Syntheses,crystal structures,and quantum chemistry calculation of two Ni(Ⅱ)coordination polymers

Two new coordination polymers,[Ni(Hpdc)(bib)(H_(2)O)]_(n)(1)and{[Ni(bib)_(3)](ClO_(4))_(2)}_(n)(2),were prepared by mixing Ni^(2+),3,5⁃pyrazoledicarboxylic acid(H3pdc)/p⁃nitrobenzoic acid and 1,4⁃bis(imidazol⁃1⁃ylmethyl)butane(bib)by a hydrothermal method,respectively.X⁃ray crystallography reveals a 2D network constructed by six⁃coordinated Ni(Ⅱ)centers,bib,and Hpdc2-ligands in complex 1,while a 2D network is built by Ni(Ⅱ)and bib ligands in 2.Furthermore,the quantum⁃chemical calculations have been performed on‘molecular fragments’extracted from the crystal structure of 1 using the PBE0/LANL2DZ method in Gaussian 16 and the VASP program.CCDC:2343794,1;2343798,2.

Syntheses and catalytic performances of three coordination polymers with tetracarboxylate ligands

Three zincand cobaltcoordination polymers,namely{[Zn_(2)(μ_(6)-adip)(phen)_(2)]·4H_(2)O}_(n)(1),{[Co_(2)(μ_(6)-adip)(bipy)_(2)]·4H_(2)O}_(n)(2),and[Co_(2)(μ4-adip)(μ-bpa)_(2)]_(n)(3)have been constructed hydrothermally using H4adip(H4adip=5,5′-azanediyldiisophthalic acid),phen(phen=1,10-phenanthroline),bipy(bipy=2,2′-bipyridine),bpa(bpa=bis(4-pyridyl)amine),and zinc and cobalt chlorides at 160℃.The products were isolated as stable crystalline solids and were characterized by IR spectra,elemental analyses,thermogravimetric analyses,and single-crystal X-ray diffrac-tion analyses.Single-crystal X-ray diffraction analyses revealed that three compounds crystallize in the orthorhom-bic system Pnna(1 and 2)or P21212(3)space groups.All compounds exhibit 3D frameworks.The catalytic perfor-mances in the Henry reaction of these compounds were investigated.Compound 3 exhibited an effective catalytic activity in the Henry reaction at 70℃.CCDC:2339391,1;2339392,2;2339393,3.

Syntheses,crystal structures,and catalytic properties of three zinc(Ⅱ),cobalt(Ⅱ)and nickel(Ⅱ)coordination polymers constructed from 5⁃(4⁃carboxyphenoxy)nicotinic acid

Three zinc(Ⅱ),cobalt(Ⅱ),and nickel(Ⅱ)coordination polymers,namely[Zn(μ^(3-)cpna)(μ-dpea)_(0.5)]_(n)(1),[Co(μ^(3-)cpna)(μ-dpey)_(0.5)]_(n)(2),and[Ni(μ^(3-)cpna)(μ-dpey)_(0.5)(H_(2)O)]_(n)(3),have been constructed hydrothermally using H_(2)cpna(5-(4-carboxyphenoxy)nicotinic acid),dpea(1,2-di(4-pyridyl)ethane),dpey(1,2-di(4-pyridyl)ethylene),and zinc,cobalt,and nickel chlorides at 160℃.The products were isolated as stable crystalline solids and were characterized by IR spectra,elemental analyses,thermogravimetric analyses,and single-crystal X-ray diffraction analyses.Single-crystal X-ray diffraction analyses revealed that three compounds crystallize in the triclinic system,space group P1.Compounds 1-3 show 2D layer structures.The catalytic activities in the Knoevenagel condensation reaction of these compounds were investigated.Compounds 1 and 2 exhibit effective catalytic activities in the Knoevenagel condensa-tion reaction at room temperature.For this reaction,various parameters were optimized,followed by the investiga-tion of the substrate scope.CCDC:2335676,1;2335677,2;2335678,3.

