[Mn12O12(O2CMe)12(NO3)4(H2O)4]: facile synthesis of a new type of Mn12 complex

The title dodecanuclear Mn complex, namely dodeca‐μ₂‐acetato‐κ²⁴O:O′‐tetraaquatetra‐μ₂‐nitrato‐κ⁸O:O′‐tetra‐μ₄‐oxido‐octa‐μ₃‐oxido‐tetramanganese(IV)octamanganese(III) nitromethane tetrasolvate, [Mn₁₂(CH₃COO)₁₂(NO₃)₄O₁₂(H₂O)₄]·4CH₃NO₂, was synthesized by the reaction of Mn²⁺ and Ce⁴⁺ sources in nitromethane with an excess of acetic acid. This compound is distinct from the previously known single‐molecule magnet [Mn₁₂O₁₂(O₂CMe)₁₆(H₂O)₄], synthesized by Lis [Acta Cryst. (1980), B 36 , 2042–2044]. It is the first Mn₁₂‐type molecule containing nitrate ligands to be directly synthesized without the use of a preformed cluster. Additionally, this molecule is distinct from all other known Mn₁₂ complexes due to intermolecular hydrogen bonds between the nitrate and water ligands, which give rise to a three‐dimensional network. The complex is compared to other known Mn₁₂ molecules in terms of its structural parameters and symmetry.     

Preparation, Crystal Structure and Thermal Behaviour of a One-dimensional Coordination Polymer [Mn（m-CPOAH）2（H2O）2]n

1 INTRODUCTION Supramolecular chemistry of manganese(II) car- boxylate coordination polymers has been inten- sively studied in recent years, within which ligand design is an important aspect in adjusting the coordi- nation framework and functionalities of the complexes formed[1～4]. Carboxyphenoxyacetic acids (CPOAH2), which have been known to show biological activities and are widely used in agriculture, are a family of multidentate flexible ligands with versatile binding abilities. …     

一维链状高价锰配合物[Mn_2(C_7H_4O_3)_4(CH_3OH)_2]·4H_2O_2CH_3OH的合成与结构

合成了一维链状高价锰配合物[Mn2(C7H4O3)4(CH3OH)2]4H2O2CH3OH,并对其进行了IR、X-射线衍射、UV-Vis和TG-DSC等表征。单晶衍射结果表明,该配合物晶体属三斜晶型,空间群P?晶胞参数a=7.653(5),b=10.486(7),c=12.943(8),=103.24(1),?=104.55(1),?=110.11(1),V=885.4(9)3,Z=1。UV-Vis光谱在547nm有一个吸收峰,相应于Mn(Ⅳ)的d-d电子跃迁光谱。     

一个新颖镍配位阳离子修饰的还原型钼磷酸盐：Ni[Mo6O12(OH)3(PO4)(HPO4)3]2][Ni(H2O)2][Ni(H2O)(bipy)2]4·5H2O

水热合成并通过红外、热重、单晶X-射线衍射表征了一个新颖镍配位阳离子修饰的还原型钼磷酸盐,Ni[Mo₆O₁₂(OH)₃(PO₄)(HPO₄)₃]₂][Ni(H₂O)₂][Ni(H₂O)(bipy)₂]₄·5H₂O。单晶X-射线衍射研究表明,两个{Mo₆P₄}簇单元通过一个镍离子连接形成一个Ni[Mo₆P₄]₂二聚结构单元,其进一步和其他的镍配位阳离子连接成钼磷酸盐一维链状结构。在H₂O₂存在下的液－固体系中,使用该化合物催化氧化苯甲醛的探针反应结果表明,该化合物具有较高的催化氧化活性。     

[M(N3)2(H2O)2]⋅(bpeado): Unusual Antiferromagnetic Heisenberg Chain (M=Mn) and Ferromagnetic Ising Chain (M=Co) with Large Coercivity and Magnetic Relaxation (bpeado=1,2‐Bis(4‐pyridyl)ethane‐N,N′‐dioxide)

Contrasting magnetic properties : Two isostructural metal‐azido magnetic chains embedded in 3D threefold interpenetrated H‐bonded frameworks and separated by a long bpeado spacer have been assembled (see figure). Incorporation of Mn²⁺ displays a rarely observed antiferromagnetic Heisenberg chain, while incorporation of Co²⁺ displays a ferromagnetic Ising chain.

