The electrical conductivity and Hall effect for T1GaSeS crystals have been investigated over a wide temperature range. The crystals we used are grown by a modified Bridgman technique and possess p-type conductivity. T...The electrical conductivity and Hall effect for T1GaSeS crystals have been investigated over a wide temperature range. The crystals we used are grown by a modified Bridgman technique and possess p-type conductivity. The energy gap has been found to be 1.63 eV, whereas the ionization energy is 0.25 eV. The variations of the Hall mobility as well as the carrier concentration with temperature have been investigated. The scattering mechanisms of the carder are checked over the whole investigated temperature range. Furthermore, the diffusion coefficient, relaxation time, and diffusion length of holes are estimated.展开更多
As an extreme physical condition,high pressure serves as a potent means to substantially modify the interatomic distances and bonding patterns within condensed matter,thereby enabling the macroscopic manipulation of m...As an extreme physical condition,high pressure serves as a potent means to substantially modify the interatomic distances and bonding patterns within condensed matter,thereby enabling the macroscopic manipulation of material properties.We employed the CALYPSO method to predict the stable structures of RbB_(2)C_(4)across the pressure range from 0 GPa to 100 GPa and investigated its physical properties through first-principles calculations.Specially,we found four novel structures,namely,P6_(3)/mcm-,Amm2-,P1-,and I4/mmm-RbB_(2)C_(4).Under pressure conditions,electronic structure calculations reveal that all of them exhibit metallic characteristics.The calculation results of formation enthalpy show that the P6_(3)/mcm structure can be synthesized within the pressure range of 0–40 GPa.Specially,the Amm2,P1,and I4/mmm structures can be synthesized above 4 GPa,6 GPa,10 GPa,respectively.Moreover,the estimated Vickers hardness value of I4/mmm-RbB_(2)C_(4)compound is 47 GPa,suggesting that it is a superhard material.Interestingly,this study uncovers the continuous transformation of the crystal structure of RbB_(2)C_(4)from a layered configuration to folded and tubular forms,ultimately attaining a stabilized cage-like structure under the pressure span of 0–100 GPa.The application of pressure offers a formidable impetus for the advancement and innovation in condensed matter physics,facilitating the exploration of novel states and functions of matter.展开更多
The magnetic refrigeration(MR)based on the principle of magnetocaloric effect(MCE)in magnetic materials was recognized as an alternative cooling way to our present commercialized vapor compression cycle technology.Evi...The magnetic refrigeration(MR)based on the principle of magnetocaloric effect(MCE)in magnetic materials was recognized as an alternative cooling way to our present commercialized vapor compression cycle technology.Evidently,a vital prerequisite for practical applications is the exploration of candidate materials with prominent magnetocaloric performances.In this paper,the polycrystalline garnet RE_(3)Al_(5)O_(12)(RE=Tb,Dy and Ho)compounds with the cubic structure(space group:Ia3d)were prepared using the Pechini sol-gel method,and their crystal structure,magnetic properties and comprehensive magnetocaloric performances were studied.The analysis of magnetic susceptibility curves in a static magnetic field H=0.1 T reveal that the Dy_(3)Al_(5)O_(12)undergoes antiferromagnetic transition with Néel temperature TN≈2.6 K,whereas the Tb_(3)Al_(5)O_(12)and Ho_(3)Al_(5)O_(12)exhibit no features indicative of the magnetic ordering processes down to 1.8 K.The comprehensive magnetocaloric performances,namely the maximum magnetic entropy change and relative cooling power,are derived indirectly from the isothermal field-dependent magnetization data,which yield 11.72,10.42,7.53 J/(kg·K)and 84.56,69.52,70.35 J/kg for the Tb_(3)Al_(5)O_(12),Dy_(3)Al_(5)O_(12)and Ho_(3)Al_(5)O_(12)under a low field change(ΔH)of 0-2 T,respectively.The superior comprehensive magnetocaloric performances and wide operating temperature range of these compounds under lowΔH make them attractive for cryogenic MR technology.展开更多
A novel compound Cu（phen）（m-CBA）2 was synthesized with m-chlorobenzoic acid（m-CBA）, 1,10-phenanthroline（phen） and Cu（OAc）2·H2O. It was characterized by IR, UV, elemental analyses and X-ray crystallograp...A novel compound Cu（phen）（m-CBA）2 was synthesized with m-chlorobenzoic acid（m-CBA）, 1,10-phenanthroline（phen） and Cu（OAc）2·H2O. It was characterized by IR, UV, elemental analyses and X-ray crystallography. It crystallizes in the monoclinic crystal system with C2/c space group, a=2.9699（4） nm, b=1.15452（2） nm, c=1.5335（2） nm, β=111.118（2）°, V=4.905 1（1） nm3, Z=8, F（000）=2 328, R1=0.072 8, wR2=0.223 4 [I2σ（I）]. Structure analysis shows that the copper center coordinates with two nitrogen atoms from one 1,10-phenanthroline molecule, two oxygen atoms from two m-chlorobenzoic acid molecules, giving a distorted squared planar coordination geometry. This novel compound shows paramagnetic interactions between copper centers.展开更多
Gd2PdSi3 single crystals were grown by a vertical floating zone method with radiation heating at a zone traveling rate of 3 mm/h. The compound exhibited congruent melting behavior at a liquidus temperature of about 17...Gd2PdSi3 single crystals were grown by a vertical floating zone method with radiation heating at a zone traveling rate of 3 mm/h. The compound exhibited congruent melting behavior at a liquidus temperature of about 1700 ＆#176;C. The slightly Pd-depleted composition of the crystal, with respect to the nominal Gd2PdSi3 stoichiometry, led to gradual accumulation of Pd in the traveling zone and to a decreasing operating temperature during the growth process. Thin platelet-like precipitates of a GdSi phase were detected in the stoichiometric feed rod growth crystal matrix which can be reduced by annealing treatment. Feed rod composition shift crystal growth was proved to be a better way of getting high quality of Gd2PdSi3 single crystal.展开更多
