Three new bridging complexes of rare earth and cobalt cluster were synthesized and characterized via ICP, IR and TG techniques. The structure of the complexes was speculated as： two rare earth atoms were bridged with...Three new bridging complexes of rare earth and cobalt cluster were synthesized and characterized via ICP, IR and TG techniques. The structure of the complexes was speculated as： two rare earth atoms were bridged with four CF3COO–, and rare earth atoms were coordinated with cobalt carbonyl clusters to form a steady structure. Application of the complexes as the catalyst precursors was explored for Fischer-Tropsch synthesis. The study showed that the bridging complexes of rare earth and cobalt cluster had large molecular size and were difficult to enter pore path of γ-Al2O3, so they were dispersed on the surface of γ-Al2O3 support. In addition, the performance of Co（Ce）/ γ-Al2O3 was the best among the catalysts with complex as precursor and maintained 77.7% CO conversion at 220 oC for 80 operation hours.展开更多
The synthesis, structure and characterization of a new one-dimensional cyanide-bridgedcomplex [Ni(pn)_2Ni(CN)4]n'nH2O (where pn = 1,2-diaminopropane) are described. The structure ofthis complex consists of a one-d...The synthesis, structure and characterization of a new one-dimensional cyanide-bridgedcomplex [Ni(pn)_2Ni(CN)4]n'nH2O (where pn = 1,2-diaminopropane) are described. The structure ofthis complex consists of a one-dimensional polymeric chain-Ni(pn)2-NC-Ni(CN)2-CN-Ni(pn)2- inwhich the Ni(II) centers are linked by two CN groups.展开更多
Reaction of(n-Bu_4N)_xNa_(4-x)[a-Mo_8O_(26)](x=1-4)and mpH_2(mpH_2=o-mercaptophenol) leads to the formation of compound(n-Bu_4N)[Mo_2O_3(mp)_3Na(EtOH)_2(MeOH)],It crystallizes in the space group P2_1/n with four molec...Reaction of(n-Bu_4N)_xNa_(4-x)[a-Mo_8O_(26)](x=1-4)and mpH_2(mpH_2=o-mercaptophenol) leads to the formation of compound(n-Bu_4N)[Mo_2O_3(mp)_3Na(EtOH)_2(MeOH)],It crystallizes in the space group P2_1/n with four molecules per unit cell.The cell dimension is a=12.776(3),b=14.154(5),c=26.281(7)(?)=95.50(2)°,V=4730.5 (?),d_c=1.407 g/cm^3.Full-matrix refinement of 496 parameters on 3348 reflection data gave final R(R_w) value of 0.072(0.072).The two oxomolybdenum-mercaptophenolate,units are triply bridged by an inorganic oxygen atom and a doubly bridging mp^(2-)ligand.展开更多
The complex polymer[Cu_2(oxap)(pyr)_2]_n(ClO_4)_(2n),where oxap^(2-)stands for N,N' -bis(2—aminopropyl)oxamide,have been synthesized.It crystallizes in monoclinic system, space group P2_1/C,with a=8.721(2),b=8.67...The complex polymer[Cu_2(oxap)(pyr)_2]_n(ClO_4)_(2n),where oxap^(2-)stands for N,N' -bis(2—aminopropyl)oxamide,have been synthesized.It crystallizes in monoclinic system, space group P2_1/C,with a=8.721(2),b=8.679(2),c=16.741(2),β=98.59(0),Z=4.The least-square refinement coverged at R=0.054,R_w=0.055 with 1869 unique reflections.The whole structure of the complcx consists of layers of two-dimensional network arraying along a-axis with perchlorate ions interspersed in the gap between layers.Inside the layer. trans-oxamide-bridged copper(Ⅱ)dimers connected by pyrimidine in an asymmetric fashion spread out along be plane to form an infinite two-dimensional network.展开更多
A novel three dimensional network complex polymer [Cu_4(oxen)_2(N_3)_3]_n(ClO_4)_n·2nH_2O, where oxen is N,N' -bis(2-aminoethyl)oxamide dianion, has been synthesized. It crystallizes in triclinic system, spac...A novel three dimensional network complex polymer [Cu_4(oxen)_2(N_3)_3]_n(ClO_4)_n·2nH_2O, where oxen is N,N' -bis(2-aminoethyl)oxamide dianion, has been synthesized. It crystallizes in triclinic system, space group P, with a=11.486(2), b=11.706(3), c=12.291(3) , α=77.42(2), β=67.59(2), γ=77.96(2)°, and z=2. The least-square refinements converged at R=0.047, with 3416 observed unique reflections. The complex has a pronounced three-dimensional character and can be viewed as the tetranuclear asymmetric repeating units through inversion and translation operations to extend a three-dimensional network. The structure of Cu_4 asymmetric unit consists of two square planar and two square pyramidal Cu central atoms linked by both azide ligands in end-on and end-to-end bonding modes, and oxamidate bridge in trans conformation.展开更多
Luminescent Single-Molecule Magnets(SMMs)have gained broad scientific attention due to their potential applications in the dual sensing of temperature and magnetic field or optical thermometry for the self-monitoring ...Luminescent Single-Molecule Magnets(SMMs)have gained broad scientific attention due to their potential applications in the dual sensing of temperature and magnetic field or optical thermometry for the self-monitoring of temperature in SMM-based devices.We present a route toward thermoresponsive emissive SMMs based on linking two molecular components separately providing luminescent thermometry and SMM features.展开更多
The title complex, mercury bridged biferrocene trinuclear complex Hg(FcL)2. Bis (S-methyl-N- (1-ferrocenyl-1-methyl) methylenedithiocarbazate) mercury,Crystallizes in space group Pbca with a =19. 510 (4), b=19. 921 (5...The title complex, mercury bridged biferrocene trinuclear complex Hg(FcL)2. Bis (S-methyl-N- (1-ferrocenyl-1-methyl) methylenedithiocarbazate) mercury,Crystallizes in space group Pbca with a =19. 510 (4), b=19. 921 (5), c=15. 581 (3)A. V=6095(3) A, Z=8,M.=863. 12, Dc=1.881 g/cm3; u=19. 24 cm-1 and F(000) = 3376. The final refinement of 2455 observed reflections is converged with R= 0. 043 and Rw=0.047. X-ray crystal structure analysis revealed that the coordinationgeometry of Hg atom is a distorted tetrahedron with two Hg-N bonds and two Hg- S bonds. The Schiff-base ligand loses a proton from its tautomeric thiol form and is cryordianted to the Hg aotm uia the mercapto sulphur and the β-nitrogen atoms.展开更多
A rapid method is applied to analyze conjugated organic ligands bridged binuclear ruthenium complexes by electrospray ionization-tandem mass spectrometry (ESI MSn).Fragmentation pattern be discussed.
