Two new compounds,1([Cu(IDB_)2]Cl_2·2CH_3CH_2OH·2H_2O(IDB = N,N-di(2-benzimidazolylmethyl)imine]) and 2([Cu(EDTB)]·2[C_6H_4(OH)COO]·6H_2O(EDTB = N,N,N',N'-tetrakis-[(2-benzimidazoly...Two new compounds,1([Cu(IDB_)2]Cl_2·2CH_3CH_2OH·2H_2O(IDB = N,N-di(2-benzimidazolylmethyl)imine]) and 2([Cu(EDTB)]·2[C_6H_4(OH)COO]·6H_2O(EDTB = N,N,N',N'-tetrakis-[(2-benzimidazolyl)methyl]-1,2-ethanediamine]),have been synthesized and their crystal structures were determined by single-crystal X-ray diffraction. Crystal 1 belongs to the triclinic system,space group P1 with a = 9.565(2),b = 9.863(2),c = 10.252(3) ?,α = 81.915,β = 88.330,γ = 87.347°,V = 956.28(40) ?3,Z = 1,F(000) = 427,D_c = 1.419 g/cm3,Mr = 817.27 and μ(MoKα) = 0.764 mm^(-1). The final R indices(I 〉 2σ(I)): R = 0.0505,wR = 0.1417; R indices(all data): R = 0.0591,wR = 0.1525. Crystal 2 is of triclinic system,space group P1 with a = 11.487(3),b = 13.396(4),c = 17.977(5) ?,α = 73.899(5),β = 86.629(5),γ = 65.018(4)°,V = 2403.8(12) ?3,Z = 2,F(000) = 1072,D3c = 1.417 g/cm,Mr = 1025.54,μ(MoKα) = 0.528 mm^(-1). The final R indices(I 〉 2σ(I)): R = 0.0769,w R = 0.163 2; R indices(all data): R = 0.0769,wR = 0.1632. The two compounds exhibit mononuclear structures. The copper(Ⅱ) atom of crystal 1 is six-coordinated by four nitrogen atoms of benzimidazole groups and two amine nitrogen atoms from the ligand IDB to adopt a distorted octahedral coordination geometry. The copper(Ⅱ) atom of crystal 2 is six-coordinated by four nitrogen atoms of benzimidazole groups and two amine nitrogen atoms from the ligand EDTB to show a distorted octahedral coordination geometry. Particularly,the two compounds exhibit fluorescent properties at room temperature in ethanol.展开更多
The coordination compounds,{Cu[CH_3C_6H_4N(CH_2COO)_2]}.2H_2O and {Cu[CH_3OC_6H_4N(CH_2COO)_2]}.2H_2O,have been prepared and its crystal struc- tures determined.The final discrepancy factors are R=0.052,R_w=0.061 for ...The coordination compounds,{Cu[CH_3C_6H_4N(CH_2COO)_2]}.2H_2O and {Cu[CH_3OC_6H_4N(CH_2COO)_2]}.2H_2O,have been prepared and its crystal struc- tures determined.The final discrepancy factors are R=0.052,R_w=0.061 for (I)and R=0.052,R_w=0.039 for(Ⅱ).The geometry of the coordination poly- hedron with Cu(Ⅱ)is a distorted tetragonal pyramid for(Ⅰ)and an unsym- metrical and extended tetragonal bipyramid for(Ⅱ),respectively.The re- sults of EHMO calculations indicate that the ligand mainly provided the field with very few of its electrons being coordinated to the central atom.展开更多
In this paper, we propose a new type of bond, continuous multi-centered d-pn bond on the basis of the Extended Huckel Tight-Banding Calculation and SCC-EHMO calculation for TaPtTe5 and its iso-structural compounds wit...In this paper, we propose a new type of bond, continuous multi-centered d-pn bond on the basis of the Extended Huckel Tight-Banding Calculation and SCC-EHMO calculation for TaPtTe5 and its iso-structural compounds with infinite continuous structrue. The results show that the d-pπbonds which are mainly responsible for the metallic properties are very strong and dispersive. The ΔE, the energy gap between half-filled band block and the unoccupied band block is closely related to the conductivity. The conductivity of TaPdTe5 and NbPtTe5 is predicted. The perturbations between Te atoms in intralayer and interlayer are discussed.展开更多
The crystal structures and magnetic properties of novel Eu TrGa3-r (T=Pd, It, Rh) in termetallic compounds are investigated by using powder x-ray diffraction and magnetic measurements. EuTrGa3-r crystallizes in orth...The crystal structures and magnetic properties of novel Eu TrGa3-r (T=Pd, It, Rh) in termetallic compounds are investigated by using powder x-ray diffraction and magnetic measurements. EuTrGa3-r crystallizes in orthorhombic structure with space group of Cmcm and Z = 4. There are four kinds of nonequivalent 4c crystal positions in EuTrGaa-r unit cell, which are occupied by 4Eu, 4GaⅠ, 4(GaⅡ, T) and 4GaⅢ, respectively. EuTrGa3-r ex- hibits the complex magnetic states in low-temperature regime, with the three-, two- and one-antiferromagnetic transitions occurring for T=Ir, T=Rh and T=Pd, respectively. It might be due to the Kondo effect: a localized antiferromagnetic interaction of the isolated impurity spins with the surrounding conduction electrons at low-temperature regime.展开更多
