Low-cost and flexible solid polymer electrolytes are promising in all-solid-state Li-metal batteries with high energy density and safety.However,both the low room-temperature ionic conductivities and the small Li^(+)t...Low-cost and flexible solid polymer electrolytes are promising in all-solid-state Li-metal batteries with high energy density and safety.However,both the low room-temperature ionic conductivities and the small Li^(+)transference number of these electrolytes significantly increase the internal resistance and overpotential of the battery.Here,we introduce Gd-doped CeO_(2) nanowires with large surface area and rich surface oxygen vacancies to the polymer electrolyte to increase the interaction between Gd-doped CeO_(2) nanowires and polymer electrolytes,which promotes the Li-salt dissociation and increases the concentration of mobile Li ions in the composite polymer electrolytes.The optimized composite polymer electrolyte has a high Li-ion conductivity of 5×10^(-4)4 S cm^(-1) at 30℃ and a large Li+transference number of 0.47.Moreover,the composite polymer electrolytes have excellent compatibility with the metallic lithium anode and high-voltage LiNi_(0.8)Mn _(0.1)Co_(0.1)O_(2)(NMC)cathode,providing the stable cycling of all-solid-state batteries at high current densities.展开更多
Janus amphiphilic polymer nanosheets(JAPNs)with anisotropic morphology and distinctive perfor-mance have aroused widespread interest.However,due to the difficulty in synthesis and poor dispersion stability,JAPNs have ...Janus amphiphilic polymer nanosheets(JAPNs)with anisotropic morphology and distinctive perfor-mance have aroused widespread interest.However,due to the difficulty in synthesis and poor dispersion stability,JAPNs have been scarcely reported in the field of enhancing oil recovery(EOR).Herein,a kind of organic-based flexible JAPNs was prepared by paraffin emulsion methods.The lateral sizes of JAPNs were ranging from hundreds of nanometers to several micrometers and the thickness was about 3 nm.The organic-based nanosheets were equipped with remarkably flexible structures,which could improve their injection performance.The dispersion and interfacial properties of JAPNs were studied systematically.By modification of crosslinking agent containing multiple amino groups,the JAPNs had excellent hydro-philicity and salt resistance compared with conventional inorganic or composite nanosheets.The settling time of nanosuspension with NaCl and CaCl_(2) at a low salinity of 1000 mg/L was over 240 h.The value could also remain 124 h under the salinity of 10,000 mg/L NaCl.With the dual functionalities of Janus amphiphilic nature and nanoparticles'Pickering effect,JAPNs could change rock wettability and form emulsions as"colloidal surfactants",In particular,a new technology called optical microrheology was pioneered to explore the destabilization state of nanosuspensions for the first time.Since precipitation lagged behind aggregation,especially for stable suspension systems,the onset of the unstable behavior was difficult to be detected by conventional methods,which should be the indicator of reduced effec-tiveness for nanofluid products.In addition,the oil displacement experiments demonstrated that the JAPNs could enhance oil recovery by 17.14%under an ultra-low concentration of 0.005%and were more suitable for low permeability cores.The findings can help for a better understanding of the material preparation of polymer nanosheets.We also hope that this study could shed more light on the nano-flooding technology for EOR.展开更多
