Two new binary cocrystals formulated as POM·NBA 1 and POM·DNSA 2 （POM = 3-methyl-4-nitro-pyridine-N-oxide, NBA = o-nitrobenzoic acid, DNSA = 3,5-dinitrosalicylic acid） have been successfully synthesized an...Two new binary cocrystals formulated as POM·NBA 1 and POM·DNSA 2 （POM = 3-methyl-4-nitro-pyridine-N-oxide, NBA = o-nitrobenzoic acid, DNSA = 3,5-dinitrosalicylic acid） have been successfully synthesized and characterized by elemental analysis, IR and X-ray single- crystal diffraction analysis. The crystal of 1 crystallizes in triclinic, space group P1, with a = 7.621（4）, b = 7.816（4）, c = 11.702（5） , α = 87.957（10）, β = 83.642（10）, γ = 81.535（10）o, C13H11N3O7, Z = 2, Mr = 321.25, V = 685.1（6） 3, Dc = 1.557 g/cm3, F（000） = 332, μ = 0.129 mm-1, the final R = 0.0632 and wR = 0.0831. The crystal of 2 crystallizes in monoclinic, space group P21/c with a = 14.910（9）, b = 5.904（3）, c =19.321（12） , β = 110.583（10）o, C13H10N4O10, Z = 4, Mr = 382.25, V = 1592.1（16） 3, Dc = 1.595 g/cm3, F（000） = 784, μ = 0.140 mm-1, the final R = 0.0598 and wR = 0.1589. Further structure analysis reveals that the POM with NBA and DNSA molecules in 1 and 2 are linked into 3D structures by the combination of strong O-H…O and weak C-H…O hydrogen bonds, π…π stackings and diverse short contacts, in which different C-H…O weak hydrogen bonds may play a key role in constructing the network structures.展开更多
Ferroelastic rare earth tantalates(RETaO_(4))are widely researched as the next-generation thermal barrier coatings(TBCs),and RETaO_(4)powders are hugely significant for synthesizing their coatings.The current research...Ferroelastic rare earth tantalates(RETaO_(4))are widely researched as the next-generation thermal barrier coatings(TBCs),and RETaO_(4)powders are hugely significant for synthesizing their coatings.The current research used chemical co-precipitation within an automated experimental device to synthesize RETaO_(4)(RE=Nd,Sm,Gd,Ho,Er)powders.The device automatically monitored and controlled the solutions'pH,improving the chemical co-precipitation efficiency.The crystal structure and microstructure of the RETaO_(4)powders can be controlled by changing the annealing temperature,and the materials undergo an m'-m phase transition.The m'-RETaO_(4)powders exhibit nano-size grains,while m-RETaO_(4)powders evince micron-size grains,altered by the annealing temperatures.A simultaneous thermal analysis es-timates the reversive ferroelastic tetragonal-monoclinic phase transition temperatures.Overall,this research focuses on the synthesis,crystal structures,microstructures,and phase transition of the fabricated RETaO_(4)powders.展开更多
The reaction of Mg^(2+)and 5-{1,3-dioxo-1H-benzo[de]isoquinolin-2(3H)-yl}terephthalic acid(H_(2)L)leads to two metal-organic frameworks,[Mg(L)(DMF)_(2)(H_(2)O)_(2)]_(2)·5DMF·2H_(2)O(1)with a 1D structure and...The reaction of Mg^(2+)and 5-{1,3-dioxo-1H-benzo[de]isoquinolin-2(3H)-yl}terephthalic acid(H_(2)L)leads to two metal-organic frameworks,[Mg(L)(DMF)_(2)(H_(2)O)_(2)]_(2)·5DMF·2H_(2)O(1)with a 1D structure and[Mg_(2)(L)_(2)(DMSO)_(3)(H_(2)O)](2)with a 2D(4,4)-net structure.Interestingly,the two compounds exhibit distinct luminescent responses to external mechanical stimuli.1 exhibited exceptional resistance mechanical chromic luminescence(RMCL),which can be attributed to the predominant hydrogen bonds and the presence of high-boiling-point solvent molecules within its structure.2 had a reversible MCL property,which can be attributed to the dominantπ-πweak interactions,coupled with the reversible destruction/restoration of its crystallinity under grinding/fumigation.CCDC:2410963,1;2410964,2.展开更多
Two new transition-metal coordination polymers,{[Cd(oba)(L)_(2)]·H_(2)O}_n(1)and[Cd(4-nph)(L)_(2)]_n(2)(H_(2)oba=4,4'-oxydibenzoic acid,4-H_(2)nph=4-nitrophthalic acid,L=2,2'-biimidazole),were successfull...Two new transition-metal coordination polymers,{[Cd(oba)(L)_(2)]·H_(2)O}_n(1)and[Cd(4-nph)(L)_(2)]_n(2)(H_(2)oba=4,4'-oxydibenzoic acid,4-H_(2)nph=4-nitrophthalic acid,L=2,2'-biimidazole),were successfully synthesized under hydrothermal conditions and characterized structurally by IR spectroscopy,elemental analyses,single-crystal X-ray diffraction,powder X-ray diffraction,and thermogravimetric analysis.The results of single-crystal X-ray diffraction show that complex 1 presents a 1D zigzag chain structure and further extends to a 2D network through N—H…O hydrogen bonds andπ-πstacking interactions.Meanwhile,complex 2 has a zero-dimensional structure and also extends to form a 2D network through N—H…O hydrogen bonds andπ-πstacking interactions.In addition,both 1and 2 exhibited luminescent properties in the solid state.Furthermore,quantum chemical calculations were carried out on the"molecular fragments"extracted from the crystal structures of 1 and 2 using the PBE0/LANL2DZ method constructed by the Gaussian 16 program.The calculated values signify a significant covalent interaction between the coordination atoms and the Cd(Ⅱ)ions.CCDC:2332173,1;2332176,2.展开更多
All-inorganic perovskites based on cesium-lead-bromine(Cs-Pb-Br)have been a prominent research focus in optoelectronics in recent years.The optimisation and tunability of their macroscopic properties exploit the confo...All-inorganic perovskites based on cesium-lead-bromine(Cs-Pb-Br)have been a prominent research focus in optoelectronics in recent years.The optimisation and tunability of their macroscopic properties exploit the conformational flexibility,resulting in various crystal structures.Varying synthesis parameters can yield distinct crystal structures from Cs,Pb,and Br precursors,and manually exploring the relationship between these synthesis parameters and the resulting crystal structure is both labour-intensive and time-consuming.Machine learning(ML)can rapidly uncover insights and drive discoveries in chemical synthesis with the support of data,significantly reducing both the cost and development cycle of materials.Here,we gathered