Four compounds with the formula[M_(2)(dmphen)4(μ-C_(2)O_(4))](ClO_(4))_(2)·2dmso[M=Fe(1),Co(2)and Zn(4);dmphen=2,9-dimethyl-1,10-phenanthroline]and[Ni2(dmphen)_(4)(μ-C_(2)O_(4))]_(3)[NbO(C_(2)O_(4))_(3)]2·...Four compounds with the formula[M_(2)(dmphen)4(μ-C_(2)O_(4))](ClO_(4))_(2)·2dmso[M=Fe(1),Co(2)and Zn(4);dmphen=2,9-dimethyl-1,10-phenanthroline]and[Ni2(dmphen)_(4)(μ-C_(2)O_(4))]_(3)[NbO(C_(2)O_(4))_(3)]2·_(16)H_(2)O(3)have been synthesized using the tris(oxalato)oxoniobate(V)complex anion as the oxalate source,and their structures have been determined by single crystal X-ray diffraction.X-ray quality crystals of highly insoluble oxalate-bridged species were obtained by taking advantage of the slow release of oxalate by the tris(oxalato)oxoniobate(V)complex anion.The structures of 1-4 all contain oxalate-bridged dimetal(Ⅱ)units with didentate dmphen molecules acting as end-cap ligands;electroneutrality is achieved by perchlorate(1-4)and oxotris(oxalato)niobate(V)(3)anions.Each divalent metal ion in 1-4 is tris-chelated in a six-coordinate distorted octahedral environment.The niobium(V)ion in 3 is seven-coordinate in a distorted pentagonal bipyramidal geometry built from one oxo group and six oxygen atoms from three didentate oxalate ligands.The values of the metal-metal separation across the bis-chelating oxalate are 5.626(1)(1),5.575(1)(2),5.434(1)to 5.447(1)(3)and 5.603(1)Å(4).The cryomagnetic measurements in the temperature range of 2.0 to 300 K for compounds 1-3 show the occurrence of antiferromagnetic interactions between the divalent metal ions across the oxalate bridge.The nature and amplitude of these magnetic interactions are rationalized by simple symmetry considerations and compared with those previously reported for related oxalate-bridged systems.展开更多
Metastasis is a major health threat for most cancer patients,thus anti-metastasis treatments that reduce cell migration and invasion are critical for cancer treatment. In this study,four anthraquinone-bridged diruthen...Metastasis is a major health threat for most cancer patients,thus anti-metastasis treatments that reduce cell migration and invasion are critical for cancer treatment. In this study,four anthraquinone-bridged diruthenium(Ⅱ) complexes,[(bpy)_(2)Ru(L)Ru(bpy)_(2)]^(4+) (Ru1,L=1,4-bis(1H-imidazo[4,5-f][1,10]phenanthrolin-2-yl)anthracene-9,10-dione;Ru2,L=1,5-bis(1H-imidazo[4,5-f][1,10]phenanthrolin-2-yl)anthracene-9,10-dione;Ru3,L=2,6-bis(1H-imidazo[4,5-f][1,10]phenanthrolin-2-yl)anthracene-9,10-dione;and Ru4,L=2,7-bis(1H-imidazo[4,5-f][1,10]phenanthrolin-2-yl)anthracene-9,10-dione) were synthesized and characterized. These Ru(Ⅱ) complexes exhibited multi-targeted anti-metastatic properties against human hepatocarcinoma MHCC97-H cells that included the inhibition of migration and invasion. Further investigation of the intracellular mechanisms revealed that Ru(Ⅱ) complexes suppressed the phosphorylation of ERK and AKT. Moreover,significant reduction of the extracellular and intracellular expression of the metastatic regulatory proteins MMP-2 and MMP-9 was also observed after Ru1–Ru4 treatment. In addition,these Ru(Ⅱ) complexes negatively modulate the actin cytoskeleton by inhibiting Cdc42 protein expression,arresting the cells in the G2/M phase. The results indicate that these ruthenium(Ⅱ) complexes have potential as drug candidates for anti-metastatic therapies.展开更多
Three dinuclear Dy(Ⅲ)complexes,[Dy_(2)(tfa)_(4)L_(2)](1),[Dy_(2)(TTA)_(4)L_(2)](2)and[Dy_(2)(dbm)_(4)L_(2)·2CH_(3)CN·0.5H_(2)O](3)(tfa=trifluoroacetylacetonate,TTA=2-thenoyltrifluoroacetone,dbm=dibenzoylmet...Three dinuclear Dy(Ⅲ)complexes,[Dy_(2)(tfa)_(4)L_(2)](1),[Dy_(2)(TTA)_(4)L_(2)](2)and[Dy_(2)(dbm)_(4)L_(2)·2CH_(3)CN·0.5H_(2)O](3)(tfa=trifluoroacetylacetonate,TTA=2-thenoyltrifluoroacetone,dbm=dibenzoylmethane and HL=2-[((4-bromophenyl)-imino)methyl]-8-hydroxyquinoline,have been synthesized,and structurally and magnetically characterized.The Dy(Ⅲ)ions are eight-coordinated with two bidentate β-diketonate and two μ_(2)-O bridging 8-hydroxyquinoline Schiff base ligands.Magnetic studies reveal that 1-3 exhibit different magnetic relaxation behaviors with the anisotropic barriers of 9.61 K(1),54.81 K(2)and 30.98 K(3),respectively.The different magnetic relaxation behaviors of the three Dy_(2)complexes originate from the different chemical environments of the central Dy3+ions with different β-diketonate coligands.展开更多
Diphenoxo bridged dinuclear zinc complexes[Zn_(2)(OMe-Phimp)_(2)(Cl)_(2)](1)(OMe-PhimpH=(E)-4-methoxy-2-((2-phenyl-2-(pyridin-2-yl)hydrazono)methyl)phenol),[Zn_(2)(Me-Phimp)_(2)(Cl)_(2)](2)(Me-PhimpH=(E)-4-methyl-2-((...Diphenoxo bridged dinuclear zinc complexes[Zn_(2)(OMe-Phimp)_(2)(Cl)_(2)](1)(OMe-PhimpH=(E)-4-methoxy-2-((2-phenyl-2-(pyridin-2-yl)hydrazono)methyl)phenol),[Zn_(2)(Me-Phimp)_(2)(Cl)_(2)](2)(Me-PhimpH=(E)-4-methyl-2-((2-phenyl-2-(pyridin-2-yl)hydrazono)methyl)phenol),[Zn_(2)(N-Phimp)_(2)(Cl)_(2)]·CH_(3)CN(3·CH_(3)CN)(N-PhimpH=(E)-1-((2-phenyl-2-(pyridin-2-yl)hydrazono)methyl)naphthalen-2-ol)and[Zn_(2)(Phimp)_(2)(Cl)_(2)](4)(PhimpH=(E)-2-((2-phenyl-2-(pyridin-2-yl)hydrazono)methyl)phenol)were synthesized and spectroscopically characterized.The molecular structures of 1 and 3·CH_(3)CN were determined using X-ray crystallography.DFT and TD-DFT calculations were performed to optimize the molecular geometry,interpret the spectroscopic results and investigate the contribution of the ligands to the redox properties of the complexes.Phenoxyl radical complexes were generated in solution via chemical oxidation using ceric ammonium nitrate(CAN)and the redox properties were examined through cyclic voltammetric measurements.All the dinuclear zinc complexes were found to be highly active in catalyzing the oxidation of the primary alcohols 3,5-di-tert-butylcatechol and o-aminophenol.The catalytic activity was found to be in the order of complex 1>complex 2>complex 4>complex 3 for both calechol oxidation and o-aminophenol oxidation.An EPR experiment clearly hinted at the generation of a radical during the oxidation of catechol and o-aminophenol.Reaction models for these processes were proposed and theoretical studies were performed to support the proposed mechanism.ESI-MS spectra clearly indicate the formation of a catalyst–substrate adduct by removal of one Cl−ion.展开更多
