Coordination polymers of macrocyclic oxamide with 1,3,5-benzenetricarboxylate: syntheses, crystal structures and magnetic properties

Solvothermal reactions of mixed ligands H(3)BTC and macrocyclic oxamide complexes (ML, M = Cu, Ni) with M(ClO(4))(2)·6H(2)O (M = Co, Zn, Ni and Cd) afford six new complexes, including [M'(4)(BTC)(2)(ML)(2)(OH)(2)(H(2)O)(2)]·2H(2)O (M' = Co, M = Ni, for (1); M' = Zn, M = Ni, for (2); M' = Zn, M = Cu, for (3)), [Ni(3)(BTC)(2)(NiL)(2)(H(2)O)(6)]·2CH(3)OH·2H(2)O (4), [Cd(4)(BTC)(2)(HBTC)(NiL)(4)(H(2)O)]·3H(2)O (5) and [Cd(HBTC)(CuL)]·H(2)O (6) (ML, H(2)L = 2, 3-dioxo-5, 6, 14, 15-dibenzo-1,4,8,12-tetraazacyclo-pentadeca-7,13-dien; H(3)BTC = 1,3,5-benzenetricarboxylic acid). Complexes 1-3 consist of a 2D layer framework formed by the linkage of M(II)(M = Ni, Cu) and M'(4) (M' = Co, Zn) cluster via the oxamide and BTC(3-) bridges and display a (3,6)-connected network with a (4(3))(2)(4(6).6(6).8(3)) topology. The structure of 4 consists of pentanuclear [Ni(II)(5)] units and arranges in a 1D cluster chain. Complex 5 exhibits a 2D layered structure characterized by 3,4,3-connected (4.6(2))(3)(4.6(3).8(2))(4(2).6(3).8)(4(2).6) topology. Complex 6 possesses a 3D network with sra topology. The magnetic properties of complexes 1 and 4 were investigated.     

Variations of structures and gas sorption properties of three coordination polymers induced by fluorine atom positions in azamacrocyclic ligands

Three coordination polymers of [(NiL(1))(3)(TCBA)(2)] (1), [(NiL(2))(3)(TCBA)(2)] (2), and [(NiL(3))(3)(TCBA)(2)] (3) have been constructed using azamacrocyclic Ni(II) complexes [NiL(1)](ClO(4))(2)/[NiL(2)](ClO(4))(2)/[NiL(3)](ClO(4))(2) and TCBA(3-) as building blocks (L(1) = 3,10-bis(2-fluorobenzyl)-1,3,5,8,10,12-hexaazacyclotetradecane; L(2) = 3,10-bis(3-fluorobenzyl)-1,3,5,8,10,12-hexaazacyclotetradecane; L(3) = 3,10-bis(4-fluorobenzyl)-1,3,5,8,10,12- hexaazacyclotetradecane; TCBA(3-) = tri(4-carboxy-benzyl)amine). The results of X-ray diffraction analyses reveal that 1 shows a 2D Borromean structure, while 2 and 3 form 2D layer structures, and the 2D layers are further connected by the interlayer F···F interactions in 2 and C-H···F interactions in 3 to generate two 3D porous structures with 1D fluorine atoms interspersed channels. Gas sorption measurements illustrate that the desolvated 2 and 3can adsorb N(2), H(2), and CO(2) molecules. The different structures and gas sorption properties of 1 and 2/3 are mainly induced by the different positions of F atoms in azamacrocycle ligands.     

