Structure and Magnetic Properties of a Manganese Complex with 1-Carboxymethylpyridinium-3-carboxylate

One complex with a zwitterionic dicarboxylate ligand, [Mn（L）（N3）]n 1 （L = 1-car- boxymethylpyridinium-3-carboxylate）, was synthesized and structurally characterized. Complex 1 crystallizes in triclinic, space group P1 with a = 7.570（2）, b = 7.808（2）, c = 9.232（3） A, β= 94.450（19）°, V= 489.0（3） A3, Z = 2, Mr = 277.11, Dc = 1.882 g/cm3, F（000） = 278,μ = 1.359 mm-1, S = 1.021, the final R = 0.0509 and wR = 0.1149 for 2236 observed reflections with 1 〉 2σ（I）. Complex 1 consists of two-dimensional coordination layers in which the anionic uniform chains with mixed triple bridges （one end-on （EO） azide and two syn-syn carboxylates） are cross-linked by the flexible cationic N-methylpyridinium spacers. Magnetic studies demonstrated that the triple bridge in 1 transmits antiferromagnetic coupling between the Mn（Ⅱ） ions.

Synthesis and Crystal Structure of a Mixed-Valence Trinuclear Manganese Complex: Mn_3O(O_2CPh)_6(Py)_3

A new mixed-valence oxo-centered trinuclear manganese complex Mn3O(O2CPh)6 (Py)3 was prepared in pyridine solvent and its crystal structure has been determined. C57H45O13N3Mn3, Mr =1144. 81, trigonal, space group R3,(No.148), unit cell parameters(H cell): a=b=43. 605 (7), c=15. 756(4), V =25946(10),Z=18, Dc=1.32 g/cm￣3 , F(000) = 10566.The final values of R and Rw are 0. 098 and 0. 087 respectively for 3087 observed reflections with Ⅰ>4σ(Ⅰ). The distances of Mn(1)-O(1), Mn(2)-O(1) and Mn(3)-O(1) are 1.855(10),1. 817(8) and 2. 089 (8), respectively, indicating the title compound is a valence-trapped situation.

Synthesis, oxygenation and catalytic performance of manganese complex with p-aminomethyl benzoic acid Schiff base

The amino acid Schiff base complex (Sal-AMBA-Mn) was prepared with p-amino-methylbenzoic acid, salicylaldehyde and Mn(OAc)2·4H2O. Its structures was characterized with IR and UV spectra. Oxygenation mechanism of the complex in N, N-dimethylformamide solution was investigated. The results show that lower temperature is in favor of the oxygenation, and energy, enthalpy and entropy are -3.8 kJ/mol, -4.2 J/mol and -161.44 J/(mol·K), respectively. In the presence of the manganese complex, dehydroepiandrosterone acetate is effectively oxidized by molecular oxygen and the corresponding enone 7-ketodehydroepiandrosterone acetate is obtained. The yield is 62.1% when the oxidation is carried out under the reaction conditions of 60 ℃, 2 MPa of O2 pressure, C5H5N as a solvent and molar ratio of the substrate to the complex of 1:10.

Hydrothermal Synthesis and Crystal Structure of a Manganese Complex

The title compound [Mn（Phen）（p-MBA）2]n（1） was synthesized via the hydro-thermal reaction of KMnO4 and NaOH with phen and p-methybenzoic acid（p-MBA） in water.The title compound was characterized by elemental analysis and infrared spectra.The crystal of 1 crystallizes in orthorhombic,space group Pbcn with a = 24.132（1）,b = 10.404（0）,c = 9.386（0） ,V = 2356.65（13） 3,Z = 4,C28H22MnN2O4,Mr = 505.42,Dc = 1.424 g/cm3,F（000） = 1044 and μ（MoKα） = 0.598 mm-1.The final R = 0.0781 and wR = 0.1363 for 1972 observed reflections with Ⅰ 〉 2σ（Ⅰ） and R = 0.0897 and wR = 0.1420 for all data.X-ray diffraction reveals that the Phen and p-methy benzoic acid ligand link the Mn atoms into a single one-dimensional coordination polymer,and extensive intermolecular π-π interactions lead these 1D chains to form a two-dimensional supramolecular architecture.

