Based on the Lagrange s equation and the finite element method, this paper establishes the dynamic equation of a radar antenna mechanic system which is a high accuracy system and consists of two flexible bodies. Mode ...Based on the Lagrange s equation and the finite element method, this paper establishes the dynamic equation of a radar antenna mechanic system which is a high accuracy system and consists of two flexible bodies. Mode coordinates are used to reduce the orders of equation. Finally, the calculation method and engineering example are given when the rotational velocity of antenna is invariable and the wind velocity is 25?m/s. The error of antenna mechanic system can be estimated using the calculation results.展开更多
Two 1D coordination polymers Cu2I（C6N3H4）2（1） and CuⅡ（C6N3H4）2·H2O（2） based on benzotriazole（Bta） were hydrothermally synthesized by controlling the crystallization temperature.Single-crystal X-ray dif...Two 1D coordination polymers Cu2I（C6N3H4）2（1） and CuⅡ（C6N3H4）2·H2O（2） based on benzotriazole（Bta） were hydrothermally synthesized by controlling the crystallization temperature.Single-crystal X-ray diffraction（XRD） analyses reveal that compound 1 is a 1D tubular structure constructed from two types of 1D chains {―Cu―N=N―N―} n,where the Cu（I） ions adopt linear,triangular,and tetrahedral coordination modes to connect two types of Bta ligands via π-π interaction inside the tubular-like chain.For compound 2,the Cu（Ⅱ） ions assume a quadrilateral coordination mode linking to the Bta ligands to give 1D straight chains,which stacks through π-π interactions to construct a 2D layer structure.Further characterizations including elemental analyses,infrared IR spectra,thermogravimetric（TG） analyses and luminescence properties have been done.展开更多
The properties of one-photon absorption(OPA),emission and two-photon absorption(TPA)of a bipyridine-based zinc ion probe are investigated employing the density functional theory in combination with response functions....The properties of one-photon absorption(OPA),emission and two-photon absorption(TPA)of a bipyridine-based zinc ion probe are investigated employing the density functional theory in combination with response functions.The responsive mechanism and coordination mode effect are explored.The structural fluctuation is illustrated by molecular dynamics simulation.The calculated OPA and emission wavelengths of the probe are consistent with the experimental data.It is found that the red-shift of OPA wavelength and the enhancement of TPA intensity are induced by the increased intra-molecular charge transfer mechanism upon metal binding.The structural fluctuation could result in the blue-shift of TPA wavelength and the decrease of the TPA cross section.The TPA properties are quite different among the zinc complexes with different coordination modes.The TPA wavelength of the complexes with two ligands is close to that of the probe,which is in agreement with the experimental observation.展开更多
One-photon absorption and two-photon absorption（TPA） properties of three tris（picolyl）amine-based zinc ion sensors are investigated by employing the density functional response theory in combination with the polar...One-photon absorption and two-photon absorption（TPA） properties of three tris（picolyl）amine-based zinc ion sensors are investigated by employing the density functional response theory in combination with the polarizable continuum model.The different isomer and coordination geometry of each probe are taken into account. Special emphasis is placed on the effects of isomerism and the coordination mode on the optical properties. The intra-molecular charge transfer（ICT）properties are specified by natural bond orbital charge analysis. It is shown that the isomerism has non-negligible effects on TPA properties of free ligands. It is found that both the TPA wavelength and the cross section are highly dependent on the coordination mode. When the zinc ion connects with the picolyl unit in the middle of a ligand, the zinc complex has a large TPA intensity in a long wavelength range due to the increased ICT mechanism.展开更多
A unique metal-organic framework（MOF） [Eu_2（L）_3（phen）_2]_n（1, H_2L = 4,6-dibenzoylisophthalic acid, phen = 1,10-phenanthroline） has been synthesized under hydrothermal conditions and characterized by single-c...A unique metal-organic framework（MOF） [Eu_2（L）_3（phen）_2]_n（1, H_2L = 4,6-dibenzoylisophthalic acid, phen = 1,10-phenanthroline） has been synthesized under hydrothermal conditions and characterized by single-crystal X-ray analysis, elemental analyses, powder X-ray diffraction, TGA measurement as well as IR spectra. The crystal is of triclinic system, space group P1, C_（90）H_（52）Eu_2N_4O_（18）, M_r = 1781.32, a = 9.8697（4）, b = 16.7466（6）, c = 22.2556（10） A, α = 87.113（3）, β = 77.575（5）, γ = 89.458（3）°, V = 3587.8（3） A^3, Z = 2, D_c = 1.649 g/cm^3, F（000） = 1780, μ（MoKα） = 1.813 mm^（-1）, Rint = 0.0181, R = 0.0260 and wR = 0.0592 for 14000 observed reflections with I 〉 2σ（I）. X-ray analysis shows that the title compound exhibits a 2D layer structure linked by L ligands with two coordination modes and two distinguished conformations, and further linked into a 3D supramolecular architecture through C-H···O weak interactions between hydrogen of phen phenyl ring and the carboxylate oxygen atom of adjacent sheets. In addition, the luminescence property of 1 was investigated.展开更多
Cyclometalated iridium complexes are widely used in optoelectronic technologies,but creating efficient red emitters remains challenging.Prior investigations have demonstrated the efficiency of electron-rich salicylald...Cyclometalated iridium complexes are widely used in optoelectronic technologies,but creating efficient red emitters remains challenging.Prior investigations have demonstrated the efficiency of electron-rich salicylaldimine and 2-picolinamide ligands in promoting red to deep red luminescence.This work introduces a series of ten new red or deep-red emitting heteroleptic bis-cyclometalated iridium(Ⅲ)complexes supported by eight different ancillary ligands,including some from the salicylaldimine and 2-picolinamide families.Our study reveals that the effectiveness of salicylaldimine ligands at supporting efficient red phosphorescence is dependent on the cyclometalating ligand they are paired with.A more significant finding is that the 2-picolinamide ligands can adopt three different coordination modes.Firstly,the N-propyl-substituted 2-picolinamide proligand can bind to the iridium center in its neutral,protonated form through the pyridyl N and amide O atoms,forming five-membered metallacycles.Furthermore,N-aryl-substituted ligands can coordinate with the iridium center in either N,N’or N(pyridyl),O modes,yielding two structurally distinct isomers.Notably,the change in coordination mode minimally influences emission wavelength while significantly modulating the photoluminescence quantum yield.This study advances our comprehension of how ligand coordination impacts cyclometalated iridium complexes,offering invaluable insights into the design of high-performance red phosphors for potential optoelectronic applications.展开更多
