The title compound [Co(en) 2(H 2O) 2] 2· [Mo Ⅴ 4Mo Ⅵ 4V Ⅳ 8O 40 (AsO 4)] was synthesized by hydrothermal method and its structure was determined with single crystal X ray analysis. The cluster anion is a tetra...The title compound [Co(en) 2(H 2O) 2] 2· [Mo Ⅴ 4Mo Ⅵ 4V Ⅳ 8O 40 (AsO 4)] was synthesized by hydrothermal method and its structure was determined with single crystal X ray analysis. The cluster anion is a tetracapped Keggin polyanion, which contains different coordinated cations. The crystal is monoclinic, space group C2/c with a =1.458 3(2) nm, b =2.174 07(13) nm, c =1.893 2(2) nm, β =91.532°, V =6.000 2(10) nm 3, Z =2, D c=1.452 g/cm 3, R =0.035 9, R w=0.079 8, S =1.092.展开更多
研究了白庙子斜发沸石在水热离子交换中阳离子交换容量、配位阳离子交换度及K+、N a+、C a2+离子在该矿样上的交换量.实验发现,该矿铵离子交换容量为1.73 mm o l/g,配位阳离子交换度C a2+>K+>M g2+>N a+.在铵改性矿样NH4Z上K+...研究了白庙子斜发沸石在水热离子交换中阳离子交换容量、配位阳离子交换度及K+、N a+、C a2+离子在该矿样上的交换量.实验发现,该矿铵离子交换容量为1.73 mm o l/g,配位阳离子交换度C a2+>K+>M g2+>N a+.在铵改性矿样NH4Z上K+离子属超容量交换,交换量达78.2 m g/g,对海水提钾有应用价值.在不同离子交换矿样上C a2+交换量NH4Z>N aZ>KZ>O rZ,在钠改性矿样N aZ上C a2+离子交换量可达32.4 m g/g,对硬水软化有应用价值.展开更多
A series of experiments were conducted to examine the interactive effects of an organic ligand,a competing cation, and pH on the dissolution of zinc (Zn) from three California soils,Maymen sandy loam,Merced clay,and Y...A series of experiments were conducted to examine the interactive effects of an organic ligand,a competing cation, and pH on the dissolution of zinc (Zn) from three California soils,Maymen sandy loam,Merced clay,and Yolo clay loam.The concentrations of soluble Zn of the three soils were low in a background solution of Ca(NO3)2.Citric acid,a common organic ligand found in the rhizosphere,was effective in mobilizing Zn in these soils;its presence enhanced the concentration of Zn in soil solution by citrate forming a complex with Zn.The ability of Zn to form a complex with citric acid in the soil solution was dependent on the concentration of citric acid,pH,and the concentration of the competing cation Ca^(2+).The pH of the soil solution determined the extent of desorption of Zn in solid phase in the presence of citric acid.The amounts of Zn released from the solid phase were proportional to the concentration of citric acid and inversely proportional to the concentration of Ca(NO3)2 background solution,which supplied the competing cation Ca^(2+) for the formation of a complex with citrate.When the soil suspension was spiked with Zn,the adsorption of Zn by the soils was retarded by citric acid via the formation of the soluble Zn-citrate complex.The dissolution of Zn in the presence of citric acid was pH dependent in both adsorption and desorption processes.展开更多
Aqueous precursors provide an alluring approach for low-cost and environmentally friendly production of earth-abundant Cu2ZnSn(S,Se)4(CZTSSe)solar cells.The key is to find an appropriate molecular agent to prepare a s...Aqueous precursors provide an alluring approach for low-cost and environmentally friendly production of earth-abundant Cu2ZnSn(S,Se)4(CZTSSe)solar cells.The key is to find an appropriate molecular agent to prepare a stable solution and optimize the coordination structure to facilitate the subsequent crystallization process.Herein,we introduce thioglycolic acid(TGA),which possesses strong coordination(SH)and hydrophilic(COOH)groups,as the agent and use deprotonation to regulate the coordination competition within the aqueous solution.Ultimately,metal cations are adequately coordinated with thiolate anions,and carboxylate anions are released to become hydrated to form an ultrastable aqueous solution.These factors have contributed to achieving CZTSSe solar cells with an efficiency as high as 12.3%(a certified efficiency of 12.0%)and providing an extremely wide time window for precursor storage and usage.This work represents significant progress in the non-toxic solution fabrication of CZTSSe solar cells and holds great potential for the development of CZTSSe and other metal sulfide solar cells.展开更多
