Synthesis,crystal structure and magnetism of a 1-D polymeric manganese(II) complex with pyrazine-2-carboxylate as bridging ligand

A one-dimensional chain complex {[Mn(pyz)(SCN)(H₂O)₂] · H₂O} (pyz = pyrazine-2-carboxylic anion) has been synthesized and its crystal structure determined by X-ray crystallography. In the complex each Mn ion is located in a distorted octahedral environment with two oxygen atoms O(3), O(4) from terminal ligands of two water molecules, another oxygen atom O(1) from the carboxylate group of pyz, and three nitrogen atoms N(1), N(2A) from two different pyz units and N(3) from the terminal ligand thiocyanate anion, in which a chelated five-membered ring is formed by coordination of O(1) and N(1) to the Mn(1) atom. Thus, an infinite zigzag chain consisting of Mn and pyz is constructed and the chains are linked together by hydrogen bonding from coordinated and uncoordinated water molecules, the sulfur atom of thiocyanate and the carboxylate oxygen of pyz. The variable-temperature magnetic susceptibility of the complex was measured in the 4–300 K range. The magnetic coupling parameter is consistent with an antiferromagnetic exchange between the two manganese(II) centers and the data fit a binuclear magnetic exchange model based on the Hamiltonian operator (H = –2JS ₁ S ₂, S ₁ = S ₂ = 5/2), giving the antiferromagnetic coupling parameter of 2J = –0.17 cm^–1. This is the first pyrazine-2-carboxylic anion bridging complex dealing with the magnetic interaction study.     

Synthesis,crystal structure and magnetism of a three-dimensional manganese(II) complex with carbamyldicyanomethanide anion (<Emphasis Type="Italic">cda</Emphasis>) as a bridging ligand

A three-dimensional complex {[Mn(cda)₂]·2MeOH}_n has been synthesized and its crystal structure determined by X-ray crystallography. In the complex each Mn ion is located in a distorted octahedral environment with two oxygen atoms O(1D) and O(1E) from two amide groups, and four nitrogen atoms N(2), N(2A), N(3B) and N(3C) from four nitrile groups of four cda anions, respectively; each cda anion as a ₃-bridging ligand provides two nitrile nitrogen atoms, and an amide oxygen atoms to coordinate three Mn ions. Thus, a three-dimensional network consisting of Mn ions and cda bridging ligands is constructed with solvent MeOH molecules trapped in the cavities. The variable-temperature magnetic susceptibility of the complex was measured in the 5–300K range. The magnetic coupling parameter is consistent with an antiferromagnetic exchange and generates the antiferromagnetic coupling parameter, 2J=–0.2cm^–1.     

Synthesis,crystal structure and magnetic properties of a novel manganese(II)-nitronyl nitroxide-azido(μ<Subscript>1,1</Subscript> and μ<Subscript>1,3</Subscript>) one-dimensional complex

A novel one-dimensional manganese(II) complex containing nitronyl nitroxide radical [Mn₂(IM2-py)₂(Ac)₂(μ_1,1-N₃)(μ_1,3-N₃) · EtOH] _n was synthesized and characterized structurally and magnetically. It crystallizes in the monoclinic space group p2₁/n. Each Mn(II) ion is six-coordinated in a distorted octahedral environment. The two N atoms of the nitronyl nitroxide radical and the two O atoms of acetate ligands are in the equatorial plane, whereas the two different azido bridging ligands are in trans axial position. Mn(II) ions are linked by nitrogen atom of μ_1,1-azido and oxygen atoms of two carboxy groups to form a Mn-Mn unit. Mn-Mn units are linked by azido ligands through μ_1,3 bridging style to form a one-dimensional chain. The compound is connected by the coordination bonds, π-π interactions and hydrogen bonds as a three-dimensional structure. Magnetic susceptibility data support that there are stronger antiferromagnetic interactions between the radical and Mn(II) ion, weak antiferromagnetic interactions between the Mn-R units, and very weak antiferromagnetic interactions between the R-Mn-Mn-R units.     

