The H2Ge=Ge：, as well as and its derivatives （X2Ge=Ge：, X=H, Me, F, C1, Br, Ph, At, ...） is a kind of new species. Its cycloaddition reactions is a new area for the study of germylene chemistry. The mechanism of t...The H2Ge=Ge：, as well as and its derivatives （X2Ge=Ge：, X=H, Me, F, C1, Br, Ph, At, ...） is a kind of new species. Its cycloaddition reactions is a new area for the study of germylene chemistry. The mechanism of the cycloaddition reaction between singlet Me2Ge=Ge： and acetaldehyde was investigated with the B3LYP/6-31G＊ method in this work. From the potential energy profile, it could be predicted that the reaction has one dominant reaction pathway. The reaction rule is that the two reactants firstly form a four-membered Ge-heterocyclic ring germylene through the [2＋2] cycloaddition reaction. Because of the 4p unoccupied orbital of Ge： atom in the four-membered Ge-heterocyclic ring germylene and the ~ orbital of acetaldehyde forming a r^--~p donor-acceptor bond, the four-membered Ge-heterocyclic ring germylene further combines with acetaldehyde to form an intermedi- ate. Because the Ge atom in intermediate happens sp3 hybridization after transition state, then, intermediate isomerizes to a spiro-Ge-heterocyclic ring compound via a transition state. The research result indicates the laws of cycloaddition reaction between Me2Ge=Ge： and ac- etaldehyde, and lays the theory foundation of the cycloaddition reaction between H2Ge=Ge： and its derivatives （X2Ge=Ge：, X=H, Me, F, C1, Br, Ph, At, ...） and asymmetric ^-bonded compounds, which are significant for the synthesis of small-ring and spiro-Ge-heterocyclic ring compounds.展开更多
H2Ge=Si： and its derivatives （X2Ge=Si：, X=H, Me, F, C1, Br, Ph, Ar, ...） are new species. Its cycloaddition reactions are new area for the study of silylene chemistry. The cycloaddition reaction mechanism of singl...H2Ge=Si： and its derivatives （X2Ge=Si：, X=H, Me, F, C1, Br, Ph, Ar, ...） are new species. Its cycloaddition reactions are new area for the study of silylene chemistry. The cycloaddition reaction mechanism of singlet H2Ge=Si： and formaldehyde has been investigated with the MP2/aug-cc-pVDZ method. From the potential energy profile, it could be predicted that the reaction has one dominant reaction pathway. The reaction rule is that two reactants firstly form a four-membered Ge-heterocyclic ring silylene through the [2＋2] cycloaddition reaction. Because of the 3p unoccupied orbital of Si： atom in the four-membered Ge-heterocyclic ring silylene and the π orbital of formaldehyde forming a π--p donor-acceptor bond, the four-membered Ge-heterocyclic ring silylene further combines with formaldehyde to form an intermediate. Because the Si： atom in the intermediate undergoes sp3 hybridization after transition state, then the intermediate isomerizes to a spiro-Si-heterocyclic ring compound involving Ge via a transition state. The result indicates the laws of cycloaddition reaction between H2Ge=Si： or its derivatives （X2Ge=Si：, X=H, Me, F, Cl, Br, Ph, Ar, ...） and asymmetric π-bonded compounds are significant for the synthesis of small-ring involving Si and Ge and spiro-Si-heterocyclic ring compounds involving Ge.展开更多
