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1990 Volume 1 Issue 3
1990, 1(3): 191-192
Abstract:
The reaction of perfluoroalkyliodides, perfluoroalkylbromide, 1, 1, 1-trifluoro-2, 2, 2-trichloro-ethane, and carbon tetrachloride with thiourea dioxide in aqueous acetonitrile solution gave the corresponding sulfinate in good yield.
The reaction of perfluoroalkyliodides, perfluoroalkylbromide, 1, 1, 1-trifluoro-2, 2, 2-trichloro-ethane, and carbon tetrachloride with thiourea dioxide in aqueous acetonitrile solution gave the corresponding sulfinate in good yield.
1990, 1(3): 193-196
Abstract:
A simple and general method for the synthesis of bi(acyl)disulfides isreported.Sulfur is allowed to react with sodium hydroxide to give sodium disulfideat 65℃ under PTC, which can react with acyl halides to afford bi(acyl)disulfides ingood to excellent isolated yields.The effects of solvents and phase transfercatalysts are discussed.
A simple and general method for the synthesis of bi(acyl)disulfides isreported.Sulfur is allowed to react with sodium hydroxide to give sodium disulfideat 65℃ under PTC, which can react with acyl halides to afford bi(acyl)disulfides ingood to excellent isolated yields.The effects of solvents and phase transfercatalysts are discussed.
1990, 1(3): 197-200
Abstract:
ESR measurements using spin trapping technique were carried out for β-carotene-halobenzene system under UV light irradiation.The ESR spectra observed in the presence and in the absence of β-carotene are markedly different.Thepossible scheme of β-carotene interacting with halogen atom was proposed.
ESR measurements using spin trapping technique were carried out for β-carotene-halobenzene system under UV light irradiation.The ESR spectra observed in the presence and in the absence of β-carotene are markedly different.Thepossible scheme of β-carotene interacting with halogen atom was proposed.
1990, 1(3): 201-204
Abstract:
Inter-and intramolecular quenching of zinc phthalocyanine fluorescence by anthraquinone has been studied.The diminutions of fluorescence quantum yield and life-time are due primarily to electron transfer.Apparent electron transfer rate constants were calculated depending on the chain length and solvent polarity.
Inter-and intramolecular quenching of zinc phthalocyanine fluorescence by anthraquinone has been studied.The diminutions of fluorescence quantum yield and life-time are due primarily to electron transfer.Apparent electron transfer rate constants were calculated depending on the chain length and solvent polarity.
1990, 1(3): 205-206
Abstract:
A method of synthesis of quinoxaline by α-ketothioanilide and o-phenylenediamine is described in this paper.
A method of synthesis of quinoxaline by α-ketothioanilide and o-phenylenediamine is described in this paper.
1990, 1(3): 207-208
Abstract:
(4S, 5R)-5-Hydroxy-4-decanolide 1, the proposed autoregulator from streptomyces Griseus was synthesized from an allyl alcohol 2, employ-ing the Sharpless kinetic resolution and the reaction of diethyl malonate with the epoxy compound 4 as two key steps.
(4S, 5R)-5-Hydroxy-4-decanolide 1, the proposed autoregulator from streptomyces Griseus was synthesized from an allyl alcohol 2, employ-ing the Sharpless kinetic resolution and the reaction of diethyl malonate with the epoxy compound 4 as two key steps.
1990, 1(3): 209-210
Abstract:
The reductive alkylation of amine with carbonyl compounds using sodium hydrogen telluride has been investigated in recent years(1).Application of this method to the synthesis of N-alkyl derivatives of biologically important amino acids and their esters is described.
The reductive alkylation of amine with carbonyl compounds using sodium hydrogen telluride has been investigated in recent years(1).Application of this method to the synthesis of N-alkyl derivatives of biologically important amino acids and their esters is described.
1990, 1(3): 211-212
Abstract:
A convenient method for preparing unsaturated amides via telluro-nium salts employing solid potassium carbonate as a base with high stereo-selectivity in excellent yields has been developed.
A convenient method for preparing unsaturated amides via telluro-nium salts employing solid potassium carbonate as a base with high stereo-selectivity in excellent yields has been developed.