Syntheses,structures,and properties of three coordination polymers based on 5⁃ethylpyridine⁃2,3⁃dicarboxylic acid and N⁃containing ligands

Three coordination polymers[Mn(epda)(2,2'⁃bipy)(H_(2)O)](1),[Mn(epda)(phen)](2),and[Co_(2)(epda)2(bpe)2(H_(2)O)_(4)]·5H_(2)O(3)(H2epda=5⁃ethyl⁃pyridine⁃2,3⁃dicarboxylic acid,2,2'⁃bipy=2,2'⁃bipyridine,phen=phenanthroline,bpe=1,2⁃bis(4⁃pyridyl)ethylene)were synthesized by solvothermal reactions and characterized by single⁃crystal X⁃ray diffraction,thermogravimetric analyses,IR spectroscopy and elemental analysis.1 displays a 1D chain struc⁃ture,and these chains are joined by O-H…O hydrogen bonding andπ⁃πstacking interactions to generate a 2D layer structure.2 displays a 2D layer structure,and adjacent layers are generated 3D architecture throughπ⁃πstacking interactions.3 displays a 1D chain structure,and adjacent chains are generated double layer structure through O-H…O hydrogen bonding.The fluorescent properties of 1 and 3 indicate that they can potentially be used as a luminescent sensor.1 was highly selective and sensitive towards o⁃nitrophenol through different detection mechanisms,however,3 was highly selective and sensitive towards 2,4,6⁃trinitrophenol.In addition,the magnetic behavior of 2 has also been investigated.CCDC:2172533,1,2355773,2,2355774,3.

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.

Synthesis and Crystal Structure of an Infinite Sandwich-type Cu(I) Coordination Polymer: {[Cu(abpy)_2](H_3bptc)·(H_2O)}_n Constructed by a Tetracarboxylic Acid

The title compound {[Cu（abpy）2]（H3bptc）·（H2O）}n, an ion-pair complex of [Cu（abpy）2]＋ with [（H3bptc）]- （abpy = 3,3＇-dimethyl-2,2＇-bipyridine and H4bptc = 1,1＇-biphenyl-2,2＇,3,3＇-tetracarboxylic acid）, has been synthesized by a hydrothermal reaction, and its structure was deter- mined by X-ray diffraction and characterized by elemental analysis and IR spectrum. The crystal is of triclinic, space group P1 with a = 8.4955（12）, b = 15.164（2）, c = 15.303（2）, α = 105.704（3）, β = 97.374（3）, γ = 96.764（3）o, CuC40H35N4O9, Mr = 779.26, V = 1857.9（4）3, Dc = 1.393 g/cm3, F（000） = 808, μ = 0.649 mm-1, S = 1.026 and Z = 2. The final R = 0.0493 and wR = 0.1034 for 4026 observed reflections with I 2σ（I）. The copper（I） coordination polymer demonstrates a 3-D sandwich-type structure containing 2-D double H3bptc-chain layers intercalated with the [Cu（abpy）2]＋ layers by extensive hydrogen bonding interactions.

Synthesis of energetic coordination polymers based on 4-nitropyrazole by solid-melt crystallization in non-ionization condition

Based on the theory of crystallization,a solvent-free solid-liquid phase crystallization method called solid-melt crystallization was designed to prepare energetic coordination polymers.Two target compounds[Cu(NPyz)_(4)NO_(3)]·NO_(3)(ECPs-1)and Cu(NPyz)_(4)(ClO_(4))_(2)(ECCs-2)were prepared through programmed heating and cooling by using 4-nitropyrazole(NPyz),(Cu(NO_(3))_(2)·5H_(2)O and Cu(ClO_(4))_(2)·5H_(2)O) as raw materials.In addition,crystallization pre-experiments and annealing experiments also verified the feasibility of the method.Their structures were confirmed by IR,elemental analysis,single-crystal X-ray diffraction and powder X-ray diffraction.The physicochemical properties and sensitivity test results showed that ECCs-2 has better thermal stability(T_(d)=221℃),while ECPs-1 is less sensitive to mechanical stimuli(IS=12 J,FS=240 N).Calculations based on EXPLO5 and the Kamlet-Jacobs equation showed that ECCs-2 has more considerable detonation performance(P=25.2 GPa,D=7.5 km/s).In comparison,the more intuitive results from the HN test,flame test,thermal resistance test and lead plate explosion test revealed that ECCs-2 has an“acceptable”detonation performance.The laser detonation test also showed that ECCs-2 is a promising excellent laser detonation material(E=408 mJ,P=24 W,τ=17 ms).