Combining photocatalytic organic reactions with CO_(2)reduction is an efficient solar energy utilization mode,but it is still limited by the organic species that can be matched and the low conversion.Herein,ultrathin ...Combining photocatalytic organic reactions with CO_(2)reduction is an efficient solar energy utilization mode,but it is still limited by the organic species that can be matched and the low conversion.Herein,ultrathin organic polymer with p-πconjugated structure(TPP)was rationally designed and prepared,and showed a high yield of CO(15.2 mmol g^(-1))and conversion of SAS coupled products(100%),far exceeding the organic polymer with P=O structure.The enhanced photoredox activity of TPP is ascribed to the orbital interaction between the p-orbital on phosphorus and theπ-orbitals of aromatic,which can accelerate the photoinduced charge carrier separation and improve the CO_(2)adsorption capacity.TPP can also be used for the dehydrocoupling of various benzyl mercaptans to the corresponding SAS bond products.This work provides a new concept for the efficient synthesis of disulfide bonds combined with CO_(2)reduction in a photoreaction system.展开更多
Molecularly imprinted polymers (MIPs) have great potential as adsorbents for selective adsorption and separation of nucleoside compounds,but effectively enhancing the affinity of recognition sites by adjusting the for...Molecularly imprinted polymers (MIPs) have great potential as adsorbents for selective adsorption and separation of nucleoside compounds,but effectively enhancing the affinity of recognition sites by adjusting the forces between template molecules and functional monomers remains an important challenge.In this work,a surface imprinting strategy was used to construct bowl-shaped molecularly imprinted composite sorbents (BHPN@MIPs) based on polydopamine (PDA) particles and have achieved selective separation and purification of 2'-deoxyadenosine (dA).Where by the base complementary pairing interaction of the combined template molecule d A and the pyrimidine functional monomer can enhance the preassembly force,and the hydrophilic bowl-shaped PDA can provide a larger storage space contact efficiency of d A in the test solution,causing the site utilization much higher and improving the kinetic adsorption performance.The equilibrium adsorption time and maximum adsorption capacity of60 min and 328.45μmol·g^(-1)were observed by static adsorption experiments,and the selectivity experimental results showed an imprinting factor IF of 1.30.After four adsorption–desorption cycles,the initial adsorption equilibrium adsorption capacity of BHPN@MIPs still retained 91.14%.By evaluating the selective adsorption of d A in spiked human serum solutions,BHPN@MIPs can be used to selectively enrich and analyze target d A in complex biological samples.展开更多
(PEO)8LiClO4-SiO2 composite polymer electrolytes(CPEs)were prepared by in-situ reaction,in which ethyl-orthosilicate(TEOS)was catalyzed by HCl and NH3.H2O,respectively.The ionic conductivity,the contact angle and the ...(PEO)8LiClO4-SiO2 composite polymer electrolytes(CPEs)were prepared by in-situ reaction,in which ethyl-orthosilicate(TEOS)was catalyzed by HCl and NH3.H2O,respectively.The ionic conductivity,the contact angle and the morphology of inorganic particles in the CPEs were investigated by AC impedance spectra,contact angle method and TEM.The conductivities of acid-catalyzed CPE and alkali-catalyzed CPE are 2.2×10-5and 1.1×10-5S/cm respectively at 30℃.The results imply that the catalyst plays an important role in the structure of in-situ preparation of SiO2,and influences the surface energy and conductivity of CPE films directly.Meanwhile,the ionic conductivity is related to the surface energy.展开更多
