Investigation on the Coordinate Structures of the Rare Earth Metal Complexes with Edta and Cydta Ligands

The crystal and molecular structures of cydta (trans-1, 2-cyclohexanediaminetetraacetic acid) have been determined by single\|crystal X-ray structure analyses. The reasons that RE Ⅲ -edta and RE Ⅲ -cydta complexes select different coordinate structures were discussed and illustrated through the comparison of the molecular and crystal structures between edta and cydta, (NH_ 4 )\[Y Ⅲ (edta)(H_ 2 O)_ 3 \]\55H_ 2 O and (NH_ 4 )\[Y Ⅲ (cydta)(H_ 2 O)_ 2 \]\55H_ 2 O as well as (NH_ 4 )\[Gd Ⅲ (edta)(H_ 2 O)_ 3 \]\55H_ 2 O and (NH_ 4 )\[Gd Ⅲ (cydta) (H_ 2 O) _ 2 \]\55H_ 2 O complexes.

Engineering the coordination structure of Cu for enhanced photocatalytic production of C_(1) chemicals from glucose

Photocatalytic decomposition of sugars is a promising way of providing H_(2),CO,and HCOOH as sus-tainable energy vectors.However,the production of C_(1) chemicals requires the cleavage of robust C−C bonds in sugars with concurrent production of H_(2),which remains challenging.Here,the photo-catalytic activity for glucose decomposition to HCOOH,CO(C_(1) chemicals),and H_(2) on Cu/TiO_(2)was enhanced by nitrogen doping.Owing to nitrogen doping,atomically dispersed and stable Cu sites resistant to light irradiation are formed on Cu/TiO_(2).The electronic interaction between Cu and nitrogen ions originates valence band structure and defect levels composed of N 2p orbit,distinct from undoped Cu/TiO_(2).Therefore,the lifetime of charge carriers is prolonged,resulting in the pro-duction of C_(1) chemicals and H_(2) with productivities 1.7 and 2.1 folds that of Cu/TiO_(2).This work pro-vides a strategy to design coordinatively stable Cu ions for photocatalytic biomass conversion.

Revealing the effect of electrolyte coordination structures on the intercalation chemistry of batteries

In-depth understanding of the electrolyte-dependent intercalation chemistry in batteries through direct operando/in situ characterizations is crucial for the development of the high-performance batteries.Herein,taking the Al/graphite battery as a model system,the effect of electrolyte coordination structure on the intercalation processes has been investigated over the batteries with either 1-hexyl-3-methylimidazolium chloride(HMICl)-AlCl_(3) or 1-ethyl-3-methylimidazolium chloride(EMICl)-AlCl_(3) ionic liquid electrolyte using operando X-ray photoelectron spectroscopy(XPS)and X-ray diffraction.With a weaker anion-cation interaction in HMI-based electrolyte,the XPS-derived atomic ratio between cointercalated N and intercalated Al is 0.9,which is lower than 1.6 for EMI-based electrolyte.Attributed to the additional de-solvation process,the batteries with the HMI-based electrolyte show a lower ionic diffusion rate,capacity,and cycling performance,which agree with the operando characterization results.Our findings highlight the critical role of the electrolyte coordination structure on the(co-)intercalation chemistry.

Investigation on Molecular and Crystal Structures of Metal Complexes with Aminopolycarboxylic Acids——Synthesis and Structure of K[In~Ⅲ(EDTA)(H_2O)]·2H_2O

The title complex was synthesised and its molecular and crystal structures were determined by single crystal X ray reflection structure analysis. The crystal data are as follows: K[In Ⅲ(EDTA)(H 2O)]·2H 2O (EDTA=ethylene diamine N, N, N′, N′ tetraacetate), Monoclinic, C c space group, a=0.9096(2) nm,b=1.1996(2) nm, c =1.5144(3) nm, β =99.40(3)°, V =1.6302(6) 3, Z =3, D c=1.498 g·cm -3 , μ =1.325 mm -1 , F (000)=726, R =0.0320 and R W=0.0903 for 2315 observed independent reflections. The complex anion [In Ⅲ(EDTA)(H 2O)] - has a seven coordinate pseudo pentagonal bipyramidal (PB D 5h ) structure, in which the EDTA serves as a hexadentate ligand with two N atoms and four O atoms and one water molecule (H 2O) directly coordinated to the central metal ion In Ⅲ as a seventh ligand. 〓〓