synthesis parameters from published literature(220 synthesis runs)and implemented eight distinct ML models,including eXtreme Gradient Boosting(XGB),Decision Tree(DT),Support Vector Machine(SVM),Random Forest(RF),Naïve Bayes(NB),Logistic Regression(LR),Gradient Boosting(GB),and K-Nearest(KN)to classify and predict Cs-Pb-Br crystal structures from given synthesis parameters.Validation accuracy,precision,F1 score,recall,and average area under the curve(AUC)are employed to evaluate these ML models.The XGB model exhibited the best performance,achieving a validation accuracy of 0.841.The trained XGB model was subsequently utilised to predict the structure from 10 experimental runs using a randomised set of parameters,achieving a testing accuracy of 0.8.The results indicate that the Cs/Pb molar ratio,reaction time,and the concentration of organic compounds(ligands)play crucial roles in synthesising various crystal structures of Cs-Pb-Br.This study demonstrates a significant decrease in effort required for experimental procedures and builds a foundational basis for predicting crystal structures from synthesis parameters.展开更多
In this study,a comprehensive analysis of microstructural features,morphology,crystal structures,and interface structures of long-period stacking ordered(LPSO)structures in a non-equilibrium Mg_(97)Zn_(1)Y_(16)Ca_(0.4...In this study,a comprehensive analysis of microstructural features,morphology,crystal structures,and interface structures of long-period stacking ordered(LPSO)structures in a non-equilibrium Mg_(97)Zn_(1)Y_(16)Ca_(0.4)alloy cast in a steel mold was carried out.The addition of Ca element plays an important role in the refinement of LPSO structure.The result reveals new poly-types including 20H F2F2F4,60R(F2F3F3)_(3),and 66H F2F3F3F2(F6)_(4)featuring a 6-Mg structure,alongside the prevalent 18R and 14H LPSO structures.The incoherent interface between 20H and the Mg matrix is split into two dislocation arrays,leading to the formation of a segment of 60R_(1).Moreover,the superstructure 116L,designated as(F2)_(18)F4,is formed through the ordered distribution of F4 stacking faults in 18R.展开更多
Novel ordered intermetallic compounds have stimulated much interest.Ru–Al alloys are a prominent class of hightemperature structural materials,but the experimentally reported crystal structure of the intermetallic Ru...Novel ordered intermetallic compounds have stimulated much interest.Ru–Al alloys are a prominent class of hightemperature structural materials,but the experimentally reported crystal structure of the intermetallic Ru_(2)Al_(5) phase remains elusive and debatable.To resolve this controversy,we extensively explored the crystal structures of Ru_(2)Al_(5) using first-principles calculations combined with crystal structure prediction technique.Among the calculated x-ray diffraction patterns and lattice parameters of five candidate Ru2Al5structures,those of the orthorhombic Pmmn structure best aligned with recent experimental results.The structural stabilities of the five Ru_(2)Al_(5)structures were confirmed through formation energy,elastic constants,and phonon spectrum calculations.We also comprehensively analyzed the mechanical and electronic properties of the five candidates.This work can guide the exploration of novel ordered intermetallic compounds in Ru–Al alloys.展开更多
Experimental crystallographic structural parameters of a range of metaled meso-substituted and unsubstituted porphyrins were reviewed to show how far the meso-substitution by any functional group and the insertion of ...Experimental crystallographic structural parameters of a range of metaled meso-substituted and unsubstituted porphyrins were reviewed to show how far the meso-substitution by any functional group and the insertion of metal in the porphyrins core macrocycle may affect the geometry. The analysis of twists and angles has shown two kinds of distortions: external [T(C<sup>β</sup>-C<sup>α</sup>-C<sup>meso</sup>-X<sup>n</sup>) and T(C<sup>β</sup>-C<sup>α</sup>-C<sup>meso</sup>-C<sup>α</sup>)] and internal [T(N<sup>m</sup>-C<sup>α</sup>-C<sup>meso</sup>-X<sup>n</sup>) and T(N<sup>n</sup>-C<sup>α</sup>-C<sup>meso</sup>-C<sup>α</sup>)] with averages of [+6°and –6°] and [–5°and +5°], respectively. In the meso-substituted case, the external and internal twists C<sup>β</sup>-C<sup>α</sup>-C<sup>meso</sup>-X and N-C<sup>α</sup>-C<sup>meso</sup>-X, respectively are oppositely orientated. Similar effect is observed in meso-unsubstituted of C<sup>β</sup>-C<sup>α</sup>- C<sup>meso</sup>-H and N-C<sup>α</sup>-C<sup>meso</sup>-H. However, the external distortions are more significant than internal. Considering the same order, the limit of distortions is [97°and 132°(–48°)] for external and [91°(–89°) and 52°] for internal. In the two cases, the substituents have opposite directions of distortions. The meso-substituted porphyrins have a high limit of twisting than usubstituted one, depending of the weight of substituents. The average of the bond angular deformations is 168°, almost planar. However, the limit of angular deformation is 94°.展开更多
Pyrrhotite is an associated mineral that exists widely in sulfide ore. The presence of pyrrhotite will affect the recovery of platinum group minerals. Therefore, researchers have paid increasing attention to the flota...Pyrrhotite is an associated mineral that exists widely in sulfide ore. The presence of pyrrhotite will affect the recovery of platinum group minerals. Therefore, researchers have paid increasing attention to the flotation separation of pyrrhotite. Pyrrhotite superstructures owning different Fe/S ratios results in various crystal structures, corresponding to different physical, chemical and electronic properties, and consequently different flotation behavior. In the present paper, a comprehensive review is conducted to discuss the influence of crystal structures on the natural floatability, mineral-reagent interaction, surface oxidation and flotation electrochemistry of pyrrhotite. The selective flotation process of pyrrhotite from its associated minerals is also reviewed in this paper. It is hoped that this review can summarize the newly published research results combined with some representative results from the past, to provide a theoretical basis for the study of the flotation mechanism of pyrrhotite and provide a new direction for future research on pyrrhotite.展开更多