Two N-donor ligands mediated Cd(Ⅱ) coordination polymers, namely,[Cd(L)(dmpz)2]n (1) and {[Cd(L)(atr)05(H20)](H2O)}n (2) (H2L = methyl-3-hydroxy-5-carboxy-2-thiophenecarboxylate, dmpz = 3,5-dimethy...Two N-donor ligands mediated Cd(Ⅱ) coordination polymers, namely,[Cd(L)(dmpz)2]n (1) and {[Cd(L)(atr)05(H20)](H2O)}n (2) (H2L = methyl-3-hydroxy-5-carboxy-2-thiophenecarboxylate, dmpz = 3,5-dimethylpyrazole, and atr= 4-amino-l,2,4-triazole), havebeen produced. Their structures were characterized by single-crystal X-ray diffraction analysis,elemental analyses and infrared spectra. Compound 1 possesses a one-dimensional (1D) chainstructure and is finally extended into a three-dimensional (3D) supramolecular architecturethough hydrogen bonding interactions. Compound 2 features a two-dimensional (2D) networkwith 4-connected sql topology based on dinuclear Cd(Ⅱ) clusters as nodes, which is alsoassembled into a 3D supramolecular architecture through hydrogen bonding interactions.Furthermore, compounds 1 and 2 exhibit high thermal stabilities and intense fluorescent emissionin the solid, and can be explored as potential luminescent materials.展开更多
The effects of SN5040 and polyethylene glycol(PEG) individually and in combination on the dispersion stability of nano-TiO2 aqueous suspension were investigated by ultraviolet-visible absorption spectroscopy. The ad...The effects of SN5040 and polyethylene glycol(PEG) individually and in combination on the dispersion stability of nano-TiO2 aqueous suspension were investigated by ultraviolet-visible absorption spectroscopy. The adsorption mechanism of these dispersants was detected by zeta potential, isothermal absorption and FTIR analysis. It is found that SN5040 is superior for stabilizing nano-TiO2 in aqueous suspension to PEG in basic region, and the optimum mass fraction of SN5040 addition is 3%. In the case of NaCl addition, the optimum value increases with .the increase of NaCl concentration in the solution. When the mixture of SN5040 and PEG is employed, the antagonism appears preponderant. When SN5040 and PEG are added sequentially, the synergistic reaction takes place. The synergistic reaction can be attributed to the mechanism that PEG adsorption decreases the electronic repulsion between SN5040 molecules, which results in the increase of SN5040 adsorption density. PEG is adsorbed by the interaction with the pre-adsorbed SN5040 layer. Furthermore, the modified inner wall latex paint with well dispersed nano-YiO2 suspension is endowed with excellent ultraviolet absorption and antibacterial properties.展开更多
A rational integration of multiple reactive centers into a combined unit to facilitate their cooperative effects is a smart approach for accelerating the catalytic activity.Here,to achieve this goal,linear imidazolium...A rational integration of multiple reactive centers into a combined unit to facilitate their cooperative effects is a smart approach for accelerating the catalytic activity.Here,to achieve this goal,linear imidazolium-based ionic polymers were confined into the nanopores of mesoporous silica nanospheres anchored with homogeneously distributed zinc salts.Owing to the flexible character and the reinforced cooperative effects of the ionic liquid(nucleophile)and zinc species(Lewis acid)in the confined mesoporous structure,the resultant composite exhibited dramatically improved catalytic performance in the cycloaddition of CO2 with epoxides to form cyclic carbonates.This was in contrast to that observed for the individual catalytic components.Moreover,such a solid catalyst could be easily recovered and reused four times without a significant loss of activity.展开更多
A new coordination polymer {[Cd(C_(21)H_(14)N_6)(C_8H_4O_4)]·H_2O}_n(1) was synthesized by an elaborate design via the reaction of 3-(2,6-di(pyrazin-2-yl)pyridin-4-yl)-1H-indole(bppi),1,4-benzene-...A new coordination polymer {[Cd(C_(21)H_(14)N_6)(C_8H_4O_4)]·H_2O}_n(1) was synthesized by an elaborate design via the reaction of 3-(2,6-di(pyrazin-2-yl)pyridin-4-yl)-1H-indole(bppi),1,4-benzene-dicarboxylic acid(H2bdc) and cadmium(Ⅱ) nitrate in CH_3OH/H_2O mixed solvents. Complex 1 crystallizes in orthorhombic,space group Ccca with a = 20.012(4),b = 31.881(6),c = 19.808(4) ?,V = 12638(4) ?