Thermodynamic data were determined for the reversible binding of O 2 to two compounds of dicobalt(II) di(meso tetra phenyl)porphyrin derivatives with different lengths of diamidoaliphatic bridge (abbreviated to Co ...Thermodynamic data were determined for the reversible binding of O 2 to two compounds of dicobalt(II) di(meso tetra phenyl)porphyrin derivatives with different lengths of diamidoaliphatic bridge (abbreviated to Co 2PP 8 and Co 2PP 4) in N,N dimethylformamide at room temperature. The partial pressure of dioxygen necessary for half oxygenation ( P 1/2 ) and Hill coefficient ( n ) at 298 K were determined as follows: P 1/2 =54.2 kPa, n =2.0 for Co 2PP 8 and P 1/2 =6.8 kPa, n =1.8 for Co 2PP 4,respectively. The rate equations of reversible oxygen binding by Co 2PP 8 were determined and the reaction path was proposed. The results of thermodynamic and kinetic studies indicate that there exists strong cooperative effect during oxygenation of the compounds. The ESR observation reveals that the dioxygen complexes formed in the solutions are of superoxo (Co O - 2) type.展开更多
Methyl 3-hydroxypropanoate was synthesized via hydroesterification of ethylene oxide with CO in the presence of dicobalt octacarbonyl catalyst and methanol solvent. The catalyst exhibited high catalytic activity. The ...Methyl 3-hydroxypropanoate was synthesized via hydroesterification of ethylene oxide with CO in the presence of dicobalt octacarbonyl catalyst and methanol solvent. The catalyst exhibited high catalytic activity. The effect of reaction temperature, CO pressure, methanol dosage, catalyst dosage and reaction time on catalytic reaction was investigated. The test results revealed that this reaction was greatly affected by reaction temperature, but it was not significantly affected by the CO pressure, the methanol dosage, the catalyst dosage and the reaction time. Under the optimal conditions, the conversion of ethylene oxide was equal to 92.24%, while the selectivity and yield of methyl 3-hydroxypropanoate reached 88.99% and 84.35%, respectively.展开更多
It has been an important project in the field of biochemistry to search for a seriesof synthetic compounds which have good abilities of carrying oxygen at room temperatureand simulating the hemoglobin’s function of c...It has been an important project in the field of biochemistry to search for a seriesof synthetic compounds which have good abilities of carrying oxygen at room temperatureand simulating the hemoglobin’s function of cooperative binding to oxygen. Uemori et al.and Tabushi et al. have reported that some dicobat(Ⅱ) diporphyrins have thecooperative effect of binding oxygn in organic solution below 0℃, the Hill coefficients areabout 1.0--1.5. We have reported the thermodynamics of a dicobalt(Ⅱ)展开更多
A mixed-valent high spin (μ-hydroxo)dicobalt(Ⅱ/Ⅲ) complex bearing N,N′-bis(5-tertbutylsalicylidene)-1,2-diaminobenzene(Salophen^(tBu)) ligand was synthesized by reacting (Salophen^(tBu))Co(Ⅱ)(Py) with O_(2) at lo...A mixed-valent high spin (μ-hydroxo)dicobalt(Ⅱ/Ⅲ) complex bearing N,N′-bis(5-tertbutylsalicylidene)-1,2-diaminobenzene(Salophen^(tBu)) ligand was synthesized by reacting (Salophen^(tBu))Co(Ⅱ)(Py) with O_(2) at low temperature.This complex was isolated and structurally characterized by single crystal X-ray diffraction and infrared spectrum.Magnetic measurement showed a quartet ground state for this complex at room temperature,which was also supported by electron paramagnetic resonance (EPR)characterization.Computational investigations indicated the deviation of the equatorial N_(2)O_(2) coordination geometry around the Co(Ⅱ) center from plane stabilized the quartet state.The end-on type O_(2) adduct of this (μ-hydroxo)dicobalt(Ⅱ/Ⅲ) complex was isolated as dark-brown crystals and structurally and spectroscopically characterized.EPR measurement of this compound in solid state at room temperature presented an isotropic singlet at g~2,revealing the superoxide-like electronic feature of the coordinated O_(2) and was in line with the calculation results.The reactivity of the Co(Ⅲ)-O_(2) complex with N-hydroxyphthalimide,which can act as hydrogen atom donor,was also examined.展开更多