In order to understand the dominant factors of the physical properties of ice in ice thermodynamics and mechanics, in-situ observations of ice growth and decay processes were carried out. Two samplings were conducted ...In order to understand the dominant factors of the physical properties of ice in ice thermodynamics and mechanics, in-situ observations of ice growth and decay processes were carried out. Two samplings were conducted in the fast and steady ice growth stages. Ice pieces were used to observe ice crystals and gas bubbles in ice, and to measure the ice density. Vertical profiles of the type and size of ice crystals, shape and size of gas bubbles, and gas bubble content, as well as the ice density, were obtained. The results show that the upper layer of the ice pieces is granular ice and the lower layer is columnar ice; the average crystal size increases with the ice depth and remains steady in the fast and steady ice growth stages; the shape of gas bubbles in the upper layer of ice pieces is spherical with higher total content, and the shape in the middle and lower layers is cylinder with lower total content; the gas bubble size and content vary with the ice growth stage; and the ice density decreases with the increase of the gas bubble content.展开更多
α‐,β‐,δ‐,andγ‐MnO2nanocrystals are successfully prepared.We then evaluated the NH3selective catalytic reduction(SCR)performance of the MnO2catalysts with different phases.The NOx conversion efficiency decrease...α‐,β‐,δ‐,andγ‐MnO2nanocrystals are successfully prepared.We then evaluated the NH3selective catalytic reduction(SCR)performance of the MnO2catalysts with different phases.The NOx conversion efficiency decreased in the order:γ‐MnO2>α‐MnO2>δ‐MnO2>β‐MnO2.The NOx conversion with the use ofγ‐MnO2andα‐MnO2catalysts reached90%in the temperature range of140–200°C,while that based onβ‐MnO2reached only40%at200°C.Theγ‐MnO2andα‐MnO2nanowire crystal morphologies enabled good dispersion of the catalysts and resulted in a relatively high specific surface area.We found thatγ‐MnO2andα‐MnO2possessed stronger reducing abilities and more and stronger acidic sites than the other catalysts.In addition,more chemisorbed oxygen existed on the surface of theγ‐MnO2andα‐MnO2catalysts.Theγ‐MnO2andα‐MnO2catalysts showed excellent performance in the low‐temperature SCR of NO to N2with NH3.展开更多
Three complexes, [Pr（NO3）3（HL）2] （1）, [Nd（NO3）3（HL）2] （2） and [Er（NO3）3（HL）2] ·0.5H2O （3）, were synthesized from the reaction of a Schiff base ligand 2-[ （4-methylphenylimino）methyl ]-6-methox...Three complexes, [Pr（NO3）3（HL）2] （1）, [Nd（NO3）3（HL）2] （2） and [Er（NO3）3（HL）2] ·0.5H2O （3）, were synthesized from the reaction of a Schiff base ligand 2-[ （4-methylphenylimino）methyl ]-6-methoxyphenol （C15 H15 NO2, HL） with Ln（NO3）3·6H2O （Ln = Pr, Nd, Er）. Characterization by single-crystal X-ray diffraction technique, elemental analysis, molar conductance, FT-IR, UV-Vis, ^1H NMR and thermal analysis shows the title complexes are neutral molecules where the central Ln（ Ⅲ） ion is ten-coordinated in biapical anti-hexahedron prism geometry, with four oxygen atoms of the phenolic hydroxy and methoxy groups in the two bidentate Schiff base ligands and six oxygen atoms provided by the three bidentate NO3 - anions. Additionally, the kinetic mechanism of thermal decomposition of complex 3 was determined with a TG-DTG curves by both integral and differential methods. The functions of thermal decomposition reaction mechanism and the equation of kinetic compensation effect were obtained.展开更多
Two novel complexes,[（C9H18NS2）3Sb（III）]（1） and [（C9H18NS2）3Bi（III）]（2）,were synthesized and characterized by elemental analysis,IR,TG and X-ray single-crystal diffraction.Both 1 and 2 crystallize in the m...Two novel complexes,[（C9H18NS2）3Sb（III）]（1） and [（C9H18NS2）3Bi（III）]（2）,were synthesized and characterized by elemental analysis,IR,TG and X-ray single-crystal diffraction.Both 1 and 2 crystallize in the monoclinic system,P21/c space group.The data for 1：a = 1.6964（3）,b = 1.02149（17）,c = 2.5650（3） nm,β = 121.824（8）°,Z = 4,V = 3.7766（10） nm^3,Dc = 1.293 g·cm^-3,F（000） = 1536,μ = 1.082 mm^-1,the final R = 0.0500,wR = 0.1562 and S =1.072.The data for 2：a = 1.6802（9）,b = 1.0256（6）,c = 2.5083（10） nm,β = 121.77（3）°,Z = 4,V = 3.675（3） nm^3,Dc = 1.486 g·cm^-3,F（000） = 1664,μ = 5.159 mm^-1,the final R = 0.0481,wR = 0.1055 and S =1.076.The coordinated geometry of the central M（III） with six sulfur atoms from three ligands is a distorted pentagonal pyramid configuration.The dimer structural system is formed by the weak interactions of M…S and C-H…S between two molecules.The complexes were valued for their antibacterial activities by agar-streak method.It was found that 1 is active against the four test bacterial organisms.展开更多
The title compounds, C7H4I2O2 1 and C13H7I2N2O3 2, have been synthesized and characterized by single-crystal X-ray diffraction. Compound 1 crystallizes in monoclinic, space group P21/c with a = 9.802（2）, b = 13.867...The title compounds, C7H4I2O2 1 and C13H7I2N2O3 2, have been synthesized and characterized by single-crystal X-ray diffraction. Compound 1 crystallizes in monoclinic, space group P21/c with a = 9.802（2）, b = 13.867（3）, c = 7.364（2） A, β = 109.74（3）°, V= 942.1（3） A^3, Dc= 2.636 g/cm^3, C7H4I2O2, Mr= 373.90, F（000） = 672, μ = 6.627 mm^-1, Z = 4, R = 0.0459 and wR = 0.1018 for 1805 observed reflections （I 〉 2 σ（I））. Compound 2 belongs to the monoclinic system, space group P21/n with a = 9.015（2）, b = 12.024（2）, c = 14.072（3） A, β = 103.91（3）°, V = 1480.6（5） A^3, Dc= 2.216 g/cm^3, C13H7I2N2O3, Mr= 494.01, F（000） = 920, p = 4.255 mm^-1, Z = 4, R = 0.0777 and wR = 0.1757 for 2896 observed reflections （I 〉 2σ（I））. Compounds 1 and 2 were assayed for antibacterial activities against three Gram positive bacterial strains （B. subtilis, S. aureus and S. faecalis） and three Gram negative bacterial strains （E. coli, P. aeruginosa and E. cloacae） by MTr method. Fortunately, compound 2 is found to show potent antibacterial activity against these six bacterial strains.展开更多