This paper analyzes the compound attractor structure of a new three-dimensional autonomous chaotic system. First, it is found that there exist five equilibria in the chaotic system, and the stabilities of these equili...This paper analyzes the compound attractor structure of a new three-dimensional autonomous chaotic system. First, it is found that there exist five equilibria in the chaotic system, and the stabilities of these equilibria are discussed under a constant scalar control input parameter m. Secondly, the trajectories of the attractors on a y-z plane are examined, the reasons why these trajectories can exist or disappear are also described. Finally, the forming procedure of the different scrolls chaotic attractor is explored by computer simulations when the parameter m is varied. It is shown that the new chaotic attractor has a compound structure, it can evolve to other three-dimensional autonomous chaotic systems. The results of theoretical analysis and simulation are helpful for better understanding of other similar chaotic systems.展开更多
The finding of the compound structure of a new four-scrolls chaotic system is reported, which is obtained by merging together two symmetrical attractors. And the two symmetrical attractors are generated only by adding...The finding of the compound structure of a new four-scrolls chaotic system is reported, which is obtained by merging together two symmetrical attractors. And the two symmetrical attractors are generated only by adding a constant gain to the original system. Also, the forming procedure of the new four-scrolls chaotic attractor is explored and the relation between the constant gain and the properties of the system is given.展开更多
The explosive reaction degree and protection from explosions are concerns in the military field.In this work,the reaction degree of the composition B explosive was investigated experimentally.Multi-layered compound st...The explosive reaction degree and protection from explosions are concerns in the military field.In this work,the reaction degree of the composition B explosive was investigated experimentally.Multi-layered compound structures were used as barriers to weaken the blast loads.A comprehensive experiment using a high-speed camera and image processing techniques,side witness plates,and bottom witness plates was presented.Using the experimental fragment velocities,fragment piercing patterns,and damage characteristics,the reaction degree of the explosive impeded by different multi-layered compound structures could be precisely differentiated.Reaction parameters of the explosive obstructed by compound structures were obtained by theoretical analysis and numerical simulations.Unlike the common method in which the explosive reaction degree is only distinguished based on the initial pressure amplitude transmitted into the explosive,a following shock wave reflected from the side steel casing was also considered.Different detonation growth paths in the explosive formed.Therefore,all these shock wave propagation characteristics must be considered to analyze the explosive response impeded by compound structures.展开更多
The three-dimensional holographic vector of atomic interaction field(3D-Ho VAIF) is used to characterize the molecular structures of 45 nitroaromatic compounds.Two quantitative structure-toxicity relationship(QSAR...The three-dimensional holographic vector of atomic interaction field(3D-Ho VAIF) is used to characterize the molecular structures of 45 nitroaromatic compounds.Two quantitative structure-toxicity relationship(QSAR) models are built up by stepwise regression(SMR),multiple linear regression(MLR) and partial least-squares regression(PLS).The correlation coefficients(R) of the models are 0.960 and 0.961,respectively.Then the models are evaluated by performing the cross-validation with the leave-one-out(LOO) procedure and the correlation coefficients(RCV) are 0.949 and 0.941,respectively.The results show that the descriptors can successfully describe the structures of organic compounds.The stability and predictability of the model are satisfactory.展开更多
