroxy-3-methoxyphenyl)heptane (2) were isolated from the rhizomes of Zingiber officinale. Their structures were elucidated by spectral methods.
2004, 15(11): 1309-1310
Abstract:
A new guaianolide was isolated from the roots of Scorzonera austriaca. The structure was elucidated on the basis of spectral methods including 2D NMR.
A new guaianolide was isolated from the roots of Scorzonera austriaca. The structure was elucidated on the basis of spectral methods including 2D NMR.
2004, 15(11): 1311-1314
Abstract:
A novel polypeptide was isolated from mistletoe Viscum coloratum. The primary structure of the polypeptide 'named viscotoxin B2' was determined to be KSCCKNTTGRNIYNT CRFAGGSRERCAKLSGCKIISASTCPSDYPK by Edman degradation. Viscotoxin B2 shared high sequence homology with viscotoxins isolated from Viscum album. Pharmacological experiments showed that viscotoxin B2 had distinct cytotoxic activity on tumor cells. Viscotoxin B2 could be used as a leading compound in cancer therapy.
A novel polypeptide was isolated from mistletoe Viscum coloratum. The primary structure of the polypeptide 'named viscotoxin B2' was determined to be KSCCKNTTGRNIYNT CRFAGGSRERCAKLSGCKIISASTCPSDYPK by Edman degradation. Viscotoxin B2 shared high sequence homology with viscotoxins isolated from Viscum album. Pharmacological experiments showed that viscotoxin B2 had distinct cytotoxic activity on tumor cells. Viscotoxin B2 could be used as a leading compound in cancer therapy.
2004, 15(11): 1315-1318
Abstract:
A new sensitive adsorptive voltammetric method was described for the determination of zirconium at a carbon paste electrode (CPE) in the presence of alizarin complexone (ALC). Optimal analytical conditions are: 1.0×10-6 or 5.0×10-7 mol/L ALC, 0.20 mol/L HAC-NaAc (pH 4.3), accumulation for 60 s at 0V (vs. SCE), and linear scanning from 0V to 1.0V at 250 mV/s. The peak potential of the complex is at 0.81V. By using a model JP-303 polarographic analyzer, 2.0×10-10 mol/L (S/N=3) zirconium can be detected with a 90 s accumulation, when the 2nd-order derivative linear sweep technique is used, and the linear range is 6.0×10-10-2.0×10-8 mol/L (5.0×10-7 mol/L ALC) and 2.0×10-8-2.0×10-7mol/L (1.0×10-6 mol/L ALC), respectively. The developed method was applied to the determination of trace zirconium in the ore samples with satisfactory results.
A new sensitive adsorptive voltammetric method was described for the determination of zirconium at a carbon paste electrode (CPE) in the presence of alizarin complexone (ALC). Optimal analytical conditions are: 1.0×10-6 or 5.0×10-7 mol/L ALC, 0.20 mol/L HAC-NaAc (pH 4.3), accumulation for 60 s at 0V (vs. SCE), and linear scanning from 0V to 1.0V at 250 mV/s. The peak potential of the complex is at 0.81V. By using a model JP-303 polarographic analyzer, 2.0×10-10 mol/L (S/N=3) zirconium can be detected with a 90 s accumulation, when the 2nd-order derivative linear sweep technique is used, and the linear range is 6.0×10-10-2.0×10-8 mol/L (5.0×10-7 mol/L ALC) and 2.0×10-8-2.0×10-7mol/L (1.0×10-6 mol/L ALC), respectively. The developed method was applied to the determination of trace zirconium in the ore samples with satisfactory results.
2004, 15(11): 1319-1322
Abstract:
Water-soluble CdSe quantum dots (QDs) capped by bovine serum albumin (BSA) is described as selective silver (Ⅰ) ion probe based on their fluorescence (FL) quenched by silver ion at pH 5.7. The detection limit is 3×10-7 mol L-1 for silver ion. The interference was also investigated.
Water-soluble CdSe quantum dots (QDs) capped by bovine serum albumin (BSA) is described as selective silver (Ⅰ) ion probe based on their fluorescence (FL) quenched by silver ion at pH 5.7. The detection limit is 3×10-7 mol L-1 for silver ion. The interference was also investigated.
2004, 15(11): 1323-1326
Abstract:
A rapid, simple and accurate method using an immunoaffinity column (IAC) and capillary electrophoresis (CE) for the analysis of the major alkaloids in opium is developed. The IAC was synthesized by coupling specific morphine polyclonal antibodies to CNBr-actived Sepharose 4B. The IAC showed high selectivity and obvious enrichment to morphine, codeine, dionin and thebaine. The extraction solution was analyzed by CE with β-cyclodextrin as an additive. Recoveries of the four alkaloids from PBS were between 93%-105% with RSD value less than 5.0%. The result showed that this method was practical for the determination of morphine analogs in opium.
