Synthesis,Structure and Physical Properties of Mn and Cd Complexes with 1,1,2,2-Tetracarboxyl-ethylene Acid

Complex [Mn（tce） 0.5（H2O） 4]（1） was obtained from Mn（OAc） 2 and tce,where tce is 1,1,2,2-tetracarboxyl-ethane. The structure of 1 is a single molecule,in which Mn（II） is a distorted octahedron coordinated to six oxygen atoms. Complex [Cd（tce） 0.5（H2O） 3]（H2O） （2） fea-tures a pillared layer architecture. The Cd（II） atom is in an octahedral environment coordinated by six oxygen donors from water molecules and tce ligands. Cd（II） atoms are interlinked by the tce ligand to generate a 2-D wavelike layer. The layers are strutted by the intermolecular O-H···O hydrogen bonds to form a 3-D open framework. Luminescence property of complex 2 was investigated. Magnetic property of complex 1 was also studied. 1 belongs to triclinic,space group P1 with a = 6.2901（12） ,b = 8.0212（15） ,c = 8.0769（15） A,α = 108.522（3） ,β = 95.068（3） ,γ = 97.086（3） °,V = 379.92（12）A^3,Mr = 456.08,Dc = 1.993 g/cm^3,F（000） = 232,μ = 1.748 mm^-1,Z = 1,the final R = 0.0297 and wR = 0.0731 for 1575 observed reflections with I 〉 2σ（I） . 2 is of monoclinic system,space group P21/c with a = 6.4367（14） ,b = 9.495（2） ,c = 13.907（3）A,β = 117.405（8） °,V = 754.6（3） A^3,Mr = 285.51,Dc = 2.513 g/cm^3,F（000） = 556,μ = 2.905 mm^-1,Z = 4,the final R = 0.0375 and wR = 0.0737 for 1521 observed reflections with I 〉 2σ（I）.

Hydrothermal Syntheses and Crystal Structures of Two Complexes of Cobalt and Manganese Assembled by 4,4'-Oxydibenzoic Acid

Two new coordination polymers [Co（oba）（mbix）]2n·nH2O （1） and [Mn（Hoba）2（H2O）2]n （2） （H2oba = 4,4＇-oxydibenzoic acid, mbix = 1,3-bis（imidazol-1-ylmethyl）benzene） have been successfully synthesized under hydrothermal conditions. Their structures have been determined by elemental analyses, IR spectroscopy, UV and single-crystal X-ray diffraction analysis. The intermolecular hydrogen bonding and π-π stacking interactions extend the complexes into a 3D supramolecular structure.

Synthesis,Crystal Structure and Luminescence Property of [MnL_2(bipy)(H_2O)_2]n

A new one-dimensional Mn（Ⅱ） complex, [MnL2（bipy）（H2O）2]n 1, has been obtained by the reaction of MnCl2·4H2O, 2,2＇-bipyridine （bipy） and 1-（4-phenoxyacetate）-5-thioacetatetetrazole （H2L）. The crystal crystallizes in the triclinic system, space group Pi with a = 7.6088（2）, b = 12.2795（2）, c = 13.6617（3）A, α = 75.416（2）, β =79.264（2）, γ = 74.271（2）°, V = 1179.48（4） A3, Z = 2, Mr = 555.43, F（000） = 570, Dc = 1.564 g/cm^3, μ = 0.704 mm^-1, the final R = 0.0454 and wR = 0.0849 for 3127 observed reflections （Ⅰ〉 2σ（Ⅰ））. The Mn（Ⅱ） is six-coordinated by two water molecules, two N atoms from bipy and two carboxylate O atoms from two L^2- to form a distorted octahedral geometry. Each L^2- ligand serves as a bridging ligand to link two Mn（Ⅱ） atoms, leading to a single-strand zigzag coordination polymer. Hydrogen-bonding interactions between adjacent chains as well as π-π stacking interactions extend the complex into a three-dimensional supramolecular architecture. Moreover, the title compound emits strong red fluorescent light （λem（max） = 610 nm） in EtOH solution.