Two new coordination polymers [ZnLI2]∞ （1） and [CdLI2]∞ （2） （L： 3,6-di-（1,2,4-triazole-l-yl）-N-hexylcarbazole） were syn- thesized and their crystal structures were determined by single-crystal X-ray diffrac...Two new coordination polymers [ZnLI2]∞ （1） and [CdLI2]∞ （2） （L： 3,6-di-（1,2,4-triazole-l-yl）-N-hexylcarbazole） were syn- thesized and their crystal structures were determined by single-crystal X-ray diffraction techniques. Complexes are both constructed with the helical chains along the 2l screw axis. The coordination bond, C-H...I weak interactions and π-π interactions play significant roles in constructing their 3D or 2D frameworks. Two different DFT calculations are performed for the weak interactions between the helical chains of the three different coordination polymers （[ZnLI2]∞[CdLI2]∞, and the reported [HgLI2]∞）. The results reveal that weak interactions play important roles in these supramolecular systems of helical configuration, namely, the trend is the shorter H…I distance and π-π stacking distance, the stronger the intermolecular interactions. The photoluminescence of the complexes measured in the solid state at room temperature indicates that the emission intensity varies extensively, which can be rationalized by the heavy atom effect. helical configuration, weak interactions, DFT calculations, photoluminescence展开更多
In this paper, we used density functional theory(DFT) computations to study the mechanisms of the hydroacylation reaction of an aldehyde with an alkene catalyzed by Wilkinson's catalyst and an organic catalyst 2-a...In this paper, we used density functional theory(DFT) computations to study the mechanisms of the hydroacylation reaction of an aldehyde with an alkene catalyzed by Wilkinson's catalyst and an organic catalyst 2-amino-3-picoline in cationic and neutral systems. An aldehyde's hydroacylation includes three stages: the C–H activation to form rhodium hydride(stage I), the alkene insertion into the Rh–H bond to give the Rh-alkyl complex(stage II), and the C–C bond formation(stage III). Possible pathways for the hydroacylation originated from the trans and cis isomers of the catalytic cycle. In this paper, we discussed the neutral and cationic pathways. The rate-determining step is the C–H activation step in neutral system but the reductive elimination step in the cationic system. Meanwhile, the alkyl group migration-phosphine ligand coordination pathway is more favorable than the phosphine ligand coordination-alkyl group migration pathway in the C–C formation stage. Furthermore, the calculated results imply that an electron-withdrawing group may decrease the energy barrier of the C–H activation in the benzaldehyde hydroacylation.展开更多
文摘The title compound [Co(en) 2(H 2O) 2] 2· [Mo Ⅴ 4Mo Ⅵ 4V Ⅳ 8O 40 (AsO 4)] was synthesized by hydrothermal method and its structure was determined with single crystal X ray analysis. The cluster anion is a tetracapped Keggin polyanion, which contains different coordinated cations. The crystal is monoclinic, space group C2/c with a =1.458 3(2) nm, b =2.174 07(13) nm, c =1.893 2(2) nm, β =91.532°, V =6.000 2(10) nm 3, Z =2, D c=1.452 g/cm 3, R =0.035 9, R w=0.079 8, S =1.092.
文摘研究了白庙子斜发沸石在水热离子交换中阳离子交换容量、配位阳离子交换度及K+、N a+、C a2+离子在该矿样上的交换量.实验发现,该矿铵离子交换容量为1.73 mm o l/g,配位阳离子交换度C a2+>K+>M g2+>N a+.在铵改性矿样NH4Z上K+离子属超容量交换,交换量达78.2 m g/g,对海水提钾有应用价值.在不同离子交换矿样上C a2+交换量NH4Z>N aZ>KZ>O rZ,在钠改性矿样N aZ上C a2+离子交换量可达32.4 m g/g,对硬水软化有应用价值.
基金Project supported by the Research Council of Norway (No.420466).