A novel nelnatic liquid crystal compound containing a cinnamoyl moiety （PCPC） and a typically cholesteric liquid crystal cholesteryl cinnamate （CC） were synthesized to explore the mechanism ofcinnamoyl compounds, ...A novel nelnatic liquid crystal compound containing a cinnamoyl moiety （PCPC） and a typically cholesteric liquid crystal cholesteryl cinnamate （CC） were synthesized to explore the mechanism ofcinnamoyl compounds, and the chemical structures of photodimerization were confirmed by Fourier transform infrared spectroscopy and 1H nuclear magnetic resonance spectral analysis. The photoreaction behaviors of these two cinnamoyl compounds in mesomorphic state and solution were investigated, UV-Vis spectral analysis was used to analyze the photoproduct. The results show that the photochemistry of PCPC in nematic state involves both photodimerization and photoisomerization, while CC shows a complex reaction which can be divided into three parts, and this has enabled us to present new data and interpretations regarding the [2＋2] photocycloaddition reaction. Additionally, the results of UV-Vis spectral analysis in solutions strongly suggest that UV-Vis spectral analysis can be used to study the kinetic behaviors of cinnamoyl moiety photoreaction.展开更多
A new supramolecular compound, { [2-（2-pyridyl）benzimidazoleH2]2＋.[SBC15]2-}2, was synthesized by the hydrothermal reaction of o-diaminobenzene, 2-pyridinecarboxylie acid and SbCl3 in 1：1 HC1 solution, and charact...A new supramolecular compound, { [2-（2-pyridyl）benzimidazoleH2]2＋.[SBC15]2-}2, was synthesized by the hydrothermal reaction of o-diaminobenzene, 2-pyridinecarboxylie acid and SbCl3 in 1：1 HC1 solution, and characterized by chemical analysis, elemental analysis, IR spectra, thermogravimetfic analysis and fluorescence spectra. The crystal structure was deter- mined by X-ray single-crystal diffraction. The crystal belongs to the monoclinic system, space group P211c, with a = 16.0397（13）, b = 14.3189（12）, c = 15.6370（13） A, β = 105.8980（10）°, V = 3454.0（5） A3, Z = 4, C24H22Cl10N6Sb2, Mr = 992.48, Dc = 1.909 g/cm3,/z = 2.366 mm-1, S = 1.010, F（000） = 1920, R = 0.0254 and wR = 0.0555. The coordination anion, [SbCl5]2- which is a distorted tetragonal pyramid, is composed by coordinating action with Sb3＋ ion and five adjacent chloride ions. Every four coordination anions of [SbCl5]2- form a biquaternion ring structure through the secondary bonding of Sb...Cl. Moreover, the compound adopts a three-dimensional network supramolecular structure because of the hydrogen bonds and π-π stacking between the rings and the 2-（2-pyridyl）benzimidazole divalent cations. The title compound also shows good fluorescent behaviors.展开更多
The title compound {[（C6H5CH2）2Sn]2（O）（Cl2）}2 has been synthesized by the reaction of bisbenzyltin dichloride with NaOH dilute solution, and its structure was determined by X-ray diffraction. The crystal belongs...The title compound {[（C6H5CH2）2Sn]2（O）（Cl2）}2 has been synthesized by the reaction of bisbenzyltin dichloride with NaOH dilute solution, and its structure was determined by X-ray diffraction. The crystal belongs to monoclinic, space group C2/c, with a = 2.5081（17）, b = 1.0089（7）, c = 2.0909（14） nm, β = 94.267（8）°, V= 5.276（6） nm^3, Z = 4, De= 1.734 g/cm^3,μ（MoKa） = 21.55 cm^-1, F（000） = 2704, R = 0.0398 and Rw = 0.1024. According to structural analysis, the tin atom adopts a distorted five-coordinate trigonal bipyramidal geometry, and the ladder-like structure is shaped by one planar four-membered Sn2O2 ring together with two planar four-membered Sn2OCl rings.展开更多
Functional organic molecular materials and conjugated oligomers or polymers now allow the low-cost fabrication of thin films for insertion into new generations of electronic and optoelectronic devices. The performance...Functional organic molecular materials and conjugated oligomers or polymers now allow the low-cost fabrication of thin films for insertion into new generations of electronic and optoelectronic devices. The performance of these devices relies on the understanding and optimization of several complementary processes. Our goal is to discuss the relationship between the molecular stacking structures and their optoelectronic properties that are of importance in all these areas. The concept of intermolecular interaction should be taken here in the special sense that is inter-dipole coupling. Specifically, we will address the impact of inter-dipole interaction between adjacent molecules in aggregate state on the solid-state emission properties.展开更多
The mixed ligand coordination compound of copper with norfloxacin (NFLX) and 1, 10-phen has been synthesized and characterized by means of X-ray single crystal diffraction. The structure features of the coordination ...The mixed ligand coordination compound of copper with norfloxacin (NFLX) and 1, 10-phen has been synthesized and characterized by means of X-ray single crystal diffraction. The structure features of the coordination compound are described. Antibacterial activities of the coordination compound have been tested against different microorganisms. The antitumor activities of the coordination compound on leukemia HL-60 cell line and liver cancer BEL-7402 cell line have been measured, respectively. The results indicated that the coordination compound has strong inhibitory effect on HL-60 and BEL-7402 cell lines.展开更多