One Novel Mn(Ⅱ)Complex with 1-Substituted-1H-1,2,3-triazole-4-carboxylic Acid:Crystal Structure,Fluorescence and Hirshfeld Surface Analysis

The crystal structure of one novel Mn（II） complex, [Mn（pmta）_3]_2[Mn（H_2O）_6]·4H_2O（1）, is reported（Hpmta = 5-methyl-1-phenyl-1H-1,2,3-triazole-4-carboxylic acid）. In the title compound, the asymmetric unit consists of a [Mn（pmta_）3]ˉ anion, half [Mn（H_2O）_6]^（2＋） counter cation and two lattice H_2O molecules, and the intra- and intermolecular hydrogen bonds connect the complex into a supramolecular structure. The liquid-state fluorescence spectra of complex 1 have been determined. Hirshfeld surface analysis was also studied. The main intermolecular interactions in the complex are O···H and H···H contacts.

Synthesis,Crystal Structure,Theoretical Calculations,and Photoluminescent Property of a Mn(Ⅱ)Complex Assembled by 5-Aminoisophthalic Acid and Phen Ligands

A coordination polymer [Mn2（ctpt）2（aic）2]n （1, ctpt = 2-（4-chloro-phenyl）-1H- 1,3,7,8-tetraaza-cyclopenta[l]phenanthrene, H2aic = 5-amino-isophthalic acid） was hydrother- mally designed and synthesized. The complex was characterized by elemental analysis, IR spectro- scopy, single-crystal X-ray diffraction, and thermogravimetric analysis （TGA）. Each Mn（II） atom is linked by the aic ligands with neighbor Mn（II） atoms, forming an infinite one-dimensional （1D） double-chain structure. Complex 1 crystallizes in monoclinic, space group C2/c, with a = 18.23（1）, b = 17.27（1）, c = 16.69（1） ？, V = 4814.0（7） ？3, C27H16ClMnN5O4, Mr = 564.84, Dc = 1.559 g/cm3, μ（MoKα） = 0.706 mm-1, F（000） = 2296, Z = 8, the final R = 0.0487 and wR = 0.1269 （I 〉 2σ（I））. The 1D chain structure of complex 1 is stable below 458 ℃. In addition, to elucidate the essential electronic characters of this complex, theoretical calculation analysis of 1 was performed by the PBE0/LANL2DZ method in Gaussian 03 Program.

Synthesis and Crystal Structure of [Mn(DPMT)_2Cl_2(H_2O)_2]

The title compound [Mn（DPMT）2Cl2（H2O）2] （DPMT = 1-[[2-（2,4-dichlorophenyl）- 1,3-dioxolan-2-yl]methyl]-1H-1,2,4-triazole） was synthesized by the reaction of MnCl2·4H2O and DPMT in ethanol solution and its structure was determined by single-crystal X-ray diffraction. The crystal belongs to monoclinic, space group P21/c with a = 23.913（4）, b = 7.8883（13）, c = 8.6291（14）A, β = 95.816（3）°, V = 1619.4（5）A^3, Z = 2, C24H26Cl6MnN6O6, Mr = 762.15, Dc = 1.563 g/cm^3, μ = 0.950 mm^-1, S = 1.045, F（000） = 774, R = 0.0462 and wR = 0.0981. The molecular structure is a centrosymmetric conformation, and two ligands are symmetrically located on both sides of the Mn atom. The manganese atom is surrounded by two nitrogen atoms from ligands, two chlorine atoms and two oxygen atoms from water molecules to form a slightly distorted octahedral geometry.

Hydrothermal Synthesis and Crystal Structure of Complex Mn_2(phen)_2(p-MBA)_4(H_2O)

A novel Mn（Ⅱ） complex Mn2（phen）2（p-MBA）4（H2O） has been hydrothermally synthesized by the reaction of p-methyl benzoic acid （p-MBA） with 1,10-phenanthroline （phen）. Crystal data for this complex： monoclinic, space group C2/c, a= 2.3328（3）, b =1.5549（2）, c = 1.5557（2） nm, β = 121.726（2）°, V= 4.7997（11） nm^3, Mr = 1028.85, Dc = 1.424 g/cm^3, Z = 4, F（000） = 2128, μ（MoKa） = 0.590mm^-1, GOOF = 1.060, R = 0.0333 and wR = 0.0767. In the crystal, each Mn（Ⅱ） ion is coordinated by two nitrogen atoms from one o-phenanthroline molecule, three oxygen atoms from three p-methyl benzoic acids and one oxygen atom from one water molecule, giving a six-coordinate distorted octahedral coordination geometry. Two neighboring Mn（Ⅱ） ions are bridged by two p-methyl benzoic acid groups and one water molecule, and their end positions are respectively coordinated by one 1,10-phenanthroline and one p-methyl benzoic acid molecule, giving a binuclear cage structure, of which the Mn（Ⅱ）…Mn（Ⅱ） distance is 0.3502 nm.