The electronic structures of a cyanide bridged Fe-Co molecular square,[Co_(2)Fe_(2)(CN)_(6)(tp*)_(2)(dtbbpy)_(4)]-(PF_(6))_(2)·2MeOH(1)(tp*=hydrotris(3,5-dimethylpyrazol-1-yl)borate,dtbbpy=4,4’-di-tert-butyl-2,2...The electronic structures of a cyanide bridged Fe-Co molecular square,[Co_(2)Fe_(2)(CN)_(6)(tp*)_(2)(dtbbpy)_(4)]-(PF_(6))_(2)·2MeOH(1)(tp*=hydrotris(3,5-dimethylpyrazol-1-yl)borate,dtbbpy=4,4’-di-tert-butyl-2,2’-bipyridine),which exhibits thermal and photo-induced two-step charge-transfer induced spin transitions(CTIST),are investigated in detail by density functional theory(DFT)and time-dependent(TD)DFT calculations.For the three phases observed in the experiment,three different model structures are constructed based on the geometries of X-ray crystallography analysis measured at low(100 K),middle(298 K)and high(330 K)temperatures.The calculated results elucidate that the ground states at the low and the high temperatures are diamagnetic[(Fe_(LS)^(Ⅱ))_(2)(Co_(LS)^(Ⅲ))_(2)]and ferromagnetic[(Fe_(LS)^(Ⅲ))_(2)(Co_(HS)^(Ⅱ))_(2)],respectively.On the other hand,the one-electron transferred[FeⅡ LSFe_(LS)^(Ⅲ)Co_(HS)^(Ⅱ)Co_(LS)^(Ⅲ)]state becomes the ground state at the intermediate temperature phase.A magnetic interaction between Fe^(Ⅲ) and Co^(Ⅱ) in the[(Fe_(LS)^(Ⅲ))_(2)(Co_(HS)^(Ⅱ))_(2)]state is ferromagnetic and the most stable spin-coupling state is the all-ferromagnetic state.The TD-DFT calculation shows the two significant peaks of Fe^(Ⅱ)t_(2g)→Co^(Ⅲ)_(eg) around 800 nm.The results support that the experimental broad absorption peak at 770 nm is an inter-valence charge transfer(IVCT)band.展开更多
Cyanide-bridged FeCo coordination clusters,recognized as exceptional candidates for molecular switches,have been the subject of extensive research efforts aimed at unraveling the key factors governing the charge trans...Cyanide-bridged FeCo coordination clusters,recognized as exceptional candidates for molecular switches,have been the subject of extensive research efforts aimed at unraveling the key factors governing the charge transfer process.Previously,we have observed that the square complex{[Fe(Tp)(CN)_(3)]_(2)[Co(vbik)2]2}^(2+)with Tp=tris(pyrazolyl)borate and vbik=bis(1-vinyl-2-imidazolyl)ketone,abbreviated as{Fe_(2)Co_(2)},undergoes thermal charge transfer in MeOH solution near room temperature allowing the obtention of a solvatomorph pair,{Fe_(2)^(Ⅱ)Co_(2)^(Ⅲ)}·2BF_(4)·2MeOH(1)and{Fe_(2)^(Ⅱ)Co_(2)^(Ⅲ)}·2BF_(4)·10H_(2)O·2MeOH(2),exhibiting distinct electronic configurations at 300 K.While 2 maintains its charge transfer ability in the solid state,1 is trapped in the paramagnetic state by solid phase interactions down to 2 K,which makes it a good candidate for investigating electron transfer under hydrostatic pressure,an external stimulus scarcely used for these systems.In the present work,we demonstrated that the synthesis method can be used to obtain a new solvatomorph with remarkable pressure-induced electron transfer.The paramagnetic{Fe_(2)^(Ⅱ)Co_(2)^(Ⅲ)}·2(PF6)·2MeOH(3)and the diamagnetic{Fe_(2)^(Ⅱ)Co_(2)^(Ⅲ)}·2(PF6)·nH_(2)O·mMeOH(4),isostructural to 1 and 2,respectively,were obtained.The stronger intermolecular interactions due to the PF6 anion lead to a greater distortion of the core structures of 3 and 4,affecting their magnetic properties under ambient and hydrostatic pressure.Notably,3 exhibits a partial pressure-induced conversion from a paramagnetic to a diamagnetic state followed by a back conversion above a pressure threshold value,which is rationalized by a symmetry-breaking phase transition at ca.0.96-1.0 GPa.This unusual behavior has been analyzed using magnetometry,X-ray diffraction,andμ-Raman spectroscopy under various pressures.A deeper understanding of the electron transfer process in 3 was achieved by analyzing its structural data under various pressures and comparing them to those of 1.The distinct electron transfer behaviors observed in the two complexes are likely correlated to the differing distortions in their square core structures induced by pressure.展开更多
The reaction of μ alkyne bridged dimolybdenum compound 〔Mo 2( μ C 2HPh)(CO) 4( η 5 C 5H 4C(O)Me) 2〕 1 with Co 2(CO) 8 in refluxing toluene gave a new butterfly compound 〔Co 2Mo 2( μ 4 C 2HPh)( μ CO) 4(CO) 4( ...The reaction of μ alkyne bridged dimolybdenum compound 〔Mo 2( μ C 2HPh)(CO) 4( η 5 C 5H 4C(O)Me) 2〕 1 with Co 2(CO) 8 in refluxing toluene gave a new butterfly compound 〔Co 2Mo 2( μ 4 C 2HPh)( μ CO) 4(CO) 4( η 5 C 5H 4C(O)Me) 2〕 2 which was fully characterized by elemental analysis, IR, 1H NMR and X ray single crystal diffraction techniques. 2 crystallized in monoclinic system, C 30 H 20 Co 2Mo 2O 10 , M r =850.23, space group P2 1/a(#14), a=14.165(5), b=12.498(2), c=16.204(2) , β = 96 50(2)°, V = 2850(1) 3, Z = 4, D c = 1.981 g cm -3 , F(000)=1672, μ (Mo Kα )=20.41 cm -1 , final R=0.030, R w =0.039 for 4831 observable reflections with I>2σ(I ). The structure contains a Co 2Mo 2 butterfly core, and each Mo-Co bond is spanned by an asymmetric semi bridging carbonyl ligand.展开更多