Two novel spiro compounds,3-benzylidene-1,5-dioxaspiro[5.5]undecane-2,4-dione 1 and 3-（2-fluorobenzylidene）-1,5-dioxaspiro[5.5]undecane-2,4-dione 2,have been synthesized and characterized by X-ray single-crystal dif...Two novel spiro compounds,3-benzylidene-1,5-dioxaspiro[5.5]undecane-2,4-dione 1 and 3-（2-fluorobenzylidene）-1,5-dioxaspiro[5.5]undecane-2,4-dione 2,have been synthesized and characterized by X-ray single-crystal diffraction,IR and elemental analysis.Compound 1 belongs to the monoclinic system,space group P21/n with a=12.326（3）,b=5.6420（11）,c=20.089（4）,β= 101.79（3）o,C16H16O4,Mr= 272.29,V=1367.7（5）3,Z=4,Dc=1.322g/cm3,F（000）=576,μ（MoKa）=0.095 mm-1,the final R=0.0420 and wR=0.1159.Compound 2 is of monoclinic system,space group P21/n with a=12.283（3）,b=5.6367（11）,c=20.055（4）,β=102.00（3）o,C16H15FO4,Mr=290.28,V=1358.2（5）3,Z=4,Dc=1.420 g/cm3,F（000）=608,μ（MoKa）=0.110 mm-1,the final R=0.0353 and wR=0.0860.展开更多
The title compounds 5-chloro-3-methyl-1-phenyl-1H-pyrazole-4-carboxylic acid（C11H9Cl N2O2, HL）（1） and [Cu（L）2（H2O）]（2） were prepared and structurally characterized by elemental analysis, IR and single-crysta...The title compounds 5-chloro-3-methyl-1-phenyl-1H-pyrazole-4-carboxylic acid（C11H9Cl N2O2, HL）（1） and [Cu（L）2（H2O）]（2） were prepared and structurally characterized by elemental analysis, IR and single-crystal X-ray diffraction. Compound 1（C11H9Cl N2O2） crystallizes in the monoclinic system, space group P21/n with a = 7.249（3）, b = 20.515（10）, c = 7.249（3）,β= 96.30°, V = 1071.6（9） ？3, Z = 4, Mr = 236.65, Dc = 1.467 g/cm3, F（000） = 488, GOOF = 1.029, μ= 0.341 mm-1, the final R = 0.0736 and w R = 0.1966 for 1500 observed reflections with I 〉 2σ（I）. Compound 2（C22H18Cl2Cu N4O5） crystallizes in the monoclinic system, space group P21/c with a = 7.2931（6）, b = 24.548（2）, c = 13.2726（11）, β= 99.4040（10）°, V = 2344.2（3） ？3, Z = 4, Mr = 552.84, Dc = 1.566 g/cm3, F（000） = 1124, GOOF = 1.050, μ= 1.201 mm-1, the final R = 0.0376 and w R = 0.1000 for 3626 observed reflections with I 〉 2σ（I）. 1 and 2 are connected through hydrogen bonding interactions to generate 2D and 3D supramolecular structures, respectively. Moreover, the preliminary antibacterial activities of 1 and 2 against the gram positive bacteria（S. aureus, C. albicans and B. subtilis） and gram negative bacteria（E. coli and P. aeruginosa） have been tested by using the microdilution method, and the results indicate that 2 is more active than 1 against the tested bacteria.展开更多
A three-dimensional（3D） coordination polymer,[Cd（SC）（DPPD）]_n（1,H_2SC = succinic acid and DPPD = 3,6-di（4-pyridyl）pyridazine）,has been synthesized by the solvothermal reaction of Cd（NO_3）_2·4H_2O with...A three-dimensional（3D） coordination polymer,[Cd（SC）（DPPD）]_n（1,H_2SC = succinic acid and DPPD = 3,6-di（4-pyridyl）pyridazine）,has been synthesized by the solvothermal reaction of Cd（NO_3）_2·4H_2O with H_2 SC and DPPD at 120 ℃ in DMF solvent. Compound 1 crystallizes in the monoclinic system,space group P2_1/c,with a = 10.7993（4）,b = 11.7705（3）,c = 13.5336（6） A,V = 1678.89（11） A^3,Z = 4,C18H14N4O_4 Cd,M_r = 462.73,D_c = 1.831 g/cm^3,μ = 1.335 mm^（-1）,F（000） = 920.0,the final R = 0.0500 and wR = 0.1567 for 3714 observed reflections with I 〉 2s（I）. In compound 1,the Cd（Ⅱ） ions are linked by the SC^2– ligands to give a two-dimensional（2D） undulating sheet based on the centrosymmetric dinuclear Cd_2（COO）_2 units. The 2D sheets are further connected by the DPPD ligands to produce a 3D structure,which is a 6-connected（4^4·6·^10·8） topological network based on the dinuclear Cd_2（COO）_2 node. Compound 1 exhibits a photoluminescent emission with a maximum at 540 nm upon excitation at 460 nm.展开更多
The fluorine-substituted benzoate ester rod-shaped liquid crystals containing an azobenzene side chain linked with terminal double bonds were synthesized and characterized.The mesophase and photoswitching properties w...The fluorine-substituted benzoate ester rod-shaped liquid crystals containing an azobenzene side chain linked with terminal double bonds were synthesized and characterized.The mesophase and photoswitching properties were determined by polarizing optical microscopy（POM）,differential scanning calorimetry（DSC） and UV-visible spectrometry.The rod-shaped compound 4a having an odd number of carbon atoms in the alkyl chains exhibits nematic phase and SmA type phase whereas compound 4b having an even number of carbon atoms showed only nematic phase.Both fluorinecontaining compounds 4c and 4d showed only SmA type phases.The photoswitching properties of these compounds showed a rate of trans to cis isomerization ranging 19-20 s,whereas reverse process took around 230 min in solution.These materials may be ideal in the field of optically rewritable applications where both on and off rates should be crucial.展开更多
Rare earth(RE)-containing crystals have been investigated as media for the immobilization of RE fission products from nuclear waste streams.During reprocessing of spent nuclear fuel,fission products including REs,alka...Rare earth(RE)-containing crystals have been investigated as media for the immobilization of RE fission products from nuclear waste streams.During reprocessing of spent nuclear fuel,fission products including REs,alkalis,and alkaline earths released from the fuel.One viable option to immobilize the RE fission products is to incorporate them into chemically durable crystalline phases in specific waste forms.This study summarizes the crystal structures and synthesis methods of six RE-containing compounds that have applications in remediation of RE fission products.These compounds include oxyapatite(AE_(2)RE_(8)(SiO_(4))_(6)O_(2)),oxychloride(REOCl),borosilicate(RE_(3)BSi_(2)O_(10)),pyrochlore(RE_(2)M_(2)O_(7)),monazite(REPO_(4)),and perovskite(REMO_(3))where AE denotes alkaline earth metals and M denotes transition metals.This review provides an overview of literature on the usage of these six compounds for immobilizing RE fission products and summarizes different synthesis methods for producing these compounds.Comparisons of structural parameters with different REs in each compound are also discussed.展开更多