Eight new complexes with the formula [PhC_2C(OH)R^2R^2]Co_2(CO)_6 were prepared from phenyl substituted propargylic alcohols and dicobalt octacarbonyl.The reactions of these propargylio alcohol complexes with active m...Eight new complexes with the formula [PhC_2C(OH)R^2R^2]Co_2(CO)_6 were prepared from phenyl substituted propargylic alcohols and dicobalt octacarbonyl.The reactions of these propargylio alcohol complexes with active methylene compounds,2,4-pentanedione or ethyl acetoacetate,in the presnce of an acid,HBF_4(40％)+P_2O_5(in excess)or BF_3·Et_2O,at room temperature in dichlorome- thane were investigated.From the 1-alkyl substituted tertiary propargylic alcohol complexes,three new conjugated ene-yne complexes produced by intramolecular dehydration reaction were isolated in high yields(82—95％).On the other hand,four new alkylated complexes were obtained with satisfactory yields(44—66％)from the secondary propargylic alcohol complexes.The influence of other acids,phosphorus pentoxide and polyphosphoric acid,on both dehydration reaction and alkylated reaction was also studied.展开更多
This paper reports the thermodynamics of reversible oxygen binding to a dicobalt di(meso-tetraphenylporphyrin) linked by a diamido- aliphatic chain in N, Ndimethylformamide solution. Thermodynamic values(standard stat...This paper reports the thermodynamics of reversible oxygen binding to a dicobalt di(meso-tetraphenylporphyrin) linked by a diamido- aliphatic chain in N, Ndimethylformamide solution. Thermodynamic values(standard state 101325 Pa O2): △G (298K)=-3.1kJ mol-1, △H (298K)=-37.1kJ·mol-1, △S (298K)=-114 J.mol-1K-1,Co:O2=1:1. The ESR parameters of the dioxygen complex in DMF at 133K are as follows: g=2.000, g=2.046, A= 15G, A =22G, The pressure of dioxygen necessary for half-oxygenation of the system (P1/2 =42.7kPa at 288K) is comparable with that for cobalt substituted human hemoglobin at T state.展开更多
Cyanide is a toxin and one of the most rapidly acting fatal poisons that human being is aware. If it is not treated promptly, encountering to cyanide poison will lead to die in minutes. Cyanide avoids cellular oxygen ...Cyanide is a toxin and one of the most rapidly acting fatal poisons that human being is aware. If it is not treated promptly, encountering to cyanide poison will lead to die in minutes. Cyanide avoids cellular oxygen usage by inactivating mitochondrial cytochrome oxidase thus inhibits cellular respiration. In this case, we represent a case report describing uncommon cyanide intoxication owing to consumption of a few portion of apricot kernels and its rapid treatment with dicobalt edetate after suspection of cyanide poisoning.展开更多
文摘Thermodynamic data were determined for the reversible binding of O 2 to two compounds of dicobalt(II) di(meso tetra phenyl)porphyrin derivatives with different lengths of diamidoaliphatic bridge (abbreviated to Co 2PP 8 and Co 2PP 4) in N,N dimethylformamide at room temperature. The partial pressure of dioxygen necessary for half oxygenation ( P 1/2 ) and Hill coefficient ( n ) at 298 K were determined as follows: P 1/2 =54.2 kPa, n =2.0 for Co 2PP 8 and P 1/2 =6.8 kPa, n =1.8 for Co 2PP 4,respectively. The rate equations of reversible oxygen binding by Co 2PP 8 were determined and the reaction path was proposed. The results of thermodynamic and kinetic studies indicate that there exists strong cooperative effect during oxygenation of the compounds. The ESR observation reveals that the dioxygen complexes formed in the solutions are of superoxo (Co O - 2) type.
基金supported by the Guangdong Province Natural Science Foundation (No. 10152500002000019)the Maoming City Science and Technology Planning Project (NO.2008024)
文摘Methyl 3-hydroxypropanoate was synthesized via hydroesterification of ethylene oxide with CO in the presence of dicobalt octacarbonyl catalyst and methanol solvent. The catalyst exhibited high catalytic activity. The effect of reaction temperature, CO pressure, methanol dosage, catalyst dosage and reaction time on catalytic reaction was investigated. The test results revealed that this reaction was greatly affected by reaction temperature, but it was not significantly affected by the CO pressure, the methanol dosage, the catalyst dosage and the reaction time. Under the optimal conditions, the conversion of ethylene oxide was equal to 92.24%, while the selectivity and yield of methyl 3-hydroxypropanoate reached 88.99% and 84.35%, respectively.