1990, 1(3): 213-214
Abstract:
Two new alkaloids, hordenine-O-α-L-rhamnopyranoside(Ⅰ)and hordenine-0-(6"-trans-cinnamoyl)-4'-O-β-D-glucopyranosyl-α-L-rhamnopyranoside (Ⅲ) isolated from Selaginella doederleinii have been synthesized the first time.A new method, in which trifluoroacetoxyl group was used both as a good leaving group and a protecting group for synthesis of O-glycosides with high stereo-selectivity was reported.
Two new alkaloids, hordenine-O-α-L-rhamnopyranoside(Ⅰ)and hordenine-0-(6"-trans-cinnamoyl)-4'-O-β-D-glucopyranosyl-α-L-rhamnopyranoside (Ⅲ) isolated from Selaginella doederleinii have been synthesized the first time.A new method, in which trifluoroacetoxyl group was used both as a good leaving group and a protecting group for synthesis of O-glycosides with high stereo-selectivity was reported.
1990, 1(3): 215-218
Abstract:
The synthesis of 5α-(17R, 20R)-14, 15-secocholestane from cholesterol was reported.
The synthesis of 5α-(17R, 20R)-14, 15-secocholestane from cholesterol was reported.
1990, 1(3): 219-220
Abstract:
A new bisdesmosidic triterpene saponin, macranthoiside I, was isolated from L.macranthoides.Its structure was determined by chemical degradation and spectroscopic analysis.
A new bisdesmosidic triterpene saponin, macranthoiside I, was isolated from L.macranthoides.Its structure was determined by chemical degradation and spectroscopic analysis.
1990, 1(3): 221-222
Abstract:
An alkaloid with a novel structure, named Hypodematine, was isolated from Hypodematium sinense Iwatsuki(belonging to Thelypterdaceae)(1).Its structure was elucidated by means of the 1H-1H COSY' 1H-13C COSY and long-range 1H-13C COSY spectroscopy to have the skeleton of benzo-aza-cyclooctatetraene with a phenyl substituent.Such basic structure has not been found in the na-tural product before.
An alkaloid with a novel structure, named Hypodematine, was isolated from Hypodematium sinense Iwatsuki(belonging to Thelypterdaceae)(1).Its structure was elucidated by means of the 1H-1H COSY' 1H-13C COSY and long-range 1H-13C COSY spectroscopy to have the skeleton of benzo-aza-cyclooctatetraene with a phenyl substituent.Such basic structure has not been found in the na-tural product before.
1990, 1(3): 223-224
Abstract:
A novel sesquiterpene tactone, versicolactone A, with 12-carbon ring skeleton, has been isolated from the roots of Aristolochia versicolar S.M.Hwang, and the structure was elucidated on the basis of 2D NMR and MS spectral data.
A novel sesquiterpene tactone, versicolactone A, with 12-carbon ring skeleton, has been isolated from the roots of Aristolochia versicolar S.M.Hwang, and the structure was elucidated on the basis of 2D NMR and MS spectral data.
1990, 1(3): 225-228
Abstract:
A reliable and sensitive method is developed for the detection of common diuretics in human urine. diuretics along with probenecid are methylated and subjected to GC-MS analysis.Both chromatographic and mass spectrometric data are obtained in selected ion monitoring and full scanning modes.The average detection limit is 0.1-1.0 ug/mi urine.This method is suitable to large-scale and routine screening or confirmation of diuretics in doping control.
A reliable and sensitive method is developed for the detection of common diuretics in human urine. diuretics along with probenecid are methylated and subjected to GC-MS analysis.Both chromatographic and mass spectrometric data are obtained in selected ion monitoring and full scanning modes.The average detection limit is 0.1-1.0 ug/mi urine.This method is suitable to large-scale and routine screening or confirmation of diuretics in doping control.
1990, 1(3): 229-230
Abstract:
In pH2.0-3.0, niobium(V) forms molybdonlobic acid with sodium molybdate.A spectrophotometric method has been developed for the deter-mination of niobium based on the formation of ion-associate compound of molybdoniobate with Butyl Rhodamine B in aqueous solution in the presence of polyvinyl alcohol and 0.4-0.7 mol/L H2SO4.The maximum absorption of ion-associate compound exhioits at 85 nm and the molar absorptivity is 7.5×1.05 L.mol-1.cm-1for niobium.The new method has been applied to the determination of microamounts niobium in silicate rock, when niobium content is at the level of 8×10-3%, with the relative standard deviation of about 3%.