The title compound 2-((2-fluorobenzyl)thio)-5-(pyridin-4-yl)-1,3,4-oxadiazole(C_(14)H_(10)FN_3OS) was synthesized,and its structure was confirmed by ~1H NMR,MS,elemental analyses and X-ray diffraction. It ...The title compound 2-((2-fluorobenzyl)thio)-5-(pyridin-4-yl)-1,3,4-oxadiazole(C_(14)H_(10)FN_3OS) was synthesized,and its structure was confirmed by ~1H NMR,MS,elemental analyses and X-ray diffraction. It crystallizes in the monoclinic system,space group P21/n with a = 11.541(16),b = 8.226(12),c = 13.683(19) ?,β = 94.872(17)o,V = 1294(3) ?~3,Z = 4 and R = 0.0648 for 2198 observed reflections with I 〉 2σ(I). The preliminary biological test shows that the title compound has good activity against Pythium ultimum with inhibitory to be 100%.展开更多
It was shown by TEM and X-ray analysis that there are four types of grains of the main Ni3Al phase in the structure of the intermetallic obtained by the self-propagation high temperature method (SHS). Every type of gr...It was shown by TEM and X-ray analysis that there are four types of grains of the main Ni3Al phase in the structure of the intermetallic obtained by the self-propagation high temperature method (SHS). Every type of grains has its own domain and dislocation structure. There are mono- and polydomains with and without dislocations. The grains of the main phase of monoand polydomains without dislocations and polydomains with dislocations were formed by diffusion in the solid phase. In these conditions NiAl3 phase is located on the grain boundary of the main phase. The Ni2Al3 phase is located at the triple joints of the main phase.展开更多
The coordination polymer [Mn2(cipt)2(aic)2]n (cipt = 2-(3-chlorophenyl)-1H- imidazo[4,5-f][1,10]phenanthroline, aic = 5-amino-isophthalic acid) has been obtained from hydrothermal reaction and characterized by...The coordination polymer [Mn2(cipt)2(aic)2]n (cipt = 2-(3-chlorophenyl)-1H- imidazo[4,5-f][1,10]phenanthroline, aic = 5-amino-isophthalic acid) has been obtained from hydrothermal reaction and characterized by elemental analysis, IR, TG and single-crystal X-ray diffraction. The title compound crystallizes in the triclinic system, space group P , with a = 11.523(3), b = 12.162(3), c = 18.706(5) A^°, β = 81.789(5)°, V = 2455.2(1) A^°3, C54H32Cl2Mn2N10O8, Mr = 1129.68, Z = 2, Dc = 1.528 g/cm3, μ = 0.692 mm^-1, F(000) = 1148, R = 0.064 and wR = 0.145 for 9571 observed reflections (I 〉 2σ(I)). In this polymer, the Mn(II) atoms adopt different coordination modes. The Mn(1) atom is five-coordinated, forming a distorted tetragonal pyramidal geometry. Mn(2) atom is six-coordinated to get a distorted octahedral geometry, which is different from the Mn(1) atom. Each Mn(II) atom is linked by aic ligands with neighboring Mn(II) atoms, forming an infinite one-dimensional (1D) double-chain structure. The existence of N–H…O hydrogen bonding interactions leads the 1D chains to generate a 2D structure. Luminescent properties for the ligand cipt and compound 1 have also been discussed in detail.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
A novel Dy^(3+) coordination compound,(H_2pipz)(H_3O)[Dy(pydc)_3]·11H_2O(1,pipz = piperazine and H_2pydc = pyridine-2,6-dicarboxylic acid),has been hydrothermally synthesized and characterized by X-ray...A novel Dy^(3+) coordination compound,(H_2pipz)(H_3O)[Dy(pydc)_3]·11H_2O(1,pipz = piperazine and H_2pydc = pyridine-2,6-dicarboxylic acid),has been hydrothermally synthesized and characterized by X-ray single-crystal diffraction,elemental analysis. It is interesting that the packing structure of compound 1 contains 22-core water clusters. Compound 1 is extended into a threedimensional supramolecular structure via O···H···O hydrogen bonding interactions. Furthermore,the luminescent property of compound 1 was also investigated.展开更多
A two-dimensional coordination polymer, [Pb(bmzbc)2]n(1)(Hbmzbc =4-benzimidazole-1-yl-benzoic acid), has been synthesized by the solvothermal reaction of Pb(NO3)2 with Hbmzbc at 120 ℃ in ethanol solvent. Comp...A two-dimensional coordination polymer, [Pb(bmzbc)2]n(1)(Hbmzbc =4-benzimidazole-1-yl-benzoic acid), has been synthesized by the solvothermal reaction of Pb(NO3)2 with Hbmzbc at 120 ℃ in ethanol solvent. Compound 1 has been characterized by single-crystal X-ray diffraction, powder X-ray diffraction, thermogravimetry analysis, and IR spectrum. Compound 1 crystallizes in the orthorhombic system, space group Pccn, with a = 12.5801(7), b = 20.0795(11), c = 9.1830(6) ?, V = 2319.6(2) A^3, Z = 4, C(28)H(18)N4O4Pb, Mr = 681.65, Dc = 1.952 g/cm^3, μ = 7.319 mm^-1, F(000) = 1312, the final R = 0.0336 and wR = 0.0965 for 1699 observed reflection with I 〉 2σ(I). In 1, the bmzbc^– ligands bridge the Pb(Ⅱ) ions to generate a 2-D sheet with(4, 4) topology. The complex exhibits turquoise photoluminescent emission with a maximum at 480 nm upon excitation at 300 nm.展开更多