A series of novel cobalt carbonyl ionic liquids based on1,1,3,3‐tetra‐alkyl‐guanidine,such as[1,1‐dimethyl‐3,3‐diethylguanidinium][Co(CO)4](3a),[1,1‐dimethyl‐3,3‐dibutylguanidinium][Co(CO)4](3b),[1,1‐dimethy...A series of novel cobalt carbonyl ionic liquids based on1,1,3,3‐tetra‐alkyl‐guanidine,such as[1,1‐dimethyl‐3,3‐diethylguanidinium][Co(CO)4](3a),[1,1‐dimethyl‐3,3‐dibutylguanidinium][Co(CO)4](3b),[1,1‐dimethyl‐3,3‐tetramethyleneguanidinium][Co(CO)4](3c),and[1,1‐dimethyl‐3,3‐pentamethyleneguanidinium][Co(CO)4](3d),were synthesized in good yields and were also characterized using infrared spectroscopy,ultraviolet‐visible spectroscopy,1H nuclear magnetic resonance(NMR)spectroscopy,13C NMR spectroscopy,high‐resolution mass spectrometry,differential scanning calorimetry,and thermogravimetric analysis.The four compounds exhibited high thermal and chemical stability.In addition,the catalytic performance of these compounds was investigated in the carbonylation of epoxides,with3a exhibiting the best catalytic activity without the aid of a base as the additive.The catalyst could be reused at least six times without significant decreases of the selectivity or conversion rate.Moreover,the catalyst system exhibited good tolerance with terminal epoxides bearing alkyl,alkenyl,aryl,alkoxy,and chloromethyl functional groups.展开更多
We tested the utility of chemical marking techniques in the juvenile black rockfish Sebastes schlegelii. Juveniles （30-40 mm total length） were immersed in a range of tetracycline hydrochloride （TC） solutions at c...We tested the utility of chemical marking techniques in the juvenile black rockfish Sebastes schlegelii. Juveniles （30-40 mm total length） were immersed in a range of tetracycline hydrochloride （TC） solutions at concentrations ranging from 300 to 500 mg/L, and alizarin complexone （ALC） solutions at concentrations ranging from 200 to 400 mg/L in filtered sea water （salinity of 30） for 24 h, respectively. Otoliths （sagittae, asteriscus）, scales, fin rays （dorsal, pectoral, ventral, anal, and caudal fin rays）, and fin spines （dorsal, ventral, and anal fin spines） were sampled and used to detect fluorescent marks after a 60-day growth experiment. With the exception of 300 mg/L TC, acceptable marks were produced in the otoliths and fin spines by all concentrations of TC and ALC. In particular, we observed clearly visible marks in the sagittae, asteriscus, and fin spines under normal light at concentrations of200~00 mg/L, 250-400 mg/L, and 250-400 mg/L ALC, respectively. Scales and fin rays had acceptable marks at much higher concentrations （_〉350 mg/L TC, 〉250 mg/L ALC for scales and _〉350 mg/L TC, 〉300 mg/L ALC for fin rays）. The best mark quality （i.e., acceptable marks were observed in all sampled structures after immersion marking） were obtained following immersion in TC at between 350-500 rag/L, and ALC between 300-400 mg/L. In addition, there was no significant difference in survival and growth of TC and ALC marked fish compared to their controls up to 60 days post-marking （P〉0.05）.展开更多
A new rare earth complex Eu（III） （TTA）2（MA）2Phen · H2O was synthesized and characterized by element analysis, FTIR, UV, thermal analysis, and fluorescence spectra. The strong fluorescence and high thermal s...A new rare earth complex Eu（III） （TTA）2（MA）2Phen · H2O was synthesized and characterized by element analysis, FTIR, UV, thermal analysis, and fluorescence spectra. The strong fluorescence and high thermal stability of Eu（III） （TTA）2（MA）2Phen · H2O were used to modify resin. The copolymer containing europium was prepared by copolymerization of Eu（III） and styrene/α- methylacrylic acid, and characterized by FTIR and fluorescence spectra. The fluorescence spectra showed that the copolymer was a sort of materials with good fluorescence property, and the higher fluorescence intensity came from the higher europium content.展开更多
The kinetics of bulk polymerization of octamethylcyclotetrasiloxane under acid circumstance is studied. A kinetic model is put forward and kinetic parameters are obtained through optimization.