Synthesis, crystal structure and magnetic properties of a novel manganese(II)-nitronyl nitroxide-azido(μ_(1,1) and μ_(1,3)) one-dimensional complex

A novel one-dimensional manganese(Ⅱ) complex containing nitronyl nitroxide radical [Mn2(IM2-py)2(Ac)2((μ1.1-N3)(μ1,3-N3) . EtOH]n was synthesized and characterized structurally and magnetically. It crystallizes in the monoclinic space group p21/n. Each Mn(Ⅱ) ion is six-coordinated in a distorted octahedral environment. The two N atoms of the nitronyl nitroxide radical and the two O atoms of acetate ligands are in the equatorial plane, whereas the two different azido bridging ligands are in trans axial position. Mn(Ⅱ) ions are linked by nitrogen atom of μ1,1-azido and oxygen atoms of two carboxy groups to form a Mn-Mn unit. Mn-Mn units are linked by azido ligands through u1,3 bridging style to form a one-dimensional chain. The compound is connected by the coordination bonds,π-π interactions and hydrogen bonds as a three-dimensional structure. Magnetic susceptibility data support that there are stronger antiferromagnetic interactions between the radical and Mn(Ⅱ) ion, weak antiferromagnetic inter     

Synthesis,crystal structure and magnetic properties of [Mn(LH)2(H2O)2] n with a two-dimensional layered structure and three-dimensional hydrogen bonding network

A new manganese polymer [Mn(LH)₂(H₂O)₂] _n (LH₂ = iminodiacetic acid) (1) has been prepared and structurally and magnetically characterized. The polymer has a two-dimensional (2D) layered structure with the unique Mn atom on an inversion center, surrounded by six oxygen atoms. In each layer, all iminodiacetic acid entities are coordinated to Mn atoms in a bridging/bidentate mode, thus linking the [Mn(LH)₂(H₂O)₂] monomeric units together to form a 2D layered polymer. Hydrogen bonding is responsible for an extended three-dimensional network. Analysis of variable-temperature magnetic susceptibility data (2–300) K shows that the polymer displays weak antiferromagnetic exchange interaction with a coupling constant, J = –0.28 cm^–1.     

X-Ray Diffraction Study on Manganese(II) Complexes with Thiophene-2-Carboxylate and Furan-3-Carboxylate Ligands

Abstract

Mn(II) cations in the crystals of trisaquobis(μ-thiophen-2-carboxylato-O,O′)(thiophen-2-carboxylato-O)manganese(II) monohydrate are bridged by oxygen atoms donated by bidentate carboxylic groups of two thiophen-2-carboxylate ligands. In addition, each Mn(II) ion is coordinated by an oxygen atom of a monodentate carboxylic group of this ligand and three oxygen atoms of water molecules. The coordination around the Mn(II) cation is octahedral. The bridging of the ligands results in molecular ribbons propagating in the c-direction of the crystal held together by C?H…O hydrogen bonds. The crystal structure of diaquobis(μ-furan-3-carboxylato-O,O′)di(μ-furan-3-carboxylato-O,O)(μ-aqua-O)manganese(II) consists of dinuclear structural units. In each molecule Mn(II) cations are O,O′ bridged by oxygen atoms of bidentate carboxylic groups of two furan-3-carboxylate ligands and have a water located between the Mn cations. The units are O,O′ bridged to Mn(II) ions located in adjacent units by bidentate oxygen atoms, forming molecular ribbons extending in the c-direction. Octahedral coordination around each Mn(II) ion is completed by two water molecules. The octahedra around two adjacent metal ions in the unit share a common apex - the bridging oxygen atom of the water molecule. The ribbons are held together by C?H…O hydrogen bonds between furan ring oxygen atoms and the carbon atoms of adjacent furan rings.     

Synthesis and Structures of Two Thiocyanato-Lanthanoid Cages

Abstract  

The cages [{La₂(NCS)₅(NCMe)₆}₂O]·MeCN and [{Eu₂(NCS)₅(NCMe)₅}₂O]·MeCN have been prepared by redox transmetallation between the lanthanoid metals and mercuric thiocyanate in acetonitrile. The structure of the former has a core of four La atoms bonded to a central oxygen atom. Two La atoms are nine coordinate being bonded to oxygen, four terminal MeCN ligands and four N-bridged thiocyanato ligands, whereas the other two are eight coordinate being bonded to oxygen, the four bridging thiocyanato ligands, two terminal acetonitrile molecules, and a terminal N-bonded thiocyanate ion. In the Eu complex, there is a similar core of four Ln atoms bound to a central oxygen atom, but all Eu atoms are eight coordinate, and have four N-bridged thiocyanate ligands. Two have three MeCN ligands, whilst the other two have one terminal NCS⁻ and two acetonitrile ligands.     

Synthesis,Characterization and Crystal Structure of a One-Dimensional Chain Copper Bipyridine Complex Bridged Through an Azobispyridine Ligand

The copper complex {[Cu(2,2'-bpy)(azpy)(H₂O)(ClO₄)} _n 1 (2,2'-bpy=2,2'bipyridine, azpy=4,4'-azopyridine), has been synthesized and characterized. X-ray analysis reveals that copper is coordinated by two N atoms of 2,2'-bpy, two N atoms from two bridging azpy ligands, one O atom of coordinated water and O atom from ClO-₄ and has a distorted octahedral coordination environment in complex 1. Copper ions are linked to each other through bridging azpy ligands to form a one-dimensional chain. Stacking the one-dimensional chains results in the formation of rhombic channels with ca. 6Å x 6Å. Variable-temperature magnetic susceptibility studies show that there is a weak antiferromagnetic interaction between the copper ions.     