Multifunctional Film Assembled from N‑Doped Carbon Nanofiber with Co–N_(4)–O Single Atoms for Highly Efficient Electromagnetic Energy Attenuation

Single-atom materials have demonstrated attractive physicochemical characteristics.However,understanding the relationships between the coordination environment of single atoms and their properties at the atomic level remains a considerable challenge.Herein,a facile waterassisted carbonization approach is developed to fabricate well-defined asymmetrically coordinated Co–N_(4)–O sites on biomass-derived carbon nanofiber(Co–N_(4)–O/NCF)for electromagnetic wave(EMW)absorption.In such nanofiber,one atomically dispersed Co site is coordinated with four N atoms in the graphene basal plane and one oxygen atom in the axial direction.In-depth experimental and theoretical studies reveal that the axial Co–O coordination breaks the charge distribution symmetry in the planar porphyrin-like Co–N_(4) structure,leading to significantly enhanced dielectric polarization loss relevant to the planar Co–N_(4) sites.Importantly,the film based on Co–N_(4)–O/NCF exhibits light weight,flexibility,excellent mechanical properties,great thermal insulating feature,and excellent EMW absorption with a reflection loss of−45.82 dB along with an effective absorption bandwidth of 4.8 GHz.The findings of this work offer insight into the relationships between the single-atom coordination environment and the dielectric performance,and the proposed strategy can be extended toward the engineering of asymmetrically coordinated single atoms for various applications.

Tuning Structural and Electronic Configuration of FeN_(4) via External S for Enhanced Oxygen Reduction Reaction

The Fe-N-C material represents an attractive oxygen reduction reaction electrocatalyst,and the FeN_(4)moiety has been identified as a very competitive catalytic active site.Fine tuning of the coordination structure of FeN_(4)has an essential impact on the catalytic performance.Herein,we construct a sulfur-modified Fe-N-C catalyst with controllable local coordination environment,where the Fe is coordinated with four in-plane N and an axial external S.The external S atom affects not only the electron distribution but also the spin state of Fe in the FeN_(4)active site.The appearance of higher valence states and spin states for Fe demonstrates the increase in unpaired electrons.With the above characteristics,the adsorption and desorption of the reactants at FeN_(4)active sites are optimized,thus promoting the oxygen reduction reaction activity.This work explores the key point in electronic configuration and coordination environment tuning of FeN_(4)through S doping and provides new insight into the construction of M-N-C-based oxygen reduction reaction catalysts.

XAFS Study of Coordination Structure of Cu（L-His）2 in Solution

Multiple coordination modes are present copper coordination environment varies in the CuII-histidine complex in solution and the with pH. In this work, we have investigated the coordination geometry of Cu（His）2 complex using X-ray absorption fine structure （XAFS） analysis. Copper K-edge XAFS spectra were acquired on aqueous Cu2＋ samples with his- tidine at different pH values. The coordination environments were further confirmed by chemically modified histidine. Results show that the caboxylate groups coordinate at acidic condition, while amino and imidazole nitrogens get coordinated at higher pH. For the co- ordination geometry of Cu（His）2 in solution at physiological pH, the sixfold coordination is preferentially formed, while the fivefold coordination can co-exist in equilibrium.

Relationship between Coordination Structure and Biological Activity of Copper(II) Nicotinate

The copper（Ⅱ） complexes of pyridine-3-carboxylic acid （nicotinic acid） and pyridine-2-carboxylic acid （isonicotinic acid） were synthesized, and their structures were characterized by elemental analysis, infrared spectrum, powder X-ray diffraction and so on. The results show that under experimental conditions, the ligands of synthesized copper nicotinate and copper isonicotinate are coordinated simultaneity with copper（Ⅱ） via the nitrogen of pyridine group and an oxygen of carboxylic acid group to form bidentate chelates. The crystal of copper nicotinate with two six-membered chelate rings belongs to monoclinic system, while that of copper isonicotinate having two five-membered chelate rings is of triclinic system. The tests show that the biological activities, such as the improvement of feed utilization, growth, anti-oxidation ability of organism and disease-resistant power, are different when copper nicotinate, copper inicotinate, copper-lysine chelate, copper-methionine chelate and copper sulphate are added in pig＇s feed, respectively. Due to its higher biological activity, less pollution and lower toxicity, copper nicotinate has wide potential applications as a feed additive.