Crystal Structure and Spectrum Properties of a Manganese Complex with Schiff Base Ligand,Mn (bzacen) (pyrimidine) (NCS)

The title complex C_(27)H_(26)MnN_5O_2S (M_r= 539. 53 ) crystallizes in monoclinic system, space group P2_1/α with α = 8. 357 (2) A, b = 19. 077 (4) A . c = 16. 267(3) A, β=95. 85(2)°, V=2580(2) A￣3, Z=4, F(000) = 1120, D_c= 1. 39 g/ cm￣3 and μ=0. 601 mm￣(-1)(MoKα). The final R and R_w are 0. 0638 and 0. 0876, respectively. The coordination geometry around Mn atom is a distorted octahedron with a equatorial plane N_2O_2 from the Schiff base ligand bzacen￣(2-), the axial atoms being two nitrogen atoms from a thiocyanate and a pyrimidine ligand. The shifts of v_c=N, v_c=O and v_c=C to lower frequencies in IR and Raman spectra indicate that the ligand bzacen￣(2-) has been coordinated to Mn atom through its nitrogen and oxygen atoms. The lines assigned to Mn-O and Mn-N vibrations were found in Raman spectrum. There is π～π￣* transition, d～π￣* charge-transfer transitions and d～d￣* transitions in electronic spectrum. The current potential curve in acetontrile reveals that Mn(Ⅲ)is in stable valence state.

Synthesis and Crystal Structure of a Mixed-ligand Manganese(Ⅱ) Complex Containing Abundant Hydrogen-bonding Interactions

A new mixed-ligand Mn（II）complex,namely [Mn（bipy）2（Huca）]·5H2O（1,bipy = 2,2＇-bipyridine,and H3uca = uracil-5-carboxylic acid）has been prepared and characterized by single-crystal X-ray diffraction,FT-IR spectroscopy and thermogravimetric analysis.It crystallizes in monoclinic,space group C2/c with a = 23.597（8）,b = 16.434（5）,c = 15.531（6）,β = 112.785（6）o,C25H28MnN6O9,Mr = 611.47,V = 5553（3）3,Z = 8,μ = 0.538,Dc = 1.463 g/cm3,F（000）= 2536,R = 0.0441 and wR = 0.1230 for all 5227 observed reflections（I 2σ（I））.The manganese（II）center is surrounded by three bidentate chelating ligands,and it displays a severely distorted octahedral geometry,with cis angles ranging from 72.14（6）to 109.78（6）o.Extensive intermolecular hydrogen bonds link the [Mn（bipy）2（Huca）] monomers and lattice water molecules to yield a three-dimensional supramolecular framework.TGA shows complete removal of all lattice water molecules above 270 ℃.

Synthesis, Structure and Catalytic Activity of a Manganese(Ⅲ) Complex Based on 2-(2-Hydroxyphenyl)-5,6-dichlorobenzimidazole Ligands