A rapid, simple and accurate method using an immunoaffinity column (IAC) and capillary electrophoresis (CE) for the analysis of the major alkaloids in opium is developed. The IAC was synthesized by coupling specific morphine polyclonal antibodies to CNBr-actived Sepharose 4B. The IAC showed high selectivity and obvious enrichment to morphine, codeine, dionin and thebaine. The extraction solution was analyzed by CE with β-cyclodextrin as an additive. Recoveries of the four alkaloids from PBS were between 93%-105% with RSD value less than 5.0%. The result showed that this method was practical for the determination of morphine analogs in opium.
2004, 15(11): 1327-1330
Abstract:
Eight pairs of enantiomers of cyclopropane derivatives were resolved on capillary gas chromatographic columns using three new 2, 6-di-O-allyl-3-O-acylated-β-cyclodextrins as chiral stationary phases. It was found that the three β-CDs can separate some of the racemic cyclopropane derivatives well.
Eight pairs of enantiomers of cyclopropane derivatives were resolved on capillary gas chromatographic columns using three new 2, 6-di-O-allyl-3-O-acylated-β-cyclodextrins as chiral stationary phases. It was found that the three β-CDs can separate some of the racemic cyclopropane derivatives well.
2004, 15(11): 1331-1334
Abstract:
Three capillary zone electrophoresis (CZE) methods of the frontal analysis (FA), vacancy peak (VP) and simplified Hummel-Dreyer (SHD) were applied to investigate interaction between bovine serum albumin (BSA) and lomefloxacin, the experimental condition was established after a large number of tests. Based on the site-binding model, the binding parameters were measured according to the site model by Scatchard.
Three capillary zone electrophoresis (CZE) methods of the frontal analysis (FA), vacancy peak (VP) and simplified Hummel-Dreyer (SHD) were applied to investigate interaction between bovine serum albumin (BSA) and lomefloxacin, the experimental condition was established after a large number of tests. Based on the site-binding model, the binding parameters were measured according to the site model by Scatchard.
2004, 15(11): 1335-1338
Abstract:
Chromatography fingerprint (CFP) of 10 samples of hongqi were studied. 23 common peaks were analyzed, their average similarity was 97.29%. CFP were positioned with main index composition such as formononetin, calycosin and then the contents of index composition were determined. The character and exclusive of CFP of 10 samples of hongqi were clear. CFP and content determination of index composition of hongqi could be used to evaluate the quality of hongqi comprehensively.
Chromatography fingerprint (CFP) of 10 samples of hongqi were studied. 23 common peaks were analyzed, their average similarity was 97.29%. CFP were positioned with main index composition such as formononetin, calycosin and then the contents of index composition were determined. The character and exclusive of CFP of 10 samples of hongqi were clear. CFP and content determination of index composition of hongqi could be used to evaluate the quality of hongqi comprehensively.
2004, 15(11): 1339-1341
Abstract:
In a phosphate buffer, a hemoglobin (Hb)-imprinted polymer complex was prepared using maleic anhydride (MAH) modified chitosan beads as matrix, acrylamide (AM) as functional monomer, N,N-methylenebisacrylamide (MBA) as cross-linker and potassiumpersulfate (KPS)/sodium hydrogen sulfite (NaHSO3) as initiators. Langmuir analysis showed that an equal class of adsorption was formed in the molecular imprinting polymer (MIP), and the MIP has high adsorption capacity and selectivity for the imprinted molecule. The MIP can be reused and the recovery was approximately 100% at low concentration.
In a phosphate buffer, a hemoglobin (Hb)-imprinted polymer complex was prepared using maleic anhydride (MAH) modified chitosan beads as matrix, acrylamide (AM) as functional monomer, N,N-methylenebisacrylamide (MBA) as cross-linker and potassiumpersulfate (KPS)/sodium hydrogen sulfite (NaHSO3) as initiators. Langmuir analysis showed that an equal class of adsorption was formed in the molecular imprinting polymer (MIP), and the MIP has high adsorption capacity and selectivity for the imprinted molecule. The MIP can be reused and the recovery was approximately 100% at low concentration.
2004, 15(11): 1342-1344
Abstract:
Porous carrier MgO which was aggregated by nano-particles has been firstly prepared by using a normal technology route. The MgO was rod-shaped and had large surface area. The factors which affect grain size and microstructure of MgO were explored.
Porous carrier MgO which was aggregated by nano-particles has been firstly prepared by using a normal technology route. The MgO was rod-shaped and had large surface area. The factors which affect grain size and microstructure of MgO were explored.