A review on the coordinative structure of human walking and the application of principal component analysis

Walking is a complex task which includes hundreds of muscles, bones and joints working together to deliver smooth movements. With the complexity, walking has been widely investigated in order to identify the pattern of multi-segment movement and reveal the control mechanism. The degree of freedom and dimensional properties provide a view of the coordinative structure during walking, which has been extensively studied by using dimension reduction technique. In this paper, the studies related to the coordinative structure, dimensions detection and pattern reorganization during walking have been reviewed. Principal component analysis, as a popular technique, is widely used in the processing of human movement data. Both the principle and the outcomes of principal component analysis were introduced in this paper. This technique has been reported to successfully reduce the redundancy within the original data, identify the physical meaning represented by the extracted principal components and discriminate the different patterns. The coordinative structure during walking assessed by this technique could provide further information of the body control mechanism and correlate walking pattern with injury.

Ionothermal Synthesis, Crystal Structure and Photocatalytic Property of a New Cobalt Coordination Polymer

The reaction of flexible bis（imidazole） ligand and 1,2-bis（imidazol-l＇-yl）methane （bimm） with Co（Ⅱ） salt under ionothermal method resulted in the formation of a new coordination polymer {[Co（bimm）3]·（PF6）2}n （1）. X-ray single-crystal diffraction determination reveals that 1 crystallizes in the triclinic Pi space group, with α = 8.647（6）, b = 12.092（9）, c = 14.967（1 l） A, α = 88.912（8）, β = 81.199（8）, ）, = 89.395（8）°, V= 1546 （2） A3, Z = 2, Mr = 793.39, Dc= 1.704 Mg/m3,μ = 0.768 mm-1 F（000） = 798, the final R = 0.0626 and wR = 0.1634 for 4319 observed reflections with I〉 2σ（I）. In compound 1, the Co（lI） ion is connected to another Co（ll） by two bimm ligands to form 1D double chains which are further linked by bimm ligands to form a 2D wavelike layer. Topologically, the structure of 1 represents a uninodal 2D 4-connected sq1/Shubnikov tetragonal plane net. Moreover, thermogravimetric analyses and photocatalytic property for 1 have also been investigated.

Helical Coordination Polymer with a 3-Fold Interpenetration Structure Based on 5-(Hydroxymethyl)isophthalic Acid

5-（Hydroxymethyl） isophthalic acid （H2HIA） as a novel organic ligand was prepared from 3,5-bis（methoxycarbonyl）benzoic acid by a two-step method. And then, a 3D helical coor- dination polymer with a 3-fold interpenetration structure, namely [Zn1/2（HIA）1/2（DPEE）1/2]n （1）, was hydrothermally synthesized at 160 ℃, using H2HIA ligands to assemble with DPEE ligands and Zn2＋ ions. Complex 1 crystalizes in orthorhombic system, space group Pnna, with a = 8.2118（5）, b = 17.1698（7）, c =14.9922（7） ？, V = 2113.82（18） ？3, μ = 1.194 mm-1, Z = 4 and S = 0.967. Moreover, some physical characteristics of complex 1, such as powder X-ray diffraction （PXRD）, thermogravimetry analyses （TGA） and photoluminescent properties, were also investigated.

Syntheses and Crystal Structures of Two New Complexes Generated from 2-（（Pyridin-3-ylmethyl）thio）-5-（6-quinolinyl）-1,3,4-oxadiazole and Ag~Ⅰ Salts

Two new Ag~Ⅰ-complexes have been synthesized based on the semi-rigid ligand 2-（（pyridin-3-ylmethyl）thio）-5-（6-quinolinyl）-1,3,4-oxadiazole（L）,obtained by the condensation reaction of 5-（6-quinolinyl）-1,3,4-oxadiazole-2-thiol and 3-chloromethyl pyridine hydrochloride. Crystallization of L with Ag OTf and Ag PF_6 in a CH_2Cl_2/MeO H mixed solvent system at room temperature affords a novel supramolecular [Ag_2L_2（CF_3SO_3）_2]（I） and a coordination polymer [Ag L（PF_6）]_n（Ⅱ）,respectively. Two complexes were characterized by TGA,X-ray powder and single-crystal diffraction.