Heteroleptic Cu(Ⅱ)compounds containing 4,4’-bis(hydroxymethyl)-2,2’-bipyridine(bipy-OH),tropolonate(Trop)and saccharinate(Sac)have been synthesized and characterized.Different synthetic procedures have been followe...Heteroleptic Cu(Ⅱ)compounds containing 4,4’-bis(hydroxymethyl)-2,2’-bipyridine(bipy-OH),tropolonate(Trop)and saccharinate(Sac)have been synthesized and characterized.Different synthetic procedures have been followed for the preparation of a neutral Sac[(bipy-OH)Cu(Trop)Sac],2,selectively isolated in its blue anhydrous 2a and green mono-hydrated 2b crystalline solid-state forms.The structural characterization of 2 has revealed that the Sac ion is bound to the Cu(Ⅱ)centre through one of the oxygen atoms of the sulphonyl group.展开更多
Target motion modes have a close relationship with the relative orientation of missile-totarget in three-dimensional highly maneuvering target interception. From the perspective of relationship between the sensor coor...Target motion modes have a close relationship with the relative orientation of missile-totarget in three-dimensional highly maneuvering target interception. From the perspective of relationship between the sensor coordinate system and the target body coordinate system, a basic model of sensor is stated and the definition of relative angular velocity between the two coordinate systems is introduced firstly. Then, the three-dimensional analytic expressions of relative angular velocity for different motion modes are derived and simplified by analyzing the influences of target centroid motion, rotation around centroid and relative motion. Finally, the relationships of the relative angular velocity directions and values with motion modes are discussed. Simulation results validate the rationality of the theoretical analysis. It is demonstrated that there are significant differences of the relative orientation in different motion modes which include luxuriant information about motion modes. The conclusions are significant for the research of motion mode identification,maneuver detection, maneuvering target tracking and interception using target signatures.展开更多
Crown ethers,which feature circular and variable coordination sites of oxygen atoms,may be ideal for the symmetry control of the mononuclear lanthanide single-molecule magnets(SMMs)by double-deckering the central meta...Crown ethers,which feature circular and variable coordination sites of oxygen atoms,may be ideal for the symmetry control of the mononuclear lanthanide single-molecule magnets(SMMs)by double-deckering the central metal ions.Herein,a series of Dy(Ⅲ)-crown-ether complexes have been prepared to test this hypothesis.With a 12-crown-4 ether(12-C-4),a half-sandwich complex Dy(12-C-4)(NO_(3))_(3)(1)was obtained,while by changing the counter-anions the double-deck-like complex Dy(12-C-4)2(CH_(3)CN)(ClO_(4))_(3)(2)could be prepared.On further adjusting the reaction conditions,a dinuclear complex Dy2(12-C-4)2(ClO_(4))4(OH)_(2)(H_(2)O)_(2)(3)was isolated.With the aid of a 15-crown-5 ether(15-C-5),another complex[Dy(12-C-4)(15-C-5)(CH_(3)CN)][Dy(12-C-4)(15-C-5)]_(2)(CH_(3)CN)_(2)(ClO_(4))_(9)(4)with a double-decker structure was formed.For the 18-crown-6 ether(18-C-6),two complexes[Dy(18-C-6)(NO_(3))2]ClO_(4)(5)and[Dy(18-C-6)(NO_(3))_(2)]BPh_(4)(6)have been synthesized using different charge balancing anions.Interestingly,the cationic components in complexes 5 and 6 are isomeric.The only difference is the dihedral angles of the two chelating NO_(3)-groups,namely 90°and 68°for 5 and 6.Systematic magnetic studies reveal that complexes 1-6 show no SMM behaviour in a zero dc field above 2 K,which is probably due to the ligand field provided by crown ethers is too weak to have much impact on the electronic structures of the central Dy(Ⅲ)ions.However,when the Dy(Ⅲ)ions are simultaneously coordinated by some counteranions such as NO_(3)−and OH−,apparent field-induced SMM behaviors can be observed in complexes 1,3,5 and 6.Moreover,we found that the axial coordination anions in complexes 5 and 6 have evident impact on the magnetic relaxation behaviours.For the 90°case(complex 5)the energy barrier for magnetisation reversal(ΔE)is 63 K,which is much higher than 43 K for the 68°case(complex 6).展开更多
Internal contamination of actinides has led to significant health hazards to the public and workers in the context of nuclear power plant accidents,uranium ore mining,and reprocessing of the used fuel.An effective seq...Internal contamination of actinides has led to significant health hazards to the public and workers in the context of nuclear power plant accidents,uranium ore mining,and reprocessing of the used fuel.An effective sequestering agent that is able to remove accidentally incorporated actinides in vivo with low toxicity is always in urgent need.The molecular decorporation ligands have been the most widely researched agents for the past few decades,while preliminary studies of functionalized nanoparticles have shown their clear advantages in metal binding selectivity,toxicity,and oxidative stress alleviation.Herein,the state-of-the-art of those two types of decorporation agents is presented with special attention being paid on the correlation between the solution and solid-state chemistry of those agents with actinides and the corresponding decorporation efficacies.展开更多