The complex [(η5-CH3C5H4)2Tb(μ-Cl) (THF)]2, has been studied by X-ray crystallography. The crystal is orthorhombic , space group Phcn with a= 20.414(2),b=9. 548(1),c=16.390(6)A.V=3194.9(6) A3, Mr=849.46,Z=4,Dc=1.77 ...The complex [(η5-CH3C5H4)2Tb(μ-Cl) (THF)]2, has been studied by X-ray crystallography. The crystal is orthorhombic , space group Phcn with a= 20.414(2),b=9. 548(1),c=16.390(6)A.V=3194.9(6) A3, Mr=849.46,Z=4,Dc=1.77 g/cm3, F(000)=1664,μ=46.37 cm-1.The Tb3+ ion is coordinated by two CH3C5H4 groups, two chloride ions and one oxygen atom from tetrahydrofuran to form a distorted trigonal bipyramidal geometry. Two bridging Tb-Cl bond lengths are 2. 716(2) and 2.790(2)A,respectively.The Tb-O (THF) and average Tb-C(CH3C5H4) bond lengths are 2.559(6) and 2.670(4)A,respectively.展开更多
The crystal structure of copper(Ⅱ) complex with a new 14-membered tetraazamacrocyclic ligand 5,5,7,12,12,14-hexamethy1-1,4,8,11-tetraazacyclotetradecane-N'N'-diacetic acid,[CuC16N4H34(CH2COO)(CH2COOH)]·C...The crystal structure of copper(Ⅱ) complex with a new 14-membered tetraazamacrocyclic ligand 5,5,7,12,12,14-hexamethy1-1,4,8,11-tetraazacyclotetradecane-N'N'-diacetic acid,[CuC16N4H34(CH2COO)(CH2COOH)]·ClO4·0. 5HCIO4·1. 5H2O was determined. Crystallographic data: Mr = 639.22,orthorhombic, space group Pcnb with a=11.743(4),b=16.446(2),c=29.611 (4) A,Z=8,V=5726(3) A3, Dc=1.482 g·cm-3, F(000)=1344,μ=9. 64 cm-1,R=0.063,and Rw=0.067 for 2386 reflections with I≥3σ(I). The structure shows an unusual configuration in which two carboxyl groups were bonded to two neighboring nitrogen atoms of the macrocycle, N1 and N4, and six methyl substituents occur on one side of the macrocycle, while two carboxyl groups on the other side, and central copper(Ⅱ) ion forms a five-coordinated geometry.展开更多
An efficient synthesis of tetrahydrofuro[3,2-b]quinolin-2（3H）-ones from α-angelica lactone and 2-aminobenzaldehydes via a tandem Aldol-Michael addition is described. The reactions were carried out using DBU as the ...An efficient synthesis of tetrahydrofuro[3,2-b]quinolin-2（3H）-ones from α-angelica lactone and 2-aminobenzaldehydes via a tandem Aldol-Michael addition is described. The reactions were carried out using DBU as the base in i-Pr OH at 0 ℃, affording tetrahydrofuro[3,2-b]quinolin-2（3H）-ones in moderate to good yields.展开更多
Zinc halide-complexed alkyl-bridged bi-heterocycles were obtained as zwitterions from the Click reaction of a series of N-cyanoalkyl-N-alkylimidazolium halide ionic liquids with sodium azide. Reaction optimization sho...Zinc halide-complexed alkyl-bridged bi-heterocycles were obtained as zwitterions from the Click reaction of a series of N-cyanoalkyl-N-alkylimidazolium halide ionic liquids with sodium azide. Reaction optimization showed fast reaction times and milder conditions compared to conventional Click syntheses from neutral nitriles.展开更多
文摘The H2Ge=Ge：, as well as and its derivatives （X2Ge=Ge：, X=H, Me, F, C1, Br, Ph, At, ...） is a kind of new species. Its cycloaddition reactions is a new area for the study of germylene chemistry. The mechanism of the cycloaddition reaction between singlet Me2Ge=Ge： and acetaldehyde was investigated with the B3LYP/6-31G＊ method in this work. From the potential energy profile, it could be predicted that the reaction has one dominant reaction pathway. The reaction rule is that the two reactants firstly form a four-membered Ge-heterocyclic ring germylene through the [2＋2] cycloaddition reaction. Because of the 4p unoccupied orbital of Ge： atom in the four-membered Ge-heterocyclic ring germylene and the ~ orbital of acetaldehyde forming a r^--~p donor-acceptor bond, the four-membered Ge-heterocyclic ring germylene further combines with acetaldehyde to form an intermedi- ate. Because the Ge atom in intermediate happens sp3 hybridization after transition state, then, intermediate isomerizes to a spiro-Ge-heterocyclic ring compound via a transition state. The research result indicates the laws of cycloaddition reaction between Me2Ge=Ge： and ac- etaldehyde, and lays the theory foundation of the cycloaddition reaction between H2Ge=Ge： and its derivatives （X2Ge=Ge：, X=H, Me, F, C1, Br, Ph, At, ...） and asymmetric ^-bonded compounds, which are significant for the synthesis of small-ring and spiro-Ge-heterocyclic ring compounds.