Synthesis, Crystal Structure and Electrochemical Properties of a One-dimensional Chain Coordination Polymer [Mn(phen)(2,4,6-TMBA)_2(H_2O)]_n

A one-dimensional chain-like coordination polymer [Mn（phen）（2,4,6-TMBA）2（H2O）]n has been synthesized from 2,4,6-trimethylbenzoic acid, 1,10-phenanthroline and anhydrous manganese（Ⅱ ） sulfate and then characterized. Crystal data for this complex： tetragonal, space group I41, a = 2.05643（16）, b = 2.05643（16）, c = 1.3939（2） nm, V = 5.8946（11） nm^3, Mr = 579.54, Z = 8, Dc = 1.306 g/cm^3, μ（MoKα） = 0.490 mm^-1, F（000） = 2424, S = 0.985, the final R = 0.0411 and wR = 0.0950. The Flack factor is -0.01（2）. The crystal structure shows that two neighboring man- ganese（Ⅱ ） ions are linked together by one bridge-chelating 2,4,6-trimethylbenzoic group, forming a one-dimensional chain structure. The manganese（Ⅱ ） ion is coordinated with two nitrogen atoms of one 1,10-phenanthroline, three oxygen atoms from three 2,4,6-trimethylbenzoic acids and one water oxygen atom, giving a distorted octahedral coordination geometry. The cyclic voltametric behavior of the complex was also investigated.

A Chain Cadmium(Ⅱ) Coordination Polymer with Diacylhydrazide: Synthesis,Crystal Structure and Luminescent Property

A novel Cd（Ⅱ） coordination polymer with diacylhydrazide ligand N,N？-bis（3-methoxysalicyl）-2,6-pyridinedicarbohydrazide（H_6msphz）,[Cd_2（H_2msphz）（Py）_4]_n（1,Py = pyridine） has been synthesized through solvothermal reaction and structurally characterized by single-crystal X-ray diffraction,IR,TGA and PXRD investigations. It crystallizes in triclinic system,space group P1,with a = 11.0230（11）,b = 11.7264（15）,c = 17.3395（14） ？,α = 70.520（9）,β = 84.806（7）,γ = 81.965（9）°,V = 2089.9（4） ？~3,Dc = 1.638 gcm^（–3）,μ = 1.083 mm^（-1）,F（000） = 1032,Z = 2 and S = 1.040. In complex 1,the H_2msphz4-ligand uses not only its coordinated pocket to catch one Cd（Ⅱ） ion,but also its two terminal groups to chelate other two Cd（Ⅱ） ions,leading to the formation of a chain structure. The adjacent chains are further assembled together by two kinds of π-π interactions between the Py rings,resulting in the finial double layered supramolecular structure. In addition,complex 1 is found to show photoluminescence in the solid state at room temperature,which can be ascribed to the intraligand π→π＊ transitions.

Crystal Structures and Photoluminescent Properties of Two Cd^(2＋) Coordination Polymers Constructed from an 8-Hydroxyquinolinate Ligand

In order to perform a study on the structural modulation in the Cd（Ⅱ）-L architecture（HL =（E）-2-[2-（3-pyridyl）ethenyl]-8-hydroxyquinoline）, two different dicarboxylic acids, namely, 2-aminoterephthalic acid（H_2ATA） and 4,4￠-biphenyldicarboxylic acid（H_2BPDC）, are employed as the secondary auxiliary ligands. Two new complexes [Cd_2L_2（ATA）]（1） and [Cd_2L_2（BPDC）·2MeO H· 4H_2O]（2） with distinct 3D frameworks were obtained. In complex 1, ligands ATA bridge the 1D Cd（Ⅱ）-L infinite chains into a 3D polymeric coordination network. Complex 2 is a 3D porous framework, in which adjacent 2D Cd（Ⅱ）-L coordination layers were linked together by the coor- dinated BPDC ligands. The variant structures of two complexes indicate that the skeleton of dicarboxylate anions plays a great role in the assembly of such different frameworks. In addition, the photoluminescent properties（fluorescent emission, lifetime, and quantum yield） of polymers 1 and 2 were also investigated in the solid state.