Investigation of porous Ni-based metal-organic frameworks containing paddle-wheel type inorganic building units via high-throughput methods

In the search of Ni based metal-organic frameworks (MOFs) containing paddle-wheel type building units, three chemical systems Ni(2+)/H(n)L/base/solvent with H(n)L = H(3)BTC (1,3,5-benzenetricarboxylic acid), H(3)BTB (4,4',4',-benzene-1,3,5-triyl-tris(benzoic acid)), and H(2)BDC (terephthalic acid) were investigated using high-throughput (HT) methods. In addition to the conventional heating, for the first time HT microwave assisted synthesis of MOFs was carried out. Six new compounds were discovered, and their fields of formation were established. In the first system, H(3)BTC was employed and a comprehensive HT-screening of compositional and process parameters was conducted. The synthesis condition for the Ni paddle-wheel unit was determined and two compounds [Ni(3)(BTC)(2)(Me(2)NH)(3)]·(DMF)(4)(H(2)O)(4) (1a) and [Ni(6)(BTC)(2)(DMF)(6)(HCOO)(6)] (1b) were discovered (Me(2)NH = dimethylamine, DMF = dimethylformamide). In the second system, the use of the extended tritopic linker H(3)BTB and the synthesis conditions for the paddle-wheel units led to the porous MOF, [Ni(3)(BTB)(2)(2-MeIm)(1.5)(H(2)O)(1.5)]·(DMF)(9)(H(2)O)(6.5) (2), (2-MeIm = 2-methylimidazole). This compound shows a selective adsorption of H(2)O and H(2) with a strong hysteresis. In the third system, H(2)BDC was used, and the base (DABCO) was incorporated as a bridging ligand into all structures. Thus, two pillared layered porous MOFs [Ni(2)(BDC)(2)(DABCO)]·(DMF)(4)(H(2)O)(1.5) (3a) and [Ni(2)(BDC)(2)(DABCO)]·(DMF)(4)(H(2)O)(4) (3b) as well as a layered compound [Ni(BDC)(DABCO)]·(DMF)(1.5)(H(2)O)(2) (3c) were isolated. The 3a and 3b polymorphs of the [Ni(2)(BDC)(2)(DABCO)] framework can be selectively synthesized. The combination of microwave assisted heating, low overall concentration, stirring of the reaction mixtures, and an excess of DABCO yields a highly crystalline pure phase of 3b. The fields of formation of all compounds were established, and scale-up was successfully performed for 1b, 2, 3a, 3b, and 3c. All compounds were structurally characterized. In addition to IR, elemental and TG analyses, gas and vapor sorption experiments were carried out.     

Hexanuclear Fe(III)2Co(III)2M(II)2 (M = Cu, Ni, Mn) clusters based on Kläui's tripodal ligand and tricyanometalates: syntheses, structures and magnetic properties

With the use of Kl?ui's tripodal ligand, [(Cp)Co(P(O)(OEt)(2))(3)](-) (L(CoEt), Cp = cyclopentadiene) as the auxiliary ligand to react with different metal salts and tricyanometalate building blocks, five neutral trimetallic hexanuclear complexes: [(Tp)(2)Fe(2)(CN)(6)Cu(2)(L(CoEt))(2)]·6H(2)O (1, Tp = hydridotris(pyrazolyl)borate), [(Tp*)(2)Fe(2)(CN)(6)Cu(2)(L(CoEt))(2)]·2H(2)O (2, Tp* = hydridotris(3,5-dimethyl-pyrazolyl)borate), [(pzTp)(2)Fe(2)(CN)(6)Cu(2)(L(CoEt))(2)]·H(2)O·3MeOH (3, pzTp = tetra(pyrazolyl)borate), [(Tp)(2)Fe(2)(CN)(6)Ni(2)(L(CoEt))(2)(MeCN)(2)]·2MeCN·2H(2)O (4) and [(Tp)(2)Fe(2)(CN)(6)Mn(2)(L(CoEt))(2)(MeCN)(2)]·2MeCN (5), have been obtained and structurally characterized. Magnetic measurements confirm that there are ferromagnetic couplings between the cyano-bridged Fe and Cu/or Ni ions and antiferromagnetic interaction between the cyano-bridged Fe and Mn ions. Slow relaxation of the magnetization is observed in complexes 1 and 4, while complex 3 exhibits metamagnetic behavior with a critical field of 17.5 kOe.     