A new ligand, 2-（2-hydroxyphenyl）-5,6-dichlorobenzimidazole, H2pbmCl2（1）, and a novel MnIII complex, [MnIII（HpbmCl2）（pbmCl2）（DMF）2]（2）,（DMF = N,N-dimethylformamide）, have been synthesized and characterized. The crystal of compound 1（C13H8Cl2N2O, Mr = 279.12） belongs to the monoclinic system, space group P21 with a = 3.770（5）, b = 25.20（3）, c = 5.865（7） A, = 92.727（17）o, V = 556.6（12） A3, Z = 2, Dc = 1.665 g/cm^3, S = 1.137, μ= 0.568 mm^-1, F（000） = 284, the final R = 0.0876 and wR = 0.2334 for 1848 independent reflections. The molecule is planar due to the presence of a strong intramolecular hydrogen bond between O–H group of phenol and N atom of imidazole. H2pbmCl2（1） molecules are arranged into a one-dimensional linear chain through intermolecular hydrogen bonds（N–H…O and C–H…Cl）. The crystal of complex 2（C32H27Cl4MnN6O4, Mr = 756.34） belongs to the monoclinic system, space group P21/c with a = 19.043（10）, b = 10.808（5）, c = 18.704（11）A, β= 115.540（6）°, V = 3473（3） A3, Z = 4, Dc = 1.446 g/cm^3, S = 1.3, μ = 0.733 mm-1, F（000） = 1544, the final R = 0.1219 and wR = 0.2681 for 7811 independent reflections. The Mn ion adopts a distorted octahedral geometry coordinated by two deprotonated H2pbmCl2 ligands and two DMF molecules. The [MnIII（HpbmCl2）（pbmCl2）（DMF）2] molecules are arranged into a three-dimensional structure through hydrogen bonds（N–H…N, C–H…N and C–H…Cl） and weak π···πinteractions. The activity measurements suggest that complex 2 is able to serve as a catalyst for H2O2 disproportionation reaction to form O2 in neutral water solution.

Synthesis, Crystal Structure, Fluorescence, Thermal Stability and Magnetic Properties of the Dinuclear Manganese(Ⅱ) Complex [Mn_2(L)_2(2,2'-bipy)_2(H_2O)_5]_2·3H_2O

A new dinuclear manganese complex [Mn2（L）2（2,2＇-bipy）2（H2O）512·3H2O has been synthesized with MnSO4·H2O, 2,2＇-bibenzoic acid （H2L） and 2,2＇-bipyridine（2,2＇-bipy） in the mixed solvent ethanol and water. It crystallizes in monoclinic, space group Pi with a = 9.9944（10）, b = 21.939（2）, c = 25.628（3） A, a = 108.429（3）, β = 100.613（4）, 7 = 102.821（3）°, V = 4997.9（9） A3, Dc= 1.355 g/cm^3, Z = 2, F（000） = 2108, GOOF = 1.074, the R= 0.0626 and wR= 0.1531. The structure of the complex contains two [Mn2（L）2（2,2＇-bipy）2] units, ten coordinated H2O molecules and three uncoordinated H2O molecules. The fluorescence, thermal stability and magnetic properties of the complex were investigated.

Synthesis and Crystal Structure of a Spiral-chain Manganese(Ⅲ) Complex Containing Azide Bridge,[Mn(bzan)N_3]_n

The title complex, C22H22MnN5O2, crystallizes in orthorhombic system, space group P212121 with a = 6.887(1), b = 11.718(2), c = 25.721(5) ? V = 2075.7(7) 3, Z = 4, Mr = 443.39, F(000) = 920, Dc = 1.419 g/cm3 and m = 0.665mm-1 (MoKa). The structure was refined to R = 0.0593 and wR = 0.1427 for 3576 observed reflections with I ≥ 2s(I). The Mn(Ⅲ) atom is coordinated to one bzan2- [bzan2- = N, N-ethylenebis(benzoylacetoneiminato)] ligand binding in the equatorial mode and two N3- ions in the axial positions. The azide acts as a trans--(1, 3) bridge, resulting in an infinite helical chain propagating along the b axis.

Synthesis and Crystal Structure of a New Dinuclear Manganese(Ⅱ) Manganese(Ⅲ) Complex of a Macrocyclic Ligand

A mixed-valence dinuclear manganese complex, [Mn ⅡMn ⅢL](ClO 4)·1/2MeOH, where L is a macrocyclic ligand derived from the cyclocondensation of sodium 2,6-diformyl-4-methylphenolate with N,N-bis(2-aminoethyl)-2-hydroxybenzyl amine, was obtained and its structure was determined by X-ray diffraction. The orange crystal is a monoclinic system with space group P2 1/c and lattice parameters a=1.1617(4), b=1.4005(3), c=1.4641(3) nm, β=113.03(2)°, and Z=2. The crystal structure shows that each pendant-arm is bonded in a bidentate fashion to the adjacent metal atom and that both the arms are on the same side of the macrocycle. The two Mn atoms are bridged by two μ 2-phenoxy oxygen atoms of the tetra-imine macrocycle, and each Mn atom, locating in a trigonal prismatic coordination environment(N 3O 3), is six-coordinated by the two imine nitrogen atoms, one tertiary nitrogen atom and a pendant phenol moiety apart from the two oxygen atoms.