The crystal structure of the title compound C 8H 16 CuN 8Ni has been determined by single crystal X ray diffraction. The crystal is triclinic with space group P1, a=6.494(3), b=7.270(4), c=7.936(5) , α=106.6...The crystal structure of the title compound C 8H 16 CuN 8Ni has been determined by single crystal X ray diffraction. The crystal is triclinic with space group P1, a=6.494(3), b=7.270(4), c=7.936(5) , α=106.67(3), β=91.33(4), γ=106.80(6)°, V=341.3(3) 3, Z=1, M r=346.54, F(000)=177, μ =2\^933mm -1 , D c =1.686 Mg/m 3. The final R factor is 0.0603 for 1214 unique observed reflections 〔 I≥2σ(I) 〕. The structure consists of 〔Cu(en) 2〕 2+ (en=ethylenediamine) cations and 〔Ni(CN) 4〕 2- anions linked together by two of the CN groups (the remaining two act as unidentate ligands) to form infinite chains, in the chain, the hydrogen bonds of N(4)…H-N(5) exist,with distance 3.148 , at the same time the hydrogen bonds of N(4)…H-N(7a) and N(5)-H…N(1a) (a: x-1,y-1,z-1 ) between the interchains also exist, with distances of 3.160 and 3.124 , so it forms a three\|dimensional structure of the title compound.展开更多
The title compound [Ni(bipy)3][(-oxo)Fe2Cl6] (bipy = 2, 2?bispyridine) was synthesized and its crystal structure was determined by X-ray diffraction method. It crystallizes in monoclinic, space group P2l/c with unit c...The title compound [Ni(bipy)3][(-oxo)Fe2Cl6] (bipy = 2, 2?bispyridine) was synthesized and its crystal structure was determined by X-ray diffraction method. It crystallizes in monoclinic, space group P2l/c with unit cell parameters: a = 9.7085(7),b = 26.409(2), c = 14.014(1) ,?= 100.237(3), V = 3535.9(2) 3,Z = 4,C30H24Cl6Fe2N6NiO,Mr = 867.66, Dc = 1.630 g/cm3,F(000) = 1744, (MoK? = 1.824 mm-1, the final R = 0.0394 and wR = 0.0475 for 2750 observed reflections with I ≥ 2(I). The title compound contains cation of [Ni(bipy)3]2+ and anion of [(-oxo)Fe2Cl6] 2- which consists of two [FeCl3] fragments connected by an oxo bridge with the bond distances of Fe(2)O(1) 1.752(2) and Fe(1)O(1) 1.763(2) , and the bond angle of Fe(2)O(1)Fe(1) 148.6(2)? In the [Fe2(-oxo)Cl6]2- complex, the two iron(Ⅲ) centers exhibit a tetrahedral coordination with the distorted tetrahedron formed by three Cl atoms and one oxo bridge.展开更多
The synthesis and 1H NMR, ESR, IR, UV spectra of binuclear bridged complex μ-4,4-bipy[VO-（acac）2]2 are reported in this paper. The structure of the complex is discussed using measured spectral parameters.It is deem...The synthesis and 1H NMR, ESR, IR, UV spectra of binuclear bridged complex μ-4,4-bipy[VO-（acac）2]2 are reported in this paper. The structure of the complex is discussed using measured spectral parameters.It is deemed that 4,4-bipy as a bridge passing through its two N atoms combined respectively with two V atoms at its sixth position, forming a binuclear bridged complex.The spectra are explained satisfactorily and coefficients of molecular orbitals,β1,β2 and 8m,are calculated from the results of ESR and UV etc.展开更多
Three azide bridged complexes,namely,[Mn_(2)L_(2)(N_(3))_(4)(H_(2)O)_(2)](1),[Co_(2)L_(2)(N_(3))_(4)]·(H_(2)O)_(3)(2)and[Ni_(2)L_(2)(N_(3))_(3)(H_(2)O)]N_(3)·(H_(2)O)4(3)(L=2-morpholine-4-yl-4,6-di-pyrazol-1...Three azide bridged complexes,namely,[Mn_(2)L_(2)(N_(3))_(4)(H_(2)O)_(2)](1),[Co_(2)L_(2)(N_(3))_(4)]·(H_(2)O)_(3)(2)and[Ni_(2)L_(2)(N_(3))_(3)(H_(2)O)]N_(3)·(H_(2)O)4(3)(L=2-morpholine-4-yl-4,6-di-pyrazol-1-yl-1,3,5-triazine),were synthesized by the reaction of L ligand,sodium azide with Mn(Ⅱ),Co(Ⅱ)and Ni(Ⅱ)chlorides.The copper(Ⅱ)chloride combined with thiocyanate and L ligand to form a mononuclear complex[CuL(CH3OH)(SCN)(NCS)](4).Complexes 1~4 were characterized by IR,elemental analysis and X-ray crystallographic analysis.It was worth noting that two Mn(Ⅱ)atoms were connected by the end-to-end mode in 1,while Co(Ⅱ)and Ni(Ⅱ)atoms were connected by the end-on mode in 2 and 3.In complex 4,the central copper atom was coordinated with a sulfur atom and a nitrogen atom of the two thiocyanate ligands,respectively.Hydrogen bonds,π-πstacking interactions,thermogravimetric analysis and fluorescence properties of 1~4 were studied.展开更多
Strain Energy of the structure can be changed with the damage at the damage location.The accurate detection of the damage location using this index in a force system is dependent on the degree of accuracy in determini...Strain Energy of the structure can be changed with the damage at the damage location.The accurate detection of the damage location using this index in a force system is dependent on the degree of accuracy in determining the structure deformation function before and after damage.The use of modal-based methods to identify damage in complex bridges is always associated with problems due to the need to consider the effects of higher modes and the adverse effct of operational conditions on the extraction of structural modal parameters.In this paper,the deformation of the structure was determined by the concept of influence line using the Betti-Maxwell theory.Then two damage detection indicators were developed based on strain energy variations.These indices were presented separately for bending and torsion changes.Finite element analysis of a five-span concrete curved bridge was done to validate the stated methods.Damage was simulated by decreasing stiffness at different sections of the deck.The response regarding displacement ofa point on the deck was measured along each span by passing a moving load on the bridge at very low speeds.Indicators of the strain energy extracted from displacement influence line and the strain energy extracted from the rotational displacement influence line(SERIL)were calculated for the studied bridge.The results show that the proposed methods have well identified the location of the damage by significantly reducing the number of sensors required to record the response.Also,the location of symmetric damages is detected with high resolution using SERIL.展开更多