Assembly and properties of transition-metal coordination polymers based on semi-rigid bis-pyridyl-bis-amide ligand: effect of polycarboxylates on the dimensionality

Seven new coordination polymers, [Co()(1,3-BDC)(H(2)O)(3)]·H(2)O (), [Co()(1,2-BDC)(H(2)O)]·H(2)O (), [Co(3)()(1,2,4-BTC)(2)(H(2)O)(4)]·4H(2)O (), [Co()(NPH)]·2H(2)O (), [Cu()(1,3-BDC)] (), [Cu()(1,2-BDC)] (), [Cu()(1,3,5-HBTC)(H(2)O)](2)·2H(2)O () ( = N,N'-bis(pyridin-3-yl)cyclohexane-1,4-dicarboxamide, 1,3-H(2)BDC = 1,3-benzenedicarboxylic acid, 1,2-H(2)BDC = 1,2-benzenedicarboxylic acid, 1,2,4-H(3)BTC = 1,2,4-benzenetricarboxylic acid, H(2)NPH = 3-nitrophthalic acid and 1,3,5-H(3)BTC = 1,3,5-benzenetricarboxylic acid) have been hydrothermally synthesized by assembling transition-metal cobalt-copper salts with semi-rigid bis-pyridyl-bis-amide ligand and different aromatic polycarboxylic acids. Complex exhibits a one-dimensional (1D) sinusoidal-like chain, which is further assembled into a three-dimensional (3D) supramolecular framework through hydrogen-bonding interactions. Complex possesses a 3D framework with 4-connected 6(6) topology, which contains a two-dimensional (2D) distorted asymmetric hexagonal grid. When 1,2,4-BTC is used in complex , a 3D framework with (6(3)·8(2)·10)(2)(6(5)·8)(2)(8) topology is constructed. Complex possesses a 3D framework with 4-connected 6(6) topology, which is similar to that of except for containing a 2D symmetric hexagonal grid. When Co(II) ion is replaced by Cu(II) ion, the 3D framework of complex with (4·6(2))(4·6(6)·8(3)) topology based on and 1,3-BDC ligands is obtained. Complex shows a 2D cross network consisting of a superposed Cu- 1D chain and 1,2-BDC, which is further expanded into a 3D supramolecular framework by hydrogen-bonding interactions. In complex , 1,3,5-HBTC is employed as the auxiliary ligand, and a 3D supramolecular framework based on the undulated 2D layers is formed through π-π stacking and hydrogen-bonding interactions. Both the metal ions and polycarboxylates play important roles in the construction of the title complexes. In addition, the electrochemical behaviors and the fluorescence properties of the seven complexes have been investigated.     

Ferromagnetic NiII-GdIII interactions in complexes with NiGd, NiGdNi, and NiGdGdNi cores supported by tripodal ligands

Dinuclear [(NiL)Gd(hfac)(2)(EtOH)](H(3)L = 1,1,1-tris(N-salicylideneaminomethyl)ethane, Hhfac = hexafluoroacetylacetone), trinuclear [(NiL)(2)Gd(NO(3))], and tetranuclear [(NiL)Gd(CH(3)CO(2))(2)(MeOH)](2) complexes, were prepared by treating [Ni(HL)] with [Gd(hfac)(3)(H(2)O)(2)], Gd(NO(3))(3).6H(2)O, and Gd(CH(3)CO(2))(3).4H(2)O, respectively, in the presence of Et(3)N. All the complexes show that ferromagnetic interactions occur between the Ni(II) and Gd(III) ions.     

