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.     

Thermal Decomposition Reactions for the Exploration of New Coordination Polymers based on Mn(NCS)2 and Pyridazine

Reaction of different ratios of manganese(II) thiocyanate with pyridazine in water at room temperature leads always to the formation of the pyridazine‐rich 1:4 compound (1:4 = ratio between metal and neutral co‐ligand) Mn(NCS)₂(pyridazine)₄ ( 1 ). In the crystal structure of 1 , the Mn²⁺ cations are coordinated by two nitrogen atoms of terminal N‐bonded thiocyanato anions and four nitrogen atoms of pyridazine ligands within slightly distorted octahedra. However, in one reaction single crystals of the new compound Mn₃(NCS)₆(pyridazine)₄(H₂O) · (pyridazine) ( 2 ) were obtained. In its crystal structure the manganese atoms are linked into chains by µ‐1, 3 and µ‐1, 1 bridging thiocyanato anions as well as bridging pyridazine ligands. Heating rate dependent DTA‐TG measurements of 1 reveal a multi‐step thermal decomposition, in which three new pyridazine‐deficient compounds of composition Mn(NCS)₂(pyridazine)₃ ( 3 ), Mn(NCS)₂(pyridazine)₂ ( 4 ) and Mn(NCS)₂(pyridazine) ( 5‐Mn ) are formed. IR‐spectroscopic investigations indicate that on heating more condensed coordination networks with µ‐1, 3‐ and µ‐1, 1‐bridging thiocyanato anions has formed. Magnetic measurements show only Curie‐Weiss paramagnetism for compounds 1 , 3 and 4 , whereas in the 1:1 compound 5 an antiferromagnetic ordering is observed at T_N = 14 K. Surprisingly, the most pyridazine deficient compound 5 transforms into 2 after storage for several weeks.     

Syntheses and Structures of Acetyl‐Acetonato‐Alumo‐Diphenylsilanolates with Magnesium(II), Iron(II), Iron(III), Cobalt(II), and Nickel(II)

Bis(acetylacetonate)alumo‐oxo‐tetraphenyldisiloxane‐metal(II) dihydrates [(acac)₂Al(O–SiPh₂–O–SiPh₂–O)]₂M(H₂O)₂ (M = Mg, Fe, Co, Ni) were obtained from the corresponding acetyl‐acetonate‐dihydrates (acac)₂M(H₂O)₂ by reaction with the alumosiloxane [O–Ph₂Si–O–SiPh₂–O]₄Al₄(OH)₄. These new compounds display two acac ligands at the aluminum atoms as well as disilatrioxy chains linking the two aluminum atoms forming a (Al–O–Si–O–Si–O)₂ cycle (X‐ray structure analyses). Within this cycle the divalent metal ions M²⁺, to which two water molecules in trans positions are linked, are installed in almost planar MO₄ coordination spheres. Using water free (acac)₂Ni a different product forms: both reactants combine in a 2:1 ratio to yield [O–Ph₂Si–O–SiPh₂–O]₄Al₄(OH)₂O(OH₂)Ni₂(acac)₄. Here, three of the acac ligands were transposed to the aluminum atoms. The nickel atoms are in a distorted octahedral coordination mode from oxygen atoms of the ligands. When iron(III)tris(acetylacetonate) reacts with the alumosiloxane [O–Ph₂Si–O–SiPh₂–O]₃Al₂O(OH)Fe₂(acac)₃ was isolated, in which the two iron atoms still display one of the acac ligands. One of the aluminum atoms is in a tetrahedral oxygen environment, whereas the other is in the center of a trigonal bi‐pyramid formed of oxygen atoms either of the siloxane or of acac. The iron atoms have five‐ or sixfold coordination from oxygen atoms of siloxane, acac, hydroxide or oxide.     

Syntheses, crystal structures, and magnetic and fluorescence properties of three complexes of mixed flexible N,N′-bis(3-pyridylmethyl)amine and rigid pyromellitate ligands

Three new complexes, {[Mn(Hbpma)₂(pm)(H₂O)₂]·8H₂O}_n, {[Co(Hbpma)₂(pm)(H₂O)₂]·8H₂O}_n and {[Zn(Hbpma)₂(pm)(H₂O)₂]·8H₂O}_n (bpma = N,N′-bis(3-pyridylmethyl)amine and H₄pm = pyromellitic acid) were synthesized and structurally characterized by single-crystal X-ray diffraction. All three complexes are isomorphous consisting of one-dimensional coordination polymers bridged by rigid pm ligands, while the flexible dipyridyl bpma only acts as a terminal ligand. The bpma ligand adopts the trans–trans conformation in all three complexes. The magnetic properties of the Mn(II) and Co(II) complexes show the occurrence of antiferromagnetic interactions between adjacent metal atoms. The Zn(II) complex exhibits fluorescent emission in the solid state at room temperature.     