基金supported by the National Natural Science Foundation of China (20661001, 21061008)the Key Grant of Inner Mongolia Natural Science Foundation of China (200408020201)
文摘Three new bridging complexes of rare earth and cobalt cluster were synthesized and characterized via ICP, IR and TG techniques. The structure of the complexes was speculated as： two rare earth atoms were bridged with four CF3COO–, and rare earth atoms were coordinated with cobalt carbonyl clusters to form a steady structure. Application of the complexes as the catalyst precursors was explored for Fischer-Tropsch synthesis. The study showed that the bridging complexes of rare earth and cobalt cluster had large molecular size and were difficult to enter pore path of γ-Al2O3, so they were dispersed on the surface of γ-Al2O3 support. In addition, the performance of Co（Ce）/ γ-Al2O3 was the best among the catalysts with complex as precursor and maintained 77.7% CO conversion at 220 oC for 80 operation hours.
文摘The synthesis, structure and characterization of a new one-dimensional cyanide-bridgedcomplex [Ni(pn)_2Ni(CN)4]n'nH2O (where pn = 1,2-diaminopropane) are described. The structure ofthis complex consists of a one-dimensional polymeric chain-Ni(pn)2-NC-Ni(CN)2-CN-Ni(pn)2- inwhich the Ni(II) centers are linked by two CN groups.
文摘Reaction of(n-Bu_4N)_xNa_(4-x)[a-Mo_8O_(26)](x=1-4)and mpH_2(mpH_2=o-mercaptophenol) leads to the formation of compound(n-Bu_4N)[Mo_2O_3(mp)_3Na(EtOH)_2(MeOH)],It crystallizes in the space group P2_1/n with four molecules per unit cell.The cell dimension is a=12.776(3),b=14.154(5),c=26.281(7)(?)=95.50(2)°,V=4730.5 (?),d_c=1.407 g/cm^3.Full-matrix refinement of 496 parameters on 3348 reflection data gave final R(R_w) value of 0.072(0.072).The two oxomolybdenum-mercaptophenolate,units are triply bridged by an inorganic oxygen atom and a doubly bridging mp^(2-)ligand.
文摘The complex polymer[Cu_2(oxap)(pyr)_2]_n(ClO_4)_(2n),where oxap^(2-)stands for N,N' -bis(2—aminopropyl)oxamide,have been synthesized.It crystallizes in monoclinic system, space group P2_1/C,with a=8.721(2),b=8.679(2),c=16.741(2),β=98.59(0),Z=4.The least-square refinement coverged at R=0.054,R_w=0.055 with 1869 unique reflections.The whole structure of the complcx consists of layers of two-dimensional network arraying along a-axis with perchlorate ions interspersed in the gap between layers.Inside the layer. trans-oxamide-bridged copper(Ⅱ)dimers connected by pyrimidine in an asymmetric fashion spread out along be plane to form an infinite two-dimensional network.
文摘A novel three dimensional network complex polymer [Cu_4(oxen)_2(N_3)_3]_n(ClO_4)_n·2nH_2O, where oxen is N,N' -bis(2-aminoethyl)oxamide dianion, has been synthesized. It crystallizes in triclinic system, space group P, with a=11.486(2), b=11.706(3), c=12.291(3) , α=77.42(2), β=67.59(2), γ=77.96(2)°, and z=2. The least-square refinements converged at R=0.047, with 3416 observed unique reflections. The complex has a pronounced three-dimensional character and can be viewed as the tetranuclear asymmetric repeating units through inversion and translation operations to extend a three-dimensional network. The structure of Cu_4 asymmetric unit consists of two square planar and two square pyramidal Cu central atoms linked by both azide ligands in end-on and end-to-end bonding modes, and oxamidate bridge in trans conformation.
基金financed by the National Science Centre of Poland,the OPUS-21 project,no.2021/41/B/ST5/02544The research has been supported by an infrastructure grant from the Faculty of Chemistry under the Strategic Programme Excellence Initiative at Jagiellonian Univ.The study was carried out using the research infrastructure co-funded by the EU in the framework of the Smart Growth Operational Program,Measure 4.2+1 种基金Grant No.POIR.04.02.00-00-D001/20,“ATOMIN 2.0-ATOMic scale science for the INnovative economy”We also gratefully acknowledge Polish high-performance computing infrastructure PLGrid(HPC Center:ACK Cyfronet AGH)for providing computer facilities and support within computational grant no.PLG/2019/013095.
文摘Luminescent Single-Molecule Magnets(SMMs)have gained broad scientific attention due to their potential applications in the dual sensing of temperature and magnetic field or optical thermometry for the self-monitoring of temperature in SMM-based devices.We present a route toward thermoresponsive emissive SMMs based on linking two molecular components separately providing luminescent thermometry and SMM features.
文摘The title complex, mercury bridged biferrocene trinuclear complex Hg(FcL)2. Bis (S-methyl-N- (1-ferrocenyl-1-methyl) methylenedithiocarbazate) mercury,Crystallizes in space group Pbca with a =19. 510 (4), b=19. 921 (5), c=15. 581 (3)A. V=6095(3) A, Z=8,M.=863. 12, Dc=1.881 g/cm3; u=19. 24 cm-1 and F(000) = 3376. The final refinement of 2455 observed reflections is converged with R= 0. 043 and Rw=0.047. X-ray crystal structure analysis revealed that the coordinationgeometry of Hg atom is a distorted tetrahedron with two Hg-N bonds and two Hg- S bonds. The Schiff-base ligand loses a proton from its tautomeric thiol form and is cryordianted to the Hg aotm uia the mercapto sulphur and the β-nitrogen atoms.