Synthesis, characterization, crystal structure and preliminary reactivity behaviour of new heteropolytopic ligands based on the 1,3,5-triazine spacer and pyrazolyl, tris-pyrazolylmethyl and tris-pyrazolylethoxy bonding fragments

Four new potentially polytopic nitrogen donor ligands based on the 1,3,5-triazine fragment, L(1)-L(4) (L(1) = 2-chloro-4,6-di(1H-pyrazol-1-yl)-1,3,5-triazine, L(2) = N,N'-bis(4,6-di(1H-pyrazol-1-yl)-1,3,5-triazin-2-yl)ethane-1,2-diamine, L(3) = 2,4,6-tris(tri(1H-pyrazol-1-yl)methyl)-1,3,5-triazine, and L(4) = 2,4,6-tris(2,2,2-tri(1H-pyrazol-1-yl)ethoxy)-1,3,5-triazine) have been synthesized and characterized. The X-ray crystal structure of L(3) confirms that its molecular nature consists of a 1,3,5-triazine ring bearing three tripodal tris(pyrazolyl) arms. L(1), L(2), and L(4) react with Cu(I), Cu(II), Pd(II) and Ag(I) salts yielding mono-, di-, and oligonuclear derivatives: [Cu(L(1))(Cy(3)P)]ClO(4), [{Ag(2)(L(2))}(CF(3)SO(3))(2)]·H(2)O, [Cu(2)(L(2))(NO(3))(2)](NO(3))(2)·H(2)O, [Cu(2)(L(2))(CH(3)COO)(2)](CH(3)COO)(2)·3H(2)O, [Pd(2)(L(2))(Cl)(4)]·2H(2)O, [Ru(L(2))(Cl)(OH)]·CH(3)OH, [Ag(3)(L(4))(2)](CF(3)SO(3))(3) and [Ag(3)(L(4))(2)](BF(4))(3). The interaction of L(3) with Ag(I), Cu(II), Zn(II) and Ru(II) complexes unexpectedly produced the hydrolysis of the ligand with formation, in all cases, of tris(pyrazolyl)methane (TPM) derivatives. In detail, the already known [Ag(TPM)(2)](CF(3)SO(3)) and [Cu(TPM)(2)](NO(3))(2), as well as the new [Zn(TPM)(2)](CF(3)SO(3))(2) and [Ru(TMP)(p-cymene)]Cl(OH)·2H(2)O complexes have been isolated. Single-crystal XRD determinations on the latter derivatives confirm their formulation, evidencing, for the Ru(II) complex, an interesting supramolecular arrangement of the anions and crystallization water molecules.     

Zn(II) and Cd(II) coordination polymers assembled by di(1H-imidazol-1-yl)methane and carboxylic acid ligands

Five new Zn(II)/Cd(II) coordination polymers constructed from di(1H-imidazol-1-yl)methane (L) mixed with different auxiliary carboxylic acid ligands formulated as [Zn(L)(H(2)L(1))(2)·(H(2)O)(0.2)](n) (1), {[Zn(L)(L(2))]·H(2)O}(n) (2), {[Cd(2)(L)(2)(L(2))(2)]·2H(2)O}(n) (3), {[Cd(L)(L(3))]·H(2)O}(n) (4) and [Cd(L)(L(4))](n) (5) (H(3)L(1) = 1,3,5-benzenetricarboxylic acid, H(2)L(2) = 4,4'-oxybis(benzoic acid), H(2)L(3) = m-phthalic acid and H(2)L(4) = p-phthalic acid) have been synthesized under hydrothermal conditions and structurally characterized. Four related auxiliary carboxylic acids were chosen to examine the influences on the construction of these coordination frameworks with distinct dimensionality and connectivity. The coordination arrays of 1-5 vary from 1D zigzag chain for 1, 2D (4,4) layer for 2-4, to 2-fold interpenetrated 3D coordination network with the α-Po topology for 5. The thermal and photoluminescence properties of complexes 1-5 in the solid state have also been investigated.     