In pH2.0-3.0, niobium(V) forms molybdonlobic acid with sodium molybdate.A spectrophotometric method has been developed for the deter-mination of niobium based on the formation of ion-associate compound of molybdoniobate with Butyl Rhodamine B in aqueous solution in the presence of polyvinyl alcohol and 0.4-0.7 mol/L H2SO4.The maximum absorption of ion-associate compound exhioits at 85 nm and the molar absorptivity is 7.5×1.05 L.mol-1.cm-1for niobium.The new method has been applied to the determination of microamounts niobium in silicate rock, when niobium content is at the level of 8×10-3%, with the relative standard deviation of about 3%.
1990, 1(3): 231-234
Abstract:
A retiabte and sensitive method is developed for the detection of β-blockers which are excreted in free or conjugated forms in human urine.9 β-blockers were derivatized by MSTFA and MBTFA and subjected to GC/MSB analysis.Both chromato-grams and mass spectrometric data were obtained from full scanning mode.This method is suitable for routine screening and confirmation of β-blockers in doping control.
A retiabte and sensitive method is developed for the detection of β-blockers which are excreted in free or conjugated forms in human urine.9 β-blockers were derivatized by MSTFA and MBTFA and subjected to GC/MSB analysis.Both chromato-grams and mass spectrometric data were obtained from full scanning mode.This method is suitable for routine screening and confirmation of β-blockers in doping control.
1990, 1(3): 235-236
Abstract:
On-line dissolution of solid metal sample can be carried out by electrolysis under the control of flow injection analyzer(FIA), and the dissolved sample can be transferred to atomic spectrometer for the direct analysis.The hyphenated technique of FIA on-line electrolytic dissolution of alloy and atomic absorption spectrometer (AAS) detection is developed.The research is focused on the effects of electrolyte composition and electrolysis parameters on the sample dissolving, as well as the quantitative analysis of Cu in Al alloy samples.
On-line dissolution of solid metal sample can be carried out by electrolysis under the control of flow injection analyzer(FIA), and the dissolved sample can be transferred to atomic spectrometer for the direct analysis.The hyphenated technique of FIA on-line electrolytic dissolution of alloy and atomic absorption spectrometer (AAS) detection is developed.The research is focused on the effects of electrolyte composition and electrolysis parameters on the sample dissolving, as well as the quantitative analysis of Cu in Al alloy samples.
1990, 1(3): 237-238
Abstract:
A quite new type of chelating resin Carboxymethylated Polyethylenimine-Polymethylenepolyphenylene Isocyanate (CPPI) is use dfor the preconcentration of Zn from high salt water such as seawater.The preconcentration is controlled through the technique of Flow Injection Analysis(FIA).The concentrated sample solution is then directly transferred to an Inductively Coupled Plasma-Atomic Fluorescence Spectrometer(ICP-AFS)for determination.The detection limit of Zn by the technique is about 0.06 ppb.
A quite new type of chelating resin Carboxymethylated Polyethylenimine-Polymethylenepolyphenylene Isocyanate (CPPI) is use dfor the preconcentration of Zn from high salt water such as seawater.The preconcentration is controlled through the technique of Flow Injection Analysis(FIA).The concentrated sample solution is then directly transferred to an Inductively Coupled Plasma-Atomic Fluorescence Spectrometer(ICP-AFS)for determination.The detection limit of Zn by the technique is about 0.06 ppb.
1990, 1(3): 239-240
Abstract:
Polarographic characteristics of Te(Ⅳ)-alkaline dye were investiga-ted at mercury electrode in acidic solution.It was found that the mechanism of the electrode process depended on the concentration of Te(Ⅳ).
Polarographic characteristics of Te(Ⅳ)-alkaline dye were investiga-ted at mercury electrode in acidic solution.It was found that the mechanism of the electrode process depended on the concentration of Te(Ⅳ).
ORGANIC NONLINEAR OPTICAL CRYSTAL:N-(4-NITROPHENYL)-(s)-(+)-2-PYRROLIDINEMETHYLENE TOSYLATE(NPP-OTs)
1990, 1(3): 241-244
Abstract:
Large crystal NPP-OTs has been obtained by growth from solution, its powder SHG efficiency is 1/3 of urea.It shows it is a new convenient approach to obtain organic second-order NLO crystal:the dipole-dipole interaction is oppos-ed by introducing a large side group.