文摘A rapid method is applied to analyze conjugated organic ligands bridged binuclear ruthenium complexes by electrospray ionization-tandem mass spectrometry (ESI MSn).Fragmentation pattern be discussed.
基金supported by the Conselho Nacional de Desenvolvimento Científico e Tecnológico(CNPq),Fundação de AmparoàPesquisa do Estado de Minas Gerais(Project PPM 00508-16)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior(CAPES)Ministerio Español de Economía y Competitividad(MINECO)(Project CTQ2016-75068P and Unidad de Excelencia María de Maetzu MDM-2015-0538).
文摘Four compounds with the formula[M_(2)(dmphen)4(μ-C_(2)O_(4))](ClO_(4))_(2)·2dmso[M=Fe(1),Co(2)and Zn(4);dmphen=2,9-dimethyl-1,10-phenanthroline]and[Ni2(dmphen)_(4)(μ-C_(2)O_(4))]_(3)[NbO(C_(2)O_(4))_(3)]2·_(16)H_(2)O(3)have been synthesized using the tris(oxalato)oxoniobate(V)complex anion as the oxalate source,and their structures have been determined by single crystal X-ray diffraction.X-ray quality crystals of highly insoluble oxalate-bridged species were obtained by taking advantage of the slow release of oxalate by the tris(oxalato)oxoniobate(V)complex anion.The structures of 1-4 all contain oxalate-bridged dimetal(Ⅱ)units with didentate dmphen molecules acting as end-cap ligands;electroneutrality is achieved by perchlorate(1-4)and oxotris(oxalato)niobate(V)(3)anions.Each divalent metal ion in 1-4 is tris-chelated in a six-coordinate distorted octahedral environment.The niobium(V)ion in 3 is seven-coordinate in a distorted pentagonal bipyramidal geometry built from one oxo group and six oxygen atoms from three didentate oxalate ligands.The values of the metal-metal separation across the bis-chelating oxalate are 5.626(1)(1),5.575(1)(2),5.434(1)to 5.447(1)(3)and 5.603(1)Å(4).The cryomagnetic measurements in the temperature range of 2.0 to 300 K for compounds 1-3 show the occurrence of antiferromagnetic interactions between the divalent metal ions across the oxalate bridge.The nature and amplitude of these magnetic interactions are rationalized by simple symmetry considerations and compared with those previously reported for related oxalate-bridged systems.
基金supported by the 973 Program(no.2015CB856301)the National Science Foundation of China(no.21471164 and 21525105)+2 种基金Guangdong Province Public Research and Capacity-Building of Special Foundation(no.2015A020211037)Guangzhou Science and Technology Project(no.201607010087)the Natural Science Foundation of Guangdong Province(no.2016A030310298).
文摘Metastasis is a major health threat for most cancer patients,thus anti-metastasis treatments that reduce cell migration and invasion are critical for cancer treatment. In this study,four anthraquinone-bridged diruthenium(Ⅱ) complexes,[(bpy)_(2)Ru(L)Ru(bpy)_(2)]^(4+) (Ru1,L=1,4-bis(1H-imidazo[4,5-f][1,10]phenanthrolin-2-yl)anthracene-9,10-dione;Ru2,L=1,5-bis(1H-imidazo[4,5-f][1,10]phenanthrolin-2-yl)anthracene-9,10-dione;Ru3,L=2,6-bis(1H-imidazo[4,5-f][1,10]phenanthrolin-2-yl)anthracene-9,10-dione;and Ru4,L=2,7-bis(1H-imidazo[4,5-f][1,10]phenanthrolin-2-yl)anthracene-9,10-dione) were synthesized and characterized. These Ru(Ⅱ) complexes exhibited multi-targeted anti-metastatic properties against human hepatocarcinoma MHCC97-H cells that included the inhibition of migration and invasion. Further investigation of the intracellular mechanisms revealed that Ru(Ⅱ) complexes suppressed the phosphorylation of ERK and AKT. Moreover,significant reduction of the extracellular and intracellular expression of the metastatic regulatory proteins MMP-2 and MMP-9 was also observed after Ru1–Ru4 treatment. In addition,these Ru(Ⅱ) complexes negatively modulate the actin cytoskeleton by inhibiting Cdc42 protein expression,arresting the cells in the G2/M phase. The results indicate that these ruthenium(Ⅱ) complexes have potential as drug candidates for anti-metastatic therapies.
基金supported financially by the National Natural Science Foundation of China(no.21271137,21571138 and 21561014).
文摘Three dinuclear Dy(Ⅲ)complexes,[Dy_(2)(tfa)_(4)L_(2)](1),[Dy_(2)(TTA)_(4)L_(2)](2)and[Dy_(2)(dbm)_(4)L_(2)·2CH_(3)CN·0.5H_(2)O](3)(tfa=trifluoroacetylacetonate,TTA=2-thenoyltrifluoroacetone,dbm=dibenzoylmethane and HL=2-[((4-bromophenyl)-imino)methyl]-8-hydroxyquinoline,have been synthesized,and structurally and magnetically characterized.The Dy(Ⅲ)ions are eight-coordinated with two bidentate β-diketonate and two μ_(2)-O bridging 8-hydroxyquinoline Schiff base ligands.Magnetic studies reveal that 1-3 exhibit different magnetic relaxation behaviors with the anisotropic barriers of 9.61 K(1),54.81 K(2)and 30.98 K(3),respectively.The different magnetic relaxation behaviors of the three Dy_(2)complexes originate from the different chemical environments of the central Dy3+ions with different β-diketonate coligands.