Synthesis, crystal structure and magnetism study on novel one-dimensional Cu(II) coordination polymers with 2,5-dimethylpyrazine-1,4-dioxide as bridging ligand

A novel one-dimensional coordination polymer [Cu(μ _1,6-dmpzdo)(dmpzdo)₂]·(ClO₄)₂ (dmpzdo = 2,5-dimethylpyrazine-1,4-dioxide) has been synthesized and its crystal structure determined by X-ray crystallography. In the complex each Cu1 atom is located in a square planar coordination environment with two oxygen atoms O2 and O2A from two dmpzdo terminal ligands, and two other oxygen atoms O3 and O3A from two μ _1,6-dmpzdo bridging ligands. The one-dimensional chain is constructed by the coordination of a μ _1,6-dmpzdo bridging ligand and Cu(II) ions. The data of the variable temperature (4–300 K) magnetic susceptibilities were fitted by using the one-dimensional chain fitting formula, which gave the magnetic coupling constants 2J = −98.88 cm⁻¹.     

Synthesis,Crystal Structure and Magnetic Property of [Mn2(mal)2(H2O)2(µ2-hmt)] n : A Novel Three-Dimensional Network Self-Assembled by hmt (hmt = Hexamethylenetetramine and mal = Malonate)

A novel three-dimensional coordination polymer [Mn₂(mal)₂(H₂O)₂(μ₂-hmt)] _n (hmt = hexamethylenetetramine, and mal = malonate) was synthesized and characterized by elemental analysis, crystal structure, IR, TG-DTA and magnetic susceptibility. The compound [Mn₂(mal)₂(H₂O)₂(μ₂-hmt)] _n crystallizes in the orthorhombic system, space group 12 mm, with a = 7.1059(11), b = 7.6986(6), c = 15.9824(13) Å, and Z = 2. Mn(II) ion has octahedral geometry coordinated by four oxygen atoms from three malonate, one oxygen atom of water and one nitrogen atom of hmt ligand. The two oxygen atoms of each malonate coordinate to the same Mn(II) ion and the other two oxygen atoms connect to two adjacent Mn(II) ions to form an infinite layer. These layers are bridged by the μ₂-hmt ligands to form a three-dimensional structure. The magnetic susceptibility data show that there is an antiferromagnetic exchange interaction in the title compound.     

A hydrogen-bonded,one-dimensional complex of cadmium(II) ions with 3,5-dinitrobenzoate and radicals: synthesis,characterization and crystal structure

A novel one-dimensional complex, [Cd(NIT4py)₂(DTB)₂(H₂O)₂] (1), (where NIT4py is 2-(4′-pyridyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide and DTB is 3,5-dinitrobenzoate) has been synthesized and characterized by elemental analyses, IR and electronic spectra, single-crystal X-ray diffraction and magnetic measurements. The Cd(II) ion lies in a distorted octahedral environment with two nitrogen atoms from two NIT4py ligands and two oxygen atoms from two DTB molecules in the basal plane, and two oxygen atoms from two water molecules in axial positions. [Cd(NIT4py)₂(DTB)₂(H₂O)₂] units are connected to form one-dimensional chains by intermolecular hydrogen bonds. The complex exhibits intramolecular antiferromagnetic interactions.     

Synthesis, Characterization and Crystal Structure of a One-dimensional Diamagnetic Metal-radical Complex: [Zn(NIT4py)2(DTB)2(H2O)2]

A novel one-dimensional complex [Zn(NIT4py)₂(DTB)₂(H₂O)₂] (1), with mixed ligands [where NIT4py is 2-(4′-pyridyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide and DTB is 3,5-dinitrobenzoate] has been synthesized and characterized by elemental analyses, i.r., u.v.–vis spectra, thermogravimetric analysis, X-ray single crystal diffraction and magnetic measurements. The complex crystallizes in the triclinic crystal system and space group Pî. The Zn ^II ion is in a distorted octahedral environment: two nitrogen atoms from two NIT4py entities, two oxygen atoms from two DTB units in the basal plane; and two oxygen atoms from the two water molecules in the axial position. The [Zn(NIT4py)₂(DTB)₂(H₂O)₂] units are connected as a one dimension chain by the intermolecular hydrogen bonds. The complex exhibits intramolecular antiferromagnetic interactions between the two radicals.     