~3,Z = 16,C_(29)H_(20)CdN_6O_5,M_r = 644.91,D_c = 1.356 g·cm^(-3),μ = 0.735 mm^(-1),F(000) = 5184,GOOF = 1.046,the final R = 0.0405 and wR = 0.1063 for 6870 observed reflections(I 〉 2σ(I)). The Cd(Ⅱ) centre is hepta-coordinated by three N and four O atoms from one bppi terminal ligand and two bdc2– ligands,respectively,displaying a capped trigonal prism geometry. Structure extension gives coordination polymeric chains,in which the bdc2– linkers connect Cd(Ⅱ) cations into a one-dimensional(1D) coordination polymer along the c axis,giving zigzag chains with the Cd···Cd separation of 11.178(1) ?. The adjacent bppi terminal ligands in the chains are anti-periplanar conformation. The three-dimensional(3D) structure is stabilized by π···π stacking and hydrogen-bonding interactions to form a supramolecular self-penetrating network with 1D channels. In 1,there are voids 2999.7 ?~3 with 23.7% of per unit cell volume. Thermal analysis indicates that the framework of 1 is stable until 651 K and the photoluminescence of 1 in the solid shows very weak fluorescence at 382 and 560 nm upon excitation at 310 nm.展开更多
Hydrothermal reactions of biphenyl-2,3,3A,5A-tetracarboxylic acid(H4bptc) with cobalt salt in the presence of 1,4-bis(2-pyridylmethyl)piperazin(bpmp) afforded one novel coordination polymer, namely, [Co(H2bptc...Hydrothermal reactions of biphenyl-2,3,3A,5A-tetracarboxylic acid(H4bptc) with cobalt salt in the presence of 1,4-bis(2-pyridylmethyl)piperazin(bpmp) afforded one novel coordination polymer, namely, [Co(H2bptc)(bpmp)0.5(H2O)]n(1). Its structure was established by single-crystal X-ray diffraction analysis and further characterized by elemental analysis, IR spectra and TG analysis. Complex 1 crystallizes in monoclinic, space group P21/c with a = 11.4839(11), b = 16.6690(16), c = 11.5559(11) A, V = 2201.8(4) A3, Mr = 539.35, Dc = 1.627 g/cm^3, μ(MoK α) = 0.841 mm-1, F(000) = 1108, Z = 4, the final R = 0.0309 and w R = 0.0705 for 4090 observed reflections(I 2σ(I)). Complex 1 displays a one-dimensional(1D) chain bridged by bpmp. Two carboxylic groups of H4 bptc ligand adopt μ01-η1:η1 and μ1-η1:η coordination modes to bridge adjacent Co(Ⅱ) ions together with bpmp ligand to give alternately arranged left- and right-handed helical chains. In addition, variable-temperature magnetic susceptibility measurements indicate that complex 1 shows weak antiferromagnetic interactions between the adjacent Co(Ⅱ) ions.展开更多
基金This work was supported by the National Natural Science Foundation of China (51973157,61904123)the Tianjin Natural Science Foundation (18JCQNJC02900)+3 种基金the Special Grade of the Financial Support from the China Postdoctoral Science Foundation (2020T130469)the Sci-ence and Technology Plans of Tianjin (19PTSYJC00010)the Science&Technol-ogy Development Fund of Tianjin Education Commission for Higher Education (2018KJ196)State Key Laboratory of Membrane and Membrane Separation,Tiangong University.
文摘Low-cost and flexible solid polymer electrolytes are promising in all-solid-state Li-metal batteries with high energy density and safety.However,both the low room-temperature ionic conductivities and the small Li^(+)transference number of these electrolytes significantly increase the internal resistance and overpotential of the battery.Here,we introduce Gd-doped CeO_(2) nanowires with large surface area and rich surface oxygen vacancies to the polymer electrolyte to increase the interaction between Gd-doped CeO_(2) nanowires and polymer electrolytes,which promotes the Li-salt dissociation and increases the concentration of mobile Li ions in the composite polymer electrolytes.The optimized composite polymer electrolyte has a high Li-ion conductivity of 5×10^(-4)4 S cm^(-1) at 30℃ and a large Li+transference number of 0.47.Moreover,the composite polymer electrolytes have excellent compatibility with the metallic lithium anode and high-voltage LiNi_(0.8)Mn _(0.1)Co_(0.1)O_(2)(NMC)cathode,providing the stable cycling of all-solid-state batteries at high current densities.