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.     

Influence of the Metal Ions on the Allylic Rearrangement Reaction of 3,4,5,6‐Tetrahydrophthalic Anhydride

To further investigate the influence of metal ions on the allylic rearrangement of 3,4,5,6‐tetrahydrophthalic anhydride during the hydrothermal reaction, metal ions such as manganese(II), zinc(II) and cadmium(II) have been employed in the synthesis, which leads to the formation of three new lamellar coordination polymers, [Mn^II₅(µ₃‐OH)₃(1‐chec)(1,2‐chedc)(2,3‐chedc)₂(H₂O)] ( 3Mn) , [Zn^II₅(µ₃‐OH)₃(1‐chec)(1,2‐chedc)(2,3‐chedc)₂(H₂O)] ( 4Zn ), and [Cd^II₃(µ₃‐OH)₂(1,2‐chedc)₂] ( 5Cd) (1‐chec=cyclohexene‐1‐carboxylate, 1,2‐chedc=cyclohexene‐1,2‐dicarboxylate, 2,3‐chedc=cyclohexene‐1,2‐dicarboxylate). Interestingly, the allylic rearrangement reaction is metal‐dependent, which occurs only in 3Mn and 4Zn , resulting in the formation of one chiral carbon atom of the corresponding dicarboxylate ligands in both compounds. In addition, the magnetic property of compound 3Mn was studied, which revealed strong antiferromagnetic interactions between the metal centers.     

四个对苯酚四唑硫酮金属(II)配合物的合成和晶体结构

四唑酸(–CN4H)与羧酸(–COOH)具有相似的酸性。对苯酚四唑硫酮(H2L)可以作为单齿(–S或–N)或双齿(–N, N或–N, S)配体与金属离子配位形成配位化合物。合成了4个以H2L为配体的金属(II)配合物：Co(HL)2(Py)2(H2O)2 (1), [Mn(HL)2(H2O)4]·2H2O (2), Mn(HL)2(Phen)2 (3), and [Zn(HL)2(Phen)2]·0.5H2O·1.5CH3OH (4),并用X−射线单晶衍射法测定了晶体结构。晶体结构分析表明,在这些配合物中所有的中心金属原子均呈现六配位的八面体构型。在配合物1和2中,HL–配体以氧原子与中心金属原子配位,而在配合物3和4中HL–配体则以硫原子与中心金属原子配位。     

Layer and Cavity Structures of Manganese(II) Diphenate Coordination Polymers

Two novel metal‐organic coordination polymers, [Mn₂(dpa)₂(4,4′‐bipy)₂(H₂O)₂]_n ( 1 ) and [Mn(Hdpa)₂(bpe)(H₂O)₂]_n ( 2 ) (H₂dpa = diphenic acid, 4,4′‐bipy = 4,4′‐dipyridine, bpe = 1,2‐bis(4‐pyridyl)ethene), have been hydrothermally synthesized. Single crystal X‐ray diffraction analyses reveal the two‐dimensional and three‐dimensional structures for complexes 1 and 2 , respectively. In 1 , the dpa ligands link metal ions with different modes into one‐dimensional chains, and the 4,4′‐bipy terminally coordinate to the metal ions extending the chains into a layer. Whereas in 2 , the flexible bpe ligands link the structure motifs into chains, and the hydrogen bonding interactions between the chains lead to the formation of cavity structure.     

Di‐μ‐acesulfamato‐κ3N,O:O;κ3O:N,O‐bis[(acesulfamato‐κ2N,O)bis(3‐methylpyridine)cadmium(II)]

In the structure of the title compound, [Cd₂(C₄H₄NO₄S)₂(C₆H₇N)₂], the dinuclear Cd^II complex is located on a twofold axis with two Cd²⁺ ions bridged by two oxide O atoms. Each Cd²⁺ ion is additionally coordinated in an equatorial plane by two N and three O atoms of the acesulfamate ligands and axially by two N atoms of the 3‐methylpyridine ligands, resulting in a distorted pentagonal bipyramidal coordination. We present here an example of a supramolecular assembly based on hydrogen bonds in a mixed‐ligand metal complex; intermolecular C—H...O hydrogen bonds give rise to R₄⁴(40) rings, which lead to one‐dimensional chains.     