Large crystal NPP-OTs has been obtained by growth from solution, its powder SHG efficiency is 1/3 of urea.It shows it is a new convenient approach to obtain organic second-order NLO crystal:the dipole-dipole interaction is oppos-ed by introducing a large side group.
1990, 1(3): 245-246
Abstract:
The new cluster[MO4(μ3-O)2O4Cl2(o-CH3C6H4COO)6]has been prepared by the reaction of molybdenum pentachloride and o-methylbenzoic acid.The crystal and molecular structures were determined by the X-ray diffraction method.It crystallizes in the orthorhombic space group Pnna with cell parameters:Mr=1361.6, a=13.792(4), b=17.957(3), c=20.974(9)Å , V=5194(2) 3, Z=4, Dc=1.74/cm3, F(OOO)=2704, μ(MoKα)=11.0/cm, R=0.074.
The new cluster[MO4(μ3-O)2O4Cl2(o-CH3C6H4COO)6]has been prepared by the reaction of molybdenum pentachloride and o-methylbenzoic acid.The crystal and molecular structures were determined by the X-ray diffraction method.It crystallizes in the orthorhombic space group Pnna with cell parameters:Mr=1361.6, a=13.792(4), b=17.957(3), c=20.974(9)Å , V=5194(2) 3, Z=4, Dc=1.74/cm3, F(OOO)=2704, μ(MoKα)=11.0/cm, R=0.074.
1990, 1(3): 247-250
Abstract:
In this paper, the Fourier transform near-infrared (FTNIR) diffuse reflectance spectroscopy is applied for the rapid determination of protein in millet.The partial least-squares (PLS) regression is successfully used as an effective multivariate calibration technique.The calibration set is composed of 20 standard millet samples that the protein contents were determined by the traditional Kjeldahl method.The optimal model dimension is found to be 5 by cross-validation.22 millet samples were determined by the proposed FTNIR-PLS method.The correlation coefficient between the concentration values obtained by the FTNIR-PLS method and the traditional Kjeldahl method is 0.9805.The standard error of prediction (SEP) is 0.28% and the mean recovery is 100.2%.The proposed method has been successfully applied for the routine analysis of protein in about 10,000 grain samples.
In this paper, the Fourier transform near-infrared (FTNIR) diffuse reflectance spectroscopy is applied for the rapid determination of protein in millet.The partial least-squares (PLS) regression is successfully used as an effective multivariate calibration technique.The calibration set is composed of 20 standard millet samples that the protein contents were determined by the traditional Kjeldahl method.The optimal model dimension is found to be 5 by cross-validation.22 millet samples were determined by the proposed FTNIR-PLS method.The correlation coefficient between the concentration values obtained by the FTNIR-PLS method and the traditional Kjeldahl method is 0.9805.The standard error of prediction (SEP) is 0.28% and the mean recovery is 100.2%.The proposed method has been successfully applied for the routine analysis of protein in about 10,000 grain samples.
1990, 1(3): 251-254
Abstract:
4-(2-thiazolyazo)-resorcinol(TAR)can form complexes FeR, FeHR and FeR2 according to numerical evaluation from experimental data of A and pH.Their cumulative stability constants(log B)are 11.48, 15.32 and 17.30 respectively.
4-(2-thiazolyazo)-resorcinol(TAR)can form complexes FeR, FeHR and FeR2 according to numerical evaluation from experimental data of A and pH.Their cumulative stability constants(log B)are 11.48, 15.32 and 17.30 respectively.
1990, 1(3): 255-256
Abstract:
Reaction of (NH4)2MoS4 with AgI in α-MePy gives the title com-pound, an X-ray analysis of which shows that the molecule forms a one-dimensional polymeric chain with continuous metal-metal bonds.
Reaction of (NH4)2MoS4 with AgI in α-MePy gives the title com-pound, an X-ray analysis of which shows that the molecule forms a one-dimensional polymeric chain with continuous metal-metal bonds.