A new luminescent compound, Zn（8-aminoql）2（SCN）2 （1, 8-aminoql = 8-amino quinoline）, has been synthesized and its structure was characterized by IR, elemental analysis and X-ray single-crystal diffraction. Compo...A new luminescent compound, Zn（8-aminoql）2（SCN）2 （1, 8-aminoql = 8-amino quinoline）, has been synthesized and its structure was characterized by IR, elemental analysis and X-ray single-crystal diffraction. Compound 1 belongs to the orthorhombic system, space group Pbca with a = 8.503（2）, b = 14.427（4）, c = 31.922（8）A, V= 3916.0（18） A3, Z = 8, C20H16N6S2Zn, Mr = 469.88, Dc = 1.594 Mg/m3, μ = 1.488 mm-1, F（000） = 1920, T = 296（2） K, the final R = 0.0293 and wR = 0.0645 for all 2763 observed reflections （1 〉 2a（/））. Compound 1 displays a 3D supramolecular architecture formed by N-H--S hydrogen bonds and π...π aromatic packing interactions. Photoluminescence studies reveal that it displays obvious fluorescent emission band （λex = 320 nm） at 533 nm in the solid state at room temperature. The emission bands possess a broad asymmetric feature, which can be assigned to ligand-to-ligand charge transfer transitions based on DFT calculations.展开更多
Organic nonlinear optical material of 4-bromo-4’-methyl benzylidene aniline (BMBA) was synthesized and single crystal of BMBA was grown by solvent evaporation method at room temperature using ethanol as solvent. The ...Organic nonlinear optical material of 4-bromo-4’-methyl benzylidene aniline (BMBA) was synthesized and single crystal of BMBA was grown by solvent evaporation method at room temperature using ethanol as solvent. The crystalline nature of the grown crystals was confirmed using powder X-ray diffraction studies. The crystals were also characterized by single crystal X-ray diffraction method and their lattice parameters were determined. Thermal properties of BMBA were evaluated with thermogravimetric, differential thermal and differential scanning calorimetric analyses. Fourier transform infrared and FT-Raman spectral studies were carried out on the BMBA material to confirm the synthesized compound. 1H and 13C-nuclear magnetic resonance spectral studies were recorded to elucidate the structure of the grown crystals. Fluorescence spectrum recorded shows a peak at 485 nm. UV-Vis-NIR spectral analysis shows transmittance of ~92% in the visible region. The mechanical stability was analyzed by Vickers microhardness tester and the work hardening coefficient of the grown crystal was calculated. Second harmonic generation efficiency of the grown crystal measured by Kurtz powder technique is ~1.8 times that of potassium dihydrogen orthophosphate.展开更多
A dinuclear Tb（Ⅲ） compound, Tb_2（μ_2-anthc）_4（anthc）_2（1,10-phen）_2（1, Hanthc = 9-anthracenecarboxylic acid and 1,10-phen = 1,10-phenanthroline）, was synthesized under solvothermal condition and structural...A dinuclear Tb（Ⅲ） compound, Tb_2（μ_2-anthc）_4（anthc）_2（1,10-phen）_2（1, Hanthc = 9-anthracenecarboxylic acid and 1,10-phen = 1,10-phenanthroline）, was synthesized under solvothermal condition and structurally characterized by single-crystal X-ray diffraction. Compound 1 crystallizes in the triclinic system, space group P1, with a = 12.5061（12）, b = 13.3168（10）, c = 15.0079（12） ？, α = 110.620（7）, β = 102.941（7）, γ = 107.036（7）o, V = 2081.8（3） ？~3, Z = 1, C_（114）H_（70）N_4O_（12）Tb_2, M_r = 2005.58, D_c = 1.600 g/cm^3, μ = 1.759 mm^（-1）, F（000） = 1008, the final R = 0.0294 and w R = 0.0608 for 8900 observed reflections with I 〉 2s（I）. In compound 1, two Tb（Ⅲ） ions are linked by four carboxylate groups of the bridging anthc– ligands to give a dinuclear Tb_2（μ_2-anthc）_4 unit wherein each Tb（III） ion is further capped by a terminal anthc– ligand and a 1,10-phen ligand in a chelating fashion. Detailed direct-current and alternating-current susceptibility measurements showed no slow magnetism relaxation phenomenon was observed for 1.展开更多
Two metal-dithiolene compounds with a formula of[4-ClBz-l-APy][Ni（dmit）2]（1）and[4-NO2Bz-l-APy][Ni（dmit）2]（2,4-ClBz-1-APy = 1-N-（4＇-chlorobenzyl）pyridinium,4-NO2Bz-1-APy = l-N-（4＇-nitrobenzyl）pyridinium,dm...Two metal-dithiolene compounds with a formula of[4-ClBz-l-APy][Ni（dmit）2]（1）and[4-NO2Bz-l-APy][Ni（dmit）2]（2,4-ClBz-1-APy = 1-N-（4＇-chlorobenzyl）pyridinium,4-NO2Bz-1-APy = l-N-（4＇-nitrobenzyl）pyridinium,dmit^（2-）= 1,3-dithiole-2-thione-4,5-dithiolate） were synthesized and characterized.Two compounds crystallize in triclinic space group P1 and P1,respectively,but with different cell parameters and packing structures.The[Ni（dmit）2]^- anions and cations of 1 form mixed column stacks along the a axis and alternately layered alignments in the crystal of 2,which are parallel to the crystallographic（110） plane.Two compounds show a similar magnetic behavior,the magnetic exchange natures are mainly antiferromagnetic,and the magnetic susceptibility data can be fitted to the simple Curie-Weiss law.For 1 and 2,the fitted Curie constants are much less than the spin-only value expected for an S =1/2 system,and the fitted Weiss constants marking magnetic interaction are also very smaller.This fact implies that the weak CurrieWeiss-type paramagnetism is not the intrinsic characteristics of two compounds.展开更多
文摘The electrical conductivity and Hall effect for T1GaSeS crystals have been investigated over a wide temperature range. The crystals we used are grown by a modified Bridgman technique and possess p-type conductivity. The energy gap has been found to be 1.63 eV, whereas the ionization energy is 0.25 eV. The variations of the Hall mobility as well as the carrier concentration with temperature have been investigated. The scattering mechanisms of the carder are checked over the whole investigated temperature range. Furthermore, the diffusion coefficient, relaxation time, and diffusion length of holes are estimated.
