CuLaSm(C4O4 )4(H2O)16]·2H2O was obtained as a single crystal from a mixture of squaric acid, lanthanum chloride, samarium chloride, and copper chloride in water. The complex crystallized in the monoclinic system,...CuLaSm(C4O4 )4(H2O)16]·2H2O was obtained as a single crystal from a mixture of squaric acid, lanthanum chloride, samarium chloride, and copper chloride in water. The complex crystallized in the monoclinic system, space group P2_1,with a=6. 728(1) . b=32. 117(9),c=8. 150(1) A ,β=111. 60(1),Z=2, M_r=1125. 24, V= 1637(1 ) A3, Dc= 2. 28g/cm3, μ(MoKα) = 38. 36 cm-1, F(000)= 1104, R= 0. 040 for 2823 independent observed reflections. The coordinated environments of the lanthanides are a 4-capped square antiprism and a 4,4, 4-tricapped trigonal prism, and that of the copper is a distorted octahedron. The complex is the first example that contains copper and two kinds of different lanthanides when the squarate is employed as the ligand.展开更多
Over the past decades,two dimensional(2D)-structured materials have attracted considerable interest due to not only their intrinsic aesthetic appeal but also their intriguing physical properties.Herein,a 2D bilayer si...Over the past decades,two dimensional(2D)-structured materials have attracted considerable interest due to not only their intrinsic aesthetic appeal but also their intriguing physical properties.Herein,a 2D bilayer silver squarate was synthesized,which showed combined colossal positive thermal expansion(PTE)along the packing direction and negative thermal expansion(NTE)within the layer.The combined analyses of high resolution synchrotron X-ray powder diffraction,atomic pair distribution function(PDF)and Raman spectra shed light on the anomalous thermal expansion behaviors being closely related to the interlayer argentophilicity and thermal flipping of the ligand.Furthermore,this compound exhibited an intrinsic moderate proton conductivity(1.2×10^(-4) S cm^(-1) at 80℃ under 98% RH).We believe that this work can not only deepen our understanding of the thermal expansion properties of 2D materials but also provide guidance for the design and synthesis of novel functional materials.展开更多
By using squarates as coordination building units,six new complexes formulated as[Mg(C_(4)O_(4))(H_(2)O)_(2)]n(1),[Pr_(2)(C_(4)O_(4))_(2)(OA)(H_(2)O)_(4)]n(2),[Eu_(2)(C_(4)O_(4))3(H_(2)O)_(8)]n(3)[Cd_(2)(C_(4)O_(4))_(...By using squarates as coordination building units,six new complexes formulated as[Mg(C_(4)O_(4))(H_(2)O)_(2)]n(1),[Pr_(2)(C_(4)O_(4))_(2)(OA)(H_(2)O)_(4)]n(2),[Eu_(2)(C_(4)O_(4))3(H_(2)O)_(8)]n(3)[Cd_(2)(C_(4)O_(4))_(2)(bpdo)(H_(2)O)_(4)]n(4),[Cd(C_(4)HO_(4))_(2)(H_(2)O)_(4)]·(MV)_(2)·(C_(4)O_(4))_(2)(5),and[Cd(C_(4)HO_(4))_(2)(H_(2)O)_(4)]·(EV)·(C_(4)HO_(4))_(2)(6),where(C_(4)O_(4))_(2)-=squarate,OA=oxalic acid,MV=methyl viologen,EV=ethyl viologen,and bpdo=4,4’-dipyrdiyl-N,N’-dioxide,have been synthesized under hydro/solvothermal conditions.They present structural dimensions from 3-D networks(1,2),2-D layers(3,4)to 0-D clusters(5,6)based on the versatile bridged modes of squarates and the introduction of second ligands.In particular,5 and 6 are the first examples incorporating squarates(electronic-rich species)with viologens(electronic-poor species)in one lattice.Consequently,they exhibit not only photocurrent responses but also reversible thermochromism,which will be beneficial for the design of multi-functional materials.展开更多
Blending of various chemical bonds with different strengths within a framework is expected to induce some anomalous physical properties.Herein,a novel metal squarate framework containing covalent bonds,coordination bo...Blending of various chemical bonds with different strengths within a framework is expected to induce some anomalous physical properties.Herein,a novel metal squarate framework containing covalent bonds,coordination bonds and hydrogen bonds was synthesized and it showed a uniaxial negative thermal expansion(NTE).A combination of in situ powder/single-crystal X-ray diffraction,Raman spectroscopy and density-functional theory(DFT)calculations revealed that this anomalous thermal expansion originates from a hydrogen bond-triggered wine-rack-like distortion.This study can provide a new strategy for the rational design of hybrid NTE compounds.展开更多
We synthesized ion pair receptors 1 and 2 consisting of a benzocrown ether cation binding site and a ferrocene-supported squaramide anion binding domain and compared their binding ability with anion receptor 3,lacking...We synthesized ion pair receptors 1 and 2 consisting of a benzocrown ether cation binding site and a ferrocene-supported squaramide anion binding domain and compared their binding ability with anion receptor 3,lacking a crown ether unit,using spectroscopic,spectrophotometric,and electrochemical measurements in acetonitrile solution.All receptors were obtained in a modular fashion by sequential amidation of dimethyl squarate with corresponding amines,which allows for the simple introduction of a ferrocene unit and enables them to act as sensors.We found that ion pair receptors 1 and 2 recognized the tested anions more strongly in the presence of cations,whereas the homotopic anion receptor 3 was unable to bind sodium or potassium salts more strongly than tetrabutylammonium salts.This enhancement in anion binding was attributed to a cation complexation induced alteration in the nature of the phenyl ring substituents,directly linked to the squaramide anion binding site,changing from electrondonating to more withdrawing.展开更多
文摘CuLaSm(C4O4 )4(H2O)16]·2H2O was obtained as a single crystal from a mixture of squaric acid, lanthanum chloride, samarium chloride, and copper chloride in water. The complex crystallized in the monoclinic system, space group P2_1,with a=6. 728(1) . b=32. 117(9),c=8. 150(1) A ,β=111. 60(1),Z=2, M_r=1125. 24, V= 1637(1 ) A3, Dc= 2. 28g/cm3, μ(MoKα) = 38. 36 cm-1, F(000)= 1104, R= 0. 040 for 2823 independent observed reflections. The coordinated environments of the lanthanides are a 4-capped square antiprism and a 4,4, 4-tricapped trigonal prism, and that of the copper is a distorted octahedron. The complex is the first example that contains copper and two kinds of different lanthanides when the squarate is employed as the ligand.