Encapsulation of lipases on coordination polymers and their catalytic performance in glycerolysis and esterification

In this study,lipases of CALB(Candida antarctica lipase B),TLL(Thermomyces lanuginosa lipase),RML(Rhizomucor miehei lipase),CALA(Candida antarctica lipase A)and LU(Lecitase?Ultra)were encapsulated into the nucleotidehybrid metal coordination polymers(CPs)for diacylglyerols(DAG)preparation.Guanosine 5'-monophosphate(GMP)and adenosine 5'-monophosphate(AMP)were used as coordinating molecules,and metal ions of Fe^(3+),Ba^(2+),Mn^(2+),Ni^(2+)and Cr^(3+)were applied to prepare matrix.Results indicated that,besides Ba^(2+)with AMP,all other metal ions can coordinate with AMP and GMP to generate CPs.In addition,the AMP/Ni was amorphous when standing temperature was 4℃,while it was crystalline when standing temperature was from 30 to 180℃.DAG content from 47.55%to 64.99%was obtained from glycerolysis by CALB@GMP/Ba,RML@GMP/Ba,TLL@GMP/Ba,RML@GMP/Mn and TLL@GMP/Mn.Additionally,CALB@GMP/Fe showed selectivity towards DAG formation in the esterification and DAG content up to 61.88%was obtained.

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

A one-dimensional chain coordination polymer [Cu（phen）（2,4,6-TMBA）2（H2O）]n has been synthesized by reacting 2,4,6-trimethyl-benzoic acid, 1,10-phenanthroline and Cu（Ⅱ） perchlorate and its structure was characterized. Crystal data for this complex： tetragonal, space group I41, a = 2.0293（3）, b = 2.0293（3）, c = 1.3758（2） nm, α =β= γ = 90°, V= 5.6657（13） nm3, Dc= 1.379 g/cm3, Z = 8, μ（MoKa） = 0.815 mm-1, Mr = 588.14, F（000） = 2456, S = 1.047, R = 0.0459 and wR = 0.1053. The crystal structure shows that two neighboring Cu（Ⅱ） ions are linked together by one bridging-chelating 2,4,6-trimethyl-benzoic group, forming a one-dimensional chain structure. Each Cu（Ⅱ） ion is coordinated with two nitrogen atoms from one 1,10-phenanthroline molecule, three oxygen atoms from three 2,4,6-trimethyl-benzoic acid molecules and one oxygen atom from one water molecule, giving a six-coordinate distorted octahedral coordination geometry. The cyclic voltammetry behavior of the complex was also investigated.

Hydrothermal Synthesis and Crystal Structure of a 1D Cu(II) Coordination Polymer: [Cu(bbpy)(H_2bptc)]_n Constructed by a Tetracarboxylic Acid

The title compound [Cu（bbpy）（H2bptc）]n （bbpy = 4,4＇-dimethyl-2,2＇-bipyridine and H4bptc = 1,1＇-biphenyl-2,2？,3,3＇-tetracarboxylic acid） has been synthesized by hydrothermal reaction, and its structure was determined by X-ray diffraction and characterized by elemental analysis, IR spectrum and thermogravimetric analysis. The crystal is of triclinic, space group P1 with a = 11.2831（12）, b = 11.6718（13）, c = 11.7771（13）, α = 105.392（2）, β = 108.382（2）, γ = 112.397（2）o, CuC28H20N2O8, Mr = 576.00, V = 1222.4（2）3, Dc = 1.565 g/cm3, F（000） = 590, μ = 0.951 mm-1, S = 1.022 and Z = 2. The final refinement gave R = 0.0405 and wR = 0.1142 for 4270 observed reflections with I 2σ（I）. The title complex has a 1D [Cu（bbpy）（H2bptc）]n chain structure, in which the extensive hydrogen-bond interactions make the chain more stable. The neighboring parallel chains are further packed into a 2D layer structure via π···π stacking interaction between the pyridine rings of bbpy ligands. Moreover, the adjacent layers are interconnected by the C–H···π interactions to form a 3D metal-organic framework.