The Ni_3B phase was formed when boron (0.5 at. pct B) was added to the intermetallic of sto- ichiometric and off-stoichiometric (Ni-24 at. pct Al) compounds. In the alloy of stoichiometric composition the particles o...The Ni_3B phase was formed when boron (0.5 at. pct B) was added to the intermetallic of sto- ichiometric and off-stoichiometric (Ni-24 at. pct Al) compounds. In the alloy of stoichiometric composition the particles of Ni_3B phase has the size around 0.1μm and is located on the grain boundary of the main phase. The decreasing of concentrations of Al in the ofF-stoichiometric alloy leads to increase in the degree of the long-range order parameter, increasing the concen- trations of boron in the solid solution and decreasing its localization on the grain boundary. Microalloying of boron leads to increasing in the fraction of grain monodomains with disloca- tions up to 0.7 in the alloy of the off-stoichiometric composition and up to 1 in the alloy of the stoichiometric composition. It was established the correlation between the degree of the concentration inhomogeneity, average density of the dislocations and the average long range-order parameter.展开更多
A dinuclear dysprosium(III) compound,[Dy2(μ2-OH)2(QLC)4(1,10-phen)2]·4H2O(1)(QLC-= 2-quinolinecarboxylate and 1,10-phen = 1,10-phenanthroline),was synthesized and structurally and magnetically charac...A dinuclear dysprosium(III) compound,[Dy2(μ2-OH)2(QLC)4(1,10-phen)2]·4H2O(1)(QLC-= 2-quinolinecarboxylate and 1,10-phen = 1,10-phenanthroline),was synthesized and structurally and magnetically characterized.Compound 1 crystallizes in triclinic system,space group P1 with a = 10.9439(3),b = 11.2823(3),c = 12.2323(4) ?,α = 107.446(3),β = 91.700(3),γ = 91.511(2)°,V = 1439.25(8) A3,Z = 1,C(64)H(50)N8O(14)Dy2,Mr = 1480.12,Dc = 1.708 g/cm3,μ = 2.653 mm-1 and F(000) = 734.The final R = 0.0366 and w R = 0.0736 for 5816 observed reflections with I 〉 2σ(I).Compound 1 contains the mononuclear [Dy(QLC)2(1,10-phen)] subunit formed from one 1,10-phen and two QLC-ligands chelating Dy(III) ion.Two mononuclear [Dy(QLC)2(1,10-phen)] subunits are bridged by a pair of μ2-OH groups to give a centrosymmetric dinuclear [Dy2(μ2-OH)2(QLC)4(1,10-phen)2] with each Dy(III) ion being eight-coordinated.Detailed susceptibility measurements revealed that compound 1 does not show slow magnetic relaxation under zero direct-current field but exhibits field-induced slow magnetic relaxation under 2 kOe applied field.展开更多
The crystal structure of [Sm(m-NO2C6H4CO2)3(H2O)2] was determined.Mr=684. 66,triclinic,space group P1.α=11. 408(6),b=12.990(6).c=9.469(3) A,α=104. 84(3),β=92.84,γ=65.31(3)°,V=1229.9(9)A3.Z=2,Dc=1.85g/cm3, F(0...The crystal structure of [Sm(m-NO2C6H4CO2)3(H2O)2] was determined.Mr=684. 66,triclinic,space group P1.α=11. 408(6),b=12.990(6).c=9.469(3) A,α=104. 84(3),β=92.84,γ=65.31(3)°,V=1229.9(9)A3.Z=2,Dc=1.85g/cm3, F(000)=674,μ=25.1 cm-1,R=0.67.The coordination number of samarium ion is eight.The metal ions are bridged by carboxylato groups to form a polymeric chain structure.The crystal data of [Ho (m-NO2C6H4CO2)3 (H2O)2] were measured:triclinic,space group P1,α=11.368(3) .b=12. 943(3),c=9.443(1) A α=104.92(1),β=92.80(3),γ=65.07(2)°,V=1214.7(4)A 3,Z=2,Dc=1.91 g/cm3.These show that the samarium and holmium cornpounds are isomorphous.展开更多
One new quaternary rare-earth sulfide, FeSm6Si2S(14), has been synthesized by a facile solid-state route with boron as the reducing reagent. It crystallizes in the noncentrosymmetric hexagonal space group P63, belon...One new quaternary rare-earth sulfide, FeSm6Si2S(14), has been synthesized by a facile solid-state route with boron as the reducing reagent. It crystallizes in the noncentrosymmetric hexagonal space group P63, belonging to the Ce6Al(3.33)S(14) structure-type, and the AxRE3MQ7 family. Its crystal structure features a 3-D framework constructed by SmS 8 bicapped trigonal prisms, where Fe and Si atoms occupy the octahedral(2a) and tetrahedral(2c) voids, respectively. The FeS 6 octahedra are connected with each other to form a chain along the b direction. FeSm6Si2S(14) represents a new chemical composition among the large family of AxRE3MQ7 compounds. The other related compounds containing transition metal are also discussed.展开更多