2004, 15(11): 1345-1348
Abstract:
The well-distributed, stable selenium nanoparticles (10 nm) with good adhesive ability and biocompatibility were successfully synthesized by using the template of chitosan cross-linked with glutaradehyde. The resulting selenium nanoparticles were used as a new carrier for horseradish peroxidase to construct H2O2 biosensors with good performances.
The well-distributed, stable selenium nanoparticles (10 nm) with good adhesive ability and biocompatibility were successfully synthesized by using the template of chitosan cross-linked with glutaradehyde. The resulting selenium nanoparticles were used as a new carrier for horseradish peroxidase to construct H2O2 biosensors with good performances.
2004, 15(11): 1349-1352
Abstract:
A new cyclometalated iridium(Ⅲ) complex with the formula [Ir(DPQ)2(acac)] (DPQ=2,3-diphenylquinoxaline; acac=acetylacetone) was prepared. The structure of the complex was confirmed by Elemental Analysis (EA), 1H NMR, and mass spectroscopy (MS). The UV-vis absorption and photoluminescent properties of the complex were investigated.
A new cyclometalated iridium(Ⅲ) complex with the formula [Ir(DPQ)2(acac)] (DPQ=2,3-diphenylquinoxaline; acac=acetylacetone) was prepared. The structure of the complex was confirmed by Elemental Analysis (EA), 1H NMR, and mass spectroscopy (MS). The UV-vis absorption and photoluminescent properties of the complex were investigated.
2004, 15(11): 1353-1356
Abstract:
A novel method for removing boron with ion exchange resin from residual brines to manufacture boron-free magnesia is described. The concentration of boron in the target magnesia manufactured thereby from Qinghai salt lakes is lower than 5μg/g, and the typical D50 size of product is 10.625μm.
A novel method for removing boron with ion exchange resin from residual brines to manufacture boron-free magnesia is described. The concentration of boron in the target magnesia manufactured thereby from Qinghai salt lakes is lower than 5μg/g, and the typical D50 size of product is 10.625μm.
2004, 15(11): 1357-1360
Abstract:
Both the unsupported and supported NiB amorphous alloy catalysts (NiB and NiB/TiO2) were prepared by the chemical reduction method. Their catalytic activities were tested by the hydrogenation of sulfolene. The interactions between the NiB alloy and TiO2 were discussed for the first time by using XRD, ICP, SEM and TEM.
Both the unsupported and supported NiB amorphous alloy catalysts (NiB and NiB/TiO2) were prepared by the chemical reduction method. Their catalytic activities were tested by the hydrogenation of sulfolene. The interactions between the NiB alloy and TiO2 were discussed for the first time by using XRD, ICP, SEM and TEM.
2004, 15(11): 1361-1364
Abstract:
Cellulose/cellulose acetate membranes were prepared and functionalized by introducing amino group on it, and then immobilized the glucose oxidase (Gox) on the functionalizd membrane. SECM was applied for the detection of enzyme activity immobilized on the membrane. Immobilized biomolecules on such membranes was combined with analysis apparatus and can be used in bioassays.
Cellulose/cellulose acetate membranes were prepared and functionalized by introducing amino group on it, and then immobilized the glucose oxidase (Gox) on the functionalizd membrane. SECM was applied for the detection of enzyme activity immobilized on the membrane. Immobilized biomolecules on such membranes was combined with analysis apparatus and can be used in bioassays.
2004, 15(11): 1365-1368
Abstract:
Europium bisphthalocyanine (EuPc2) nanowires were prepared by electrochemical deposition method. Scanning electron microscopy (SEM) images show the evolution of the morphologies of nanowires obtained under different deposition time (Td). The optical properties of europium bisphthalocyanine films were studied by UV-Vis absorption spectra. The morphology of EuPc2 nanowires could be controlled by changing deposition conditions, which provides a useful method to make organic nanowires.
Europium bisphthalocyanine (EuPc2) nanowires were prepared by electrochemical deposition method. Scanning electron microscopy (SEM) images show the evolution of the morphologies of nanowires obtained under different deposition time (Td). The optical properties of europium bisphthalocyanine films were studied by UV-Vis absorption spectra. The morphology of EuPc2 nanowires could be controlled by changing deposition conditions, which provides a useful method to make organic nanowires.
2004, 15(11): 1369-1372
Abstract:
In order to search for the high efficiency and low sheet resistance counter electrode in dye-sensitized solar cell, we used Ti plate as the conducting substrate to prepare the counter electrode by thermal decomposition of H2PtCl6. Ti plate counter electrode shows low sheet resistance, good reflecting performance and matching kinetics. The dye-sensitized solar cell with the Ti plate counter electrode shows better photovoltaic performance than that of the cell with the fluorine-doped tin oxide-coated glass counter electrode.