Urothermal Synthesis and Crystal Structure of a Zn(Ⅱ) Coordination Polymer with a 3-D Supramolecular Structure

A new metal-organic coordination polymer [Zn（hfipbb）（e-urea）]n（1,H2hfipbb = 4,4＇-（hexafluoroisopropylidene）bis（benzoic acid）,e-urea = ethylene urea） has been urothermally synthesized and characterized by elemental analysis and single-crystal X-ray diffraction.The title complex crystallizes in monoclinic,space group P21/c with a = 13.302（4）,b = 10.981（3）,c = 13.804（4） ,β = 93.587（5）°,V = 2012.3（10） 3,C20H14N2O5F6Zn,Mr = 541.72,Z = 4,Dc = 0.447 g/cm3, = 0.328 mm-1,F（000） = 272,R = 0.0340 and wR = 0.1107 for 4528 observed reflections（I 〉2σ（I））.In the structure of compound 1,two Zn（Ⅱ） ions are bridged by two carboxylate groups from two hfipbb ligands to form a dinuclear unit,and each dinuclear Zn（Ⅱ） unit is linked with its two adjacent dinuclear units through four hfipbb ligands into an infinite one-dimensional double-chain.The interesting structural feature of compound 1 is that the one-D double-chains are self-interconnected into a three-D supramolecular structure through hydrogen bonds between the coordinated e-urea molecules and carboxylate oxygen atoms（N1 and O2,N2 and O4）.

Synthesis and Crystal Structure of a 1D Chained Coordination Polymer Containing One-dimensional Egg-like Channels:{[Cu_2(C_2O_4)_2(inta)_4](inta)}_n (inta=Isonicotinamide)

A new one-dimensional copper coordination polymer chain has been prepared and fully characterized by single-crystal X-ray diffraction, elemental analyses and IR spectroscopy. The compound { [Cu2（C2O4）2（inta）4]（inta）}n 1 crystallizes in the triclinic system, space group P1, with a = 8.4722（5）, b = 10.9825（6）, c = 11.6128（6）A, α= 104.8050（10）,β = 102.5740（10）, γ= 109.6890（10）°, V= 927.18（9） A3, Mr = 929.79, Z = 1, Dc = 1.665 g/cm^3, F（000） = 475, μ = 1.231 mm^-1, R = 0.0453 and wR = 0.1185 for 3290 observed reflections （Ⅰ 〉 2σ（Ⅰ））. Of the compound, the Cu center is octahedrally coordinated with oxalate acting as a tetra-dentate ligand coordinated to the copper atom and each inta serving as a terminal ligand by employing only one N-donor to coordinate with the Cu center. An infinite {Cu2（C2O4）2}∞ chain is formed along the c axis. Furthermore, the 1D chains are held together via extensive hydrogen-bonding interactions to generate a three-dimensional network with 1D channels （ca. 5.491A×11.507A） where inta molecules are filled.

A New One-dimensional Coordination Polymer Based on 3,5-Dinitro-salicylic Acid:Synthesis,Crystal Structure,Luminescent Property and Theoretical Calculation

A new one-dimensional Mg（Ⅱ） coordination polymer, [Mg（L）（phen）（H2O）]（1）, has been hydrothermally synthesized by using 3,5-dinitro-salicylic acid（H2L） and 1,10-phenanthroline（phen）. It crystallizes in monoclinic, space group C2/c with a = 33.038（7）, b = 6.6481（13）, c = 22.750（5） A, β = 126.99（3）°, V = 3991.1（14） A3, Z = 8, C19H12 MgN4O8, Mr = 448.64, Dc = 1.493 g/cm3, F（000） = 1840, μ（Mo Ka） = 0.146 mm-1, R = 0.0559 and w R = 0.0975. In 1, each L anion bridges two Mg（Ⅱ） atoms to give one-dimensional zigzag chains with the Mg…Mg separation of 5.34 ？, which are extended by π-π stacking interactions between 1,10-phenanthroline ligands into a two-dimensional supramolecular layer. Moreover, the O–H…O hydrogen-bonding interactions further stabilize the layer structure of 1. The luminescent property was also studied for 1 in solid state at room temperature. In addition, natural bond orbital（NBO） analysis was performed by the B3LYP/LANL2 DZ method in Gaussian 09 Program. The calculation results show obvious covalent interaction between the coordinated atoms and Mg（Ⅱ） ion.