基金Project supported by the Jilin Provincial Science and Technology Development Joint Fund Project(Grant No.YDZJ202201ZYTS581)supported by the Scientific and Technological Research Project of Jilin Provincial Education Department(Grant No.JJKH20240077KJ).
文摘As an extreme physical condition,high pressure serves as a potent means to substantially modify the interatomic distances and bonding patterns within condensed matter,thereby enabling the macroscopic manipulation of material properties.We employed the CALYPSO method to predict the stable structures of RbB_(2)C_(4)across the pressure range from 0 GPa to 100 GPa and investigated its physical properties through first-principles calculations.Specially,we found four novel structures,namely,P6_(3)/mcm-,Amm2-,P1-,and I4/mmm-RbB_(2)C_(4).Under pressure conditions,electronic structure calculations reveal that all of them exhibit metallic characteristics.The calculation results of formation enthalpy show that the P6_(3)/mcm structure can be synthesized within the pressure range of 0–40 GPa.Specially,the Amm2,P1,and I4/mmm structures can be synthesized above 4 GPa,6 GPa,10 GPa,respectively.Moreover,the estimated Vickers hardness value of I4/mmm-RbB_(2)C_(4)compound is 47 GPa,suggesting that it is a superhard material.Interestingly,this study uncovers the continuous transformation of the crystal structure of RbB_(2)C_(4)from a layered configuration to folded and tubular forms,ultimately attaining a stabilized cage-like structure under the pressure span of 0–100 GPa.The application of pressure offers a formidable impetus for the advancement and innovation in condensed matter physics,facilitating the exploration of novel states and functions of matter.
基金supported by the National Natural Science Foundation of China(52301240,52472274)the Fundamental Research Funds for the Provincial Universities of Zhejiang(GK259909299001-022)。
文摘The magnetic refrigeration(MR)based on the principle of magnetocaloric effect(MCE)in magnetic materials was recognized as an alternative cooling way to our present commercialized vapor compression cycle technology.Evidently,a vital prerequisite for practical applications is the exploration of candidate materials with prominent magnetocaloric performances.In this paper,the polycrystalline garnet RE_(3)Al_(5)O_(12)(RE=Tb,Dy and Ho)compounds with the cubic structure(space group:Ia3d)were prepared using the Pechini sol-gel method,and their crystal structure,magnetic properties and comprehensive magnetocaloric performances were studied.The analysis of magnetic susceptibility curves in a static magnetic field H=0.1 T reveal that the Dy_(3)Al_(5)O_(12)undergoes antiferromagnetic transition with Néel temperature TN≈2.6 K,whereas the Tb_(3)Al_(5)O_(12)and Ho_(3)Al_(5)O_(12)exhibit no features indicative of the magnetic ordering processes down to 1.8 K.The comprehensive magnetocaloric performances,namely the maximum magnetic entropy change and relative cooling power,are derived indirectly from the isothermal field-dependent magnetization data,which yield 11.72,10.42,7.53 J/(kg·K)and 84.56,69.52,70.35 J/kg for the Tb_(3)Al_(5)O_(12),Dy_(3)Al_(5)O_(12)and Ho_(3)Al_(5)O_(12)under a low field change(ΔH)of 0-2 T,respectively.The superior comprehensive magnetocaloric performances and wide operating temperature range of these compounds under lowΔH make them attractive for cryogenic MR technology.
基金Project (21001118) supported by the National Natural Science Foundation of China
文摘A novel compound Cu（phen）（m-CBA）2 was synthesized with m-chlorobenzoic acid（m-CBA）, 1,10-phenanthroline（phen） and Cu（OAc）2·H2O. It was characterized by IR, UV, elemental analyses and X-ray crystallography. It crystallizes in the monoclinic crystal system with C2/c space group, a=2.9699（4） nm, b=1.15452（2） nm, c=1.5335（2） nm, β=111.118（2）°, V=4.905 1（1） nm3, Z=8, F（000）=2 328, R1=0.072 8, wR2=0.223 4 [I2σ（I）]. Structure analysis shows that the copper center coordinates with two nitrogen atoms from one 1,10-phenanthroline molecule, two oxygen atoms from two m-chlorobenzoic acid molecules, giving a distorted squared planar coordination geometry. This novel compound shows paramagnetic interactions between copper centers.