     

K4H2[SiW5Mo6Mn(H2O)O39]·22H2O的晶体结构

合成了一个锰硅钼钨四元取代含氧簇合物,用单晶X射线衍射方法测定了结构,该晶体属于四方晶系,空间群P4/mnc,a=14.119(3),c=12.496(4),V=2490.9(12)3,Mr=2862.70,z=2,Dc=3.817g*cm-3,μ=15.922mm-1,R=0.0462,wR=0.1232.锰硅钼钨阴离子中,中心SiO4四面体在C4轴的两个位置上是无序的.     

Unexpected proline coordination in the copper chain polymer [Cu(μ‐Cl)2(μ‐DL‐proline‐κ2O:O′)]1∞

In catena‐poly[copper(II)‐di‐μ‐chlorido‐μ‐proline‐κ²O:O′], [CuCl₂(C₅H₉NO₂)]_n, two symmetry‐independent metal cations adopt distorted octahedral coordination, typical for d⁹ Jahn–Teller systems. Each chloride bridge is involved in both a short and a very long interaction with a Cu^II centre. The centrosymmetric crystal structure contains homochiral chains of opposite handedness which extend along the shortest lattice parameter (i.e. a). The O:O′‐bridging coordination mode of proline, although a common motif for such complexes in general, is remarkable for Cu^II; the vast majority of amino acid derivatives of this cation are characterized by N,O‐chelation.     

Crystallographic report: catena‐Poly[aqua(phenyl‐1,3‐bisoxyacetato) tris(pyridine)cadmium(II)], [(H2O)(C5H5N)3 (O2CCH2OC6H4OCH2CO2)Cd]n

The [O₂CCH₂OC₆H₄OCH₂CO₂]^2? group bridges adjacent planar [(H₂O)(C₅H₅N)₃Cd]²⁺ units into a linear chain. The carboxyl groups occupy opposite sites in the octahedral environment of the cadmium atom. Copyright © 2004 John Wiley & Sons, Ltd.     

Synthesis, Crystal Structure and Magnetic Properties of Novel Three-dimensional Frameworks [Mn(PDC)H2O]n

A novel coordination polymer, [Mn(PDC)H2O]n (1) (H2PDC＝pyridine-2,3-dicarboxylic acid), has been hydrothermally synthesized and characterized by elemental analysis, IR and single crystal X-ray diffraction. X-ray single crystal structural analyses revealed that two-dimensional frameworks were formed, and further assembled into a three-dimensional supramolecular structure bridged by PDC ligands. Moreover, the magnetic study of complex 1 shows weak antiferromagnetic interaction between the neighboring Mn(II) centers within the chains and even weak ferromagnetic interactions between the Mn(II) centers in different chains.     

Synthesis and Structural Characterization of [Mn（phen）2（H2O）2]（OAc）2.6H2O

1 INTRODUCTION Water oxidation to oxygen gas by photo- synthetic apparatus of green plants and cyano- bacteria is the origin of this gas in the atmosphere. The water oxidation center is a tetranuclear, oxide- bridged manganese cluster with O,N-based peri- pheral ligation by amino acid side-chain group[1, 2]. The binding of aqua to the Mn site may be impor- tant to the oxidation of aqua for producing dioxygen. 1,10-Phenanthroline has been adopted to simulate coordination sphere of manga…     

A one‐dimensional coordination polymer formed from the reaction of 1,1‐diphenyl‐3,3′‐[(1R,2R)‐cyclohexane‐1,2‐diylbis(azanediyl)]dibut‐2‐en‐1‐one with MnCl2·4H2O

In the title coordination polymer, catena‐poly[[dichloridomanganese(II)]‐μ‐1,1‐diphenyl‐3,3′‐[(1R,2R)‐cyclohexane‐1,2‐diylbis(azaniumylylidene)]dibut‐1‐en‐1‐olate‐κ²O:O′], [MnCl₂(C₂₆H₃₀N₂)]_n, synthesized by the reaction of the chiral Schiff base ligand 1,1‐diphenyl‐3,3′‐[(1R,2R)‐cyclohexane‐1,2‐diylbis(azanediyl)]dibut‐2‐en‐1‐one (L) with MnCl₂·4H₂O, the asymmetric unit contains one crystallographically unique Mn^II ion, one unique spacer ligand, L, and two chloride ions. Each Mn^II ion is four‐coordinated in a distorted tetrahedral coordination environment by two O atoms from two L ligands and by two chloride ligands. The Mn^II ions are bridged by L ligands to form a one‐dimensional chain structure along the a axis. The chloride ligands are monodentate (terminal). The ligand is in the zwitterionic enol form and displays intramolecular ionic N⁺—H...O⁻ hydrogen bonding and π–π interactions between pairs of phenyl rings which strengthen the chains.     