Two new compounds containing triarylamine and benzoic hydrazide units, 4- [N,N-di(4-toyl)amino]benzaldehyde-N-(4-ethoxylphenyl)-formyl hydrazone 3a and 4-[N,N-di(4- toyl) amino]benzaldehyde-N-(2-ethoxylphenyl)-formyl ...Two new compounds containing triarylamine and benzoic hydrazide units, 4- [N,N-di(4-toyl)amino]benzaldehyde-N-(4-ethoxylphenyl)-formyl hydrazone 3a and 4-[N,N-di(4- toyl) amino]benzaldehyde-N-(2-ethoxylphenyl)-formyl hydrazone 3b, have been synthesized and their crystal structures (C30H29N3O2, Mr = 463.56) were interpreted by a combination technique of 1HNMR, IR, elemental analysis, mass spectra, UV-Vis spectra and X-ray crystallography, respec- tively. The crystal of 3a belongs to monoclinic, space group P21/n with a = 9.321(3) ? b = 11.046(4) ? c = 24.335(9) ? b =92.649(7), V = 2502.7(16) ?, Z = 4, m = 0.078 mm-1, Dc =1.230 g/cm3, F(000) = 984, the final R = 0.0590 and wR = 0.1316 for 4367 observed reflections with I > 2s(I). The crystal of 3b belongs to monoclinic, space group P21/c with a = 10.637(4) ? b = 24.138(10) ? c = 10.398(4) ? b = 104.913(8), V = 2579.8(17) ?, Z = 4, m = 0.075 mm-1, Dc = 1.194 g/cm3, F(000) = 984, the final R =0.0631 and wR =0.1006 for 4463 observed reflections with I > 2s(I). X-ray crystallography revealed that the nitrogen atom in the triarylamine moiety is of sp2 hybridization with the three phenyl rings twisted to each other.展开更多
Six new transition metal complexes, [Zn（HBTC）（PYTPY）]n·n PYTPY（1）, [Cu（HBTC）（PYTPY）]n·n PYTPY（2）, [Co（HBTC）（PYTPY）]n·n DMF（3）, [Mn（HBTC）（PYTPY）]n·n DMF（4）, [Cd（HBTC）（PYTP...Six new transition metal complexes, [Zn（HBTC）（PYTPY）]n·n PYTPY（1）, [Cu（HBTC）（PYTPY）]n·n PYTPY（2）, [Co（HBTC）（PYTPY）]n·n DMF（3）, [Mn（HBTC）（PYTPY）]n·n DMF（4）, [Cd（HBTC）（PYTPY）（H2O）]n·2nH2O（5）, and [Co（HBTC）（PYTPY）（H2O）2]（6）,（H3BTC = 1,3,5-benzenetricarboxylic acid, PYTPY = 4＇-（4-pyridyl）-2,2＇：6＇,2＇＇-terpyridine, DMF = N,N？-dimethylformamide）, have been synthesized and characterized by elemental analysis, IR and X-ray single-crystal diffraction. Complexes 1~5 all feature one-dimensional chain structures, and complex 6 exhibits a zero-dimensional structure. Complexes 1~5 present three-dimensional（3D） supramolecular frameworks via π-π stacking interactions, whenas 6 has also a 3D supramolecular structure assembled by hydrogen bonding. Meanwhile, complexes 1 ~ 6 exhibit the thermal stabilities and photoluminescent properties.展开更多
A complex [NIL2] was synthesized, in which L, or to be exact, a Schiff base ligand （HL）, was derived from the condensation of 1-phenyl-3-methyl-4-phenylacetyl-5-pyrazolone （PMPAP） with L-phenylalanine methyl ester...A complex [NIL2] was synthesized, in which L, or to be exact, a Schiff base ligand （HL）, was derived from the condensation of 1-phenyl-3-methyl-4-phenylacetyl-5-pyrazolone （PMPAP） with L-phenylalanine methyl ester. They were characterized by IR and single-crystal X-ray diffraction. Green block crystals of both ligand and its complex were grown at room temperature. The ligand, which consists of two individual fragments, crystalizes in the P1 space group （a = 5.6268（5）, b = 10.6892（11） and c = 19.4869（18） A）. The complex crystalizes in the P21 space group （a -- 21.4076（18）, b = 9.4792（8） and c = 25.287（2） A）, which consists of a nickel six-coordinated compound. Every fragment is a distorted octahedron with four oxygen and two nitrogen atoms. The Schiff base ligand （HL） and its complex have been tested in vitro to evaluate their antibacterial activity against bacteria Escherichia Coli and Bacillus subtilis. It is found that the complex has higher activity than the corresponding free Schiff base ligand （HL） against the same bacterial.展开更多
Five lanthanide complexes of Ln2（dpdc）2（tpy）2（NO3）2（H2O）2 [Ln=La （1）, Ce （2）, Pr （3）, Sm （4）, Gd （5）, H2dpdc=2,2’-biphenyldicarboxylic acid and tpy=2,2’：6’,2’’-terpyridine] were prepared at roo...Five lanthanide complexes of Ln2（dpdc）2（tpy）2（NO3）2（H2O）2 [Ln=La （1）, Ce （2）, Pr （3）, Sm （4）, Gd （5）, H2dpdc=2,2’-biphenyldicarboxylic acid and tpy=2,2’：6’,2’’-terpyridine] were prepared at room temperature and characterized by X-ray diffraction, FT-IR and thermo-gravimetric analysis. The results showed that complexes 1–5 were isostructural and consisted of dinuclear units [Ln2（dpdc）2（tpy）2（NO3）（H2O）2] bridged by two dpdc2？ ligands. The dinuclear units with strong intramolecular hydrogen bonds were assembled into 2D supramolecular layers by the weak π？？？π staking interactions between pyridine rings of tpy. The TG analysis showed that the complexes 1–5 behaved higher thermal stability with no mass loss at 〈 320 °C. The lanthanide contraction effect and the solid state luminescence properties of complexes 1–5 were also investigated. The luminescence emission spectra of complexes 1–5 exhibited ligands emission bands and complex 3 and 4 had no typical emission in the visible region.展开更多
A one dimension solid and a two dimension solid consisting of polyoxoanions bridged by {CoO 3N 2} and {CoO 4} groups respectively have been synthesized by the hydrothermal method and structurally characterized by...A one dimension solid and a two dimension solid consisting of polyoxoanions bridged by {CoO 3N 2} and {CoO 4} groups respectively have been synthesized by the hydrothermal method and structurally characterized by X Ray crystallography. Each structure has the [(PO 4) 4Mo 6O 15 ] 12- cluster that is commonly observed in many molybdophosphates. In compound 1, [(PO 4) 4Mo 6O 15 ] 12- clusters are linked by {CoO 3N 2} groups to form a chain like structure, and the chains are hydrogen bonded into a network. Compound 2 is a layer structure with channnels constructed from [(PO 4) 4Mo 6O 15 ] 12- clusters and {CoO 4} groups, the organic molecules and the lattice water molecules are distributed disorderly in the interlamellar region and form strong hydrogen bonds with inorganic framework. The IR and the fluorescent spectra were investigated and discussed.展开更多