This paper studied the mechanism of the alkene insertion elementary step in the asymmetric hydroformylation （AHF） catalyzed by RhH（CO）2[（R,S）-Yanphos] using four alkene substrates （CH2=CH- Ph, CH2=CH-Ph-（p）-M...This paper studied the mechanism of the alkene insertion elementary step in the asymmetric hydroformylation （AHF） catalyzed by RhH（CO）2[（R,S）-Yanphos] using four alkene substrates （CH2=CH- Ph, CH2=CH-Ph-（p）-Me, CH2=CH-C（==O）OCH3 and CH2=CH-OC（=O）-Ph, abbreviated as A1-A4）. Interestingly, the equatorial vertical coordination mode （A mode） with respect to the Rh center was found for AI and A2 but not for A3 and A4, although the equatorial in-plane coordination mode （E mode） was found for A1 -A4. The relative energy of the E mode of the -q2-intermediates is lower than that of the A mode. In the alkene insertion step, Path 1 is more favorable than Path 2 for this system. As for AI and A2, there could be a transformation between 2eq and 2ax.展开更多
In this work, it is found that 1,8-dihydroxyimino-1,2,7,8-tetraphenyl-3,6-diazocta-2,6-diene(PhdoenH2) could react with nickel(Ⅱ) salt to yield a mononickel complex Ni(Phdoen)(1) with unusual [2N2O]-coordinated mode,...In this work, it is found that 1,8-dihydroxyimino-1,2,7,8-tetraphenyl-3,6-diazocta-2,6-diene(PhdoenH2) could react with nickel(Ⅱ) salt to yield a mononickel complex Ni(Phdoen)(1) with unusual [2N2O]-coordinated mode, while the analogous diimine-dioxime ligands usually form the [4N]-coordinated mode. The novel complex 1 has been carefully characterized by 1H NMR, elemental analysis, and X-ray diffraction structure analysis. The influences of the coordination modes on the structures and redox properties have been further investigated. Theoretical investigations revealed that the different coordination modes were ascribed to the thermodynamic properties of ligands.展开更多
Two-dimensional conductive metal-organic frameworks(2D c-MOFs),constructed by coordination between metal ions andπ-conjugated ligands,represent a unique class of materials that combine intrinsic porosity and electric...Two-dimensional conductive metal-organic frameworks(2D c-MOFs),constructed by coordination between metal ions andπ-conjugated ligands,represent a unique class of materials that combine intrinsic porosity and electrical conductivity.However,the contribution of metal nodes to the overall electrical properties remains unclear.In this work,we systematically investigate the role of metal centers on a series of six highly crystalline hexahydroxytriphenylene(HHTP)based c-MOFs,M-HHTP,which incorporate alkaline earth including magnesium and calcium,as well as transition metals including cobalt,nickel,copper,and zinc.Comprehensive structural characterizations reveal that while all M-HHTP frameworks adopt a general honeycomb lattice,however,subtle variations in stacking patterns and coordination environments are induced by different metal ions.Electrical measurements show a pronounced dependence of conductivity on the nature of the metal nodes,in which the conductivity differs by four orders of magnitude due to the difference in metal centers.Furthermore,non-contact terahertz spectroscopy combined with theoretical calculations suggests that in alkaline earth metal-based MOFs,charge transport may proceed via a through-space hopping mechanism between organic ligands.This study elucidates the critical role of metal centers in governing charge transport in M-HHTP MOFs and offers valuable guidance for the rational design of high-performance 2D conductive frameworks.展开更多
Ethylene trimerization toward 1-hexene catalytic system with 2,5-dimethylpyrrole （2,5-DMP）/Cr（III）/alkylaluminum/tetrachloroethane （TCE） was investigated. The effects of various cocatalysts on catalytic activity...Ethylene trimerization toward 1-hexene catalytic system with 2,5-dimethylpyrrole （2,5-DMP）/Cr（III）/alkylaluminum/tetrachloroethane （TCE） was investigated. The effects of various cocatalysts on catalytic activity and product selectivity were discussed. The results showed that triethylaluminum （TEA）, trimethylaluminum （TMA）, tri-n-hexylaluminum （TNHA） and tri-isobutylaluminum （TIBA） were all effective cocatalysts for ethylene trimerization toward 1-hexene. 2,5-DMP/Cr（III）/TEA/TCE catalytic system afforded the best results for ethylene trimerization, while reducing the level of by-product formation. Some specific interaction modes of alkylaluminum with active Cr species in the catalytic cycle were proposed to explain the effect of cocatalyst on catalytic activity and 1-hexene selectivity.展开更多
Two coordination compounds [Pb4（BDT）3（OH）2（H2O）4].H2O （1） and [Mn（H20）6]·（HBDT）2.2H2O （2） [H2BDT= 5,5＇-（1,4-phenylene）bis（1H-tetrazole）] had been hydrothermally synthesized. 1 and 2 had been ch...Two coordination compounds [Pb4（BDT）3（OH）2（H2O）4].H2O （1） and [Mn（H20）6]·（HBDT）2.2H2O （2） [H2BDT= 5,5＇-（1,4-phenylene）bis（1H-tetrazole）] had been hydrothermally synthesized. 1 and 2 had been characterized by single-crystal X-ray diffraction, IR, elemental and thermal analyses. Structural analysis reveals that 1 exhibits 2D layer structure extended through BDT with two different coordination modes rings in transverse and vertical. 2 consists of [Mn（H2O）6]2＋, free HBDT and water. In addition, 1 and 2 were explored as luminescent materials and additives to promote the thermal decomposition of ammonium perchlorate by differential scanning calorimetry.展开更多
The hydrothermal reactions of Ni（Ⅱ）, 1,2,3-benzenetricarboxylic acid （1,2,3-H3btc） and 4,4＇-bipyfidine （4,4＇-bpy）/1,2-bis（4-pyridyl）ethane （bpa） yield two layered nickel（II） coordination polymers, [Ni2...The hydrothermal reactions of Ni（Ⅱ）, 1,2,3-benzenetricarboxylic acid （1,2,3-H3btc） and 4,4＇-bipyfidine （4,4＇-bpy）/1,2-bis（4-pyridyl）ethane （bpa） yield two layered nickel（II） coordination polymers, [Ni2（l,2,3-btc）（OAc）- （4,4＇-bpy）2（H20）]o2H2O （1） and [Ni（ip）（bpa）] （2） （ip=isophthalate）, respectively. Both complexes are 2-D coordi- nation network based on 1-D Ni-carboxylate chains. The 1,2,3-btc ligand adopts 3-bridging mode in complex 1, but transformed to isophthalate （ip） ligand through decarboxylation in 2. The formation of the two complexes indicates that hydrothermal conditions and in-situ ligand reaction have significant effect on constructing coordination polymers.展开更多