1990, 1(3): 257-260
Abstract:
An enzyme is a kind of protein with catalytic activity and long chain, and its structure and shape are determined by the hybridized state of atomic orbital.The fractal dimension (Df) is closely related to the hybridization, e.g.Df=2ln2/ln[2(1+α/(1-α))]for the spa type, where a denotes the fraction of the s orbital in the hybridized molecular orbital.This relationship and the five fractal theorems introduced by the present paper play an important role in the investigations of the model of imitative enzyme.
An enzyme is a kind of protein with catalytic activity and long chain, and its structure and shape are determined by the hybridized state of atomic orbital.The fractal dimension (Df) is closely related to the hybridization, e.g.Df=2ln2/ln[2(1+α/(1-α))]for the spa type, where a denotes the fraction of the s orbital in the hybridized molecular orbital.This relationship and the five fractal theorems introduced by the present paper play an important role in the investigations of the model of imitative enzyme.
1990, 1(3): 261-262
Abstract:
Photoelectrochemicat cells, composed of different epitaxial n-Si photoele trodes coated with metal such as nickel o platinum and immersed in a solution of redox couple Br Br2 or Fe(CN)64-/3-, are investigated.A high conversion efficiency from optical to electri-cal energy up to 13.6% can be achieved under optimum conditions.
Photoelectrochemicat cells, composed of different epitaxial n-Si photoele trodes coated with metal such as nickel o platinum and immersed in a solution of redox couple Br Br2 or Fe(CN)64-/3-, are investigated.A high conversion efficiency from optical to electri-cal energy up to 13.6% can be achieved under optimum conditions.
1990, 1(3): 263-264
Abstract:
Six coordination compounds of Pt(Ⅱ)L2 and Ir(Ⅲ)L3 type(where L is PT-, 3Me-PT- or 4Me-PT-) are reported here.Four coordination compounds of the latter two ligands have never been reported before, while PT-'s were synthesized with H2PtCl6 and (NH4)3IrCl6 respectively, which were different from the methods of Davidson et al.1 and Sterinbrec H2.They were characterized by elemental analysis, UV, IR, 1HNMR and molar conductance.Their structural formulas have beendetermined, and the mechanism of synthetic reaction has been discussed.
Six coordination compounds of Pt(Ⅱ)L2 and Ir(Ⅲ)L3 type(where L is PT-, 3Me-PT- or 4Me-PT-) are reported here.Four coordination compounds of the latter two ligands have never been reported before, while PT-'s were synthesized with H2PtCl6 and (NH4)3IrCl6 respectively, which were different from the methods of Davidson et al.1 and Sterinbrec H2.They were characterized by elemental analysis, UV, IR, 1HNMR and molar conductance.Their structural formulas have beendetermined, and the mechanism of synthetic reaction has been discussed.
1990, 1(3): 265-268
Abstract:
It is reported that a variety of trimethylsilyl enol ethers of ketones and aldehydes can be used to initiate GTP of methacrylates and acryl-ates.The new initiators are easy to prepare from ketones or aldehydes.PMMA and PMA with controlled molecular weight and low polydispersity were obtained by using non-acetal initiators in the presence of bibenzoate, bifluo ide or Hgl2, The living nature of polymerization is shown by the correspondence of theoretical and observed molecular weight and the preparation of A-B-A type triblock copolymer with methacrylate and acrylate segments can be prepared.
It is reported that a variety of trimethylsilyl enol ethers of ketones and aldehydes can be used to initiate GTP of methacrylates and acryl-ates.The new initiators are easy to prepare from ketones or aldehydes.PMMA and PMA with controlled molecular weight and low polydispersity were obtained by using non-acetal initiators in the presence of bibenzoate, bifluo ide or Hgl2, The living nature of polymerization is shown by the correspondence of theoretical and observed molecular weight and the preparation of A-B-A type triblock copolymer with methacrylate and acrylate segments can be prepared.
1990, 1(3): 269-270
Abstract:
A simple and effective method of removing polluted organics in water is reported here.Titanium dioxide is a catalyst in photo-oxidation of monocrotophos.The mechanism of photocatalytic oxidation and the kinetics of the reaction were studied.This same principle also leads to the construction of instrument of PTR-FIA analysis for monitoring organic phosphorus and phosphate in water.
A simple and effective method of removing polluted organics in water is reported here.Titanium dioxide is a catalyst in photo-oxidation of monocrotophos.The mechanism of photocatalytic oxidation and the kinetics of the reaction were studied.This same principle also leads to the construction of instrument of PTR-FIA analysis for monitoring organic phosphorus and phosphate in water.