基金supported by the National Natural Science Foundation of China(52074320)Petrochina Strategic Cooperation Science and Technology Project(ZLZX2020-01-04-03)。
文摘Janus amphiphilic polymer nanosheets(JAPNs)with anisotropic morphology and distinctive perfor-mance have aroused widespread interest.However,due to the difficulty in synthesis and poor dispersion stability,JAPNs have been scarcely reported in the field of enhancing oil recovery(EOR).Herein,a kind of organic-based flexible JAPNs was prepared by paraffin emulsion methods.The lateral sizes of JAPNs were ranging from hundreds of nanometers to several micrometers and the thickness was about 3 nm.The organic-based nanosheets were equipped with remarkably flexible structures,which could improve their injection performance.The dispersion and interfacial properties of JAPNs were studied systematically.By modification of crosslinking agent containing multiple amino groups,the JAPNs had excellent hydro-philicity and salt resistance compared with conventional inorganic or composite nanosheets.The settling time of nanosuspension with NaCl and CaCl_(2) at a low salinity of 1000 mg/L was over 240 h.The value could also remain 124 h under the salinity of 10,000 mg/L NaCl.With the dual functionalities of Janus amphiphilic nature and nanoparticles'Pickering effect,JAPNs could change rock wettability and form emulsions as"colloidal surfactants",In particular,a new technology called optical microrheology was pioneered to explore the destabilization state of nanosuspensions for the first time.Since precipitation lagged behind aggregation,especially for stable suspension systems,the onset of the unstable behavior was difficult to be detected by conventional methods,which should be the indicator of reduced effec-tiveness for nanofluid products.In addition,the oil displacement experiments demonstrated that the JAPNs could enhance oil recovery by 17.14%under an ultra-low concentration of 0.005%and were more suitable for low permeability cores.The findings can help for a better understanding of the material preparation of polymer nanosheets.We also hope that this study could shed more light on the nano-flooding technology for EOR.
基金the financial support of the research fund of the Science and Technology Innovation Program of Hunan Province(2020RC2076)the General Project of Education Department of Hunan Province(21C008)+2 种基金the Open Research Fund of School of Chemistry and Chemical Engineering,Henan Normal University(2022C02)the Youth Science and Technology Talent Project of Hunan Province(2022RC1197)the Hunan Provincial Natural Science Foundation of China(2021JJ40529)。
文摘Combining photocatalytic organic reactions with CO_(2)reduction is an efficient solar energy utilization mode,but it is still limited by the organic species that can be matched and the low conversion.Herein,ultrathin organic polymer with p-πconjugated structure(TPP)was rationally designed and prepared,and showed a high yield of CO(15.2 mmol g^(-1))and conversion of SAS coupled products(100%),far exceeding the organic polymer with P=O structure.The enhanced photoredox activity of TPP is ascribed to the orbital interaction between the p-orbital on phosphorus and theπ-orbitals of aromatic,which can accelerate the photoinduced charge carrier separation and improve the CO_(2)adsorption capacity.TPP can also be used for the dehydrocoupling of various benzyl mercaptans to the corresponding SAS bond products.This work provides a new concept for the efficient synthesis of disulfide bonds combined with CO_(2)reduction in a photoreaction system.
基金financially supported by the National Natural Science Foundation of China (22078132 and 22108103)Open Funding Project of the National Key Laboratory of Biochemical Engineering (2021KF-02)+3 种基金China Postdoctoral Science Foundation (2021M691301)Jiangsu Agricultural Independent Innovation Fund Project (CX(21)3079)Graduate Research Innovation Program of Jiangsu Province (KYCX20-3040)China Postdoctoral Science Foundation (2021M691301)。
文摘Molecularly imprinted polymers (MIPs) have great potential as adsorbents for selective adsorption and separation of nucleoside compounds,but effectively enhancing the affinity of recognition sites by adjusting the forces between template molecules and functional monomers remains an important challenge.In this work,a surface imprinting strategy was used to construct bowl-shaped molecularly imprinted composite sorbents (BHPN@MIPs) based on polydopamine (PDA) particles and have achieved selective separation and purification of 2'-deoxyadenosine (dA).Where by the base complementary pairing interaction of the combined template molecule d A and the pyrimidine functional monomer can enhance the preassembly force,and the hydrophilic bowl-shaped PDA can provide a larger storage space contact efficiency of d A in the test solution,causing the site utilization much higher and improving the kinetic adsorption performance.The equilibrium adsorption time and maximum adsorption capacity of60 min and 328.45μmol·g^(-1)were observed by static adsorption experiments,and the selectivity experimental results showed an imprinting factor IF of 1.30.After four adsorption–desorption cycles,the initial adsorption equilibrium adsorption capacity of BHPN@MIPs still retained 91.14%.By evaluating the selective adsorption of d A in spiked human serum solutions,BHPN@MIPs can be used to selectively enrich and analyze target d A in complex biological samples.