Molecular and Supramolecular Structures of Manganese(Ⅱ) and Cobalt(Ⅱ) Complexes with 1-Carboxymethylpyridinium-4-carboxylate

Two complexes with a zwitterionic dicarboxylate ligand,Mn（L）2（H2O）4 1 and Co（L）2（H2O）4 2（L = 1-carboxymethylpyridinium-4-carboxylate）,were synthesized and structurally characterized.Complex 1 crystallizes in monoclinic,space group P21 with a = 6.490（2）,b = 19.210（7）,c = 7.813（3） ,β = 92.716（5）o,V = 972.9（6） 3,Z = 2,Mr = 487.28,Dc = 1.663 g/cm3,F（000） = 502,μ = 0.749 mm-1,S = 1.060,the final R = 0.0377 and wR = 0.0893 for 3292 observed reflections with I 2σ（I）.Complex 2 is isomorphous with 1,with a = 6.478（2）,b = 19.052（7）,c = 7.742（3） ,β = 92.690（4）o,V = 954.6（6） 3,Z = 2,Mr = 491.28,Dc = 1.709 g/cm3,F（000） = 506,μ = 0.971 mm-1,S = 1.035,the final R = 0.0425 and wR = 0.0809 for 3289 observed reflections with I 2σ（I）.In the compounds,the mononuclear [M（L）2（H2O）4] units with trans-octahedral coordination geometry are linked into 3D architectures via hydrogen bonding（or second-sphere coordination） involving carboxylate groups and coordinated water molecules.The 3D networks illustrate a 3,8-connected net with Schlfli symbol（4·62）2（42·623·83）.

Theoretical and experimental investigations of the enantioselective epoxidation of olefins catalyzed by manganese complexes

The enantioselective epoxidation of olefin by Mn^(II)(R,R-PMCP)(OTf)2, H_(2)O_(2) and H_(2)SO_(4) was explored by DFT calculations and experiments. Theoretical results suggest that [Mn^(V)(O)(R,R-PMCP)(SO_(4))]^(+) species with a triplet ground spin state serves as the active species for the olefin epoxidation. It can be generated by the H_(2)SO_(4) assisted O-O heterolysis of Mn^(III)(OOH) species. Mn^(III)-persulfate is also involved in this system, but it cannot promote the olefin epoxidation directly, preferring instead to transform into Mn^(V)(O). Actually, the asymmetric epoxidation reactions with H_(2)O_(2)/H_(2)SO_(4) or Oxone provide similar enantioselectivity in the presence of manganese catalyst. These observations further support the transformation of Mn^(III)-persulfate to Mn^(V)(O) species.

Solvothermal Synthesis and Crystal Structures of Two Manganese Complexes [Mn（Ⅱ）（acac-）2（4,4＇-bipy）]n （bipy-4,4＇-bipyridine） and [Mn（Ⅲ）（acac-）3].4CO（NH2）2

Two special manganese complexes [Mn（II）（acac ）2（4,4＇-bipy）]n （bipy=4,4＇-bipyridine） （complex 1） and [Mn（II1）（acac-）3].4CO（NH2）2 （acacH=acetylacetone） （complex 2） were synthesized in the same strategy by sol- vothermal method. Single crystal X-ray diffraction revealed the complex 1 consists of one-dimensional infinite coordination chain, with the manganese centers bridged by 4,4＇-bipy. And free carbamides of complex 2 connect with each other through the hydrogen bonds to form a 14-membered carbamide ring and a zig-zag plane. Both enantiomers of Mn（III）（acac ）3 exist in the structure, forming a racemate. Furthermore, these enantiomers and those zig-zag planes are linked with hydrogen bonds to form an unique spatial network.