文摘H2Ge=Si： and its derivatives （X2Ge=Si：, X=H, Me, F, C1, Br, Ph, Ar, ...） are new species. Its cycloaddition reactions are new area for the study of silylene chemistry. The cycloaddition reaction mechanism of singlet H2Ge=Si： and formaldehyde has been investigated with the MP2/aug-cc-pVDZ method. From the potential energy profile, it could be predicted that the reaction has one dominant reaction pathway. The reaction rule is that two reactants firstly form a four-membered Ge-heterocyclic ring silylene through the [2＋2] cycloaddition reaction. Because of the 3p unoccupied orbital of Si： atom in the four-membered Ge-heterocyclic ring silylene and the π orbital of formaldehyde forming a π--p donor-acceptor bond, the four-membered Ge-heterocyclic ring silylene further combines with formaldehyde to form an intermediate. Because the Si： atom in the intermediate undergoes sp3 hybridization after transition state, then the intermediate isomerizes to a spiro-Si-heterocyclic ring compound involving Ge via a transition state. The result indicates the laws of cycloaddition reaction between H2Ge=Si： or its derivatives （X2Ge=Si：, X=H, Me, F, Cl, Br, Ph, Ar, ...） and asymmetric π-bonded compounds are significant for the synthesis of small-ring involving Si and Ge and spiro-Si-heterocyclic ring compounds involving Ge.
基金supported by the National Natural Science Foundation of China(21373248,21673260,21133011)~~
文摘A series of novel cobalt carbonyl ionic liquids based on1,1,3,3‐tetra‐alkyl‐guanidine,such as[1,1‐dimethyl‐3,3‐diethylguanidinium][Co(CO)4](3a),[1,1‐dimethyl‐3,3‐dibutylguanidinium][Co(CO)4](3b),[1,1‐dimethyl‐3,3‐tetramethyleneguanidinium][Co(CO)4](3c),and[1,1‐dimethyl‐3,3‐pentamethyleneguanidinium][Co(CO)4](3d),were synthesized in good yields and were also characterized using infrared spectroscopy,ultraviolet‐visible spectroscopy,1H nuclear magnetic resonance(NMR)spectroscopy,13C NMR spectroscopy,high‐resolution mass spectrometry,differential scanning calorimetry,and thermogravimetric analysis.The four compounds exhibited high thermal and chemical stability.In addition,the catalytic performance of these compounds was investigated in the carbonylation of epoxides,with3a exhibiting the best catalytic activity without the aid of a base as the additive.The catalyst could be reused at least six times without significant decreases of the selectivity or conversion rate.Moreover,the catalyst system exhibited good tolerance with terminal epoxides bearing alkyl,alkenyl,aryl,alkoxy,and chloromethyl functional groups.
基金Supported by the Special Fund for Agro-Scientific Research in the Public Interest(No.201003068)the National Natural Science Foundation of China(Nos.31172447,41176117)
文摘We tested the utility of chemical marking techniques in the juvenile black rockfish Sebastes schlegelii. Juveniles （30-40 mm total length） were immersed in a range of tetracycline hydrochloride （TC） solutions at concentrations ranging from 300 to 500 mg/L, and alizarin complexone （ALC） solutions at concentrations ranging from 200 to 400 mg/L in filtered sea water （salinity of 30） for 24 h, respectively. Otoliths （sagittae, asteriscus）, scales, fin rays （dorsal, pectoral, ventral, anal, and caudal fin rays）, and fin spines （dorsal, ventral, and anal fin spines） were sampled and used to detect fluorescent marks after a 60-day growth experiment. With the exception of 300 mg/L TC, acceptable marks were produced in the otoliths and fin spines by all concentrations of TC and ALC. In particular, we observed clearly visible marks in the sagittae, asteriscus, and fin spines under normal light at concentrations of200~00 mg/L, 250-400 mg/L, and 250-400 mg/L ALC, respectively. Scales and fin rays had acceptable marks at much higher concentrations （_〉350 mg/L TC, 〉250 mg/L ALC for scales and _〉350 mg/L TC, 〉300 mg/L ALC for fin rays）. The best mark quality （i.e., acceptable marks were observed in all sampled structures after immersion marking） were obtained following immersion in TC at between 350-500 rag/L, and ALC between 300-400 mg/L. In addition, there was no significant difference in survival and growth of TC and ALC marked fish compared to their controls up to 60 days post-marking （P〉0.05）.