2D coordination polymers of macrocyclic oxamide with polycarboxylates: syntheses, crystal structures and magnetic properties

Five new 2D coordination polymers, [Co(nip)(CuL)(H(2)O)]·CH(3)OH (1), [Mn(ip)(NiL)]·0.63H(2)O (2), [Cu(ip)(CuL)] (3), [Mn(6)(CuL)(6)(btc)(4)(H(2)O)(4)]·7H(2)O (4), and [Cu(CuL)(Hbtc)(H(2)O)] (5)(ML, H(2)L = 2,3-dioxo-5,6,14,15-dibenzo-1,4,8,12-tetraazacyclo-pentadeca-7,13-diene; H(2)nip = 5-nitroisophthalic acid; H(2)ip = m-isophthalic acid; H(3)btc = 1,3,5-benzenetricarboxylic acid) have been synthesized by a solvothermal method and characterized by single-crystal X-ray diffraction. Complexes 1-5 exhibit different 2D layered structures formed by Co(2)Cu(2) (1), Mn(2)Ni(2) (2), Cu(4) (3), Mn(3)Ni(3) (4), Cu(4) (5) units, respectively, via the oxamide and diverse carboxylic acid bridges. Compounds 1, 2, 3 and 5 are uninodal 4-connected (4, 4)-grids topology, while complex 4 possesses a 2D network with (3, 4)-connected (4(2).8)(4)(4(3).6(2).8)(3) topology. The results of magnetic determination show pronounced antiferromagnetic interactions in 1-4.     

Homochiral frameworks formed by reactions of lanthanide ions with a chiral antimony tartrate secondary building unit

A chiral cluster compound, dipotassium bis(μ-tartrato)diantimony(III), K(2)Sb(2)L(2) (H(4)L = L-tartaric acid), was used as a secondary building unit to react with lanthanide ions. Three series of homochiral coordination compounds were obtained: 0D [La(H(2)L)(H(2)O)(4)](2)[Sb(2)L(2)]·7H(2)O (0D-La), 1D Ln(Sb(2)L(2))(H(2)O)(5)(NO(3))·H(2)O (1D-Ln) (Ln = La-Lu or Y, expect Pm), 2D(I) [(Ln(H(2)O)(5))(2)(Sb(2)L(2))(3)]·5H(2)O (2D(I)-Ln) (Ln = La, Ce, Pr), and 2D(II) [(La(H(2)O)(5))(2)(Sb(2)L(2))(3)]·6H(2)O (2D(II)-La). Single-crystal X-ray diffraction studies indicated that 0D-La crystallizes in space group P1, and the structure contains isolated Sb(2)L(2)(2-) units located between chains of composition La(H(2)L)(H(2)O)(4). The series of 1D-Ln compounds is isostructural and crystallizes in space group P2(1)2(1)2(1). In the structure, Sb(2)L(2)(2-) units are coordinated to two Ln ions by two out of the four free tartrate oxygen atoms to form a linear chain. To the best of our knowledge, this is the first example of a homochiral structure that can be formed for the whole lanthanide series. In the 2D(I)-Ln structure series, which crystallizes in space group P2(1), the Sb(2)L(2)(2-) units have two distinct coordination modes: one is the same as that found in the 1D structure, while in the other all four free tartrate oxygen atoms are coordinated to four Ln ions in a very distorted tetrahedral arrangement. The connectivity between Sb(2)L(2)(2-) secondary units and LnO(9) polyhedra gives rise to infinite layers. 2D(II) [(La(H(2)O)(5))(2)(Sb(2)L(2))(3)]·6H(2)O, which crystallizes in space group C2, has a similar network to the 2D(I)-Ln compounds. The trends in lattice parameters, bond lengths, and ionic radii in the 1D-Ln series were analyzed to show the effect of the lanthanide contraction.     