Synthesis,Crystal Structure and Luminescent Properties of a Mn(Ⅱ) Complex Constructed from 2,2'-Bibenzimidazole

A new complex associated with Mn ion,[Mn（Hbibm）（SO4）]·0.5H2O（1,Hbibm= 2,2＇-bibenzimidazole）,was prepared under solvothermal conditions,and characterized by single-crystal X-ray diffraction,elemental analysis and IR spectra.The complex belongs to the triclinic system,space group P1 with a=8.9250（5）,b=12.8022（8）,c=13.3505（8）,α=66.614（2）,β= 72.567（2）,γ=80.627（2）°,V=1334.1（1）3,Z=1,Dc=1.565 g/cm3,S=0.996,μ=0.628 mm-1,F（000）=644,R=0.0447 and wR=0.0586 for 5155 observed reflections（Ⅰ〉 2σ（Ⅰ））.Complex 1 is a mononuclear Mn（II） complex.The π-π interactions and interchain hydrogen-bonding interactions further extend the mononuclear for 1,generating a 3D supramolecular architecture.Complex 1 shows strong blue fluorescent emissions in the solid state upon 395 nm photo-excitation at room temperature.

Synthesis of Nonionic Oligomeric Manganese(Ⅱ) Complexes and Investigation of Their Toxicity andΤ_1-Relaxation Enhancement

Six nonionic oligomeric manganese （ Ⅱ ） complexes with oligomeric phosphate-polyglycol-EDTA ester ligands were synthesized and characterized. The longitudinal relaxivities of these complexes were measured. One of these complexes, which showed the highest relaxivity, was chosen to be used in the acute toxicity test and the T1-weighted imaging experiment. It has been found that compared to Gd-DTPA, this nonionic oligomeric Mn（ Ⅱ ） complex exhibits no acute toxicity, generates highly enhanced MRI signals and increases the intention time in the rat liver tissue.

Syntheses, Crystal Structures and Antibacterial Activities of Cobalt(Ⅱ) and Manganese(Ⅱ) Complexes with Schiff Base Ligand Derived from Tryptamine

Two new mononuclear complexes, namely [Co（L）2]（1） and [Mn（L）2]（2）（HL = N-（3-methylsalicylidene）tryptamine）, have been synthesized by the reactions of the ligand with cobalt acetate or manganese acetate in anhydrous ethanol. The crystal structures of the complexes were characterized by IR spectrum, elemental analysis, PXRD and single-crystal X-ray diffraction analysis. Complex 1 crystallizes in monoclinic, space group C2/c, with a = 23.146（2）, b = 9.4864（10）, c = 13.9261（15）A, β = 102.898（2）°, V = 2980.6（5） ？3, Z = 4, Dc = 1.367 g/cm3, F（000） = 1284 and μ = 0.616 mm^-1. Complex 2 crystallizes in monoclinic, space group P21/n, with a = 14.807（11）, b = 13.118（10）, c = 16.663（13） A, β = 111.237（14）°, V = 3017（4） A^3, Z = 4, Dc = 1.342 g/cm^3, F（000） = 1276 and μ = 0.477 mm-1. The units of complex 1 are linked by intermolecular N–H…π hydrogen bonds into infinite 1D chains, which are further extended into a 3D supramolecular structure by a series of π···π stacking interactions. The units of complex 2 are linked by intermolecular N–H…π hydrogen bonds and C–H…π hydrogen bonds into an infinite 3D supramolecular structure. Meanwhile, the antibacterial activities of the ligand and its complexes have been tested against four kinds of bacteria. The results show that the three compounds all have excellent antibacterial activities and that 1 and 2 possess stronger inhibiting effects against the bacteria than the Schiff base.