文摘(PEO)8LiClO4-SiO2 composite polymer electrolytes(CPEs)were prepared by in-situ reaction,in which ethyl-orthosilicate(TEOS)was catalyzed by HCl and NH3.H2O,respectively.The ionic conductivity,the contact angle and the morphology of inorganic particles in the CPEs were investigated by AC impedance spectra,contact angle method and TEM.The conductivities of acid-catalyzed CPE and alkali-catalyzed CPE are 2.2×10-5and 1.1×10-5S/cm respectively at 30℃.The results imply that the catalyst plays an important role in the structure of in-situ preparation of SiO2,and influences the surface energy and conductivity of CPE films directly.Meanwhile,the ionic conductivity is related to the surface energy.
基金supported by the National Natural Science of Foundation of China(No.21671094)
文摘Two N-donor ligands mediated Cd(Ⅱ) coordination polymers, namely,[Cd(L)(dmpz)2]n (1) and {[Cd(L)(atr)05(H20)](H2O)}n (2) (H2L = methyl-3-hydroxy-5-carboxy-2-thiophenecarboxylate, dmpz = 3,5-dimethylpyrazole, and atr= 4-amino-l,2,4-triazole), havebeen produced. Their structures were characterized by single-crystal X-ray diffraction analysis,elemental analyses and infrared spectra. Compound 1 possesses a one-dimensional (1D) chainstructure and is finally extended into a three-dimensional (3D) supramolecular architecturethough hydrogen bonding interactions. Compound 2 features a two-dimensional (2D) networkwith 4-connected sql topology based on dinuclear Cd(Ⅱ) clusters as nodes, which is alsoassembled into a 3D supramolecular architecture through hydrogen bonding interactions.Furthermore, compounds 1 and 2 exhibit high thermal stabilities and intense fluorescent emissionin the solid, and can be explored as potential luminescent materials.
基金Project(04GK2007) supported by Hunan Industrial Key Project of Science and Technology
文摘The effects of SN5040 and polyethylene glycol(PEG) individually and in combination on the dispersion stability of nano-TiO2 aqueous suspension were investigated by ultraviolet-visible absorption spectroscopy. The adsorption mechanism of these dispersants was detected by zeta potential, isothermal absorption and FTIR analysis. It is found that SN5040 is superior for stabilizing nano-TiO2 in aqueous suspension to PEG in basic region, and the optimum mass fraction of SN5040 addition is 3%. In the case of NaCl addition, the optimum value increases with .the increase of NaCl concentration in the solution. When the mixture of SN5040 and PEG is employed, the antagonism appears preponderant. When SN5040 and PEG are added sequentially, the synergistic reaction takes place. The synergistic reaction can be attributed to the mechanism that PEG adsorption decreases the electronic repulsion between SN5040 molecules, which results in the increase of SN5040 adsorption density. PEG is adsorbed by the interaction with the pre-adsorbed SN5040 layer. Furthermore, the modified inner wall latex paint with well dispersed nano-YiO2 suspension is endowed with excellent ultraviolet absorption and antibacterial properties.