Two Coordination Polymers Containing Linear Co(Ⅱ)-Trinuclear and Cu(Ⅱ)-Chain Assembled from 4-Fluorocinnamic Acid and N-Donor Ligand

Two new coordination polymers,named {[Co3（pfca）6（phen）2]·2H2O}n（1） and[Cu（pfca）2（4,4＇-bpy）（H2O）]n（2）（Hpfca = 4-fluorocinnamic acid and 4,4-bpy = 4,4-bipyridine）,were hydrothermally synthesized and characterized by elemental analysis,IR spectroscopy,thermogravimetric analysis（TGA）,and single-crystal X-ray diffraction.Complex 1 crystallizes in the triclinic crystal system,space group P1 with a = 10.939（3）,b = 12.430（4）,c = 13.815（4） A,α=78.436（3）,β= 70.261（3）,γ= 80.268（3）°,V= 1721.8（9） A^3,Dc = 1.508 g/cm^3,Mr= 1564.06,Z = 1,F（000） = 799,μ= 0.802 mm^（-1）,the final R = 0.0432 and wR = 0.1015 for 13250 observed reflections with I 2σ（I）.Complex 2 is of monoclinic system,space group P2／lc with a =15.4985（14）,b = 15.8424（14）,c = 10.9528（10） A,β= 107.1600（10）°,V= 2569.6（4） A^3,Dc = 1.468g/cm^3,Mr = 568.02,Z = 4,F（000） = 1164,μ= 0.906 mm^（-1）,the final R = 0.0371 and wR = 0.0842 for 18183 observed reflections with I〉 2σ（I）.Complex 1 features linear Co（Ⅱ）-trinuclear units,which are assembled into a final 3D supramolecular structure through π…π stacking interactions and F-H weak interactions.Complex 2 consists of 1D polymeric Cu（Ⅱ）-chains that are further cohered together by extensive H-bonds.

Hydrothermal Synthesis, Crystal Structure and Properties of a New Copper Coordination Polymer [Cu2I（C7H5N4）2]n with 3-（Pyridin-2-yl）-1,2,4-triazole) Ligand

A new copper coordination polymer[Cu2I(C7H5N4)2]n(1)with the 3-(pyridin-2-yl)-1,2,4-triazole(Hpt)and copper iodide was synthesized.It crystallizes in the triclinic space group P1 with a=8.6380(9),b=9.2434(9),c=11.8588(12)A,α=99.5890(10)o,β=109.0990(10)o,γ=105.2800(10)o,V=829.25(15)A^3,Dc=2.180 g/cm3,Z=2,F(000)=522,GOOF=1.046,the final R=0.0245 and wR=0.0598.The crystal structure shows that two copper ions are bridged by twoμ2-η1:η0-3-(pyridin-2-yl)-1,2,4-triazole anions and two iodide ions.The coordination environments of the Cu ion are Cu(1)N5 and Cu(2)N2I2,giving distorted square pyramidal geometry and trigon pyramid geometry.The magnetic and fluorescent properties of 1 were studied.

Synthesis,Crystal Structure and Thermal Stability Properties of a Binuclear Copper(Ⅱ) Coordination Polymer {[Cu_2(4,4'-bipy)_2(o-ABA)_4(H_2O)_2][(H_2O)_2]}_n

One-dimensional chain copper（Ⅱ） coordination polymer has been synthesized and characterized in the solvent mixture of water and alcohol with o-acetamidobenzoic acid,4,4＇-bipyridine and copper perchlorate.It is of tetragonal,space group P41212 with a=1.57756（10）,b= 1.57756（10）,c=2.1438（3）nm,V=5.3352（8） nm^3,Dc=1.524 g/cm^3,Z=4,F（000）=2536,R= 0.0479 and wR=0.0979.The crystal structure shows two coordination modes.The copper（1） is coordinated with two nitrogen atoms of one 4,4＇-bipyridine molecule and two oxygen atoms from two o-acetamidobenzoic acid molecules,forming a distorted tetrahedral coordination geometry; the copper（2） is coordinated with two nitrogen atoms of one 4,4＇-bipyridine molecule,four oxygen atoms from two o-acetamidobenzoic acid molecules and two water molecules,generating a distorted octahedral coordination geometry.The result of TG analysis shows that the title complex is stable below 180.0 ℃.