A new homochiral ligand,（R）-2-（4-pyridyl）-4,5-dihydrothiazole-4-carboxylic acid（HL^R）, has been synthesized. Two complexes, [ZnL2^R（H2O）2]·H2O（1） and [MnL2^R（H2O）2]？H2O（2） have been prepared by the...A new homochiral ligand,（R）-2-（4-pyridyl）-4,5-dihydrothiazole-4-carboxylic acid（HL^R）, has been synthesized. Two complexes, [ZnL2^R（H2O）2]·H2O（1） and [MnL2^R（H2O）2]？H2O（2） have been prepared by the reactions of Zn（Ⅱ） and Mn（Ⅱ） ions with the ligand HLR, and characterized by single-crystal X-ray diffraction analysis and fluorescence. Complexes 1 and 2 are isomorphs, and both of the Zn（Ⅱ） and Mn（Ⅱ） centers in 1 and 2 are six-coordinated by the two NO units of two ligands and two water oxygen atoms, showing distorted octahedral coordination geometry. Complexes 1 and 2 show fluorescent properties in the solid state at room temperature.展开更多
基金supported by the National Natural Science Foundation of China (No. 50872057)
文摘Two new binary cocrystals formulated as POM·NBA 1 and POM·DNSA 2 （POM = 3-methyl-4-nitro-pyridine-N-oxide, NBA = o-nitrobenzoic acid, DNSA = 3,5-dinitrosalicylic acid） have been successfully synthesized and characterized by elemental analysis, IR and X-ray single- crystal diffraction analysis. The crystal of 1 crystallizes in triclinic, space group P1, with a = 7.621（4）, b = 7.816（4）, c = 11.702（5） , α = 87.957（10）, β = 83.642（10）, γ = 81.535（10）o, C13H11N3O7, Z = 2, Mr = 321.25, V = 685.1（6） 3, Dc = 1.557 g/cm3, F（000） = 332, μ = 0.129 mm-1, the final R = 0.0632 and wR = 0.0831. The crystal of 2 crystallizes in monoclinic, space group P21/c with a = 14.910（9）, b = 5.904（3）, c =19.321（12） , β = 110.583（10）o, C13H10N4O10, Z = 4, Mr = 382.25, V = 1592.1（16） 3, Dc = 1.595 g/cm3, F（000） = 784, μ = 0.140 mm-1, the final R = 0.0598 and wR = 0.1589. Further structure analysis reveals that the POM with NBA and DNSA molecules in 1 and 2 are linked into 3D structures by the combination of strong O-H…O and weak C-H…O hydrogen bonds, π…π stackings and diverse short contacts, in which different C-H…O weak hydrogen bonds may play a key role in constructing the network structures.
基金the Rare and Precious Metals Material Genetic Engineering Project of Yunnan Province(202102AB080019-1)National Key Research and Development Program of China(2022YFB3708600)the National Natural Science Foundation of China(91960103).
文摘Ferroelastic rare earth tantalates(RETaO_(4))are widely researched as the next-generation thermal barrier coatings(TBCs),and RETaO_(4)powders are hugely significant for synthesizing their coatings.The current research used chemical co-precipitation within an automated experimental device to synthesize RETaO_(4)(RE=Nd,Sm,Gd,Ho,Er)powders.The device automatically monitored and controlled the solutions'pH,improving the chemical co-precipitation efficiency.The crystal structure and microstructure of the RETaO_(4)powders can be controlled by changing the annealing temperature,and the materials undergo an m'-m phase transition.The m'-RETaO_(4)powders exhibit nano-size grains,while m-RETaO_(4)powders evince micron-size grains,altered by the annealing temperatures.A simultaneous thermal analysis es-timates the reversive ferroelastic tetragonal-monoclinic phase transition temperatures.Overall,this research focuses on the synthesis,crystal structures,microstructures,and phase transition of the fabricated RETaO_(4)powders.
文摘The reaction of Mg^(2+)and 5-{1,3-dioxo-1H-benzo[de]isoquinolin-2(3H)-yl}terephthalic acid(H_(2)L)leads to two metal-organic frameworks,[Mg(L)(DMF)_(2)(H_(2)O)_(2)]_(2)·5DMF·2H_(2)O(1)with a 1D structure and[Mg_(2)(L)_(2)(DMSO)_(3)(H_(2)O)](2)with a 2D(4,4)-net structure.Interestingly,the two compounds exhibit distinct luminescent responses to external mechanical stimuli.1 exhibited exceptional resistance mechanical chromic luminescence(RMCL),which can be attributed to the predominant hydrogen bonds and the presence of high-boiling-point solvent molecules within its structure.2 had a reversible MCL property,which can be attributed to the dominantπ-πweak interactions,coupled with the reversible destruction/restoration of its crystallinity under grinding/fumigation.CCDC:2410963,1;2410964,2.
文摘Two new transition-metal coordination polymers,{[Cd(oba)(L)_(2)]·H_(2)O}_n(1)and[Cd(4-nph)(L)_(2)]_n(2)(H_(2)oba=4,4'-oxydibenzoic acid,4-H_(2)nph=4-nitrophthalic acid,L=2,2'-biimidazole),were successfully synthesized under hydrothermal conditions and characterized structurally by IR spectroscopy,elemental analyses,single-crystal X-ray diffraction,powder X-ray diffraction,and thermogravimetric analysis.The results of single-crystal X-ray diffraction show that complex 1 presents a 1D zigzag chain structure and further extends to a 2D network through N—H…O hydrogen bonds andπ-πstacking interactions.Meanwhile,complex 2 has a zero-dimensional structure and also extends to form a 2D network through N—H…O hydrogen bonds andπ-πstacking interactions.In addition,both 1and 2 exhibited luminescent properties in the solid state.Furthermore,quantum chemical calculations were carried out on the"molecular fragments"extracted from the crystal structures of 1 and 2 using the PBE0/LANL2DZ method constructed by the Gaussian 16 program.The calculated values signify a significant covalent interaction between the coordination atoms and the Cd(Ⅱ)ions.CCDC:2332173,1;2332176,2.
基金the Italian Space Agency(Agenzia Spaziale Italiana,ASI)in the framework of the Research Day“Giornate della Ricerca Spaziale”initiative through the contract ASI N.2023-4-U.0.