基金supported by the National Natural Science Foundation of China(Grant No.22005340 and 21875285)the Fundamental Research Funds for the Central Universities(20CX06047A)+1 种基金the Taishan Scholar Foundation(ts201511019)the Development Projects of Shandong Province(Grant 2019JZZY010331).
文摘Over the past decades,two dimensional(2D)-structured materials have attracted considerable interest due to not only their intrinsic aesthetic appeal but also their intriguing physical properties.Herein,a 2D bilayer silver squarate was synthesized,which showed combined colossal positive thermal expansion(PTE)along the packing direction and negative thermal expansion(NTE)within the layer.The combined analyses of high resolution synchrotron X-ray powder diffraction,atomic pair distribution function(PDF)and Raman spectra shed light on the anomalous thermal expansion behaviors being closely related to the interlayer argentophilicity and thermal flipping of the ligand.Furthermore,this compound exhibited an intrinsic moderate proton conductivity(1.2×10^(-4) S cm^(-1) at 80℃ under 98% RH).We believe that this work can not only deepen our understanding of the thermal expansion properties of 2D materials but also provide guidance for the design and synthesis of novel functional materials.
基金support for this research by the National Natural Science Foundation of China(No.:21271043,21771038)the Qishan Scholars Program of Fuzhou University(No.:XQS-1403).
文摘By using squarates as coordination building units,six new complexes formulated as[Mg(C_(4)O_(4))(H_(2)O)_(2)]n(1),[Pr_(2)(C_(4)O_(4))_(2)(OA)(H_(2)O)_(4)]n(2),[Eu_(2)(C_(4)O_(4))3(H_(2)O)_(8)]n(3)[Cd_(2)(C_(4)O_(4))_(2)(bpdo)(H_(2)O)_(4)]n(4),[Cd(C_(4)HO_(4))_(2)(H_(2)O)_(4)]·(MV)_(2)·(C_(4)O_(4))_(2)(5),and[Cd(C_(4)HO_(4))_(2)(H_(2)O)_(4)]·(EV)·(C_(4)HO_(4))_(2)(6),where(C_(4)O_(4))_(2)-=squarate,OA=oxalic acid,MV=methyl viologen,EV=ethyl viologen,and bpdo=4,4’-dipyrdiyl-N,N’-dioxide,have been synthesized under hydro/solvothermal conditions.They present structural dimensions from 3-D networks(1,2),2-D layers(3,4)to 0-D clusters(5,6)based on the versatile bridged modes of squarates and the introduction of second ligands.In particular,5 and 6 are the first examples incorporating squarates(electronic-rich species)with viologens(electronic-poor species)in one lattice.Consequently,they exhibit not only photocurrent responses but also reversible thermochromism,which will be beneficial for the design of multi-functional materials.
基金supported by the National Natural Science Foundation of China(Grant No.22005340).
文摘Blending of various chemical bonds with different strengths within a framework is expected to induce some anomalous physical properties.Herein,a novel metal squarate framework containing covalent bonds,coordination bonds and hydrogen bonds was synthesized and it showed a uniaxial negative thermal expansion(NTE).A combination of in situ powder/single-crystal X-ray diffraction,Raman spectroscopy and density-functional theory(DFT)calculations revealed that this anomalous thermal expansion originates from a hydrogen bond-triggered wine-rack-like distortion.This study can provide a new strategy for the rational design of hybrid NTE compounds.
基金supported by Grant No.2018/30/E/ST5/00841 from the National Science Centre,Poland.
文摘We synthesized ion pair receptors 1 and 2 consisting of a benzocrown ether cation binding site and a ferrocene-supported squaramide anion binding domain and compared their binding ability with anion receptor 3,lacking a crown ether unit,using spectroscopic,spectrophotometric,and electrochemical measurements in acetonitrile solution.All receptors were obtained in a modular fashion by sequential amidation of dimethyl squarate with corresponding amines,which allows for the simple introduction of a ferrocene unit and enables them to act as sensors.We found that ion pair receptors 1 and 2 recognized the tested anions more strongly in the presence of cations,whereas the homotopic anion receptor 3 was unable to bind sodium or potassium salts more strongly than tetrabutylammonium salts.This enhancement in anion binding was attributed to a cation complexation induced alteration in the nature of the phenyl ring substituents,directly linked to the squaramide anion binding site,changing from electrondonating to more withdrawing.