A new complex with the formula [Co(acac)_2(NITQ)_2]×2CH_2Cl_2 1(acac = acetylacetone, NITQ = 2-(2′-quinoxalinyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide), was synthesized and elucidated structurall...A new complex with the formula [Co(acac)_2(NITQ)_2]×2CH_2Cl_2 1(acac = acetylacetone, NITQ = 2-(2′-quinoxalinyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide), was synthesized and elucidated structurally as well as magnetically in detail. The crystal belongs to the monoclinic system, space group P2_1/c with a = 9.6896(1), b = 20.539(4), c = 12.147(2) ?, β = 93.84(3)°, M_r = 997.65, V = 2412.1(8) ?~3, Z = 2, Dc = 1.374 g/cm, F(000) = 1038, m = 0.635 mm^(-1), the final R = 0.0539 and w R = 0.1289 for 5998 observed reflections(I 〉 2σ(I)). The Co(Ⅱ) ion is coordinated by two nitrogen atoms of quinoxaline rings from two NITQs and four oxygen atoms from two acac ions to complete a distorted octahedral coordination environment. Compound 1 is further linked into a three-dimensional(3D) supramolecular network by hydrogen-bonding, Cl×××O weak contact and π···π stacking interactions. The magnetic measurements show compound 1 exhibits weak ferromagnetic interactions.展开更多
基金supported by Research Fund for the Doctor Program of Hubei University of Technology(No.BSQD12139)Ministry of Science and Technology Small and Medium-sized Enterprise Venture Funds(No.12C26214204453)+1 种基金Natural Foundation of Hubei Province(No.2010CDA020)the Key Foundation of Industry-University-Research Cooperation of Education Department,Hubei Province(No.CXY2009A010)
文摘Two new compounds,1([Cu(IDB_)2]Cl_2·2CH_3CH_2OH·2H_2O(IDB = N,N-di(2-benzimidazolylmethyl)imine]) and 2([Cu(EDTB)]·2[C_6H_4(OH)COO]·6H_2O(EDTB = N,N,N',N'-tetrakis-[(2-benzimidazolyl)methyl]-1,2-ethanediamine]),have been synthesized and their crystal structures were determined by single-crystal X-ray diffraction. Crystal 1 belongs to the triclinic system,space group P1 with a = 9.565(2),b = 9.863(2),c = 10.252(3) ?,α = 81.915,β = 88.330,γ = 87.347°,V = 956.28(40) ?3,Z = 1,F(000) = 427,D_c = 1.419 g/cm3,Mr = 817.27 and μ(MoKα) = 0.764 mm^(-1). The final R indices(I 〉 2σ(I)): R = 0.0505,wR = 0.1417; R indices(all data): R = 0.0591,wR = 0.1525. Crystal 2 is of triclinic system,space group P1 with a = 11.487(3),b = 13.396(4),c = 17.977(5) ?,α = 73.899(5),β = 86.629(5),γ = 65.018(4)°,V = 2403.8(12) ?3,Z = 2,F(000) = 1072,D3c = 1.417 g/cm,Mr = 1025.54,μ(MoKα) = 0.528 mm^(-1). The final R indices(I 〉 2σ(I)): R = 0.0769,w R = 0.163 2; R indices(all data): R = 0.0769,wR = 0.1632. The two compounds exhibit mononuclear structures. The copper(Ⅱ) atom of crystal 1 is six-coordinated by four nitrogen atoms of benzimidazole groups and two amine nitrogen atoms from the ligand IDB to adopt a distorted octahedral coordination geometry. The copper(Ⅱ) atom of crystal 2 is six-coordinated by four nitrogen atoms of benzimidazole groups and two amine nitrogen atoms from the ligand EDTB to show a distorted octahedral coordination geometry. Particularly,the two compounds exhibit fluorescent properties at room temperature in ethanol.
基金Subject supported by the Doctoral Foundation of National Education Commission of China
文摘The coordination compounds,{Cu[CH_3C_6H_4N(CH_2COO)_2]}.2H_2O and {Cu[CH_3OC_6H_4N(CH_2COO)_2]}.2H_2O,have been prepared and its crystal struc- tures determined.The final discrepancy factors are R=0.052,R_w=0.061 for (I)and R=0.052,R_w=0.039 for(Ⅱ).The geometry of the coordination poly- hedron with Cu(Ⅱ)is a distorted tetragonal pyramid for(Ⅰ)and an unsym- metrical and extended tetragonal bipyramid for(Ⅱ),respectively.The re- sults of EHMO calculations indicate that the ligand mainly provided the field with very few of its electrons being coordinated to the central atom.
文摘In this paper, we propose a new type of bond, continuous multi-centered d-pn bond on the basis of the Extended Huckel Tight-Banding Calculation and SCC-EHMO calculation for TaPtTe5 and its iso-structural compounds with infinite continuous structrue. The results show that the d-pπbonds which are mainly responsible for the metallic properties are very strong and dispersive. The ΔE, the energy gap between half-filled band block and the unoccupied band block is closely related to the conductivity. The conductivity of TaPdTe5 and NbPtTe5 is predicted. The perturbations between Te atoms in intralayer and interlayer are discussed.