文摘All-inorganic perovskites based on cesium-lead-bromine(Cs-Pb-Br)have been a prominent research focus in optoelectronics in recent years.The optimisation and tunability of their macroscopic properties exploit the conformational flexibility,resulting in various crystal structures.Varying synthesis parameters can yield distinct crystal structures from Cs,Pb,and Br precursors,and manually exploring the relationship between these synthesis parameters and the resulting crystal structure is both labour-intensive and time-consuming.Machine learning(ML)can rapidly uncover insights and drive discoveries in chemical synthesis with the support of data,significantly reducing both the cost and development cycle of materials.Here,we gathered synthesis parameters from published literature(220 synthesis runs)and implemented eight distinct ML models,including eXtreme Gradient Boosting(XGB),Decision Tree(DT),Support Vector Machine(SVM),Random Forest(RF),Naïve Bayes(NB),Logistic Regression(LR),Gradient Boosting(GB),and K-Nearest(KN)to classify and predict Cs-Pb-Br crystal structures from given synthesis parameters.Validation accuracy,precision,F1 score,recall,and average area under the curve(AUC)are employed to evaluate these ML models.The XGB model exhibited the best performance,achieving a validation accuracy of 0.841.The trained XGB model was subsequently utilised to predict the structure from 10 experimental runs using a randomised set of parameters,achieving a testing accuracy of 0.8.The results indicate that the Cs/Pb molar ratio,reaction time,and the concentration of organic compounds(ligands)play crucial roles in synthesising various crystal structures of Cs-Pb-Br.This study demonstrates a significant decrease in effort required for experimental procedures and builds a foundational basis for predicting crystal structures from synthesis parameters.
基金supported by the open research fund of Songshan Lake Materials Laboratory(No.2022SLABFN08)Guangxi Science and Technology Base and Talents Special Project(Nos.Guike AD20297034 and AD21220053)+2 种基金the National Natural Science Foundation of China(No.51801214 and 52171021)the Research Start-up Funding from Guangxi University of Science and Technology(No.03200150)the Middle-aged and Young Teachers’Basic Ability Promotion Project of Guangxi(No.2022KY0329)。
文摘In this study,a comprehensive analysis of microstructural features,morphology,crystal structures,and interface structures of long-period stacking ordered(LPSO)structures in a non-equilibrium Mg_(97)Zn_(1)Y_(16)Ca_(0.4)alloy cast in a steel mold was carried out.The addition of Ca element plays an important role in the refinement of LPSO structure.The result reveals new poly-types including 20H F2F2F4,60R(F2F3F3)_(3),and 66H F2F3F3F2(F6)_(4)featuring a 6-Mg structure,alongside the prevalent 18R and 14H LPSO structures.The incoherent interface between 20H and the Mg matrix is split into two dislocation arrays,leading to the formation of a segment of 60R_(1).Moreover,the superstructure 116L,designated as(F2)_(18)F4,is formed through the ordered distribution of F4 stacking faults in 18R.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11965005 and 11964026)the Natural Science Basic Research Plan in Shaanxi Province,China(Grant Nos.2023-JC-YB-021 and 2022JM-035)+1 种基金the Fundamental Research Funds for the Central Universitiesthe 111 Project(Grant No.B17035)。
文摘Novel ordered intermetallic compounds have stimulated much interest.Ru–Al alloys are a prominent class of hightemperature structural materials,but the experimentally reported crystal structure of the intermetallic Ru_(2)Al_(5) phase remains elusive and debatable.To resolve this controversy,we extensively explored the crystal structures of Ru_(2)Al_(5) using first-principles calculations combined with crystal structure prediction technique.Among the calculated x-ray diffraction patterns and lattice parameters of five candidate Ru2Al5structures,those of the orthorhombic Pmmn structure best aligned with recent experimental results.The structural stabilities of the five Ru_(2)Al_(5)structures were confirmed through formation energy,elastic constants,and phonon spectrum calculations.We also comprehensively analyzed the mechanical and electronic properties of the five candidates.This work can guide the exploration of novel ordered intermetallic compounds in Ru–Al alloys.
文摘Experimental crystallographic structural parameters of a range of metaled meso-substituted and unsubstituted porphyrins were reviewed to show how far the meso-substitution by any functional group and the insertion of metal in the porphyrins core macrocycle may affect the geometry. The analysis of twists and angles has shown two kinds of distortions: external [T(C<sup>β</sup>-C<sup>α</sup>-C<sup>meso</sup>-X<sup>n</sup>) and T(C<sup>β</sup>-C<sup>α</sup>-C<sup>meso</sup>-C<sup>α</sup>)] and internal [T(N<sup>m</sup>-C<sup>α</sup>-C<sup>meso</sup>-X<sup>n</sup>) and T(N<sup>n</sup>-C<sup>α</sup>-C<sup>meso</sup>-C<sup>α</sup>)] with averages of [+6°and –6°] and [–5°and +5°], respectively. In the meso-substituted case, the external and internal twists C<sup>β</sup>-C<sup>α</sup>-C<sup>meso</sup>-X and N-C<sup>α</sup>-C<sup>meso</sup>-X, respectively are oppositely orientated. Similar effect is observed in meso-unsubstituted of C<sup>β</sup>-C<sup>α</sup>- C<sup>meso</sup>-H and N-C<sup>α</sup>-C<sup>meso</sup>-H. However, the external distortions are more significant than internal. Considering the same order, the limit of distortions is [97°and 132°(–48°)] for external and [91°(–89°) and 52°] for internal. In the two cases, the substituents have opposite directions of distortions. The meso-substituted porphyrins have a high limit of twisting than usubstituted one, depending of the weight of substituents. The average of the bond angular deformations is 168°, almost planar. However, the limit of angular deformation is 94°.
基金supported by National Natural Science Foundation of China (NSFC52174246,NSFC51864003)Guangxi Natural Science Foundation (2018GXNSFAA050127)。
文摘Pyrrhotite is an associated mineral that exists widely in sulfide ore. The presence of pyrrhotite will affect the recovery of platinum group minerals. Therefore, researchers have paid increasing attention to the flotation separation of pyrrhotite. Pyrrhotite superstructures owning different Fe/S ratios results in various crystal structures, corresponding to different physical, chemical and electronic properties, and consequently different flotation behavior. In the present paper, a comprehensive review is conducted to discuss the influence of crystal structures on the natural floatability, mineral-reagent interaction, surface oxidation and flotation electrochemistry of pyrrhotite. The selective flotation process of pyrrhotite from its associated minerals is also reviewed in this paper. It is hoped that this review can summarize the newly published research results combined with some representative results from the past, to provide a theoretical basis for the study of the flotation mechanism of pyrrhotite and provide a new direction for future research on pyrrhotite.