A New Cd(Ⅱ) Coordination Polymer Constructed by 1,10-Phenanthroline Derivative: Syntheses, Structure, Physical Properties and Theoretical Calculation

A new Cd（Ⅱ） coordination polymer, [Cd（L）2（H2O）]n（1）, has been hydrothermally synthesized by using 1-（1 H-imidazo[4,5-f][1,10]phenanthrolin-2-yl）naphthalen-2-ol（HL）,(3-（4-（carboxymethoxy）phenyl）acrylic acid and Cd（NO3）·4 H2O. It crystallizes in monoclinic, space group P21/c with a = 19.41（2）, b = 11.078（12）, c = 20.09（2） ?, β = 116.824（17）o, V = 3855（7） ?3, Z = 4, C46H28CdN8O3, Mr = 853.17, Dc = 1.470 g/cm3, F（000） = 1728, μ（Mo Ka） = 0.621 mm-1, R = 0.0338 and wR = 0.0890. 1 shows a one-dimensional（1 D） zigzag chain structure. The neighboring chains are extended into a two-dimensional（2 D） layer structure by π-π interactions between adjacent L ligands. In addition, Natural Bond Orbital（NBO） analysis was performed by the B3LYP/LANL2DZ method in Gaussian 09 Program. The calculation results show the obvious covalent interaction between the coordinated atoms and Cd（Ⅱ） ion.

In Situ Synthesis, Structural Characterization and Catalytic Properties of a 2D Cu(Ⅰ)-cyanide Coordination Polymer

A new Cu(Ⅰ) coordination polymer(CP) formulated as [Cu2(L)(CN)2]n(1, L =1,1′-bis(5,6-dimethylbenzimidazole)methane) was synthesized, in which the cyanide anions were generated in situ by the cleavage of C–C bond of acetonitrile under hydrothermal conditions. CP 1 was characterized by elemental analysis, IR spectroscopy and single-crystal X-ray diffraction. It crystallizes in the orthorhombic system, Pccn space group, with a = 10.314(3), b = 20.966(7), c =9.432(3)?, V = 2039.5(11)?3, Z = 4, C21 H20 Cu2 N6, Mr = 483.51, Dc = 1.575 g×cm^-3,μ= 2.105 mm-1 and F(000)= 984, the final R = 0.0608 and wR = 0.1942 for 1226 observed reflections with Ⅰ> 2s(Ⅰ)for the CP 1. The CP 1 possesses a 2D {63} layer structure which is composed of Cu(Ⅰ) centers bridged by L and CN– ligands. The thermal stability and luminescence properties of CP 1 are discussed in detail. The complex also displays a remarkable activity for the degradation of methyl orange by hydrogen peroxide in a Fenton-like process.

Hydrothermal in situ Ligand Synthesis from 1,10-Phenanthroline-5,6-dione and Characterization of 1D Coordination Polymers [Co(bpdc)(H_2O)_3]·H_2O and [Cu(bpy)V_2O_6]

Hydrothermal treatment of MCl2 （ M = Co or Cu ） , NH4 VO3, and 1,10-phenanthroline-5,6-dione （pdon） resulted in the formation of a duplex coordination polymer [ Co （ bpdc ） （ H2O ） 3 ] · H2O （ bpdc = 2,2＇-bipyridine-3,3＇-dicarboxylate） and a chain-like coordination polymer [ Cu （bpy） V2O6 ] （ bpy = 2,2＇-bipyridine ）. X-ray single-crystal structural analysis shows that under hydrothermal conditions and in the presence of different transition metals, the organic reagent pdon was transformed in situ into bpdc and bpy, respectively. Mechanism of the in situ ligand synthesis reaction has been discussed.

Synthesis and Crystal Structure of a Novel 2D Coordination Polymer [Cu_3(mal)_2(di-2-pyridlyktone)_2]

A novel coordination polymer of Cu II with flexible ligands,namely,[Cu 3 （mal） 2 （di2-pyridlyktone） 2 ] （1,H 2 mal=maleic acid）,was synthesized and characterized by single-crystal X-ray diffraction,thermogravimetric analyses,elemental analysis and IR spectroscopy.The structure indicates that the complex crystallizes in monoclinic,space group P2 1 /c with a=10.268（2）,b=17.737（3）,c=8.038（1）,β=98.275（2）°,V=1448.6（4） 3,Z=2,D c=1.883 Mg·m-3,μ=2.260 mm-1,F（000）=826,and the final R=0.0321 and wR=0.0820.In 1,three Cu II centers （Cu（1）,Cu（2）,Cu（1A）） are bridged by two uncommon μ 3-bridging H 2 mal ligands,furnishing a centrosymmetric trimetallic unit.Via further Cu-O COO coordination interactions,extention of these trimetallic units in two directions gives rise to an infinite corrugated 2D layer.In addition,thermal stability and electrochemistry of 1 were studied.