三个双肼桥连金属配合物的合成,结构和磁性

采用水热合成方法得到3个新的双肼桥连过渡金属化合物：[M（N₂H₄）₂Cl₂]_n（M=Mn（1）,Ni（2））,{[Co_1.5（N₂H₄）₃PO₄（H₂O）]·H₂O}_n（3）,用单晶X射线衍射方法对其晶体结构进行表征。化合物1是以2个肼分子桥联金属Mn和Ni形成1D链状结构,而粉末XRD显示1与2是同构的。化合物3是以2个肼分子桥联金属Co形成1D链,不同的1D链再通过磷酸根PO₄^3-进一步堆积形成3D结构。磁性测试表明肼桥在磁性中心之间传递反铁磁耦合作用。     

Crystal structure,spectroscopic and thermal properties of copper(II) and manganese(II) coordination polymers based on triazole-benzoic acid ligands

Two transition metal coordination polymers {[Cu(tba)₂(H₂O)]·2H₂O} _n (1) and {[Mn(Htta)₂(H₂O)₂]·2H₂O} _n (2) {Htba = 3-[1,2,4]triazol-1-yl-benzoic acid, H₂tta = 2-[1,2,4]triazol-1-yl-terephthalic acid} have been synthesized under solvothermal conditions. Both complexes have been characterized by single-crystal X-ray diffraction, X-ray powder diffraction, elemental analysis and FTIR spectroscopy. Complex 1 has a 1-D chain structure in which Cu(II) atoms are doubly bridged by tba^? ligands, which is further stabilized by hydrogen bonding and π–π stacking interactions to give a 3-D supramolecular framework. In complex 2, Mn(II) atoms are doubly bridged by Htta^? ligands to form 1-D chains, which are further connected by intermolecular hydrogen bonds to form a 3-D supramolecular framework. The electronic spectra and thermal behaviors of complexes 1 and 2 are also reported.     

Hydrothermal Synthesis of a 3D Polymeric Cobalt(II) Carboxylate Derivative from 1,2,4,5‐Benzenetetracarbonitrile

The metal‐organic complexes Co₂(terpy)₂(btec)·H₂O 1 (terpy = 2,2′:6′,2″‐terpyridine, btec = 1,2,4,5‐benzenetetracarboxylate) was synthesized by hydrothermal synthesis method, using 1,2,4,5‐benzenetetracarbonitrile, terpy and CoAc₂·4H₂O. Single crystal X‐ray diffraction showed that each btec^4– ligand links four Co^II atoms and each Co^II atom links to two btec^4– ligands forming a 1D double‐chain structure. Furthermore, the chains pack together through short face–face π–π interactions forming a 3D supramolecular structure. Additionally, the magnetic measurements show antiferromagnetic interactions among metal ions for compound 1 .     

Hydrothermal synthesis and crystal structure of [Ni(Bptc)<Subscript>2</Subscript>(Bimb)<Subscript>2</Subscript>(H<Subscript>2</Subscript>O)<Subscript>2</Subscript>]

In the compound [Ni(Bptc)₂(Bimb)₂(H₂O)₂] (I), where H₄Bptc is 3,3′,4,4′-biphenyltetracarboxylic acid; Bimb is 4,4′-bis(1-imidazolyl)biphenyl), Ni(II) has a distorted octahedral coordination geometry, which was bonded with two N atoms from two Bimb ligands, two O atoms from two H₂Bptc²⁻ ligands and two water O atoms. The crystal structure of compound I is stabilized by the π-π-stacking and hydrogen bonds interaction.     