Synthesis,crystal structure and magnetic behavior of a two-dimensional copper(II) complex with mellitic anion as bridging ligand

A two-dimensional complex Cu₃[C₆(COO)₆](H₂O)₁₀ · 2H₂O has been prepared and its crystal structure determined by X-ray crystallography. In the complex each mellitic anion provides four carboxylate groups as coordinate groups and, according to the coordination, the four carboxylate groups are classified as two types according to its coordinate modes. The first is that a carboxylate group coordinates a copper(II) ion via its one oxygen atom, and the second one is that a carboxylate group, as a two-dentate ligand, coordinates to two copper(II) ions. The copper(II) ions also are classified as being of two types according to their coordinate modes. The configuration around each copper(II) ion is a distorted pyramid. The variable-temperature magnetic susceptibility of the complex was measured in the 4–300 K range and the magnetic data indicate that the magnetic interaction between bridging copper(II) ions displays an antiferromagnetic coupling below 42 K, while above 42 K a ferromagnetic interaction appears.     

Synthesis and magnetic properties of the one-dimensional linear chain structure cyano-bridged complex [Cu(teta)(H2O)2][Cu(teta) Fe(CN)6]ClO4·2H2O (teta=5,7,7,12,14,14-hexamethyl-1,4,8,11-tetraazacylotetradecane)

Reaction of either K₃[Fe(CN)₆] or K₄[Fe(CN)₆] with a macrocyclic Cu^II complex, [Cu(teta)](ClO₄)₂ (teta = 5,7,7,12,14,14-hexamethyl-1,4,8,11-tetraazacylotetradecane), in aqueous solution gave the same product as shown by spectroscopic and physicochemical characterisation. The crystal structure of the complex shows that it is a one-dimensional linear chain type heterobinuclear Fe^III–Cu^II polymer. The unit is composed of a [Cu(teta)(H₂O)₂]²⁺ cationic complex, a Fe^III–Cu^II alternate linear chain unit, a ClO ₄ ^– ion and four water molecules. The Cu atom is coordinated in a distorted octahedral arrangement by four nitrogen atoms from one teta ligand and two nitrogen atoms of the bridging cyanide groups. The Cu—N bond distances involving the cyanide bridges, 2.522(7) and 2.608(7)Å, respectively, indicate weak antiferromagnetic interactions between the Fe^III and Cu^II atoms.     

一个新的噻二唑衍生物H2ADTZ与锰的二维聚合物的合成与晶体结构(英)

A new 1,3,4 thiadiazole-derivative ligand 2,5-(s-acetic acid) dimercapto-1,3,4 thiadiazole (H₂ADTZ) and its one-dimensional manganese polymer Mn(ADTZ)·4H₂O had been synthesized and structurally characterized by X-ray single crystal diffraction in this paper. The Mn(Ⅱ) ion is coordinated with a distorted octahedron by two oxygen atoms from neighboring two deprotonated ligands ADTZ^2- and other four oxygen atoms from four coordinated water molecules. The structural feature of the title compound is the formation of one-dimensional manganese chains polymer through the bridging of dioxygen O-O units. In the solid state structure of the complex, one-dimensional manganese chains are joined together by the weak intermolecular hydrogen bonds and vander Waals interactions forming a two-dimensional supramolecular compound. Furthermore, the UV spectra and electro-chemical properties of the title compound were also investigated. CCDC: 260532.     

Synthesis,Crystal Structures and Spectrothermal Characterization of a Heptacoordinated Dimeric Salicylato Cadmium(II) Complex with 2,2′‐Azobispyridine (abpy), (µ‐abpy)[Cd(Hsal)2(abpy)]2

µ‐2,2′‐Azobispyridinebis[2,2′‐azobispyridinesalicylato(O)salicylato(O,O′) cadmium(II)], (µ‐abpy)[Cd(Hsal)₂(abpy)]₂ ( I ) was synthesized and characterized by IR and UV/ Vis spectroscopy, thermal analysis, and X‐ray diffraction techniques. Two abpy ligands and two salicylato ligands coordinate to the Cd²⁺ ion in a monocapped trigonal‐prismatic arrangement. The capping atom is the N3 atom. One of the two abpy ligands behaves as a “s‐frame” bridging ligand and adopts a s‐cis/ E/ s‐cis conformation, whereas the other one adopts as a s‐cis/ E/ s‐trans conformation. One of the two salicylato ligands acts as a monodentate ligand, which coordinates with the carboxylate oxygen atom, whereas the other one adopts bidentate coordination through two carboxylate oxygen atoms. The hydroxy groups of salicylato ligands, which coordinate in a monodentate fashion, are disordered over two positions, with occupancies of 0.52 for group A and 0.48 for group B. The decomposition reaction takes place in the temperature range 20–1000 °C under nitrogen. Thermal decomposition of the title complex proceeds in two stages.     