基金supported by the National Natural Science Foundation of China (Grant No.50879008)the Open Fund of State Key Laboratory of Frozen Soil Engineering (Grant No. SKLFSE200904)+1 种基金the Vilho,Yrj and Kalle Visl Fund of the Finnish Academy of Sciences and Lettersthe Norwegian Research Council Project AMORA (Grant No.193592/S30)
文摘In order to understand the dominant factors of the physical properties of ice in ice thermodynamics and mechanics, in-situ observations of ice growth and decay processes were carried out. Two samplings were conducted in the fast and steady ice growth stages. Ice pieces were used to observe ice crystals and gas bubbles in ice, and to measure the ice density. Vertical profiles of the type and size of ice crystals, shape and size of gas bubbles, and gas bubble content, as well as the ice density, were obtained. The results show that the upper layer of the ice pieces is granular ice and the lower layer is columnar ice; the average crystal size increases with the ice depth and remains steady in the fast and steady ice growth stages; the shape of gas bubbles in the upper layer of ice pieces is spherical with higher total content, and the shape in the middle and lower layers is cylinder with lower total content; the gas bubble size and content vary with the ice growth stage; and the ice density decreases with the increase of the gas bubble content.
基金supported by the National Natural Science Foundation of China(51502221)~~
文摘α‐,β‐,δ‐,andγ‐MnO2nanocrystals are successfully prepared.We then evaluated the NH3selective catalytic reduction(SCR)performance of the MnO2catalysts with different phases.The NOx conversion efficiency decreased in the order:γ‐MnO2>α‐MnO2>δ‐MnO2>β‐MnO2.The NOx conversion with the use ofγ‐MnO2andα‐MnO2catalysts reached90%in the temperature range of140–200°C,while that based onβ‐MnO2reached only40%at200°C.Theγ‐MnO2andα‐MnO2nanowire crystal morphologies enabled good dispersion of the catalysts and resulted in a relatively high specific surface area.We found thatγ‐MnO2andα‐MnO2possessed stronger reducing abilities and more and stronger acidic sites than the other catalysts.In addition,more chemisorbed oxygen existed on the surface of theγ‐MnO2andα‐MnO2catalysts.Theγ‐MnO2andα‐MnO2catalysts showed excellent performance in the low‐temperature SCR of NO to N2with NH3.
文摘Three complexes, [Pr（NO3）3（HL）2] （1）, [Nd（NO3）3（HL）2] （2） and [Er（NO3）3（HL）2] ·0.5H2O （3）, were synthesized from the reaction of a Schiff base ligand 2-[ （4-methylphenylimino）methyl ]-6-methoxyphenol （C15 H15 NO2, HL） with Ln（NO3）3·6H2O （Ln = Pr, Nd, Er）. Characterization by single-crystal X-ray diffraction technique, elemental analysis, molar conductance, FT-IR, UV-Vis, ^1H NMR and thermal analysis shows the title complexes are neutral molecules where the central Ln（ Ⅲ） ion is ten-coordinated in biapical anti-hexahedron prism geometry, with four oxygen atoms of the phenolic hydroxy and methoxy groups in the two bidentate Schiff base ligands and six oxygen atoms provided by the three bidentate NO3 - anions. Additionally, the kinetic mechanism of thermal decomposition of complex 3 was determined with a TG-DTG curves by both integral and differential methods. The functions of thermal decomposition reaction mechanism and the equation of kinetic compensation effect were obtained.
基金Project supported by the Science & Technology Innovation Foundation of Henan Province (No. 092102310309)the Natural Science Foundation of Education Department of Henan Province (No. 2011B150025)
文摘Two novel complexes,[（C9H18NS2）3Sb（III）]（1） and [（C9H18NS2）3Bi（III）]（2）,were synthesized and characterized by elemental analysis,IR,TG and X-ray single-crystal diffraction.Both 1 and 2 crystallize in the monoclinic system,P21/c space group.The data for 1：a = 1.6964（3）,b = 1.02149（17）,c = 2.5650（3） nm,β = 121.824（8）°,Z = 4,V = 3.7766（10） nm^3,Dc = 1.293 g·cm^-3,F（000） = 1536,μ = 1.082 mm^-1,the final R = 0.0500,wR = 0.1562 and S =1.072.The data for 2：a = 1.6802（9）,b = 1.0256（6）,c = 2.5083（10） nm,β = 121.77（3）°,Z = 4,V = 3.675（3） nm^3,Dc = 1.486 g·cm^-3,F（000） = 1664,μ = 5.159 mm^-1,the final R = 0.0481,wR = 0.1055 and S =1.076.The coordinated geometry of the central M（III） with six sulfur atoms from three ligands is a distorted pentagonal pyramid configuration.The dimer structural system is formed by the weak interactions of M…S and C-H…S between two molecules.The complexes were valued for their antibacterial activities by agar-streak method.It was found that 1 is active against the four test bacterial organisms.
基金supported by the National Natural Science Foundation of China (No 30772627)
文摘The title compounds, C7H4I2O2 1 and C13H7I2N2O3 2, have been synthesized and characterized by single-crystal X-ray diffraction. Compound 1 crystallizes in monoclinic, space group P21/c with a = 9.802（2）, b = 13.867（3）, c = 7.364（2） A, β = 109.74（3）°, V= 942.1（3） A^3, Dc= 2.636 g/cm^3, C7H4I2O2, Mr= 373.90, F（000） = 672, μ = 6.627 mm^-1, Z = 4, R = 0.0459 and wR = 0.1018 for 1805 observed reflections （I 〉 2 σ（I））. Compound 2 belongs to the monoclinic system, space group P21/n with a = 9.015（2）, b = 12.024（2）, c = 14.072（3） A, β = 103.91（3）°, V = 1480.6（5） A^3, Dc= 2.216 g/cm^3, C13H7I2N2O3, Mr= 494.01, F（000） = 920, p = 4.255 mm^-1, Z = 4, R = 0.0777 and wR = 0.1757 for 2896 observed reflections （I 〉 2σ（I））. Compounds 1 and 2 were assayed for antibacterial activities against three Gram positive bacterial strains （B. subtilis, S. aureus and S. faecalis） and three Gram negative bacterial strains （E. coli, P. aeruginosa and E. cloacae） by MTr method. Fortunately, compound 2 is found to show potent antibacterial activity against these six bacterial strains.