New family of silver(I) complexes based on hydroxyl and carboxyl groups decorated arenesulfonic acid: syntheses, structures, and luminescent properties

Self-assembly of silver(I) salts and three ortho-hydroxyl and carboxyl groups decorated arenesulfonic acids affords the formation of nine silver(I)-sulfonates, (NH(4))·[Ag(HL1)(NH(3))(H(2)O)] (1), {(NH(4))·[Ag(3)(HL1)(2)(NH(3))(H(2)O)]}(n) (2), [Ag(2)(HL1)(H(2)O)(2)](n) (3), [Ag(2)(HL2)(NH(3))(2)]·H(2)O (4), [Ag(H(2)L2)(H(2)O)](n) (5), [Ag(2)(HL2)](n) (6), [Ag(3)(L3)(NH(3))(3)](n) (7), [Ag(2)(HL3)](n) (8), and [Ag(6)(L3)(2)(H(2)O)(3)](n) (9) (H(3)L1 = 2-hydroxyl-3-carboxyl-5-bromobenzenesulfonic acid, H(3)L2 = 2-hydroxyl-4-carboxylbenzenesulfonic acid, H(3)L3 = 2-hydroxyl-5-carboxylbenzenesulfonic acid), which are characterized by elemental analysis, IR, TGA, PL, and single-crystal X-ray diffraction. Complex 1 is 3-D supramolecular network extended by [Ag(HL1)(NH(3))(H(2)O)](-) anions and NH(4)(+) cations. Complex 2 exhibits 3-D host-guest framework which encapsulates ammonium cations as guests. Complex 3 presents 2-D layer structure constructed from 1-D tape of sulfonate-bridged Ag1 dimers linked by [(Ag2)(2)(COO)(2)] binuclear units. Complex 4 exhibits 3-D hydrogen-bonding host-guest network which encapsulates water molecules as guests. Complex 5 shows 3-D hybrid framework constructed from organic linker bridged 1-D Ag-O-S chains while complex 6 is 3-D pillared layered framework with the inorganic substructure constructing from the Ag2 polyhedral chains interlinked by Ag1 dimers and sulfonate tetrahedra. The hybrid 3-D framework of complex 7 is formed by L3(-) trianions bridging short trisilver(I) sticks and silver(I) chains. Complex 8 also presents 3-D pillared layered framework, and the inorganic layer substructure is formed by the sulfonate tetrahedrons bridging [(Ag1O(4))(2)(Ag2O(5))(2)](∞) motifs. Complex 9 represents the first silver-based metal-polyhedral framework containing four kinds of coordination spheres with low coordination numbers. The structural diversities and evolutions can be attributed to the synthetic methods, different ligands and coordination modes of the three functional groups, that is, sulfonate, hydroxyl and carboxyl groups. The luminescent properties of the nine complexes have also been investigated at room temperature, especially, complex 1 presents excellent blue luminescence and can sensitize Tb(III) ion to exhibit characteristic green emission.     

Construction of metal-organic frameworks: versatile behaviour of a ligand containing mono- and bidentate coordination sites

Five new coordination polymers based on a new 2,2'-bipyridine derived ligand N,N'-bis(pyridin-4-yl)-2,2'-bipyridine-5,5'-dicarboxamide (=L) are reported herein. Isostructural three-dimensional coordination polymers with a rare (4,6)-connected network of {4(4).6(2)}(3){4(6).8(9)}(2) topology were synthesised from Cu(NO(3))(2), Zn(NO(3))(2) or a mixture of Cu(NO(3))(2)/Fe(BF(4))(2) with L in complexes {[Cu(5)L(6)]·(NO(3))(10)·(H(2)O)(18)}(∞) (1), {[Zn(5)L(6)]·(NO(3))(10)·(H(2)O)(18)}(∞) (2) and {[Fe(x)Cu(y)L(6)]·(NO(3))(10)·(H(2)O)(18)}(∞) (3; where x+y=5). Complexes with two-dimensional grid structures resulted from treatment with CoCl(2) or Cd(NO(3))(2) with L in complexes {[CoLCl(2)]·DMF}(∞) (4) and {CdL(NO(3))(2)}(∞) (5).     