基金supported by the National Natural Science Foundation of China(201573136,21603128,U1510105)the Natural Science Foundation for Young Scientists of Shanxi Province(2016021034)the Scientific Research Start-up Funds of Shanxi University(RSC723)~~
文摘A rational integration of multiple reactive centers into a combined unit to facilitate their cooperative effects is a smart approach for accelerating the catalytic activity.Here,to achieve this goal,linear imidazolium-based ionic polymers were confined into the nanopores of mesoporous silica nanospheres anchored with homogeneously distributed zinc salts.Owing to the flexible character and the reinforced cooperative effects of the ionic liquid(nucleophile)and zinc species(Lewis acid)in the confined mesoporous structure,the resultant composite exhibited dramatically improved catalytic performance in the cycloaddition of CO2 with epoxides to form cyclic carbonates.This was in contrast to that observed for the individual catalytic components.Moreover,such a solid catalyst could be easily recovered and reused four times without a significant loss of activity.
基金supported by the National Natural Science Foundation of China(Nos.21571118&21271121)
文摘A new coordination polymer {[Cd(C_(21)H_(14)N_6)(C_8H_4O_4)]·H_2O}_n(1) was synthesized by an elaborate design via the reaction of 3-(2,6-di(pyrazin-2-yl)pyridin-4-yl)-1H-indole(bppi),1,4-benzene-dicarboxylic acid(H2bdc) and cadmium(Ⅱ) nitrate in CH_3OH/H_2O mixed solvents. Complex 1 crystallizes in orthorhombic,space group Ccca with a = 20.012(4),b = 31.881(6),c = 19.808(4) ?,V = 12638(4) ?~3,Z = 16,C_(29)H_(20)CdN_6O_5,M_r = 644.91,D_c = 1.356 g·cm^(-3),μ = 0.735 mm^(-1),F(000) = 5184,GOOF = 1.046,the final R = 0.0405 and wR = 0.1063 for 6870 observed reflections(I 〉 2σ(I)). The Cd(Ⅱ) centre is hepta-coordinated by three N and four O atoms from one bppi terminal ligand and two bdc2– ligands,respectively,displaying a capped trigonal prism geometry. Structure extension gives coordination polymeric chains,in which the bdc2– linkers connect Cd(Ⅱ) cations into a one-dimensional(1D) coordination polymer along the c axis,giving zigzag chains with the Cd···Cd separation of 11.178(1) ?. The adjacent bppi terminal ligands in the chains are anti-periplanar conformation. The three-dimensional(3D) structure is stabilized by π···π stacking and hydrogen-bonding interactions to form a supramolecular self-penetrating network with 1D channels. In 1,there are voids 2999.7 ?~3 with 23.7% of per unit cell volume. Thermal analysis indicates that the framework of 1 is stable until 651 K and the photoluminescence of 1 in the solid shows very weak fluorescence at 382 and 560 nm upon excitation at 310 nm.
基金supported by the National Natural Science Foundation of China(No.21273101 and 21302082)the Foundation of the Program for Backbone Teachers in Universities of Henan Province(No.2012GGJS158)
文摘Hydrothermal reactions of biphenyl-2,3,3A,5A-tetracarboxylic acid(H4bptc) with cobalt salt in the presence of 1,4-bis(2-pyridylmethyl)piperazin(bpmp) afforded one novel coordination polymer, namely, [Co(H2bptc)(bpmp)0.5(H2O)]n(1). Its structure was established by single-crystal X-ray diffraction analysis and further characterized by elemental analysis, IR spectra and TG analysis. Complex 1 crystallizes in monoclinic, space group P21/c with a = 11.4839(11), b = 16.6690(16), c = 11.5559(11) A, V = 2201.8(4) A3, Mr = 539.35, Dc = 1.627 g/cm^3, μ(MoK α) = 0.841 mm-1, F(000) = 1108, Z = 4, the final R = 0.0309 and w R = 0.0705 for 4090 observed reflections(I 2σ(I)). Complex 1 displays a one-dimensional(1D) chain bridged by bpmp. Two carboxylic groups of H4 bptc ligand adopt μ01-η1:η1 and μ1-η1:η coordination modes to bridge adjacent Co(Ⅱ) ions together with bpmp ligand to give alternately arranged left- and right-handed helical chains. In addition, variable-temperature magnetic susceptibility measurements indicate that complex 1 shows weak antiferromagnetic interactions between the adjacent Co(Ⅱ) ions.