基金Project(51301021)supported by the National Natural Science Foundation of ChinaProjects(2013G1311051,CHD2011JC139)supported by the Fundamental Research Funds for the Central Universities,ChinaProject(SKLSP201302)supported by the State Key Laboratory of Solidification Processing in NWPU,China
文摘Gd2PdSi3 single crystals were grown by a vertical floating zone method with radiation heating at a zone traveling rate of 3 mm/h. The compound exhibited congruent melting behavior at a liquidus temperature of about 1700 ＆#176;C. The slightly Pd-depleted composition of the crystal, with respect to the nominal Gd2PdSi3 stoichiometry, led to gradual accumulation of Pd in the traveling zone and to a decreasing operating temperature during the growth process. Thin platelet-like precipitates of a GdSi phase were detected in the stoichiometric feed rod growth crystal matrix which can be reduced by annealing treatment. Feed rod composition shift crystal growth was proved to be a better way of getting high quality of Gd2PdSi3 single crystal.
文摘A novel nelnatic liquid crystal compound containing a cinnamoyl moiety （PCPC） and a typically cholesteric liquid crystal cholesteryl cinnamate （CC） were synthesized to explore the mechanism ofcinnamoyl compounds, and the chemical structures of photodimerization were confirmed by Fourier transform infrared spectroscopy and 1H nuclear magnetic resonance spectral analysis. The photoreaction behaviors of these two cinnamoyl compounds in mesomorphic state and solution were investigated, UV-Vis spectral analysis was used to analyze the photoproduct. The results show that the photochemistry of PCPC in nematic state involves both photodimerization and photoisomerization, while CC shows a complex reaction which can be divided into three parts, and this has enabled us to present new data and interpretations regarding the [2＋2] photocycloaddition reaction. Additionally, the results of UV-Vis spectral analysis in solutions strongly suggest that UV-Vis spectral analysis can be used to study the kinetic behaviors of cinnamoyl moiety photoreaction.
基金Supported by the Natural Science Foundation of Henan Province (No. 0611023700)Natural Science Foundation of Education Department of Henan Province (No. 2006150019)
文摘A new supramolecular compound, { [2-（2-pyridyl）benzimidazoleH2]2＋.[SBC15]2-}2, was synthesized by the hydrothermal reaction of o-diaminobenzene, 2-pyridinecarboxylie acid and SbCl3 in 1：1 HC1 solution, and characterized by chemical analysis, elemental analysis, IR spectra, thermogravimetfic analysis and fluorescence spectra. The crystal structure was deter- mined by X-ray single-crystal diffraction. The crystal belongs to the monoclinic system, space group P211c, with a = 16.0397（13）, b = 14.3189（12）, c = 15.6370（13） A, β = 105.8980（10）°, V = 3454.0（5） A3, Z = 4, C24H22Cl10N6Sb2, Mr = 992.48, Dc = 1.909 g/cm3,/z = 2.366 mm-1, S = 1.010, F（000） = 1920, R = 0.0254 and wR = 0.0555. The coordination anion, [SbCl5]2- which is a distorted tetragonal pyramid, is composed by coordinating action with Sb3＋ ion and five adjacent chloride ions. Every four coordination anions of [SbCl5]2- form a biquaternion ring structure through the secondary bonding of Sb...Cl. Moreover, the compound adopts a three-dimensional network supramolecular structure because of the hydrogen bonds and π-π stacking between the rings and the 2-（2-pyridyl）benzimidazole divalent cations. The title compound also shows good fluorescent behaviors.
基金Supported by the Science and Technology Fund of Hunan Province (2007FJ4140)the Key Fund of Education Committee of Hunan Province (06009)the Construct Program of the Key Discipline in Hunan Province
文摘The title compound {[（C6H5CH2）2Sn]2（O）（Cl2）}2 has been synthesized by the reaction of bisbenzyltin dichloride with NaOH dilute solution, and its structure was determined by X-ray diffraction. The crystal belongs to monoclinic, space group C2/c, with a = 2.5081（17）, b = 1.0089（7）, c = 2.0909（14） nm, β = 94.267（8）°, V= 5.276（6） nm^3, Z = 4, De= 1.734 g/cm^3,μ（MoKa） = 21.55 cm^-1, F（000） = 2704, R = 0.0398 and Rw = 0.1024. According to structural analysis, the tin atom adopts a distorted five-coordinate trigonal bipyramidal geometry, and the ladder-like structure is shaped by one planar four-membered Sn2O2 ring together with two planar four-membered Sn2OCl rings.
文摘Functional organic molecular materials and conjugated oligomers or polymers now allow the low-cost fabrication of thin films for insertion into new generations of electronic and optoelectronic devices. The performance of these devices relies on the understanding and optimization of several complementary processes. Our goal is to discuss the relationship between the molecular stacking structures and their optoelectronic properties that are of importance in all these areas. The concept of intermolecular interaction should be taken here in the special sense that is inter-dipole coupling. Specifically, we will address the impact of inter-dipole interaction between adjacent molecules in aggregate state on the solid-state emission properties.
基金funded by the National Natural Science Foundation of China(No.50073019)
文摘The mixed ligand coordination compound of copper with norfloxacin (NFLX) and 1, 10-phen has been synthesized and characterized by means of X-ray single crystal diffraction. The structure features of the coordination compound are described. Antibacterial activities of the coordination compound have been tested against different microorganisms. The antitumor activities of the coordination compound on leukemia HL-60 cell line and liver cancer BEL-7402 cell line have been measured, respectively. The results indicated that the coordination compound has strong inhibitory effect on HL-60 and BEL-7402 cell lines.