Specific interactions between the macrocycle backbone,solvent and counter anions control configurational interconversions of novel organoruthenium(Ⅱ)metallamacrocycles[Ru(η^(6)-p-cymene)(μ_(2)-m-bitmb)Cl]_(2)·...Specific interactions between the macrocycle backbone,solvent and counter anions control configurational interconversions of novel organoruthenium(Ⅱ)metallamacrocycles[Ru(η^(6)-p-cymene)(μ_(2)-m-bitmb)Cl]_(2)·2X,m-bitmb=1,3,5-trimethyl-2,4-di(imidazole-1-ylmethyl)benzene,X=Cl^(-)(1.2Cl),NO_(3)^(-)(1-2NO_(3)),CF_(3)SO_(3)^(-)(1.2CF_(3)SO_(3)),PF_6^(-)(1.2PF_(6)),or BF_(4)^(-)(1.2BF_(4)).X-ray crystal structures reveal 1.2Cl in boat and chair conformations,1.2NO_(3)in twist-boat and chair conformations,and 1.2CF_(3)SO_(3)in a chair conformation.Chair/boat isomers of mono-and bis-DMSO adducts from 1.2Cl,1.2CF_(3)SO_(3)or 1.2NO_(3)in DMSO/H_(2)O were separated and characterized.Slow anion-dependent interconversion of configurational isomers was observed in solution.Ligand field molecular mechanics and density functional theory calculations suggest an unusual macrochelate ring-opening isomerization mechanism.Such dynamic stimuliresponsive configurational changes offer scope for design of metallocycles for induced-fit recognition of biological targets.展开更多
Although great efforts have been made to explore the exquisite rare-earth(RE)clusters,the design and construction of planar RE clusters with disk-like geometrical features are still scarce.Herein,a novel disklike RE-c...Although great efforts have been made to explore the exquisite rare-earth(RE)clusters,the design and construction of planar RE clusters with disk-like geometrical features are still scarce.Herein,a novel disklike RE-cluster Y_(12)(abbreviated as 1),formulated as[Y_(12)(L)_(10)(CO_(3))_(4)(NO_(3))_(2)(μ_(3)-OH)_(6)](H_(2)L=7,7’-(2-methylmethylene)bis(8-quinolonol))was synthesized successfully under solvothermal conditions.Owing to the template effect and fruitful coordination modes of NO_(3)^(-),a novel Y_(2)⊂Y_(10)type structure with dual-core in the center position of the cluster,which distinguishes it from the traditional brucite-type disk-like REcluster was achieved.Based on the ESI-MS analysis,the possible assembly mechanism of Y_(5)→Y_(8)→Y_(12)is proposed.The luminescence investigation illustrates that this cluster not only shows green emission in solid-state and common organic solvents but also has obvious electroluminescent performance,which can be used as the emitting layer in organic light-emitting diodes(OLEDs).展开更多
Five novel metal-based complexes of Ag(Ⅰ)[Ag(ATV)](1),Zn(Ⅱ)[Zn(ATV)_(2)(H_(2)O)_(2)]·2H_(2)O(2),[Zn(ATV)_(2)(CH_(3)OH)_(2)]·H_(2)O(3),{Zn(ATV)_(2)}_(n)(4),and Cu(Ⅱ)[Cu(ATV)_(2)](5),with the antimalarial n...Five novel metal-based complexes of Ag(Ⅰ)[Ag(ATV)](1),Zn(Ⅱ)[Zn(ATV)_(2)(H_(2)O)_(2)]·2H_(2)O(2),[Zn(ATV)_(2)(CH_(3)OH)_(2)]·H_(2)O(3),{Zn(ATV)_(2)}_(n)(4),and Cu(Ⅱ)[Cu(ATV)_(2)](5),with the antimalarial naphthoquinone atovaquone(ATV)were synthesized and characterized.Ag(Ⅰ)and Cu(Ⅱ)complexes were thoroughly analyzed using IR,NMR,EPR,and conductivity measurements,whereas the crystal structures of the three Zn(Ⅱ)complexes were determined by single-crystal X-ray diffraction,supported by complementary analytical techniques.Depending on the metal center,ATV coordinates in either a monodentate or bidentate coordination mode,producing highly stable metal complexes both in the solid state and in DMSO solution.These metal-ATV complexes retain the potent antiplasmodial activity of ATV against chloroquine-sensitive and-resistant Plasmodium falciparum strains and introduce additional mechanisms of action.According to FT IR results,Zn(Ⅱ)complexes inhibit β-hematin formation,complex 3 accelerates ring-stage parasite killing,and complex 5 promotes intracellular copper accumulation,which correlate with enhanced antiplasmodial potency.These results demonstrate that metal coordination can fine-tune the ATV biological profile,positioning these compounds as promising leads for the design of new antimalarial drugs.展开更多
Zirconium oxo clusters with programmable ligand coordination modes show unprecedented potential as next-generation extreme ultraviolet lithography(EUVL)photoresists by enabling atomic-level control.Herein,we report th...Zirconium oxo clusters with programmable ligand coordination modes show unprecedented potential as next-generation extreme ultraviolet lithography(EUVL)photoresists by enabling atomic-level control.Herein,we report three methacrylate-coordinated Zr6 clusters—Zr6(OH)8(μ_(1)-OMc)6(μ_(2)-OMc)6(μ_(1)-6),Zr_(6)O_(4)(OH)4(μ_(1)-OMc)4(μ_(2)-OMc)8(μ_(1)-4),and Zr6O8(μ_(1)-OMc)3(μ_(2)-OMc)9(μ_(1)-3)—synthesized through ligandratio-control strategies to systematically investigate howμ_(1)(chelating)andμ_(2)(bridging)coordination modes govern lithographic performance.Density functional theory calculations reveal thatμ_(1)-OMc ligands exhibit lower dissociation energy(3.95 eV)compared toμ_(2)-OMc ligands(4.76 eV),enablingμ_(1)-6 to achieve a high sensitivity at 300 pC/cm in electron beam lithography.Meanwhile,μ_(1)-3,dominated byμ_(2)-OMc ligands,delivers superior resolution(line edge roughness=2.53 nm)at the expense of higher exposure dose requirements(950 pC/cm).Interestingly,μ_(1)-4 balances these extremes,achieving a critical dimension of 15 nm at an exposure dose of 460 pC/cm while exhibiting exceptional plasma etch resistance(selectivity ratio=0.45 relative to Si).Mechanistic studies confirm thatμ_(1)-OMc-rich clusters undergo rapid decarboxylation and crosslinking under irradiation,whileμ_(2)-OMc ligands enhance structural rigidity for pattern fidelity.This work establishes ligand coordination engineering as a universal paradigm to transcend the sensitivity-resolution-etch resistance trade-off in metal-organic cluster photoresists,advancing EUVL toward sub-10-nm technology nodes.展开更多
文摘Based on the Lagrange s equation and the finite element method, this paper establishes the dynamic equation of a radar antenna mechanic system which is a high accuracy system and consists of two flexible bodies. Mode coordinates are used to reduce the orders of equation. Finally, the calculation method and engineering example are given when the rotational velocity of antenna is invariable and the wind velocity is 25?m/s. The error of antenna mechanic system can be estimated using the calculation results.