基金SERB-DST(SR/S1/IC-47/2012 dated Oct 2013),New Delhi,India for financial assistanceUGC for financial assistance。
文摘Diphenoxo bridged dinuclear zinc complexes[Zn_(2)(OMe-Phimp)_(2)(Cl)_(2)](1)(OMe-PhimpH=(E)-4-methoxy-2-((2-phenyl-2-(pyridin-2-yl)hydrazono)methyl)phenol),[Zn_(2)(Me-Phimp)_(2)(Cl)_(2)](2)(Me-PhimpH=(E)-4-methyl-2-((2-phenyl-2-(pyridin-2-yl)hydrazono)methyl)phenol),[Zn_(2)(N-Phimp)_(2)(Cl)_(2)]·CH_(3)CN(3·CH_(3)CN)(N-PhimpH=(E)-1-((2-phenyl-2-(pyridin-2-yl)hydrazono)methyl)naphthalen-2-ol)and[Zn_(2)(Phimp)_(2)(Cl)_(2)](4)(PhimpH=(E)-2-((2-phenyl-2-(pyridin-2-yl)hydrazono)methyl)phenol)were synthesized and spectroscopically characterized.The molecular structures of 1 and 3·CH_(3)CN were determined using X-ray crystallography.DFT and TD-DFT calculations were performed to optimize the molecular geometry,interpret the spectroscopic results and investigate the contribution of the ligands to the redox properties of the complexes.Phenoxyl radical complexes were generated in solution via chemical oxidation using ceric ammonium nitrate(CAN)and the redox properties were examined through cyclic voltammetric measurements.All the dinuclear zinc complexes were found to be highly active in catalyzing the oxidation of the primary alcohols 3,5-di-tert-butylcatechol and o-aminophenol.The catalytic activity was found to be in the order of complex 1>complex 2>complex 4>complex 3 for both calechol oxidation and o-aminophenol oxidation.An EPR experiment clearly hinted at the generation of a radical during the oxidation of catechol and o-aminophenol.Reaction models for these processes were proposed and theoretical studies were performed to support the proposed mechanism.ESI-MS spectra clearly indicate the formation of a catalyst–substrate adduct by removal of one Cl−ion.
基金supported by Grant-in-Aid for Scientific Research(KAKENHI)(C)(no.26410093)from the Japan Society for the Promotion of Science(JSPS)Grant-in-Aid for Scientific Research on Innovative Areas(“Coordination programming”,no.24108721)from the Ministry of Education,Culture,Sports,Science and Technology(MEXT)the Inter-University Cooperative Research Program of the Institute for Materials Research,Tohoku University(proposal no.14K0008,15K0118).
文摘The electronic structures of a cyanide bridged Fe-Co molecular square,[Co_(2)Fe_(2)(CN)_(6)(tp*)_(2)(dtbbpy)_(4)]-(PF_(6))_(2)·2MeOH(1)(tp*=hydrotris(3,5-dimethylpyrazol-1-yl)borate,dtbbpy=4,4’-di-tert-butyl-2,2’-bipyridine),which exhibits thermal and photo-induced two-step charge-transfer induced spin transitions(CTIST),are investigated in detail by density functional theory(DFT)and time-dependent(TD)DFT calculations.For the three phases observed in the experiment,three different model structures are constructed based on the geometries of X-ray crystallography analysis measured at low(100 K),middle(298 K)and high(330 K)temperatures.The calculated results elucidate that the ground states at the low and the high temperatures are diamagnetic[(Fe_(LS)^(Ⅱ))_(2)(Co_(LS)^(Ⅲ))_(2)]and ferromagnetic[(Fe_(LS)^(Ⅲ))_(2)(Co_(HS)^(Ⅱ))_(2)],respectively.On the other hand,the one-electron transferred[FeⅡ LSFe_(LS)^(Ⅲ)Co_(HS)^(Ⅱ)Co_(LS)^(Ⅲ)]state becomes the ground state at the intermediate temperature phase.A magnetic interaction between Fe^(Ⅲ) and Co^(Ⅱ) in the[(Fe_(LS)^(Ⅲ))_(2)(Co_(HS)^(Ⅱ))_(2)]state is ferromagnetic and the most stable spin-coupling state is the all-ferromagnetic state.The TD-DFT calculation shows the two significant peaks of Fe^(Ⅱ)t_(2g)→Co^(Ⅲ)_(eg) around 800 nm.The results support that the experimental broad absorption peak at 770 nm is an inter-valence charge transfer(IVCT)band.
基金the GuangZhou Elite Project Scholars Association for awarding a three-year grant to Xu Buqin and the PMD2X X-ray diffraction facility of the CRM2 laboratory(Universitéde Lorraine)for X-ray diffraction measurements(https://crm2.univ-lorraine.fr/plateformes/pmd2x/)M.D.thank M.Nespolo for his help with non-conventional settings.
文摘Cyanide-bridged FeCo coordination clusters,recognized as exceptional candidates for molecular switches,have been the subject of extensive research efforts aimed at unraveling the key factors governing the charge transfer process.Previously,we have observed that the square complex{[Fe(Tp)(CN)_(3)]_(2)[Co(vbik)2]2}^(2+)with Tp=tris(pyrazolyl)borate and vbik=bis(1-vinyl-2-imidazolyl)ketone,abbreviated as{Fe_(2)Co_(2)},undergoes thermal charge transfer in MeOH solution near room temperature allowing the obtention of a solvatomorph pair,{Fe_(2)^(Ⅱ)Co_(2)^(Ⅲ)}·2BF_(4)·2MeOH(1)and{Fe_(2)^(Ⅱ)Co_(2)^(Ⅲ)}·2BF_(4)·10H_(2)O·2MeOH(2),exhibiting distinct electronic configurations at 300 K.While 2 maintains its charge transfer ability in the solid state,1 is trapped in the paramagnetic state by solid phase interactions down to 2 K,which makes it a good candidate for investigating electron transfer under hydrostatic pressure,an external stimulus scarcely used for these systems.In the present work,we demonstrated that the synthesis method can be used to obtain a new solvatomorph with remarkable pressure-induced electron transfer.The paramagnetic{Fe_(2)^(Ⅱ)Co_(2)^(Ⅲ)}·2(PF6)·2MeOH(3)and the diamagnetic{Fe_(2)^(Ⅱ)Co_(2)^(Ⅲ)}·2(PF6)·nH_(2)O·mMeOH(4),isostructural to 1 and 2,respectively,were obtained.The stronger intermolecular interactions due to the PF6 anion lead to a greater distortion of the core structures of 3 and 4,affecting their magnetic properties under ambient and hydrostatic pressure.Notably,3 exhibits a partial pressure-induced conversion from a paramagnetic to a diamagnetic state followed by a back conversion above a pressure threshold value,which is rationalized by a symmetry-breaking phase transition at ca.0.96-1.0 GPa.This unusual behavior has been analyzed using magnetometry,X-ray diffraction,andμ-Raman spectroscopy under various pressures.A deeper understanding of the electron transfer process in 3 was achieved by analyzing its structural data under various pressures and comparing them to those of 1.The distinct electron transfer behaviors observed in the two complexes are likely correlated to the differing distortions in their square core structures induced by pressure.