基金Research Topics of Shanghai Scientific Committee,China (No.065458025)
文摘A new rare earth complex Eu（III） （TTA）2（MA）2Phen · H2O was synthesized and characterized by element analysis, FTIR, UV, thermal analysis, and fluorescence spectra. The strong fluorescence and high thermal stability of Eu（III） （TTA）2（MA）2Phen · H2O were used to modify resin. The copolymer containing europium was prepared by copolymerization of Eu（III） and styrene/α- methylacrylic acid, and characterized by FTIR and fluorescence spectra. The fluorescence spectra showed that the copolymer was a sort of materials with good fluorescence property, and the higher fluorescence intensity came from the higher europium content.
文摘The kinetics of bulk polymerization of octamethylcyclotetrasiloxane under acid circumstance is studied. A kinetic model is put forward and kinetic parameters are obtained through optimization.
文摘The complex [(η5-CH3C5H4)2Tb(μ-Cl) (THF)]2, has been studied by X-ray crystallography. The crystal is orthorhombic , space group Phcn with a= 20.414(2),b=9. 548(1),c=16.390(6)A.V=3194.9(6) A3, Mr=849.46,Z=4,Dc=1.77 g/cm3, F(000)=1664,μ=46.37 cm-1.The Tb3+ ion is coordinated by two CH3C5H4 groups, two chloride ions and one oxygen atom from tetrahydrofuran to form a distorted trigonal bipyramidal geometry. Two bridging Tb-Cl bond lengths are 2. 716(2) and 2.790(2)A,respectively.The Tb-O (THF) and average Tb-C(CH3C5H4) bond lengths are 2.559(6) and 2.670(4)A,respectively.
文摘The crystal structure of copper(Ⅱ) complex with a new 14-membered tetraazamacrocyclic ligand 5,5,7,12,12,14-hexamethy1-1,4,8,11-tetraazacyclotetradecane-N'N'-diacetic acid,[CuC16N4H34(CH2COO)(CH2COOH)]·ClO4·0. 5HCIO4·1. 5H2O was determined. Crystallographic data: Mr = 639.22,orthorhombic, space group Pcnb with a=11.743(4),b=16.446(2),c=29.611 (4) A,Z=8,V=5726(3) A3, Dc=1.482 g·cm-3, F(000)=1344,μ=9. 64 cm-1,R=0.063,and Rw=0.067 for 2386 reflections with I≥3σ(I). The structure shows an unusual configuration in which two carboxyl groups were bonded to two neighboring nitrogen atoms of the macrocycle, N1 and N4, and six methyl substituents occur on one side of the macrocycle, while two carboxyl groups on the other side, and central copper(Ⅱ) ion forms a five-coordinated geometry.
基金National Natural Science Foundation of China(Grant No.21372019)
文摘An efficient synthesis of tetrahydrofuro[3,2-b]quinolin-2（3H）-ones from α-angelica lactone and 2-aminobenzaldehydes via a tandem Aldol-Michael addition is described. The reactions were carried out using DBU as the base in i-Pr OH at 0 ℃, affording tetrahydrofuro[3,2-b]quinolin-2（3H）-ones in moderate to good yields.
基金supported by the US Air Force Office of Scientific Research (F49550-10-1-0521)
文摘Zinc halide-complexed alkyl-bridged bi-heterocycles were obtained as zwitterions from the Click reaction of a series of N-cyanoalkyl-N-alkylimidazolium halide ionic liquids with sodium azide. Reaction optimization showed fast reaction times and milder conditions compared to conventional Click syntheses from neutral nitriles.