基金supported by the Natural Science Foundation of Shandong Province (No. Y2008B29)
文摘Two novel spiro compounds,3-benzylidene-1,5-dioxaspiro[5.5]undecane-2,4-dione 1 and 3-（2-fluorobenzylidene）-1,5-dioxaspiro[5.5]undecane-2,4-dione 2,have been synthesized and characterized by X-ray single-crystal diffraction,IR and elemental analysis.Compound 1 belongs to the monoclinic system,space group P21/n with a=12.326（3）,b=5.6420（11）,c=20.089（4）,β= 101.79（3）o,C16H16O4,Mr= 272.29,V=1367.7（5）3,Z=4,Dc=1.322g/cm3,F（000）=576,μ（MoKa）=0.095 mm-1,the final R=0.0420 and wR=0.1159.Compound 2 is of monoclinic system,space group P21/n with a=12.283（3）,b=5.6367（11）,c=20.055（4）,β=102.00（3）o,C16H15FO4,Mr=290.28,V=1358.2（5）3,Z=4,Dc=1.420 g/cm3,F（000）=608,μ（MoKa）=0.110 mm-1,the final R=0.0353 and wR=0.0860.
基金Supported by the National Natural Science Foundation of China(No.20662007)the Bureau of Education of Jiangxi Province(No.GJJ09064)Jiangxi Science and Technology Support Program(20112BBF60009)
文摘The title compounds 5-chloro-3-methyl-1-phenyl-1H-pyrazole-4-carboxylic acid（C11H9Cl N2O2, HL）（1） and [Cu（L）2（H2O）]（2） were prepared and structurally characterized by elemental analysis, IR and single-crystal X-ray diffraction. Compound 1（C11H9Cl N2O2） crystallizes in the monoclinic system, space group P21/n with a = 7.249（3）, b = 20.515（10）, c = 7.249（3）,β= 96.30°, V = 1071.6（9） ？3, Z = 4, Mr = 236.65, Dc = 1.467 g/cm3, F（000） = 488, GOOF = 1.029, μ= 0.341 mm-1, the final R = 0.0736 and w R = 0.1966 for 1500 observed reflections with I 〉 2σ（I）. Compound 2（C22H18Cl2Cu N4O5） crystallizes in the monoclinic system, space group P21/c with a = 7.2931（6）, b = 24.548（2）, c = 13.2726（11）, β= 99.4040（10）°, V = 2344.2（3） ？3, Z = 4, Mr = 552.84, Dc = 1.566 g/cm3, F（000） = 1124, GOOF = 1.050, μ= 1.201 mm-1, the final R = 0.0376 and w R = 0.1000 for 3626 observed reflections with I 〉 2σ（I）. 1 and 2 are connected through hydrogen bonding interactions to generate 2D and 3D supramolecular structures, respectively. Moreover, the preliminary antibacterial activities of 1 and 2 against the gram positive bacteria（S. aureus, C. albicans and B. subtilis） and gram negative bacteria（E. coli and P. aeruginosa） have been tested by using the microdilution method, and the results indicate that 2 is more active than 1 against the tested bacteria.
基金Supported by the National Natural Science Foundation of China(No.21361011 and 21101081)Science Founds of State key Laboratory of Structural Chemistry(20130011)
文摘A three-dimensional（3D） coordination polymer,[Cd（SC）（DPPD）]_n（1,H_2SC = succinic acid and DPPD = 3,6-di（4-pyridyl）pyridazine）,has been synthesized by the solvothermal reaction of Cd（NO_3）_2·4H_2O with H_2 SC and DPPD at 120 ℃ in DMF solvent. Compound 1 crystallizes in the monoclinic system,space group P2_1/c,with a = 10.7993（4）,b = 11.7705（3）,c = 13.5336（6） A,V = 1678.89（11） A^3,Z = 4,C18H14N4O_4 Cd,M_r = 462.73,D_c = 1.831 g/cm^3,μ = 1.335 mm^（-1）,F（000） = 920.0,the final R = 0.0500 and wR = 0.1567 for 3714 observed reflections with I 〉 2s（I）. In compound 1,the Cd（Ⅱ） ions are linked by the SC^2– ligands to give a two-dimensional（2D） undulating sheet based on the centrosymmetric dinuclear Cd_2（COO）_2 units. The 2D sheets are further connected by the DPPD ligands to produce a 3D structure,which is a 6-connected（4^4·6·^10·8） topological network based on the dinuclear Cd_2（COO）_2 node. Compound 1 exhibits a photoluminescent emission with a maximum at 540 nm upon excitation at 460 nm.
基金supported by UMP Research(No.RDU 100338)RAGS(No.RDU131408)
文摘The fluorine-substituted benzoate ester rod-shaped liquid crystals containing an azobenzene side chain linked with terminal double bonds were synthesized and characterized.The mesophase and photoswitching properties were determined by polarizing optical microscopy（POM）,differential scanning calorimetry（DSC） and UV-visible spectrometry.The rod-shaped compound 4a having an odd number of carbon atoms in the alkyl chains exhibits nematic phase and SmA type phase whereas compound 4b having an even number of carbon atoms showed only nematic phase.Both fluorinecontaining compounds 4c and 4d showed only SmA type phases.The photoswitching properties of these compounds showed a rate of trans to cis isomerization ranging 19-20 s,whereas reverse process took around 230 min in solution.These materials may be ideal in the field of optically rewritable applications where both on and off rates should be crucial.
文摘Rare earth(RE)-containing crystals have been investigated as media for the immobilization of RE fission products from nuclear waste streams.During reprocessing of spent nuclear fuel,fission products including REs,alkalis,and alkaline earths released from the fuel.One viable option to immobilize the RE fission products is to incorporate them into chemically durable crystalline phases in specific waste forms.This study summarizes the crystal structures and synthesis methods of six RE-containing compounds that have applications in remediation of RE fission products.These compounds include oxyapatite(AE_(2)RE_(8)(SiO_(4))_(6)O_(2)),oxychloride(REOCl),borosilicate(RE_(3)BSi_(2)O_(10)),pyrochlore(RE_(2)M_(2)O_(7)),monazite(REPO_(4)),and perovskite(REMO_(3))where AE denotes alkaline earth metals and M denotes transition metals.This review provides an overview of literature on the usage of these six compounds for immobilizing RE fission products and summarizes different synthesis methods for producing these compounds.Comparisons of structural parameters with different REs in each compound are also discussed.