Hydrogen Bonding and Iodine Bonding Interactions in Sustaining Two Coordination Polymers Base on Square Grids and Tetranuclear Cobalt Clusters

Two new coordination polymers [Co(H₂O)₂(bpy)₂]·2(Adi) (1) and [Co₄(OH)₂(Adi)₆(bpe)₂] (2) (HAdi = 4-amino-3,5-diiodobenzoic acid, bpy = 4,4′-bipyridine, bpe = 1,2-bis(4-pyridyl)ethylene) have been synthesized by methods of hydrothermal reactions and their crystal structures determined. In 1, the mononuclear Co atoms are linked by bpy ligands forming cationic two-dimensional square grids, which are connected by the intercalated Adi guest molecules through significant hydrogen-bonding interactions to give a three-dimensional supramolecular porous network with one-dimensional channels. 2 has a one-dimensional chain structure based on rhombic tetranuclear Co^II clusters, connected by bpe ligands. Through special I···I interactions, adjacent chains are extended into a three-dimensional supramolecular structure. The structure versatility indicates that the amino and iodo groups of Adi ligands play a crucial role in modulating the coordination polymers. A discussion of the crystal structures, thermal stabilities, as well as the noncovalent interactions of Adi molecules is provided. IR, elemental analysis and XRPD confirmed the phase purity of the bulk materials. Magnetic properties of 2 in the 300–2 K have been discussed, which reveal the occurrence of antiferromagnetic interactions between Co^II ions.     

Syntheses, crystal structures, and magnetic properties of four one-dimensional metal–nitroxide coordination polymers linked by flexible dicarboxylate anions

Four new one-dimensional coordination polymers [Co(IM4Py)₂(adi)(H₂O)₂] _n , [Zn(IM4Py)₂(adi)(H₂O)₂] _n , [Cd(IM4Py)₂(adi)(H₂O)₂] _n , and [Ni(IM4Py)₂(glu)(H₂O)₂] _n (IM4Py = 2-(4′-pyridyl)-4,4,5,5-tetramethylimidazoline-1-oxyl, adi = adipate anion and glu = glutarate anion) were synthesized and structurally characterized. The single-crystal X-ray analyses indicate that all four complexes crystallize in neutral one-dimensional chains in which the nitroxide–metal–nitroxide units are bridged by the flexible dicarboxylate anions. The adipate anions adopt the anti/gauche/anti and anti/anti/anti conformations in the Co(II), Zn(II), and Cd(II) complexes, while the glutarate anions only possess the anti/anti conformation in the Ni(II) complex. The magnetic properties of the Co(II) and Ni(II) complexes show the occurrence of weak antiferromagnetic interactions between the metal atoms and the nitroxide radicals.     

三个双肼桥连金属配合物的合成,结构和磁性

采用水热合成方法得到3个新的双肼桥连过渡金属化合物：[M（N₂H₄）₂Cl₂]_n（M=Mn（1）,Ni（2））,{[Co_1.5（N₂H₄）₃PO₄（H₂O）]·H₂O}_n（3）,用单晶X射线衍射方法对其晶体结构进行表征。化合物1是以2个肼分子桥联金属Mn和Ni形成1D链状结构,而粉末XRD显示1与2是同构的。化合物3是以2个肼分子桥联金属Co形成1D链,不同的1D链再通过磷酸根PO₄^3-进一步堆积形成3D结构。磁性测试表明肼桥在磁性中心之间传递反铁磁耦合作用。     

A multi-functional 3D polymolybdate-based copper(II) complex based on an asymmetric pyridyl-amide ligand: synthesis,structure and properties

A polymolybdate-based metal–organic compound {H₂[Cu₂(L)₂(Mo₈O₂₇)(H₂O)₄]} (1) [L = N-(pyridin-3-yl)isonicotinamide] has been synthesized under solvothermal (methanol–water mixed solvent) conditions and structurally characterized by single-crystal X-ray diffraction. Compound 1 exhibits a 3D metal–organic network containing unusual 1D [Mo₈O₂₇] _n ^6n? inorganic chains, with adjacent 1D chains connected by Cu(II) atoms and L ligands to form a 3D framework with a trinodal 4,4,6-connected {4².6³.8}₂{4⁴.6⁸.8³} topology. The electrocatalytic activities of compound 1 and its photocatalytic properties for the degradation of organic dyes have also been investigated.     