基金Project supported by the Research Foundation of the State Education Commission of China.
文摘It has been an important project in the field of biochemistry to search for a seriesof synthetic compounds which have good abilities of carrying oxygen at room temperatureand simulating the hemoglobin’s function of cooperative binding to oxygen. Uemori et al.and Tabushi et al. have reported that some dicobat(Ⅱ) diporphyrins have thecooperative effect of binding oxygn in organic solution below 0℃, the Hill coefficients areabout 1.0--1.5. We have reported the thermodynamics of a dicobalt(Ⅱ)
基金the National Natural Science Foundation of China(21988101,21801044,22071122,U19B6002)Shanghai Sailing Program(18YF1401800)。
文摘A mixed-valent high spin (μ-hydroxo)dicobalt(Ⅱ/Ⅲ) complex bearing N,N′-bis(5-tertbutylsalicylidene)-1,2-diaminobenzene(Salophen^(tBu)) ligand was synthesized by reacting (Salophen^(tBu))Co(Ⅱ)(Py) with O_(2) at low temperature.This complex was isolated and structurally characterized by single crystal X-ray diffraction and infrared spectrum.Magnetic measurement showed a quartet ground state for this complex at room temperature,which was also supported by electron paramagnetic resonance (EPR)characterization.Computational investigations indicated the deviation of the equatorial N_(2)O_(2) coordination geometry around the Co(Ⅱ) center from plane stabilized the quartet state.The end-on type O_(2) adduct of this (μ-hydroxo)dicobalt(Ⅱ/Ⅲ) complex was isolated as dark-brown crystals and structurally and spectroscopically characterized.EPR measurement of this compound in solid state at room temperature presented an isotropic singlet at g~2,revealing the superoxide-like electronic feature of the coordinated O_(2) and was in line with the calculation results.The reactivity of the Co(Ⅲ)-O_(2) complex with N-hydroxyphthalimide,which can act as hydrogen atom donor,was also examined.
基金Work supported by the National Natural Science Foundation of China.
文摘Eight new complexes with the formula [PhC_2C(OH)R^2R^2]Co_2(CO)_6 were prepared from phenyl substituted propargylic alcohols and dicobalt octacarbonyl.The reactions of these propargylio alcohol complexes with active methylene compounds,2,4-pentanedione or ethyl acetoacetate,in the presnce of an acid,HBF_4(40％)+P_2O_5(in excess)or BF_3·Et_2O,at room temperature in dichlorome- thane were investigated.From the 1-alkyl substituted tertiary propargylic alcohol complexes,three new conjugated ene-yne complexes produced by intramolecular dehydration reaction were isolated in high yields(82—95％).On the other hand,four new alkylated complexes were obtained with satisfactory yields(44—66％)from the secondary propargylic alcohol complexes.The influence of other acids,phosphorus pentoxide and polyphosphoric acid,on both dehydration reaction and alkylated reaction was also studied.
文摘This paper reports the thermodynamics of reversible oxygen binding to a dicobalt di(meso-tetraphenylporphyrin) linked by a diamido- aliphatic chain in N, Ndimethylformamide solution. Thermodynamic values(standard state 101325 Pa O2): △G (298K)=-3.1kJ mol-1, △H (298K)=-37.1kJ·mol-1, △S (298K)=-114 J.mol-1K-1,Co:O2=1:1. The ESR parameters of the dioxygen complex in DMF at 133K are as follows: g=2.000, g=2.046, A= 15G, A =22G, The pressure of dioxygen necessary for half-oxygenation of the system (P1/2 =42.7kPa at 288K) is comparable with that for cobalt substituted human hemoglobin at T state.
文摘Cyanide is a toxin and one of the most rapidly acting fatal poisons that human being is aware. If it is not treated promptly, encountering to cyanide poison will lead to die in minutes. Cyanide avoids cellular oxygen usage by inactivating mitochondrial cytochrome oxidase thus inhibits cellular respiration. In this case, we represent a case report describing uncommon cyanide intoxication owing to consumption of a few portion of apricot kernels and its rapid treatment with dicobalt edetate after suspection of cyanide poisoning.