基金Supported by the National Natural Science Foundation of China under Grant No 11274110
文摘The crystal structures and magnetic properties of novel Eu TrGa3-r (T=Pd, It, Rh) in termetallic compounds are investigated by using powder x-ray diffraction and magnetic measurements. EuTrGa3-r crystallizes in orthorhombic structure with space group of Cmcm and Z = 4. There are four kinds of nonequivalent 4c crystal positions in EuTrGaa-r unit cell, which are occupied by 4Eu, 4GaⅠ, 4(GaⅡ, T) and 4GaⅢ, respectively. EuTrGa3-r ex- hibits the complex magnetic states in low-temperature regime, with the three-, two- and one-antiferromagnetic transitions occurring for T=Ir, T=Rh and T=Pd, respectively. It might be due to the Kondo effect: a localized antiferromagnetic interaction of the isolated impurity spins with the surrounding conduction electrons at low-temperature regime.
文摘This paper analyzes the compound attractor structure of a new three-dimensional autonomous chaotic system. First, it is found that there exist five equilibria in the chaotic system, and the stabilities of these equilibria are discussed under a constant scalar control input parameter m. Secondly, the trajectories of the attractors on a y-z plane are examined, the reasons why these trajectories can exist or disappear are also described. Finally, the forming procedure of the different scrolls chaotic attractor is explored by computer simulations when the parameter m is varied. It is shown that the new chaotic attractor has a compound structure, it can evolve to other three-dimensional autonomous chaotic systems. The results of theoretical analysis and simulation are helpful for better understanding of other similar chaotic systems.
文摘The finding of the compound structure of a new four-scrolls chaotic system is reported, which is obtained by merging together two symmetrical attractors. And the two symmetrical attractors are generated only by adding a constant gain to the original system. Also, the forming procedure of the new four-scrolls chaotic attractor is explored and the relation between the constant gain and the properties of the system is given.
基金The authors are very grateful for the support received from the National Natural Science Foundation of China(No.11872121).
文摘The explosive reaction degree and protection from explosions are concerns in the military field.In this work,the reaction degree of the composition B explosive was investigated experimentally.Multi-layered compound structures were used as barriers to weaken the blast loads.A comprehensive experiment using a high-speed camera and image processing techniques,side witness plates,and bottom witness plates was presented.Using the experimental fragment velocities,fragment piercing patterns,and damage characteristics,the reaction degree of the explosive impeded by different multi-layered compound structures could be precisely differentiated.Reaction parameters of the explosive obstructed by compound structures were obtained by theoretical analysis and numerical simulations.Unlike the common method in which the explosive reaction degree is only distinguished based on the initial pressure amplitude transmitted into the explosive,a following shock wave reflected from the side steel casing was also considered.Different detonation growth paths in the explosive formed.Therefore,all these shock wave propagation characteristics must be considered to analyze the explosive response impeded by compound structures.
基金supported by the Youth Foundation of Education Bureau,Sichuan Province(13ZB0003)
文摘The three-dimensional holographic vector of atomic interaction field(3D-Ho VAIF) is used to characterize the molecular structures of 45 nitroaromatic compounds.Two quantitative structure-toxicity relationship(QSAR) models are built up by stepwise regression(SMR),multiple linear regression(MLR) and partial least-squares regression(PLS).The correlation coefficients(R) of the models are 0.960 and 0.961,respectively.Then the models are evaluated by performing the cross-validation with the leave-one-out(LOO) procedure and the correlation coefficients(RCV) are 0.949 and 0.941,respectively.The results show that the descriptors can successfully describe the structures of organic compounds.The stability and predictability of the model are satisfactory.
基金funded by the Natural Science Foundation of Zhejiang Province(No.LY16C140007)the program of Science and Technology of Jiangsu Province(BY2014108-14)
文摘The title compound 2-((2-fluorobenzyl)thio)-5-(pyridin-4-yl)-1,3,4-oxadiazole(C_(14)H_(10)FN_3OS) was synthesized,and its structure was confirmed by ~1H NMR,MS,elemental analyses and X-ray diffraction. It crystallizes in the monoclinic system,space group P21/n with a = 11.541(16),b = 8.226(12),c = 13.683(19) ?,β = 94.872(17)o,V = 1294(3) ?~3,Z = 4 and R = 0.0648 for 2198 observed reflections with I 〉 2σ(I). The preliminary biological test shows that the title compound has good activity against Pythium ultimum with inhibitory to be 100%.