文摘A series of experiments were conducted to examine the interactive effects of an organic ligand,a competing cation, and pH on the dissolution of zinc (Zn) from three California soils,Maymen sandy loam,Merced clay,and Yolo clay loam.The concentrations of soluble Zn of the three soils were low in a background solution of Ca(NO3)2.Citric acid,a common organic ligand found in the rhizosphere,was effective in mobilizing Zn in these soils;its presence enhanced the concentration of Zn in soil solution by citrate forming a complex with Zn.The ability of Zn to form a complex with citric acid in the soil solution was dependent on the concentration of citric acid,pH,and the concentration of the competing cation Ca^(2+).The pH of the soil solution determined the extent of desorption of Zn in solid phase in the presence of citric acid.The amounts of Zn released from the solid phase were proportional to the concentration of citric acid and inversely proportional to the concentration of Ca(NO3)2 background solution,which supplied the competing cation Ca^(2+) for the formation of a complex with citrate.When the soil suspension was spiked with Zn,the adsorption of Zn by the soils was retarded by citric acid via the formation of the soluble Zn-citrate complex.The dissolution of Zn in the presence of citric acid was pH dependent in both adsorption and desorption processes.
基金supported by the National Natural Science Foundation of China(51961165108,51421002,51972332 and 51627803)。
文摘Aqueous precursors provide an alluring approach for low-cost and environmentally friendly production of earth-abundant Cu2ZnSn(S,Se)4(CZTSSe)solar cells.The key is to find an appropriate molecular agent to prepare a stable solution and optimize the coordination structure to facilitate the subsequent crystallization process.Herein,we introduce thioglycolic acid(TGA),which possesses strong coordination(SH)and hydrophilic(COOH)groups,as the agent and use deprotonation to regulate the coordination competition within the aqueous solution.Ultimately,metal cations are adequately coordinated with thiolate anions,and carboxylate anions are released to become hydrated to form an ultrastable aqueous solution.These factors have contributed to achieving CZTSSe solar cells with an efficiency as high as 12.3%(a certified efficiency of 12.0%)and providing an extremely wide time window for precursor storage and usage.This work represents significant progress in the non-toxic solution fabrication of CZTSSe solar cells and holds great potential for the development of CZTSSe and other metal sulfide solar cells.
基金supported by the National Natural Science Foundation of China (20771001, 50703001, 21071001)Education Committee of Anhui Province (KJ2009A52, KJ2010A30)+2 种基金the Team for Scientific Innovation Foundation of Anhui Province (2006KJ007TD)Ministry of Education and Person with Ability Foundation of Anhui University, Science and Techno- logical Fund of Anhui Province for Outstanding Youth (10040606Y22)the 211 Project of Anhui University
文摘Two new coordination polymers [ZnLI2]∞ （1） and [CdLI2]∞ （2） （L： 3,6-di-（1,2,4-triazole-l-yl）-N-hexylcarbazole） were syn- thesized and their crystal structures were determined by single-crystal X-ray diffraction techniques. Complexes are both constructed with the helical chains along the 2l screw axis. The coordination bond, C-H...I weak interactions and π-π interactions play significant roles in constructing their 3D or 2D frameworks. Two different DFT calculations are performed for the weak interactions between the helical chains of the three different coordination polymers （[ZnLI2]∞[CdLI2]∞, and the reported [HgLI2]∞）. The results reveal that weak interactions play important roles in these supramolecular systems of helical configuration, namely, the trend is the shorter H…I distance and π-π stacking distance, the stronger the intermolecular interactions. The photoluminescence of the complexes measured in the solid state at room temperature indicates that the emission intensity varies extensively, which can be rationalized by the heavy atom effect. helical configuration, weak interactions, DFT calculations, photoluminescence
基金supported by the National Natural Science Foundation of China(21373023,21203006,21072018)
文摘In this paper, we used density functional theory(DFT) computations to study the mechanisms of the hydroacylation reaction of an aldehyde with an alkene catalyzed by Wilkinson's catalyst and an organic catalyst 2-amino-3-picoline in cationic and neutral systems. An aldehyde's hydroacylation includes three stages: the C–H activation to form rhodium hydride(stage I), the alkene insertion into the Rh–H bond to give the Rh-alkyl complex(stage II), and the C–C bond formation(stage III). Possible pathways for the hydroacylation originated from the trans and cis isomers of the catalytic cycle. In this paper, we discussed the neutral and cationic pathways. The rate-determining step is the C–H activation step in neutral system but the reductive elimination step in the cationic system. Meanwhile, the alkyl group migration-phosphine ligand coordination pathway is more favorable than the phosphine ligand coordination-alkyl group migration pathway in the C–C formation stage. Furthermore, the calculated results imply that an electron-withdrawing group may decrease the energy barrier of the C–H activation in the benzaldehyde hydroacylation.