Synthesis,Structure and Photoluminescence of a New Pb(Ⅱ)Coordination Polymer[Pb(1,4-chdc)(L)]n·nH2O Based on a Flexible 1,4-Cyclohexanedicarboxylic Acid

A new Pb（Ⅱ） coordination polymer, [Pb（1,4-chdc）（L）]_n·nH_2O（1）, was synthesized under hydrothermal condition（1,4-H2 chdc = 1,4-cyclohexanedicarboxylic acid and L = 2-（3-fluorophenyl）-1H-imidazo[4,5-f][1,10]phenanthroline）. Its crystal structure was determined by singlecrystal X-ray diffraction. Compound 1 crystallizes in triclinic, space group P1 with a = 9.1182（8）, b = 11.3249（10）, c = 12.7326（12） A, α = 77.897（2）, β = 81.644（2）, γ = 84.491（2）°, V = 1269.0（2） A^3, Z = 2, C_（27）H_（24）FN_4O_5Pb, M_r = 710.69, D_c = 1.860 g/cm^3, F（000） = 690, μ（MoKa） = 6.701 mm^（-1）, R = 0.0349 and wR = 0.0746. In 1, each 1,4-chdc anion bridges two neighboring Pb（Ⅱ） atoms in a bidentate chelating coordination mode to give a chain structure. The L ligands are attached on one side of the chain through chelating the Pb（Ⅱ） atoms, and are stacked with those of an adjacent chain through π-π interactions, yielding a layer structure. The O-H···O and N-H···O hydrogen bonding interactions further stabilize the supramolecular layer structure of 1. Moreover, solid state luminescent property of 1 was also studied.

Synthesis,Crystal Structure and Photoluminescent Property of a Novel Dy^(3+) Coordination Compound Containing Rare(H_2O)_(22) Clusters

A novel Dy^（3＋） coordination compound,（H_2pipz）（H_3O）[Dy（pydc）_3]·11H_2O（1,pipz = piperazine and H_2pydc = pyridine-2,6-dicarboxylic acid）,has been hydrothermally synthesized and characterized by X-ray single-crystal diffraction,elemental analysis. It is interesting that the packing structure of compound 1 contains 22-core water clusters. Compound 1 is extended into a threedimensional supramolecular structure via O···H···O hydrogen bonding interactions. Furthermore,the luminescent property of compound 1 was also investigated.

Transformation of Structure and Properties of Vesicles Induced by Transition Metal Ions

This paper proved that octodecyl propylenediamine could form vesicles in pure water and aqueous solution of CuCl2 or Cu（NO3）2. The structure and morphology of vesicles were different when the copper （Ⅱ） salt was added to the solution. The results showed that both the counterions and the ligands had strong influence on the configuration of coordinated structures and packing model in bilayer membrane of vesicles.

Solvothermal Synthesis,Crystal Structure and Photoluminescence Property of a 3D Lead(Ⅱ)Coordination Polymer Based on Terephthalic Acid

Solvothermal reaction of Pb（NO3）2·6H2O with rigid linear ligand terephthalic acid（H2pta） in N,N-dimethylformamide（DMF） produced a new three-dimensional（3D） lead（Ⅱ）coordination polymer[Pb2（pta）1.5（μ4-OH）（DMF）]n 1,and its structure was characterized by single-crystal X-ray diffraction analyses.In polymer 1,the μ4-OH bridges the nearby lead（Ⅱ） ions into an infinite one-dimensional（1D） chain,and then the organic ligand pta^2- joins the neighbored chains into a 3D structure by two similar connection modes in different configurations.The solid-state photoluminescent studies revealed that 1 exhibits a strong greenish emission mainly originating from ligand-to-metal charge transfer between the delocalized π bonds of the aromatic carboxylate ligand pta^2- and the p orbitals of the Pb^2＋ centers.

First-principles study of the local structure and crystal field of Yb^(2+) in sodium and potassium halides

The local coordination structures around the doping Yb2＋ ions in sodium and potassium halides were calculated by using the first-principles supercell model. Both the cases with and without the charge compensation vacancy in the local environment of the doping Yb2＋ were calculated to study the effect of the doping on the local coordination structures of Yb2＋. Using the calculated local structures, we obtained the crystal-field parameters for the Yb2＋ ions doped in sodium and potassium halides by a method based on the combination of the quantum-chemical calculations and the effective Hamiltonian method. The calculated crystal-field parameters were analyzed and compared with the fitted results.