基金This project was supported by the National Natural Science Foundation of China (No. 20072018 and 29832030)
文摘Two new compounds containing triarylamine and benzoic hydrazide units, 4- [N,N-di(4-toyl)amino]benzaldehyde-N-(4-ethoxylphenyl)-formyl hydrazone 3a and 4-[N,N-di(4- toyl) amino]benzaldehyde-N-(2-ethoxylphenyl)-formyl hydrazone 3b, have been synthesized and their crystal structures (C30H29N3O2, Mr = 463.56) were interpreted by a combination technique of 1HNMR, IR, elemental analysis, mass spectra, UV-Vis spectra and X-ray crystallography, respec- tively. The crystal of 3a belongs to monoclinic, space group P21/n with a = 9.321(3) ? b = 11.046(4) ? c = 24.335(9) ? b =92.649(7), V = 2502.7(16) ?, Z = 4, m = 0.078 mm-1, Dc =1.230 g/cm3, F(000) = 984, the final R = 0.0590 and wR = 0.1316 for 4367 observed reflections with I > 2s(I). The crystal of 3b belongs to monoclinic, space group P21/c with a = 10.637(4) ? b = 24.138(10) ? c = 10.398(4) ? b = 104.913(8), V = 2579.8(17) ?, Z = 4, m = 0.075 mm-1, Dc = 1.194 g/cm3, F(000) = 984, the final R =0.0631 and wR =0.1006 for 4463 observed reflections with I > 2s(I). X-ray crystallography revealed that the nitrogen atom in the triarylamine moiety is of sp2 hybridization with the three phenyl rings twisted to each other.
基金Supported by the National Natural Science Foundation of China(No.21576112)Natural Science Foundation of Jilin Province(20150623024TC-19,20170520147JH)the Science and Technology Development Plan of Siping City(2015049)
文摘Six new transition metal complexes, [Zn（HBTC）（PYTPY）]n·n PYTPY（1）, [Cu（HBTC）（PYTPY）]n·n PYTPY（2）, [Co（HBTC）（PYTPY）]n·n DMF（3）, [Mn（HBTC）（PYTPY）]n·n DMF（4）, [Cd（HBTC）（PYTPY）（H2O）]n·2nH2O（5）, and [Co（HBTC）（PYTPY）（H2O）2]（6）,（H3BTC = 1,3,5-benzenetricarboxylic acid, PYTPY = 4＇-（4-pyridyl）-2,2＇：6＇,2＇＇-terpyridine, DMF = N,N？-dimethylformamide）, have been synthesized and characterized by elemental analysis, IR and X-ray single-crystal diffraction. Complexes 1~5 all feature one-dimensional chain structures, and complex 6 exhibits a zero-dimensional structure. Complexes 1~5 present three-dimensional（3D） supramolecular frameworks via π-π stacking interactions, whenas 6 has also a 3D supramolecular structure assembled by hydrogen bonding. Meanwhile, complexes 1 ~ 6 exhibit the thermal stabilities and photoluminescent properties.
文摘A complex [NIL2] was synthesized, in which L, or to be exact, a Schiff base ligand （HL）, was derived from the condensation of 1-phenyl-3-methyl-4-phenylacetyl-5-pyrazolone （PMPAP） with L-phenylalanine methyl ester. They were characterized by IR and single-crystal X-ray diffraction. Green block crystals of both ligand and its complex were grown at room temperature. The ligand, which consists of two individual fragments, crystalizes in the P1 space group （a = 5.6268（5）, b = 10.6892（11） and c = 19.4869（18） A）. The complex crystalizes in the P21 space group （a -- 21.4076（18）, b = 9.4792（8） and c = 25.287（2） A）, which consists of a nickel six-coordinated compound. Every fragment is a distorted octahedron with four oxygen and two nitrogen atoms. The Schiff base ligand （HL） and its complex have been tested in vitro to evaluate their antibacterial activity against bacteria Escherichia Coli and Bacillus subtilis. It is found that the complex has higher activity than the corresponding free Schiff base ligand （HL） against the same bacterial.
基金Project supported by National Basic Research Program of China(2010CB732300)Foundation of Zhejiang Province Education Commission of China(Y201224213)
文摘Five lanthanide complexes of Ln2（dpdc）2（tpy）2（NO3）2（H2O）2 [Ln=La （1）, Ce （2）, Pr （3）, Sm （4）, Gd （5）, H2dpdc=2,2’-biphenyldicarboxylic acid and tpy=2,2’：6’,2’’-terpyridine] were prepared at room temperature and characterized by X-ray diffraction, FT-IR and thermo-gravimetric analysis. The results showed that complexes 1–5 were isostructural and consisted of dinuclear units [Ln2（dpdc）2（tpy）2（NO3）（H2O）2] bridged by two dpdc2？ ligands. The dinuclear units with strong intramolecular hydrogen bonds were assembled into 2D supramolecular layers by the weak π？？？π staking interactions between pyridine rings of tpy. The TG analysis showed that the complexes 1–5 behaved higher thermal stability with no mass loss at 〈 320 °C. The lanthanide contraction effect and the solid state luminescence properties of complexes 1–5 were also investigated. The luminescence emission spectra of complexes 1–5 exhibited ligands emission bands and complex 3 and 4 had no typical emission in the visible region.
文摘A one dimension solid and a two dimension solid consisting of polyoxoanions bridged by {CoO 3N 2} and {CoO 4} groups respectively have been synthesized by the hydrothermal method and structurally characterized by X Ray crystallography. Each structure has the [(PO 4) 4Mo 6O 15 ] 12- cluster that is commonly observed in many molybdophosphates. In compound 1, [(PO 4) 4Mo 6O 15 ] 12- clusters are linked by {CoO 3N 2} groups to form a chain like structure, and the chains are hydrogen bonded into a network. Compound 2 is a layer structure with channnels constructed from [(PO 4) 4Mo 6O 15 ] 12- clusters and {CoO 4} groups, the organic molecules and the lattice water molecules are distributed disorderly in the interlamellar region and form strong hydrogen bonds with inorganic framework. The IR and the fluorescent spectra were investigated and discussed.
基金supported by the National Natural Science Foundation of China(No.21271129)
文摘A new homochiral ligand,（R）-2-（4-pyridyl）-4,5-dihydrothiazole-4-carboxylic acid（HL^R）, has been synthesized. Two complexes, [ZnL2^R（H2O）2]·H2O（1） and [MnL2^R（H2O）2]？H2O（2） have been prepared by the reactions of Zn（Ⅱ） and Mn（Ⅱ） ions with the ligand HLR, and characterized by single-crystal X-ray diffraction analysis and fluorescence. Complexes 1 and 2 are isomorphs, and both of the Zn（Ⅱ） and Mn（Ⅱ） centers in 1 and 2 are six-coordinated by the two NO units of two ligands and two water oxygen atoms, showing distorted octahedral coordination geometry. Complexes 1 and 2 show fluorescent properties in the solid state at room temperature.