一维链状2-氧-1(4H)-吡啶乙酸桥联钙配位聚合物[Ca(2-OPA)_2(H_2O)_2]_n的合成、晶体结构及热稳定性研究

由于吡啶乙酸及其衍生物具有多种的键合模式和广泛的生物学特性,近十年来由其与金属离子所形成的配合物研究已引起了人们的极大关注[1]。目前的研究多集中于过渡金属和稀土金属离子体系[2￣5],而对于主族金属离子所形成的配合物报道较少。镁钙离子在调节细胞壁的功能、控制半透     

MnIII2 (5-Rsaltmen)2NiII(pao)2(L)]2+: an S(T)=3 building block for a single-chain magnet that behaves as a single-molecule magnet

Mn(III)-Ni(II)-Mn(III) linear-type trinuclear complexes bridged by oximate groups were selectively synthesized by the assembly reaction of [Mn2(5-Rsaltmen)2(H2O)2](ClO4)2 (5-Rsaltmen2-=N,N'-(1,1,2,2-tetramethylethylene) bis(5-R-salicylideneiminate); R=Cl, Br) with [Ni(pao)2(phen)] (pao-=pyridine-2-aldoximate; phen=1,10-phenanthroline) in methanol/water: [Mn2(5-Rsaltmen)2Ni(pao)2(phen)](ClO4)2 (R=Cl, 1; R=Br, 2). Structural analysis revealed that the [Mn(III)-ON-Ni(II)-NO-Mn(III)] skeleton of these trimers is in every respect similar to the repeating unit found in the previously reported series of 1D materials [Mn2(saltmen)2Ni(pao)2(L1)2](A)(2) (L(1)=pyridine, 4-picoline, 4-tert-butylpyridine, N-methylimidazole; A=ClO4-, BF4-, PF6-, ReO4-). Recently, these 1D compounds have attracted a great deal of attention for their magnetic properties, since they exhibit slow relaxation of the magnetization (also called single-chain magnet (SCM) behavior). This unique magnetic behavior was explained in the framework of Glauber's theory, generalized for chains of ferromagnetically coupled anisotropic spins. Thus, in these 1D compounds, the [Mn(III)-ON-Ni(II)-NO-Mn(III)] unit was considered as an S(T)=3 anisotropic spin. Direct-current magnetic measurements on 1 and 2 confirm their S(T)=3 ground state and strong uniaxial anisotropy (D/k(B) approximately -2.4 K), in excellent agreement with the magnetic characteristic deduced in the study on the SCM series. The ac magnetic susceptibility of these trimers is strongly frequency-dependent and characteristic of single-molecule magnet (SMM) behavior. The relaxation time tau shows a thermally activated (Arrhenius) behavior with tau0 approximately 1x10(-7) s and Delta(eff)/k(B) approximately 18 K. The effective energy barrier for reversal of the magnetization Delta(eff) is consistent with the theoretical value (21 K) estimated from |D| S2T. The present results reinforce consistently the interpretation of the SCM behavior observed in the [Mn2(saltmen)2Ni(pao)2(L1)2](A)2 series and opens new perspectives to design single-chain magnets.     

Crystallographic report: A two‐dimensional layer structure containing calcium: [Ca3(1,3,5‐benzenetricarboxylate)2(H2O)12]n

In the crystal structure, an eight‐coordinated calcium center is connected to adjacent seven‐coordinated calcium ions by a pair of µ‐aqua bridging ligands, leading to the formation of a chain, which is linked via benzenetricarboxylate ligands to neighboring chains to furnish a two‐dimensional layer structure. Layers are connected into a three‐dimensional structure facilitated by hydrogen bonding interactions. Copyright © 2004 John Wiley & Sons, Ltd.     

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(III)(acac^?)₃]·4CO(NH₂)₂ (acacH=acetylacetone) (complex 2 ) were synthesized in the same strategy by solvothermal 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.     

Crystallographic report: Diiodo[tris(2‐pyridyl)amine]mercury(II), [(C5H4N)3N]HgI2

In mononuclear HgI₂[(C₅H₄N)₃N], mercury is tetrahedrally coordinated by two nitrogen atoms of a tris(2‐pyridyl)amine ligand and two iodides. The coordination moieties are connected by weak intermolecular Hg(II)···I interactions to give a one‐dimensional structure. Copyright © 2003 John Wiley & Sons, Ltd.