基金Supported by the National Natural Science Foundation of China(Nos.20701015,21071059,20788101)
文摘Two 1D coordination polymers Cu2I（C6N3H4）2（1） and CuⅡ（C6N3H4）2·H2O（2） based on benzotriazole（Bta） were hydrothermally synthesized by controlling the crystallization temperature.Single-crystal X-ray diffraction（XRD） analyses reveal that compound 1 is a 1D tubular structure constructed from two types of 1D chains {―Cu―N=N―N―} n,where the Cu（I） ions adopt linear,triangular,and tetrahedral coordination modes to connect two types of Bta ligands via π-π interaction inside the tubular-like chain.For compound 2,the Cu（Ⅱ） ions assume a quadrilateral coordination mode linking to the Bta ligands to give 1D straight chains,which stacks through π-π interactions to construct a 2D layer structure.Further characterizations including elemental analyses,infrared IR spectra,thermogravimetric（TG） analyses and luminescence properties have been done.
基金the Natural Science Foundation of Shandong Province,China(Grant No.ZR2014AM026).
文摘The properties of one-photon absorption(OPA),emission and two-photon absorption(TPA)of a bipyridine-based zinc ion probe are investigated employing the density functional theory in combination with response functions.The responsive mechanism and coordination mode effect are explored.The structural fluctuation is illustrated by molecular dynamics simulation.The calculated OPA and emission wavelengths of the probe are consistent with the experimental data.It is found that the red-shift of OPA wavelength and the enhancement of TPA intensity are induced by the increased intra-molecular charge transfer mechanism upon metal binding.The structural fluctuation could result in the blue-shift of TPA wavelength and the decrease of the TPA cross section.The TPA properties are quite different among the zinc complexes with different coordination modes.The TPA wavelength of the complexes with two ligands is close to that of the probe,which is in agreement with the experimental observation.
基金Project supported by the Natural Science Foundation of Shandong Province,China(Grant No.ZR2014AM026)the Taishan Scholar Project of Shandong Province,China
文摘One-photon absorption and two-photon absorption（TPA） properties of three tris（picolyl）amine-based zinc ion sensors are investigated by employing the density functional response theory in combination with the polarizable continuum model.The different isomer and coordination geometry of each probe are taken into account. Special emphasis is placed on the effects of isomerism and the coordination mode on the optical properties. The intra-molecular charge transfer（ICT）properties are specified by natural bond orbital charge analysis. It is shown that the isomerism has non-negligible effects on TPA properties of free ligands. It is found that both the TPA wavelength and the cross section are highly dependent on the coordination mode. When the zinc ion connects with the picolyl unit in the middle of a ligand, the zinc complex has a large TPA intensity in a long wavelength range due to the increased ICT mechanism.
基金supported by the NNSFC(No.21301170)Xiaonei Foundation of Changchun University of Technology
文摘A unique metal-organic framework（MOF） [Eu_2（L）_3（phen）_2]_n（1, H_2L = 4,6-dibenzoylisophthalic acid, phen = 1,10-phenanthroline） has been synthesized under hydrothermal conditions and characterized by single-crystal X-ray analysis, elemental analyses, powder X-ray diffraction, TGA measurement as well as IR spectra. The crystal is of triclinic system, space group P1, C_（90）H_（52）Eu_2N_4O_（18）, M_r = 1781.32, a = 9.8697（4）, b = 16.7466（6）, c = 22.2556（10） A, α = 87.113（3）, β = 77.575（5）, γ = 89.458（3）°, V = 3587.8（3） A^3, Z = 2, D_c = 1.649 g/cm^3, F（000） = 1780, μ（MoKα） = 1.813 mm^（-1）, Rint = 0.0181, R = 0.0260 and wR = 0.0592 for 14000 observed reflections with I 〉 2σ（I）. X-ray analysis shows that the title compound exhibits a 2D layer structure linked by L ligands with two coordination modes and two distinguished conformations, and further linked into a 3D supramolecular architecture through C-H···O weak interactions between hydrogen of phen phenyl ring and the carboxylate oxygen atom of adjacent sheets. In addition, the luminescence property of 1 was investigated.
基金the Welch Foundation(Grant E-1887)the National Science Foundation(Grant CHE-1846831)for funding this work.
文摘Cyclometalated iridium complexes are widely used in optoelectronic technologies,but creating efficient red emitters remains challenging.Prior investigations have demonstrated the efficiency of electron-rich salicylaldimine and 2-picolinamide ligands in promoting red to deep red luminescence.This work introduces a series of ten new red or deep-red emitting heteroleptic bis-cyclometalated iridium(Ⅲ)complexes supported by eight different ancillary ligands,including some from the salicylaldimine and 2-picolinamide families.Our study reveals that the effectiveness of salicylaldimine ligands at supporting efficient red phosphorescence is dependent on the cyclometalating ligand they are paired with.A more significant finding is that the 2-picolinamide ligands can adopt three different coordination modes.Firstly,the N-propyl-substituted 2-picolinamide proligand can bind to the iridium center in its neutral,protonated form through the pyridyl N and amide O atoms,forming five-membered metallacycles.Furthermore,N-aryl-substituted ligands can coordinate with the iridium center in either N,N’or N(pyridyl),O modes,yielding two structurally distinct isomers.Notably,the change in coordination mode minimally influences emission wavelength while significantly modulating the photoluminescence quantum yield.This study advances our comprehension of how ligand coordination impacts cyclometalated iridium complexes,offering invaluable insights into the design of high-performance red phosphors for potential optoelectronic applications.