文摘It was shown by TEM and X-ray analysis that there are four types of grains of the main Ni3Al phase in the structure of the intermetallic obtained by the self-propagation high temperature method (SHS). Every type of grains has its own domain and dislocation structure. There are mono- and polydomains with and without dislocations. The grains of the main phase of monoand polydomains without dislocations and polydomains with dislocations were formed by diffusion in the solid phase. In these conditions NiAl3 phase is located on the grain boundary of the main phase. The Ni2Al3 phase is located at the triple joints of the main phase.
基金supported by the National Natural Science Foundation of China(No.21406085)
文摘The coordination polymer [Mn2(cipt)2(aic)2]n (cipt = 2-(3-chlorophenyl)-1H- imidazo[4,5-f][1,10]phenanthroline, aic = 5-amino-isophthalic acid) has been obtained from hydrothermal reaction and characterized by elemental analysis, IR, TG and single-crystal X-ray diffraction. The title compound crystallizes in the triclinic system, space group P , with a = 11.523(3), b = 12.162(3), c = 18.706(5) A^°, β = 81.789(5)°, V = 2455.2(1) A^°3, C54H32Cl2Mn2N10O8, Mr = 1129.68, Z = 2, Dc = 1.528 g/cm3, μ = 0.692 mm^-1, F(000) = 1148, R = 0.064 and wR = 0.145 for 9571 observed reflections (I 〉 2σ(I)). In this polymer, the Mn(II) atoms adopt different coordination modes. The Mn(1) atom is five-coordinated, forming a distorted tetragonal pyramidal geometry. Mn(2) atom is six-coordinated to get a distorted octahedral geometry, which is different from the Mn(1) atom. Each Mn(II) atom is linked by aic ligands with neighboring Mn(II) atoms, forming an infinite one-dimensional (1D) double-chain structure. The existence of N–H…O hydrogen bonding interactions leads the 1D chains to generate a 2D structure. Luminescent properties for the ligand cipt and compound 1 have also been discussed in detail.
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financially supported by the Foundation of Fujian Educational Committee(JA14348)
文摘A novel Dy^(3+) coordination compound,(H_2pipz)(H_3O)[Dy(pydc)_3]·11H_2O(1,pipz = piperazine and H_2pydc = pyridine-2,6-dicarboxylic acid),has been hydrothermally synthesized and characterized by X-ray single-crystal diffraction,elemental analysis. It is interesting that the packing structure of compound 1 contains 22-core water clusters. Compound 1 is extended into a threedimensional supramolecular structure via O···H···O hydrogen bonding interactions. Furthermore,the luminescent property of compound 1 was also investigated.
基金Supported by the National Natural Science Foundation of China(No.21361011 and 21101081)the Natural Science Foundation of Jiangxi Province(No.20151BAB203002)Science Founds of State key laboratory of Structural Chemistry(20130011)
文摘A two-dimensional coordination polymer, [Pb(bmzbc)2]n(1)(Hbmzbc =4-benzimidazole-1-yl-benzoic acid), has been synthesized by the solvothermal reaction of Pb(NO3)2 with Hbmzbc at 120 ℃ in ethanol solvent. Compound 1 has been characterized by single-crystal X-ray diffraction, powder X-ray diffraction, thermogravimetry analysis, and IR spectrum. Compound 1 crystallizes in the orthorhombic system, space group Pccn, with a = 12.5801(7), b = 20.0795(11), c = 9.1830(6) ?, V = 2319.6(2) A^3, Z = 4, C(28)H(18)N4O4Pb, Mr = 681.65, Dc = 1.952 g/cm^3, μ = 7.319 mm^-1, F(000) = 1312, the final R = 0.0336 and wR = 0.0965 for 1699 observed reflection with I 〉 2σ(I). In 1, the bmzbc^– ligands bridge the Pb(Ⅱ) ions to generate a 2-D sheet with(4, 4) topology. The complex exhibits turquoise photoluminescent emission with a maximum at 480 nm upon excitation at 300 nm.
文摘The Ni_3B phase was formed when boron (0.5 at. pct B) was added to the intermetallic of sto- ichiometric and off-stoichiometric (Ni-24 at. pct Al) compounds. In the alloy of stoichiometric composition the particles of Ni_3B phase has the size around 0.1μm and is located on the grain boundary of the main phase. The decreasing of concentrations of Al in the ofF-stoichiometric alloy leads to increase in the degree of the long-range order parameter, increasing the concen- trations of boron in the solid solution and decreasing its localization on the grain boundary. Microalloying of boron leads to increasing in the fraction of grain monodomains with disloca- tions up to 0.7 in the alloy of the off-stoichiometric composition and up to 1 in the alloy of the stoichiometric composition. It was established the correlation between the degree of the concentration inhomogeneity, average density of the dislocations and the average long range-order parameter.