In order to search for the high efficiency and low sheet resistance counter electrode in dye-sensitized solar cell, we used Ti plate as the conducting substrate to prepare the counter electrode by thermal decomposition of H2PtCl6. Ti plate counter electrode shows low sheet resistance, good reflecting performance and matching kinetics. The dye-sensitized solar cell with the Ti plate counter electrode shows better photovoltaic performance than that of the cell with the fluorine-doped tin oxide-coated glass counter electrode.
2004, 15(11): 1373-1376
Abstract:
A novel organic soluble and thermal-stable fullerene-perylene dyad, in which a perylene moietyis attached to C60, has been prepared by 1, 3-dipolar cycloaddition of the azomethine ylides generated in situ from the aldehyde and N-methylglycine and characterized by NMR, FT-IR, TGA, absorption and fluorescent spectra etc.
A novel organic soluble and thermal-stable fullerene-perylene dyad, in which a perylene moietyis attached to C60, has been prepared by 1, 3-dipolar cycloaddition of the azomethine ylides generated in situ from the aldehyde and N-methylglycine and characterized by NMR, FT-IR, TGA, absorption and fluorescent spectra etc.
2004, 15(11): 1377-1379
Abstract:
Cyclic oligomers of phenolphthalein polyarylene ether sulfone(ketone) were prepared through cyclo-depolymerisation of corresponding polymers using CsF as the catalyst in dipolar aprotic solvent DMAc and DMF, and a family of macrocycles containing from dimer up to at least heptamer were confirmed by GPC, HPLC and MALDI-TOF-MS. The yields of cyclics get as high as 86.3% and 87.9% respectively.
Cyclic oligomers of phenolphthalein polyarylene ether sulfone(ketone) were prepared through cyclo-depolymerisation of corresponding polymers using CsF as the catalyst in dipolar aprotic solvent DMAc and DMF, and a family of macrocycles containing from dimer up to at least heptamer were confirmed by GPC, HPLC and MALDI-TOF-MS. The yields of cyclics get as high as 86.3% and 87.9% respectively.
2004, 15(11): 1380-1382
Abstract:
A 3 D-QSAR about nAChRs agonists-epibatidine analogues was performed using the CoMFA and CoMSIA. The correlation coefficients were Rcv2=0.546, Rncv2=0.907 in CoMFA and Rcv2=0.655, Rncv2=0.962 in CoMSIA of the final model. The prediction using the final models to the test set was r2=0.675 in CoMFA and r2=0.462 in CoMSIA. This model will be useful in the design of novel compounds with high affinity.
A 3 D-QSAR about nAChRs agonists-epibatidine analogues was performed using the CoMFA and CoMSIA. The correlation coefficients were Rcv2=0.546, Rncv2=0.907 in CoMFA and Rcv2=0.655, Rncv2=0.962 in CoMSIA of the final model. The prediction using the final models to the test set was r2=0.675 in CoMFA and r2=0.462 in CoMSIA. This model will be useful in the design of novel compounds with high affinity.
2004, 15(11): 1383-1386
Abstract:
Intramolecular proton transfer of hypomycin A in the ground state S0 and singlet excited state S1 were calculated by high level quantum chemical method in this letter. It was found that the IPT barriers for I→TS1 are 38.56 kJ/mol in S0 and 8.19 kJ/mol in S1, while those for I→TS4 get approximately 17 kJ/mol higher in S0 and 28 kJ/mol higher in S1. The calculation of IPT rate constants suggests that the experiment observed process of PQD is in S1. The height of the IPT barriers correlate not only with the variance of charge for labile hydrogen, the change of H-bond's length, the change of O-H bond's length and the change of O-O distance, but also with the reactant molecular H-bond's length. Moreover, the correlations are the same for S0 and S1.
Intramolecular proton transfer of hypomycin A in the ground state S0 and singlet excited state S1 were calculated by high level quantum chemical method in this letter. It was found that the IPT barriers for I→TS1 are 38.56 kJ/mol in S0 and 8.19 kJ/mol in S1, while those for I→TS4 get approximately 17 kJ/mol higher in S0 and 28 kJ/mol higher in S1. The calculation of IPT rate constants suggests that the experiment observed process of PQD is in S1. The height of the IPT barriers correlate not only with the variance of charge for labile hydrogen, the change of H-bond's length, the change of O-H bond's length and the change of O-O distance, but also with the reactant molecular H-bond's length. Moreover, the correlations are the same for S0 and S1.