文摘The reaction of μ alkyne bridged dimolybdenum compound 〔Mo 2( μ C 2HPh)(CO) 4( η 5 C 5H 4C(O)Me) 2〕 1 with Co 2(CO) 8 in refluxing toluene gave a new butterfly compound 〔Co 2Mo 2( μ 4 C 2HPh)( μ CO) 4(CO) 4( η 5 C 5H 4C(O)Me) 2〕 2 which was fully characterized by elemental analysis, IR, 1H NMR and X ray single crystal diffraction techniques. 2 crystallized in monoclinic system, C 30 H 20 Co 2Mo 2O 10 , M r =850.23, space group P2 1/a(#14), a=14.165(5), b=12.498(2), c=16.204(2) , β = 96 50(2)°, V = 2850(1) 3, Z = 4, D c = 1.981 g cm -3 , F(000)=1672, μ (Mo Kα )=20.41 cm -1 , final R=0.030, R w =0.039 for 4831 observable reflections with I>2σ(I ). The structure contains a Co 2Mo 2 butterfly core, and each Mo-Co bond is spanned by an asymmetric semi bridging carbonyl ligand.
文摘The crystal structure of the title compound C 8H 16 CuN 8Ni has been determined by single crystal X ray diffraction. The crystal is triclinic with space group P1, a=6.494(3), b=7.270(4), c=7.936(5) , α=106.67(3), β=91.33(4), γ=106.80(6)°, V=341.3(3) 3, Z=1, M r=346.54, F(000)=177, μ =2\^933mm -1 , D c =1.686 Mg/m 3. The final R factor is 0.0603 for 1214 unique observed reflections 〔 I≥2σ(I) 〕. The structure consists of 〔Cu(en) 2〕 2+ (en=ethylenediamine) cations and 〔Ni(CN) 4〕 2- anions linked together by two of the CN groups (the remaining two act as unidentate ligands) to form infinite chains, in the chain, the hydrogen bonds of N(4)…H-N(5) exist,with distance 3.148 , at the same time the hydrogen bonds of N(4)…H-N(7a) and N(5)-H…N(1a) (a: x-1,y-1,z-1 ) between the interchains also exist, with distances of 3.160 and 3.124 , so it forms a three\|dimensional structure of the title compound.
基金Supported by the foundation of Education Committee of Fujian Province (JB01045)
文摘The title compound [Ni(bipy)3][(-oxo)Fe2Cl6] (bipy = 2, 2?bispyridine) was synthesized and its crystal structure was determined by X-ray diffraction method. It crystallizes in monoclinic, space group P2l/c with unit cell parameters: a = 9.7085(7),b = 26.409(2), c = 14.014(1) ,?= 100.237(3), V = 3535.9(2) 3,Z = 4,C30H24Cl6Fe2N6NiO,Mr = 867.66, Dc = 1.630 g/cm3,F(000) = 1744, (MoK? = 1.824 mm-1, the final R = 0.0394 and wR = 0.0475 for 2750 observed reflections with I ≥ 2(I). The title compound contains cation of [Ni(bipy)3]2+ and anion of [(-oxo)Fe2Cl6] 2- which consists of two [FeCl3] fragments connected by an oxo bridge with the bond distances of Fe(2)O(1) 1.752(2) and Fe(1)O(1) 1.763(2) , and the bond angle of Fe(2)O(1)Fe(1) 148.6(2)? In the [Fe2(-oxo)Cl6]2- complex, the two iron(Ⅲ) centers exhibit a tetrahedral coordination with the distorted tetrahedron formed by three Cl atoms and one oxo bridge.
文摘The synthesis and 1H NMR, ESR, IR, UV spectra of binuclear bridged complex μ-4,4-bipy[VO-（acac）2]2 are reported in this paper. The structure of the complex is discussed using measured spectral parameters.It is deemed that 4,4-bipy as a bridge passing through its two N atoms combined respectively with two V atoms at its sixth position, forming a binuclear bridged complex.The spectra are explained satisfactorily and coefficients of molecular orbitals,β1,β2 and 8m,are calculated from the results of ESR and UV etc.
文摘Three azide bridged complexes,namely,[Mn_(2)L_(2)(N_(3))_(4)(H_(2)O)_(2)](1),[Co_(2)L_(2)(N_(3))_(4)]·(H_(2)O)_(3)(2)and[Ni_(2)L_(2)(N_(3))_(3)(H_(2)O)]N_(3)·(H_(2)O)4(3)(L=2-morpholine-4-yl-4,6-di-pyrazol-1-yl-1,3,5-triazine),were synthesized by the reaction of L ligand,sodium azide with Mn(Ⅱ),Co(Ⅱ)and Ni(Ⅱ)chlorides.The copper(Ⅱ)chloride combined with thiocyanate and L ligand to form a mononuclear complex[CuL(CH3OH)(SCN)(NCS)](4).Complexes 1~4 were characterized by IR,elemental analysis and X-ray crystallographic analysis.It was worth noting that two Mn(Ⅱ)atoms were connected by the end-to-end mode in 1,while Co(Ⅱ)and Ni(Ⅱ)atoms were connected by the end-on mode in 2 and 3.In complex 4,the central copper atom was coordinated with a sulfur atom and a nitrogen atom of the two thiocyanate ligands,respectively.Hydrogen bonds,π-πstacking interactions,thermogravimetric analysis and fluorescence properties of 1~4 were studied.
文摘Strain Energy of the structure can be changed with the damage at the damage location.The accurate detection of the damage location using this index in a force system is dependent on the degree of accuracy in determining the structure deformation function before and after damage.The use of modal-based methods to identify damage in complex bridges is always associated with problems due to the need to consider the effects of higher modes and the adverse effct of operational conditions on the extraction of structural modal parameters.In this paper,the deformation of the structure was determined by the concept of influence line using the Betti-Maxwell theory.Then two damage detection indicators were developed based on strain energy variations.These indices were presented separately for bending and torsion changes.Finite element analysis of a five-span concrete curved bridge was done to validate the stated methods.Damage was simulated by decreasing stiffness at different sections of the deck.The response regarding displacement ofa point on the deck was measured along each span by passing a moving load on the bridge at very low speeds.Indicators of the strain energy extracted from displacement influence line and the strain energy extracted from the rotational displacement influence line(SERIL)were calculated for the studied bridge.The results show that the proposed methods have well identified the location of the damage by significantly reducing the number of sensors required to record the response.Also,the location of symmetric damages is detected with high resolution using SERIL.