1990, 1(3): 271-274
Abstract:
Forty para-disubstituted benzylidene-aniline derivatives were synthesized, and their second harmonic generation (SHG) efficiency was measured by the Kurtz powder technique.The effect of the electronic property and the position of the substituents on powder SHG efficiency was studied.
Forty para-disubstituted benzylidene-aniline derivatives were synthesized, and their second harmonic generation (SHG) efficiency was measured by the Kurtz powder technique.The effect of the electronic property and the position of the substituents on powder SHG efficiency was studied.
1990, 1(3): 275-276
Abstract:
The good potentiality of the In2O3 anodic film as a photoanodic material has been demonstrated.The anodic oxidation of In substrate in alkaline solution for obtaining In2O3 film has been developed and their semiconducting properties have been investigated through capacitance, photoelectrochemistry and electroreflection measurements.
The good potentiality of the In2O3 anodic film as a photoanodic material has been demonstrated.The anodic oxidation of In substrate in alkaline solution for obtaining In2O3 film has been developed and their semiconducting properties have been investigated through capacitance, photoelectrochemistry and electroreflection measurements.
1990, 1(3): 277-278
Abstract:
A new method for preparing fine α-Al2O3 by thermal decomposition from hydrazine-containing aluminum salt was described.The process of the thermal decomposition of the hydrazine-containing aluminum salt was investigated by thermal analysis (TG and DTA) and the thermally decomposed products were studied by S.E.M and X-ray diffraction.The result indicated the particles of α-Al2O3 obtained in this way at 12500℃ were < 1μm in size.
A new method for preparing fine α-Al2O3 by thermal decomposition from hydrazine-containing aluminum salt was described.The process of the thermal decomposition of the hydrazine-containing aluminum salt was investigated by thermal analysis (TG and DTA) and the thermally decomposed products were studied by S.E.M and X-ray diffraction.The result indicated the particles of α-Al2O3 obtained in this way at 12500℃ were < 1μm in size.
1990, 1(3): 279-282
Abstract:
Raney-Copper (R-Cu) catalyst was prepared and its sintering behaviour in atmospheres at teperature 300℃-600℃ was detected by methods of SSA, PSD, XRD and SEM.It was found that sintering of R-Cu started from much lower temperature than the melting point of copper.Changes both on the surface and in the body phase were discovered.There is a rule in the extent of sintering for R-Cu in different atmospheres which is related to the adsorption of the particular gases molecules on the surface of the catalyst.Dynamical equations of the surface decrease is established and the mechanism of sintering is discussed.Calculations of quantum mechanics givethe similar results.
Raney-Copper (R-Cu) catalyst was prepared and its sintering behaviour in atmospheres at teperature 300℃-600℃ was detected by methods of SSA, PSD, XRD and SEM.It was found that sintering of R-Cu started from much lower temperature than the melting point of copper.Changes both on the surface and in the body phase were discovered.There is a rule in the extent of sintering for R-Cu in different atmospheres which is related to the adsorption of the particular gases molecules on the surface of the catalyst.Dynamical equations of the surface decrease is established and the mechanism of sintering is discussed.Calculations of quantum mechanics givethe similar results.
1990, 1(3): 283-284
Abstract:
The thermal stability of New Zealand culture rabbit muscle aldolase was investigated by differential scanning calorimetry in the water content range 0.23-3.70 g water per g protein.The experimental results showed that at water contents below 0.47g/g, an endothermic peak was observed and at water contents above 0.57g/g, an endothermic and an exothermic peak were both observed on DSC thermogram.Thermal denaturation result of the enzyme and the relationship between two transition temperatures and water contents were first reported in this paper.Up to now we have not seen any similar reports concerning the exothermic transition.
The thermal stability of New Zealand culture rabbit muscle aldolase was investigated by differential scanning calorimetry in the water content range 0.23-3.70 g water per g protein.The experimental results showed that at water contents below 0.47g/g, an endothermic peak was observed and at water contents above 0.57g/g, an endothermic and an exothermic peak were both observed on DSC thermogram.Thermal denaturation result of the enzyme and the relationship between two transition temperatures and water contents were first reported in this paper.Up to now we have not seen any similar reports concerning the exothermic transition.