基金support was received from the Ministero dell’Universitàe della Ricerca(MUR),for F.S.POR Calabria FESR-FSE 2014/2020-Linea(B)Azione 10.5.12。
文摘Heteroleptic Cu(Ⅱ)compounds containing 4,4’-bis(hydroxymethyl)-2,2’-bipyridine(bipy-OH),tropolonate(Trop)and saccharinate(Sac)have been synthesized and characterized.Different synthetic procedures have been followed for the preparation of a neutral Sac[(bipy-OH)Cu(Trop)Sac],2,selectively isolated in its blue anhydrous 2a and green mono-hydrated 2b crystalline solid-state forms.The structural characterization of 2 has revealed that the Sac ion is bound to the Cu(Ⅱ)centre through one of the oxygen atoms of the sulphonyl group.
基金supported by the Specialized Research Fund for the Doctoral Program of China Higher Education (No. 20134307110012)the National Natural Science Foundation of China (No. 61101186)
文摘Target motion modes have a close relationship with the relative orientation of missile-totarget in three-dimensional highly maneuvering target interception. From the perspective of relationship between the sensor coordinate system and the target body coordinate system, a basic model of sensor is stated and the definition of relative angular velocity between the two coordinate systems is introduced firstly. Then, the three-dimensional analytic expressions of relative angular velocity for different motion modes are derived and simplified by analyzing the influences of target centroid motion, rotation around centroid and relative motion. Finally, the relationships of the relative angular velocity directions and values with motion modes are discussed. Simulation results validate the rationality of the theoretical analysis. It is demonstrated that there are significant differences of the relative orientation in different motion modes which include luxuriant information about motion modes. The conclusions are significant for the research of motion mode identification,maneuver detection, maneuvering target tracking and interception using target signatures.
基金supported by“973 projects”(2012CB619401 and 2012CB619402),NSFC(21473129,21201137,21103137,21503155 and IRT13034)the open funding of Wuhan National High Magnetic Field Center(2015KF06)the Fundamental Research Funds for Central Universities.
文摘Crown ethers,which feature circular and variable coordination sites of oxygen atoms,may be ideal for the symmetry control of the mononuclear lanthanide single-molecule magnets(SMMs)by double-deckering the central metal ions.Herein,a series of Dy(Ⅲ)-crown-ether complexes have been prepared to test this hypothesis.With a 12-crown-4 ether(12-C-4),a half-sandwich complex Dy(12-C-4)(NO_(3))_(3)(1)was obtained,while by changing the counter-anions the double-deck-like complex Dy(12-C-4)2(CH_(3)CN)(ClO_(4))_(3)(2)could be prepared.On further adjusting the reaction conditions,a dinuclear complex Dy2(12-C-4)2(ClO_(4))4(OH)_(2)(H_(2)O)_(2)(3)was isolated.With the aid of a 15-crown-5 ether(15-C-5),another complex[Dy(12-C-4)(15-C-5)(CH_(3)CN)][Dy(12-C-4)(15-C-5)]_(2)(CH_(3)CN)_(2)(ClO_(4))_(9)(4)with a double-decker structure was formed.For the 18-crown-6 ether(18-C-6),two complexes[Dy(18-C-6)(NO_(3))2]ClO_(4)(5)and[Dy(18-C-6)(NO_(3))_(2)]BPh_(4)(6)have been synthesized using different charge balancing anions.Interestingly,the cationic components in complexes 5 and 6 are isomeric.The only difference is the dihedral angles of the two chelating NO_(3)-groups,namely 90°and 68°for 5 and 6.Systematic magnetic studies reveal that complexes 1-6 show no SMM behaviour in a zero dc field above 2 K,which is probably due to the ligand field provided by crown ethers is too weak to have much impact on the electronic structures of the central Dy(Ⅲ)ions.However,when the Dy(Ⅲ)ions are simultaneously coordinated by some counteranions such as NO_(3)−and OH−,apparent field-induced SMM behaviors can be observed in complexes 1,3,5 and 6.Moreover,we found that the axial coordination anions in complexes 5 and 6 have evident impact on the magnetic relaxation behaviours.For the 90°case(complex 5)the energy barrier for magnetisation reversal(ΔE)is 63 K,which is much higher than 43 K for the 68°case(complex 6).
基金supported by grants from the National Natural Science Foundation of China(Nos.21976127,U2167222,21790370,22106116)the Natural Science Foundation of Jiangsu Province(No.BK20190044,BK20210736)+1 种基金funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)China Postdoctoral Science Foundation(No.2020M681716)。
文摘Internal contamination of actinides has led to significant health hazards to the public and workers in the context of nuclear power plant accidents,uranium ore mining,and reprocessing of the used fuel.An effective sequestering agent that is able to remove accidentally incorporated actinides in vivo with low toxicity is always in urgent need.The molecular decorporation ligands have been the most widely researched agents for the past few decades,while preliminary studies of functionalized nanoparticles have shown their clear advantages in metal binding selectivity,toxicity,and oxidative stress alleviation.Herein,the state-of-the-art of those two types of decorporation agents is presented with special attention being paid on the correlation between the solution and solid-state chemistry of those agents with actinides and the corresponding decorporation efficacies.
基金in part supported by the National Natural Science Foundation of China (Nos. 21072018 and 21203006)
文摘This paper studied the mechanism of the alkene insertion elementary step in the asymmetric hydroformylation （AHF） catalyzed by RhH（CO）2[（R,S）-Yanphos] using four alkene substrates （CH2=CH- Ph, CH2=CH-Ph-（p）-Me, CH2=CH-C（==O）OCH3 and CH2=CH-OC（=O）-Ph, abbreviated as A1-A4）. Interestingly, the equatorial vertical coordination mode （A mode） with respect to the Rh center was found for AI and A2 but not for A3 and A4, although the equatorial in-plane coordination mode （E mode） was found for A1 -A4. The relative energy of the E mode of the -q2-intermediates is lower than that of the A mode. In the alkene insertion step, Path 1 is more favorable than Path 2 for this system. As for AI and A2, there could be a transformation between 2eq and 2ax.