基金Supported by the NNSFC(21361011 and 21561015)the Natural Science Foundation of Jiangxi Province(20151BAB203002)the Open Project Program of Key Laboratory of Functional Small Organic Molecule,Ministry of Education,Jiangxi Normal University(KLFS-KF-201412)
基金Supported by the National Natural Science Foundation of China(No.21561015)
文摘A dinuclear dysprosium(III) compound,[Dy2(μ2-OH)2(QLC)4(1,10-phen)2]·4H2O(1)(QLC-= 2-quinolinecarboxylate and 1,10-phen = 1,10-phenanthroline),was synthesized and structurally and magnetically characterized.Compound 1 crystallizes in triclinic system,space group P1 with a = 10.9439(3),b = 11.2823(3),c = 12.2323(4) ?,α = 107.446(3),β = 91.700(3),γ = 91.511(2)°,V = 1439.25(8) A3,Z = 1,C(64)H(50)N8O(14)Dy2,Mr = 1480.12,Dc = 1.708 g/cm3,μ = 2.653 mm-1 and F(000) = 734.The final R = 0.0366 and w R = 0.0736 for 5816 observed reflections with I 〉 2σ(I).Compound 1 contains the mononuclear [Dy(QLC)2(1,10-phen)] subunit formed from one 1,10-phen and two QLC-ligands chelating Dy(III) ion.Two mononuclear [Dy(QLC)2(1,10-phen)] subunits are bridged by a pair of μ2-OH groups to give a centrosymmetric dinuclear [Dy2(μ2-OH)2(QLC)4(1,10-phen)2] with each Dy(III) ion being eight-coordinated.Detailed susceptibility measurements revealed that compound 1 does not show slow magnetic relaxation under zero direct-current field but exhibits field-induced slow magnetic relaxation under 2 kOe applied field.
文摘The crystal structure of [Sm(m-NO2C6H4CO2)3(H2O)2] was determined.Mr=684. 66,triclinic,space group P1.α=11. 408(6),b=12.990(6).c=9.469(3) A,α=104. 84(3),β=92.84,γ=65.31(3)°,V=1229.9(9)A3.Z=2,Dc=1.85g/cm3, F(000)=674,μ=25.1 cm-1,R=0.67.The coordination number of samarium ion is eight.The metal ions are bridged by carboxylato groups to form a polymeric chain structure.The crystal data of [Ho (m-NO2C6H4CO2)3 (H2O)2] were measured:triclinic,space group P1,α=11.368(3) .b=12. 943(3),c=9.443(1) A α=104.92(1),β=92.80(3),γ=65.07(2)°,V=1214.7(4)A 3,Z=2,Dc=1.91 g/cm3.These show that the samarium and holmium cornpounds are isomorphous.
基金supported by the Higher Education Science Foundation of Jiangsu Province(No.15KJB150031)State Key Laboratory of Structural Chemistry(No.20150009)Yangzhou Engineering Technology Research Center of Petrochemical New Materials(YZM2015086)
文摘One new quaternary rare-earth sulfide, FeSm6Si2S(14), has been synthesized by a facile solid-state route with boron as the reducing reagent. It crystallizes in the noncentrosymmetric hexagonal space group P63, belonging to the Ce6Al(3.33)S(14) structure-type, and the AxRE3MQ7 family. Its crystal structure features a 3-D framework constructed by SmS 8 bicapped trigonal prisms, where Fe and Si atoms occupy the octahedral(2a) and tetrahedral(2c) voids, respectively. The FeS 6 octahedra are connected with each other to form a chain along the b direction. FeSm6Si2S(14) represents a new chemical composition among the large family of AxRE3MQ7 compounds. The other related compounds containing transition metal are also discussed.
基金supported by the National Natural Science Foundation of China(No.21071006)the Natural Science Foundation of Henan Province(No.102102210457)the Natural Science Foundation of the Henan Higher Education Institutions of China(No.2010B150001)
文摘A new complex with the formula [Co(acac)_2(NITQ)_2]×2CH_2Cl_2 1(acac = acetylacetone, NITQ = 2-(2′-quinoxalinyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide), was synthesized and elucidated structurally as well as magnetically in detail. The crystal belongs to the monoclinic system, space group P2_1/c with a = 9.6896(1), b = 20.539(4), c = 12.147(2) ?, β = 93.84(3)°, M_r = 997.65, V = 2412.1(8) ?~3, Z = 2, Dc = 1.374 g/cm, F(000) = 1038, m = 0.635 mm^(-1), the final R = 0.0539 and w R = 0.1289 for 5998 observed reflections(I 〉 2σ(I)). The Co(Ⅱ) ion is coordinated by two nitrogen atoms of quinoxaline rings from two NITQs and four oxygen atoms from two acac ions to complete a distorted octahedral coordination environment. Compound 1 is further linked into a three-dimensional(3D) supramolecular network by hydrogen-bonding, Cl×××O weak contact and π···π stacking interactions. The magnetic measurements show compound 1 exhibits weak ferromagnetic interactions.