Cobalt(II), nickel(II) and copper(II) complexes of iso­quinoline‐3‐carbox­ylate

The crystal structures of the title complexes, namely trans‐bis­(iso­quinoline‐3‐carboxyl­ato‐κ²N,O)­bis­(methanol‐κO)cobalt(II), [Co(C₁₀H₆NO₂)₂(CH₃OH)₂], and the corresponding nickel(II) and copper(II) complexes, [Ni(C₁₀H₆NO₂)₂(CH₃OH)₂] and [Cu(C₁₀H₆NO₂)₂(CH₃OH)₂], are isomorphous and contain metal ions at centres of inversion. The three compounds have the same distorted octahedral coordination geometry, and each metal ion is bonded by two quinoline N atoms, two carboxyl­ate O atoms and two methanol O atoms. Two iso­quinoline‐3‐carboxyl­ate ligands lie in trans positions, forming the equatorial plane, and the two methanol ligands occupy the axial positions. The complex mol­ecules are linked together by O—H⋯O hydrogen bonds between the methanol ligands and neighbouring carboxyl­ate groups.     

Poly[[diaqua‐μ‐4,4′‐bipyridine‐dinitratodi‐μ‐l‐tyrosinato‐dicopper(II)]: a chiral two‐dimensional coordination polymer

The title compound, [Cu₂(C₉H₁₀NO₃)₂(NO₃)₂(C₁₀H₈N₂)(H₂O)₂]_n, contains Cu^II atoms and l ‐tyrosinate (l ‐tyr) and 4,4′‐bipyridine (4,4′‐bipy) ligands in a 2:2:1 ratio. Each Cu atom is coordinated by one amino N atom and two carboxylate O atoms from two l ‐tyr ligands, one N atom from a 4,4′‐bipy ligand, a monodentate nitrate ion and a water molecule in an elongated octahedral geometry. Adjacent Cu atoms are bridged by the bidentate carboxylate groups into a chain. These chains are further linked by the bridging 4,4′‐bipy ligands, forming an undulated chiral two‐dimensional sheet. O—H...O and N—H...O hydrogen bonds connect the sheets in the [100] direction. This study offers useful information for the engineering of chiral coordination polymers with amino acids and 4,4′‐bipy ligands by considering the ratios of the metal ion and organic components.     

Supramolecular architectures assembled by the interaction of purine nucleobases with metal-oxalato frameworks. Non-covalent stabilization of the 7H-adenine tautomer in the solid-state

The synthesis, crystal structure and variable-temperature magnetic measurements of the compounds [Mn(mu-ox)(H2O)(7H-pur-kappaN9)]n (1), {[Mn(mu-ox)(H2O)2].(7H-ade).(H2O)}n (2) and {[Cu(mu-ox)(H2O)(7H-ade-kappaN9)][Cu(mu-ox)(mu-H2O)(7H-ade-kappaN9)]. approximately 10/3H2O}n (3), (where ox: oxalato dianion, pur: purine, and ade: adenine) are reported. Compounds 1and 2 contain one-dimensional chains in which manganese(II) atoms are bridged by bis-bidentate oxalato ligands. The distorted octahedral geometry around each metal centre is completed in compound 1 by one water molecule and the imidazole N9 donor site of the purine ligand, which is a rare example of direct binding between the Mn(II) ion and the N donor site of an isolated nucleobase. Unlike 1, the adenine moiety in compound 2 is not bonded to manganese atoms and the metal coordination polyhedron is filled by two water molecules in a cis-arrangement. Its crystal building is constructed from pi-stacked layers of Watson-Crick hydrogen-bonded adenine...(H2O2)...adenine aggregates and zig-zag Mn(II)-oxalato chains held together by means of a strong network of hydrogen bonding interactions. The nucleobase exists in the lattice as the 7H-adenine tautomer which represents an unprecedented solid-state characterization of this minor tautomer as free molecule (without metal coordination) stabilized through non-covalent interactions. Compound consists of two slightly different [Cu(ox)(H2O)(7H-ade-kappaN9)] units in which the nucleobase coordinates through the imidazole N9 atom. The planar complex entities are parallel stacked and joined by means of long Cu-O bonds involving oxygen atoms from the oxalato and the aqua ligands, giving one-dimensional chains with a [4 + 1] square-planar pyramidal and a [4 + 2] octahedral coordination around the metal centre, respectively. Self-assembled process of compound 3 is further driven by an in-plane network of hydrogen bonding interactions to generate a porous 3D structure containing parallel channels filled by guest water molecules. Variable-temperature magnetic susceptibility measurements of all the complexes show the occurrence of antiferromagnetic interactions between the paramagnetic centres. DFT calculations have been performed to check the influence of packing in the stability of the 7H-amino tautomer of 2 and in the complex geometry of 3.