基金the Natural Science Foundation of China(21773184 and 21671158)。
文摘In this work, it is found that 1,8-dihydroxyimino-1,2,7,8-tetraphenyl-3,6-diazocta-2,6-diene(PhdoenH2) could react with nickel(Ⅱ) salt to yield a mononickel complex Ni(Phdoen)(1) with unusual [2N2O]-coordinated mode, while the analogous diimine-dioxime ligands usually form the [4N]-coordinated mode. The novel complex 1 has been carefully characterized by 1H NMR, elemental analysis, and X-ray diffraction structure analysis. The influences of the coordination modes on the structures and redox properties have been further investigated. Theoretical investigations revealed that the different coordination modes were ascribed to the thermodynamic properties of ligands.
基金supported by the National Natural Science Foundation of China(22305238,22475203)Anhui Provincial Natural Science Foundation(2308085MB35)the Innovation Program for Quantum Science and Technology(2021zD0303303).
文摘Two-dimensional conductive metal-organic frameworks(2D c-MOFs),constructed by coordination between metal ions andπ-conjugated ligands,represent a unique class of materials that combine intrinsic porosity and electrical conductivity.However,the contribution of metal nodes to the overall electrical properties remains unclear.In this work,we systematically investigate the role of metal centers on a series of six highly crystalline hexahydroxytriphenylene(HHTP)based c-MOFs,M-HHTP,which incorporate alkaline earth including magnesium and calcium,as well as transition metals including cobalt,nickel,copper,and zinc.Comprehensive structural characterizations reveal that while all M-HHTP frameworks adopt a general honeycomb lattice,however,subtle variations in stacking patterns and coordination environments are induced by different metal ions.Electrical measurements show a pronounced dependence of conductivity on the nature of the metal nodes,in which the conductivity differs by four orders of magnitude due to the difference in metal centers.Furthermore,non-contact terahertz spectroscopy combined with theoretical calculations suggests that in alkaline earth metal-based MOFs,charge transport may proceed via a through-space hopping mechanism between organic ligands.This study elucidates the critical role of metal centers in governing charge transport in M-HHTP MOFs and offers valuable guidance for the rational design of high-performance 2D conductive frameworks.
基金Project supported by the Program for New Century Excelleni Talents in University （No. NCET-07-0142）, the Program for New Century Excellent Talents in Heilongjiang Provincial University （No. NCET-06-010）, the National Natural Science Foundation of China （No. 20972025） and the Science Foundation of Tianjin University of Science ＆ Technology （No. 20090420）.
文摘Ethylene trimerization toward 1-hexene catalytic system with 2,5-dimethylpyrrole （2,5-DMP）/Cr（III）/alkylaluminum/tetrachloroethane （TCE） was investigated. The effects of various cocatalysts on catalytic activity and product selectivity were discussed. The results showed that triethylaluminum （TEA）, trimethylaluminum （TMA）, tri-n-hexylaluminum （TNHA） and tri-isobutylaluminum （TIBA） were all effective cocatalysts for ethylene trimerization toward 1-hexene. 2,5-DMP/Cr（III）/TEA/TCE catalytic system afforded the best results for ethylene trimerization, while reducing the level of by-product formation. Some specific interaction modes of alkylaluminum with active Cr species in the catalytic cycle were proposed to explain the effect of cocatalyst on catalytic activity and 1-hexene selectivity.
基金Project supported by the National Natural Science Foundation of China （No. 20873100）, and the Natural Science Foundation of Shaanxi Province （Nos. FF10091, SJ08B09）.
文摘Two coordination compounds [Pb4（BDT）3（OH）2（H2O）4].H2O （1） and [Mn（H20）6]·（HBDT）2.2H2O （2） [H2BDT= 5,5＇-（1,4-phenylene）bis（1H-tetrazole）] had been hydrothermally synthesized. 1 and 2 had been characterized by single-crystal X-ray diffraction, IR, elemental and thermal analyses. Structural analysis reveals that 1 exhibits 2D layer structure extended through BDT with two different coordination modes rings in transverse and vertical. 2 consists of [Mn（H2O）6]2＋, free HBDT and water. In addition, 1 and 2 were explored as luminescent materials and additives to promote the thermal decomposition of ammonium perchlorate by differential scanning calorimetry.
基金Project supported by the National Natural Science Foundation of China （No. 20901018） and Natural Science Foundations of Guangdong Province （No. 9451009101003177）.
文摘The hydrothermal reactions of Ni（Ⅱ）, 1,2,3-benzenetricarboxylic acid （1,2,3-H3btc） and 4,4＇-bipyfidine （4,4＇-bpy）/1,2-bis（4-pyridyl）ethane （bpa） yield two layered nickel（II） coordination polymers, [Ni2（l,2,3-btc）（OAc）- （4,4＇-bpy）2（H20）]o2H2O （1） and [Ni（ip）（bpa）] （2） （ip=isophthalate）, respectively. Both complexes are 2-D coordi- nation network based on 1-D Ni-carboxylate chains. The 1,2,3-btc ligand adopts 3-bridging mode in complex 1, but transformed to isophthalate （ip） ligand through decarboxylation in 2. The formation of the two complexes indicates that hydrothermal conditions and in-situ ligand reaction have significant effect on constructing coordination polymers.
基金funded by the Original Exploration Program and General program of National Natural Science Foundation of China(Nos.22350001,21977052,22077066)Anglo American and EPSRC(No.EP/P030572/1)for funding platinum group metals(PGM)research in his laboratorythe Natural Science Foundation of Anhui Higher Education Institutions(No.2022AH051716)。
文摘Specific interactions between the macrocycle backbone,solvent and counter anions control configurational interconversions of novel organoruthenium(Ⅱ)metallamacrocycles[Ru(η^(6)-p-cymene)(μ_(2)-m-bitmb)Cl]_(2)·2X,m-bitmb=1,3,5-trimethyl-2,4-di(imidazole-1-ylmethyl)benzene,X=Cl^(-)(1.2Cl),NO_(3)^(-)(1-2NO_(3)),CF_(3)SO_(3)^(-)(1.2CF_(3)SO_(3)),PF_6^(-)(1.2PF_(6)),or BF_(4)^(-)(1.2BF_(4)).X-ray crystal structures reveal 1.2Cl in boat and chair conformations,1.2NO_(3)in twist-boat and chair conformations,and 1.2CF_(3)SO_(3)in a chair conformation.Chair/boat isomers of mono-and bis-DMSO adducts from 1.2Cl,1.2CF_(3)SO_(3)or 1.2NO_(3)in DMSO/H_(2)O were separated and characterized.Slow anion-dependent interconversion of configurational isomers was observed in solution.Ligand field molecular mechanics and density functional theory calculations suggest an unusual macrochelate ring-opening isomerization mechanism.Such dynamic stimuliresponsive configurational changes offer scope for design of metallocycles for induced-fit recognition of biological targets.