Synthesis and Structure of a Manganese(Ⅱ) Complex: [Mn_2·(dinitrobenzoic acid)_4·(1,10-phen)_2]_n

The title compound, [Mn2·（dinitrobenzoic acid）4·（1,10-phen）2]n, has a linear chain structure containing binuclear [Mn2·（dinitrobenzoic acid）4（1,10-phen）2] repeat units. It crystallizes in the triclinic system, space group Pi with a = 7.9261（8）, b = 12.1329（15）, c = 14.847（2）A, α = 103.845（5）, β = 101.424（5）, γ = 92.618（4）°, Mr= 657.37, V = 1352.3（2）A^3, Z = 2, De= 1.614 g/cm^3, F（000） = 666,μ = 0.567 mm^-1, the final R = 0.0407 and wR = 0.1015 for 4081 observed reflections with I 〉 2σ（I）. The Mn atom is six-coordinated by two N and four O atoms, forming a slightly distorted octahedral geometry. All Mn-O and Mn-N bond distances range from 2.093（2） to 2.310（2）A. Two adjacent octahdral units are bridged together by two pairs of bi-monodentate carboxyl groups of different dinitrobenzoic acids to form an eight-membered ring with chair-typed configuration, thus generating a one-dimensional chain along the a axis.

Synthcsis, Structure and Magnetochemistry of a New Hexanuclear Manganese Oxide Complex of the Formula [Mn_6O_2 (O_2CPh)_(10)(CH_3CN)_4]

The reported X-ray structure and magnetochemical properties of [Mn6O2 (OCPh)10, (CH3CN)4], effectively derived from [NBu4][Mn4O2(O2CPh)9 (H2O)] with equivalent of tren in CH3CN is shown.

Synthesis and Crystal Structure of a Bimetallic Cyanide-bridged Complex Derived from Manganese(Ⅲ) Schiff-base Complex and Pentacyanidonitrosylferrate(Ⅱ) Building Blocks

A new cyanide-bridged bimetallic assembly [Mn（3-meosalpn）（H2O）]2[Fe（CN）5NO]（1） was obtained by the reaction of [Fe（CN）5NO]2-with [Mn（3-meosalpn）]＋,and characterized by elemental analysis,IR and single-crystal X-ray structure analysis.The complex crystallizes in the monoclinic system,space group P21/c with a = 12.992（5）,b = 13.274（6）,c = 14.644（6） ,β = 115.198（4）o,V = 2285.2（16）3,Z = 2,C43H44FeMn2N10O11,Mr = 1042.61,Dc = 1.515 g/cm3,F（000） = 1072,μ = 0.928 mm-1,S = 1.052,the final R = 0.0347 and wR = 0.0957 for 17377 observed reflections（Ⅰ 〉 2σ（Ⅰ））.X-ray single-crystal diffraction analysis reveals that 1 has a trinuclear molecular structure,in which the two [Mn（3-meosalpn）（H2O）]＋ cations are linked by the central [Fe（CN）5NO]2-anion via two trans CN-groups.Furthermore,the two [Mn（3-meo-salpn）（H2O）]＋ cations and [Fe（CN）5NO]2-anion are connected into a one-dimensional zigzag chain through hydrogen bonding interactions.

Synthesis and Structure of a Manganese(Ⅱ) Complex [Mn·(p-Methoxybenzoato)_2·(2,2'-bipy)·H_2O]·(p-methoxybenzoic Acid)

The title compound, {[MnL2·（2,2＇-bipy）-H2O]-（HL）}, has been synthesized （HL = p-methoxybenzoic acid, 2,2＇-bipy = 2,2＇-bipyridine） by the reaction of MnCl2-6H2O with p-methoxybenzoic and 2,2＇-bipyridine in an alcohol-water solution. It crystallizes in the tricfinic system, space group PI with α = 10.1138（5）, b = 11.2811（5）, c = 16.2210（8） A, α = 77.5920（10）,β = 72.1890（10）, γ = 66.2320（10）°, Mr = 683.56, V=1603.65（13） A3, Z= 2, Dc = 1.416 g/cm^3, F（000） = 710,μ = 0.473 mm^-1, the final R = 0.0619 and wR = 0.1571 for 4724 observed reflections with I 〉 20（I）. The structure determined demonstrated that it is an isomeric modification of the structure reported before. The Mn atom is six-coordinated by two N and four O atoms, forming a distorted octabedral geometry. All Mn-O and Mn-N distances range from 2.113（3）-2.410（3） A. There also exists a dissociative p-methoxybenzoic acid beside the octahedron.