Artificial Mn4-oxido complexes mimic the oxygen-evolving center in photosynthesis

The understanding of the structure-function relationship of the oxygen-evolving center(OEC), a Mn_4 Cacluster, in photosystem II is impeded mainly due to the complexity of the protein environment and lack of rational chemical models as a reference. In this study, two novel Mn_4-oxido complexes have been synthesized and characterized, in which the peripheral ligands of the [Mn_4~Ⅲ] core are provided by eight μ_2-carboxylate groups and two neutral terminal ligands(pyridine or isoquinoline). This type of peripheral ligation is very similar to the Mn_4Ca-oxide model complexes recently reported to mimic the OEC. The new Mn_4-oxide complex can catalyze the oxygen-evolving reaction in the presence of Bu^tOOH as an oxidant. The structure and redox properties comparison of the Mn_4-oxido and Mn_4Ca-oxido complexes provide important clues to understanding the functional role of Ca in the OEC in natural photosynthesis, and develop more efficient artificial catalysts for the water-splitting reaction in the future.

Hydrothermal Synthesis, Crystal Structure and Luminescence Property of a 2D Manganese(Ⅱ) Coordination Polymer

Solvothermal reactions of MnCl_2·4H_2O with(pyridin-2-yl)methyl 4-(2-(4-((pyridin-2-yl)methoxy)phenyl)diazenyl)benzoate(L1) via an in situ ligand transformation reaction produced a new coordination polymer, {[Mn_(2.5)Cl_3L_2(H_2O)]·H_2O}_n(1, where HL = 4-(2-(4-((pyridin-2-yl)methoxy)phenyl)diazenyl)benzoic acid). The L1 ligand was decomposed in situ to L^- which was coordinated with Mn(Ⅱ) to form compound 1 in the solvothermal synthesis process. Complex 1 was characterized by IR spectroscopy, powder X-ray diffraction and single-crystal X-ray diffraction.Compound 1 possesses a 2D network. In addition, stability and photoluminescent property of 1 were also investigated.

Synthesis,Crystal Structure and Theoretical Calculations of a Manganese(Ⅱ) Coordination Polymer Assembled by 2,5-Thiophenedicarboxylic Acid and 3-(2-Pyridyl)pyrazole Ligands

A new Mn（Ⅱ） complex, [Mn_（0.5）（tdc）0.5（L）]2n（1, H2 tdc = 2,5-thiophenedicarboxylic acid, L = 3-（2-pyridyl）pyrazole）, has been successfully synthesized under hydrothermal conditions. Its structure has been determined by single-crystal X-ray diffraction analysis, elemental analyses, IR, TG and UV spectrum. Single-crystal X-ray diffraction analysis reveals that complex 1 belongs to the orthorhombic system, space group Pnna with a = 11.5184（6）, b = 16.8399（8）, c = 11.7249（5） A^°, V = 2274.26（19） A^°^3, Z = 4, D3c = 1.505 g/cm^3, μ = 0.715 mm^-1, Mr = 515.41, F（000） = 1052, the final R = 0.0336 and w R = 0.0802 with I 〉 2σ（I）. It exhibits a one-dimensional zigzag-chain structure, which was stabilized through intermolecular C–H…O and intramolecular N–H…O hydrogen bonding interactions. Moreover, we analyzed Natural Bond Orbital（NBO） by using the PBE0/LANL2 DZ method built in Gaussian 09 Program. The calculation results showed obvious covalent interaction between the coordinated atoms and Mn（Ⅱ） ion.

A New Mn(Ⅱ) Complex Assembled by 2,5-Dihydroxy-1,4-benzenedicarboxylic Acid and 2,2΄-Bipyridine: Synthesis, Structure and Theoretical Calculation

A new complex[Mn(DHTA)(bipy)0.5]n(1,H2DHTA=2,5-dihydroxy-1,4-benzenedicarboxylic acid,bipy=2,2΄-bipyridine)was hydrothermally synthesized and structurally characterized by elemental analysis,IR spectrum,single-crystal and power X-ray diffraction.It belongs to monoclinic system,C2/c space group with a=12.874(13),b=11.302(12),c=17.352(18)Å,β=101.574(15)°,V=2474(4)Å3 and Z=4.It displays a one-dimensional zigzag chain-like structure,which was further extended into a three-dimensional supramolecular structure by hydrogen bonds andπ-πinteractions.Moreover,we analyzed Natural Bond Orbital(NBO)of 1 in using the PBE0/LANL2DZ method built in Gaussian 03 Program.The calculation results show the obvious covalent interaction between the coordinated atoms and Mn(Ⅱ)ion.