基金supported by the NSFC of China(22271217,21571139,22035003 and 22001132).
文摘Although great efforts have been made to explore the exquisite rare-earth(RE)clusters,the design and construction of planar RE clusters with disk-like geometrical features are still scarce.Herein,a novel disklike RE-cluster Y_(12)(abbreviated as 1),formulated as[Y_(12)(L)_(10)(CO_(3))_(4)(NO_(3))_(2)(μ_(3)-OH)_(6)](H_(2)L=7,7’-(2-methylmethylene)bis(8-quinolonol))was synthesized successfully under solvothermal conditions.Owing to the template effect and fruitful coordination modes of NO_(3)^(-),a novel Y_(2)⊂Y_(10)type structure with dual-core in the center position of the cluster,which distinguishes it from the traditional brucite-type disk-like REcluster was achieved.Based on the ESI-MS analysis,the possible assembly mechanism of Y_(5)→Y_(8)→Y_(12)is proposed.The luminescence investigation illustrates that this cluster not only shows green emission in solid-state and common organic solvents but also has obvious electroluminescent performance,which can be used as the emitting layer in organic light-emitting diodes(OLEDs).
基金funded by the Brazilian agencies:FAPEMIG:APQ-00201-24Conselho Nacional de Desenvolvimento Científico e Tecnológico(CNPq grants 422821/2025-0 and 440227/2022-4)+7 种基金CAPES(Finance Code 001)the Direction Générale de l’Armement[grant NBC-2-B-2120]the National Research Agency under the“Investments for Future”programme[grant ANR-10-IAHU]the European Regional Development Fund(FEDER)[grant FEDER IHUPERF]support of MCT/FINEP/CT-INFRA(grant no.01/2013-REF 0633/13,coordinated by Prof.M.de Oliveira)FAPESP and the Redoxoma project(grant no.2013/07937-8)for funding the EPR instrumentationPTDC/QUI-QIN/29697/2017 and PTDC/QUI-QIN/3898/2020(2021-2024)support provided by MINDLab(https://www.mindlab.pt)。
文摘Five novel metal-based complexes of Ag(Ⅰ)[Ag(ATV)](1),Zn(Ⅱ)[Zn(ATV)_(2)(H_(2)O)_(2)]·2H_(2)O(2),[Zn(ATV)_(2)(CH_(3)OH)_(2)]·H_(2)O(3),{Zn(ATV)_(2)}_(n)(4),and Cu(Ⅱ)[Cu(ATV)_(2)](5),with the antimalarial naphthoquinone atovaquone(ATV)were synthesized and characterized.Ag(Ⅰ)and Cu(Ⅱ)complexes were thoroughly analyzed using IR,NMR,EPR,and conductivity measurements,whereas the crystal structures of the three Zn(Ⅱ)complexes were determined by single-crystal X-ray diffraction,supported by complementary analytical techniques.Depending on the metal center,ATV coordinates in either a monodentate or bidentate coordination mode,producing highly stable metal complexes both in the solid state and in DMSO solution.These metal-ATV complexes retain the potent antiplasmodial activity of ATV against chloroquine-sensitive and-resistant Plasmodium falciparum strains and introduce additional mechanisms of action.According to FT IR results,Zn(Ⅱ)complexes inhibit β-hematin formation,complex 3 accelerates ring-stage parasite killing,and complex 5 promotes intracellular copper accumulation,which correlate with enhanced antiplasmodial potency.These results demonstrate that metal coordination can fine-tune the ATV biological profile,positioning these compounds as promising leads for the design of new antimalarial drugs.
基金the financial support from the National Natural Science Foundation of China(grant nos.22090010,22090011,and 22378052)Liaoning Binhai Laboratory(grant no.LBLB-2023-03)+1 种基金Fundamental Research Funds for the Central Universities(grant no.DUT22LAB608)the Shanghai Synchrotron Radiation Facility for providing the beamline(grant no.BL08U1B).
文摘Zirconium oxo clusters with programmable ligand coordination modes show unprecedented potential as next-generation extreme ultraviolet lithography(EUVL)photoresists by enabling atomic-level control.Herein,we report three methacrylate-coordinated Zr6 clusters—Zr6(OH)8(μ_(1)-OMc)6(μ_(2)-OMc)6(μ_(1)-6),Zr_(6)O_(4)(OH)4(μ_(1)-OMc)4(μ_(2)-OMc)8(μ_(1)-4),and Zr6O8(μ_(1)-OMc)3(μ_(2)-OMc)9(μ_(1)-3)—synthesized through ligandratio-control strategies to systematically investigate howμ_(1)(chelating)andμ_(2)(bridging)coordination modes govern lithographic performance.Density functional theory calculations reveal thatμ_(1)-OMc ligands exhibit lower dissociation energy(3.95 eV)compared toμ_(2)-OMc ligands(4.76 eV),enablingμ_(1)-6 to achieve a high sensitivity at 300 pC/cm in electron beam lithography.Meanwhile,μ_(1)-3,dominated byμ_(2)-OMc ligands,delivers superior resolution(line edge roughness=2.53 nm)at the expense of higher exposure dose requirements(950 pC/cm).Interestingly,μ_(1)-4 balances these extremes,achieving a critical dimension of 15 nm at an exposure dose of 460 pC/cm while exhibiting exceptional plasma etch resistance(selectivity ratio=0.45 relative to Si).Mechanistic studies confirm thatμ_(1)-OMc-rich clusters undergo rapid decarboxylation and crosslinking under irradiation,whileμ_(2)-OMc ligands enhance structural rigidity for pattern fidelity.This work establishes ligand coordination engineering as a universal paradigm to transcend the sensitivity-resolution-etch resistance trade-off in metal-organic cluster photoresists,advancing EUVL toward sub-10-nm technology nodes.