Synthesis,Crystal Structure and Fluorescence of A 1-D Polymeric Zinc(Ii) Complex with Pyrazine-2-Carboxylate as a Bridging Ligand

A one-dimensional chain complex {[Zn(pyz)(SCN)(H₂O)₂]·H₂O}_∞ (pyz = pyrazine-2-carboxylic anion) has been synthesized and its crystal structure determined by X-ray crystallography. The complex crystallizes in an orthorhombic system and the space group is P2 ₁2₁2₁ with a = 6.873(3), b = 9.847(4), c = 16.466(7) Å. The Zn(II) ion is located in a distorted octahedral environment with two oxygen atoms O(3) and O(4) from terminal ligands of two water molecules, another oxygen atom O(1) from the carboxylate group of pyz, and three nitrogen atoms, N(1), and N(2A) from two different pyz and N(3) from a terminal thiocyanate anion, in which a chelated five-membered ring is formed by coordination of O(1) and N(1) to the Zn(1) atom. Therefore, an infinite zigzag chain consisting of Zn(II) ions and pyz anions is constructed and the chains are linked together with hydrogen bonding from coordinated and uncoordinated water molecules. The fluorescence spectra for the bridging ligand Na(pyz) and the complex were measured at room temperature in aqueous solution and in the solid state.     

SYNTHESIS AND CRYSTAL STRUCTURE OF A MANGANESE(II) COMPLEX,Mn(phen)2(phcoo)2 2HzO

Abstract

The title complex has been prepared by the reaction of Mn(phcoo)2 with phen in EtOH/H₂O solution (where phcoo = the anion of benzoic acid, phen= 1,10-phenanthroline). The crystal structure has been determined by X-ray diffraction. The complex molecule has distorted octahedron geometry. Carboxyl O atoms coordinate to Mn(II) from unidentate ligands with a cis-configuration. Two uncoordinated O atoms of benzoate anions locate on the one side of the coordination plane so that there is free space on the other side of the plane; such a spatial arrangement may promote the attack of a water molecule at the manganese atom in the oxygen evolution process in photosystem II.     

Synthesis and crystal structure of a 3-d polymeric cobalt(II) and sodium complex with pyrazine-2-carboxylate as a bridging ligand

A complex with a three-dimensional structure {[Na₃Co(pyz)₃(H₂O)₄(ClO₄)₂]} _n (pyz = pyrazine-2-carboxylate anion) has been synthesized and its crystal structure determined by X-ray crystallography. The complex crystallizes in a triclinic system with a space group Pī and a = 8.598(11), b = 11.382(15), c = 14.496(19)?Å, α = 87.79(2), β = 88.21(2), γ = 82.08(2)°. The Co(II) ion is located in a distorted octahedral environment with three oxygen atoms and three nitrogen atoms, from the three pyr ligands. Na(1) ion is coordinated by four oxygen atoms and two nitrogen atoms, in which O(1), O(2), O(2A), N(4A) and N(6A) come from ligand pyr while O(15) comes from H₂O. Na(2) and Na(3) ions are each coordinated by six oxygen atoms. Through coordination of the bridging ligand pyr with Co(II) and Na(I) a three-dimensional net structure is formed.     

Synthesis,crystal structure,and magnetism of [Mn(hfac)2NIT(Ph-m-OPh)]

A new complex [Mn(hfac)₂NIT(Ph-m-OPh)] has been synthesized and structurally characterized by X-ray diffraction. It crystallizes in the monoclinic space group P2(1)/c. The structure consists of a 1-D chain with Mn(II) bridged by NIT(Ph-m-OPh). The manganese(II) is in a distorted octahedral environment formed by one oxygen from NIT(Ph-m-OPh) and three atoms from hexafluoro acetylacetone (hfac) in the equatorial plane and two oxygens from hfac and the other NIT(Ph-m-OPh) in the axial position. The units of [Mn(hfac)₂NIT(Ph-m-OPh)] are connected as a 1-D chain by Mn(II) and oxygen of N–O in bridging NIT(Ph-m-OPh) along the b-axis. The 2-D layer in the ab plane is formed via hydrogen interactions to connect neighboring chains. The complex exhibits intramolecular antiferromagnetic interactions between Mn(II) and NIT(Ph-m-OPh).