Synthesis, Crystal Structure and Theoretical Calculation of a Novel 2D Network of Manganese(Ⅱ) Complex

A novel complex, [Mn（2-NCP）（H2BTC）（H2O）]n（1, 1,3,5-H3BTC = 1,3,5-benzenetricarboxylic acid, 2-HNCP = 2-（2-carboxyphenyl）-1 H-imidazo（4,5-f）-（1,10）phenanthroline）, was hydrothermally synthesized and structurally characterized by elemental analysis, IR, XRD and single-crystal X-ray diffraction. Structural analyses reveal that complex 1 exhibits a（6, 6）-connected topology network with a Schl?fli symbol of（63）. The adjacent 2 D layers are further stacked via strong hydrogen-bonding interactions, giving a 3 D supramolecular framework. In addition, the structure of complex 1 was calculated by the B3LYP/LANL2 DZ method by Gaussian program. The results from natural bond orbital（NBO） analysis shows obvious covalent interaction between the coordinated atoms and Mn（Ⅱ） ion.

Hydrothermal Synthesis and Crystal Structure of a New Manganese(II) Complex with 2,4-Pyridine-dicarboxylic Acid and 2,2′-Bipyridine Ligands

A new metal-organic complex [Mn2（PDC）2（bipy）2（H2O）2] （H2PDC = 2,4-pyridine-dicarboxylic acid, bipy = 2,2′-bipyridine） 1 has been hydrothermally synthesized and structurally characterized by elemental analysis, IR spectrum, TG and single-crystal X-ray diffraction. The compound crystallizes in triclinic, space group P ^-1 with a = 7.376（3）, b = 9.990（4）, c = 11.950（5） A^°, α= 75.217（5）, β = 78.052（5）, γ = 70.655（5）°, V = 796.0（5）A^°3, C34HE6Mn2N6O10, Mr = 788.49, De = 1.645 g/cm^3,μ（MoKa） = 0.866 mm^-1, F（000） = 235, Z = 1, the final R = 0.0425 and wR = 0.0700 for 1971 observed reflections （I 〉 2σ（I））. In the crystal structure, the manganese atom is six-coordinated by two carboxylate oxygen atoms from two different PDC ligands, one aqua ligand, and three nitrogen atoms from 2,2′-bipy and PDC ligands, giving a distorted octahedral geometry. It exhibits a three-dimensional supramolecular network defined by O-H…O hydrogen-bonding interactions.

Hydrothermal Synthesis and Crystal Structure of a Manganese(Ⅱ) Complex:Mn_(1.5)(cbba)_3(phen)

A new metal-organic complex Mn1.5（cbba）3（phen）（Hcbba = 2-（4＇-chlorine-ben-zoyl）benzoic acid,phen = 1,10-phenanthroline） 1 has been hydrothermally synthesized and struc-turally characterized by single-crystal X-ray diffraction,elemental analyses,TG and IR spectro-scopy.The compound crystallizes in triclinic,space group P1 with a = 12.137（2）,b = 14.535（3）,c = 14.894（3）,α = 86.380（3）,β = 70.381（3）,γ = 72.647（3）°,V = 2360.3（8）3,C107H64Cl6Mn3N4O18,Mr = 2071.14,Dc = 1.457 g/cm3,μ（MoKα） = 0.638 mm-1,F（000） = 1055,Z = 1,the final R = 0.0638 and wR = 0.1905 for 6155 observed reflections（I 2σ（I））.It exhibits a 3D supramolecular network through hydrogen bonding and π-π stacking interactions.