基金supported by the National Natural Science Foundation of China(No.20971004)the Natural Science Foundation of Anhui Provincial Educational Commission(No.KJ2010A229,No.2011SQRL098)
文摘A new luminescent compound, Zn（8-aminoql）2（SCN）2 （1, 8-aminoql = 8-amino quinoline）, has been synthesized and its structure was characterized by IR, elemental analysis and X-ray single-crystal diffraction. Compound 1 belongs to the orthorhombic system, space group Pbca with a = 8.503（2）, b = 14.427（4）, c = 31.922（8）A, V= 3916.0（18） A3, Z = 8, C20H16N6S2Zn, Mr = 469.88, Dc = 1.594 Mg/m3, μ = 1.488 mm-1, F（000） = 1920, T = 296（2） K, the final R = 0.0293 and wR = 0.0645 for all 2763 observed reflections （1 〉 2a（/））. Compound 1 displays a 3D supramolecular architecture formed by N-H--S hydrogen bonds and π...π aromatic packing interactions. Photoluminescence studies reveal that it displays obvious fluorescent emission band （λex = 320 nm） at 533 nm in the solid state at room temperature. The emission bands possess a broad asymmetric feature, which can be assigned to ligand-to-ligand charge transfer transitions based on DFT calculations.
文摘Organic nonlinear optical material of 4-bromo-4’-methyl benzylidene aniline (BMBA) was synthesized and single crystal of BMBA was grown by solvent evaporation method at room temperature using ethanol as solvent. The crystalline nature of the grown crystals was confirmed using powder X-ray diffraction studies. The crystals were also characterized by single crystal X-ray diffraction method and their lattice parameters were determined. Thermal properties of BMBA were evaluated with thermogravimetric, differential thermal and differential scanning calorimetric analyses. Fourier transform infrared and FT-Raman spectral studies were carried out on the BMBA material to confirm the synthesized compound. 1H and 13C-nuclear magnetic resonance spectral studies were recorded to elucidate the structure of the grown crystals. Fluorescence spectrum recorded shows a peak at 485 nm. UV-Vis-NIR spectral analysis shows transmittance of ~92% in the visible region. The mechanical stability was analyzed by Vickers microhardness tester and the work hardening coefficient of the grown crystal was calculated. Second harmonic generation efficiency of the grown crystal measured by Kurtz powder technique is ~1.8 times that of potassium dihydrogen orthophosphate.
基金Supported by the National Natural Science Foundation of China(No.21361011 and 21101081)Science Founds of State Key Laboratory of Structural Chemistry(20130011)
文摘A dinuclear Tb（Ⅲ） compound, Tb_2（μ_2-anthc）_4（anthc）_2（1,10-phen）_2（1, Hanthc = 9-anthracenecarboxylic acid and 1,10-phen = 1,10-phenanthroline）, was synthesized under solvothermal condition and structurally characterized by single-crystal X-ray diffraction. Compound 1 crystallizes in the triclinic system, space group P1, with a = 12.5061（12）, b = 13.3168（10）, c = 15.0079（12） ？, α = 110.620（7）, β = 102.941（7）, γ = 107.036（7）o, V = 2081.8（3） ？~3, Z = 1, C_（114）H_（70）N_4O_（12）Tb_2, M_r = 2005.58, D_c = 1.600 g/cm^3, μ = 1.759 mm^（-1）, F（000） = 1008, the final R = 0.0294 and w R = 0.0608 for 8900 observed reflections with I 〉 2s（I）. In compound 1, two Tb（Ⅲ） ions are linked by four carboxylate groups of the bridging anthc– ligands to give a dinuclear Tb_2（μ_2-anthc）_4 unit wherein each Tb（III） ion is further capped by a terminal anthc– ligand and a 1,10-phen ligand in a chelating fashion. Detailed direct-current and alternating-current susceptibility measurements showed no slow magnetism relaxation phenomenon was observed for 1.
基金supported by the National Natural Science Foundation of ChinaNatural Science Foundation of High Learning Institutions of Anhui ProvinceScience Supported Foundation of Nanjing Xiaozhuang College(No.21201103,KJ2012ZD11 and 2014XZRC01)
文摘Two metal-dithiolene compounds with a formula of[4-ClBz-l-APy][Ni（dmit）2]（1）and[4-NO2Bz-l-APy][Ni（dmit）2]（2,4-ClBz-1-APy = 1-N-（4＇-chlorobenzyl）pyridinium,4-NO2Bz-1-APy = l-N-（4＇-nitrobenzyl）pyridinium,dmit^（2-）= 1,3-dithiole-2-thione-4,5-dithiolate） were synthesized and characterized.Two compounds crystallize in triclinic space group P1 and P1,respectively,but with different cell parameters and packing structures.The[Ni（dmit）2]^- anions and cations of 1 form mixed column stacks along the a axis and alternately layered alignments in the crystal of 2,which are parallel to the crystallographic（110） plane.Two compounds show a similar magnetic behavior,the magnetic exchange natures are mainly antiferromagnetic,and the magnetic susceptibility data can be fitted to the simple Curie-Weiss law.For 1 and 2,the fitted Curie constants are much less than the spin-only value expected for an S =1/2 system,and the fitted Weiss constants marking magnetic interaction are also very smaller.This fact implies that the weak CurrieWeiss-type paramagnetism is not the intrinsic characteristics of two compounds.