New coordination polymers with extended arm cyclotriguaiacyclene ligands: 1D chains, and interpenetrating or polycatenating 2D (4(2).6(2))(4.6(2))2 networks

A series of new 1D chain and 2D coordination polymers with cyclotriguaiacylene-type ligands are reported. A zig-zag 1D coordination chain is found in complex [Cd(2)(4ph4py)(NO(3))(3)(H(2)O)(2)(DMA)(2)]·(NO(3))·(DMA)(4), where 4ph4py = tris[4-(4-pyridyl)benzoyl]-cyclotriguaiacylene and DMA = dimethylacetamide, while complex [Zn(4ph4py)(2)(CF(3)COO)(H(2)O)]·(CF(3)COO)(NMP)(7), where NMP = N-methylpyrrolidone, has a doubly bridged coordination chain structure. Complexes [M(3ph3py)(NO(3))(2)]·(NMP)(4) where M = Co or Zn, 3ph3py = tris[3-(3-pyridyl)benzoyl]cyclotriguaiacylene, are isostructural and feature 1D ladder coordination chains. Complexes [Cd(2)(4ph4py)(2)(NO(3))(4)(NMP)]·(NMP)(9)(H(2)O)(4) and [Co(4ph4py)(H(2)O)(2)]·(NO(3))(2)·(DMF)(2), where DMF = dimethylformamide, both have (3,4)-connected 2D coordination polymers with a rare (4(2).6(2))(4.6(2))(2) topology. A 2D coordination polymer with this topology is also found in complex [Co(2)(3ph4py)(2)(NO(3))(H(2)O)(5)]·(NO(3))(3)·(DMF)(9) where 3ph4py = tris[3-(4-pyridyl)benzoyl]cyclotriguaiacylene. All 2D coordination polymer complexes are interpenetrating or polycatenating. [Co(2)(3ph4py)(2)(NO(3))(H(2)O)(5)](3+)polymers form a 2D→3D polycatenation showing self-complementary "hand-shake" interactions between the host-type ligands.     

Step-wise synthesis of inorganic-organic hybrid based on γ-octamolybdate-based tectons

With the bottom-up design principle, we use metal-ions to bridge the predesigned tectons (1 [(H(2)L(1))(2)(Mo(8)O(26))]·4H(2)O and 3 [(H(2)L(2))(L(2))(0.5)(Mo(8)O(26))(0.5)]·H(2)O) so that two higher dimensional γ-octamolybdate based inorganic-organic hybrid compounds 2 [Cu(I)(2)(L(1))(3)(Mo(8)O(26))(0.5)] and 4 [Ni(L(2))(2)(HL(2))(2)(Mo(8)O(26))]·4H(2)O are successfully obtained.     

Synthesis, structure and magnetism of homodinuclear complexes of Co, Ni and Cu supported by a novel bitriazine scaffold

Btzn (1), an amine-functionalized bi(1,3,5-triazine) 4,4'-(NH(2))(2)-6,6'-(NHC(6)H(5))(2)-2,2'-(1,3,5-C(3)N(3))(2), is reported, and its coordination with Co, Ni and Cu is explored. Reactions of metal salts (2 equiv) with Btzn (1 equiv) result in dimeric species [(Btzn)Co(2)(NCS)(4)(EtOH)(2)(DMF)(2)], (2), [(Btzn)Ni(2)(η(1)-ONO(2))(2)(MeOH)(4)(DMF)(2)]·2[NO(3)], (3), [(Btzn)Cu(2)Cl(4)(DMF)(2)], (4), and [(Btzn)Cu(2)(η(2)-O(2)NO)(2)(OH(2))(2)(DMF)(2)]·2[NO(3)], (5). These complexes are the first examples of the coordination of transition metals with bi(1,3,5-triazine) ligands. Their structures display a bridging bis-bidentate coordination mode for Btzn. Variable-temperature magnetic susceptibility of the complexes reveals antiferromagnetic exchange between the spin carriers, with calculated exchange coupling values (J) of -4.7 cm(-1) for 3, -18.2 cm(-1) for 4, and -5.5 cm(-1) for 5. An in-depth evaluation of the metal geometry highlights the inefficient overlap of the magnetic d-orbitals through the bridging ligand, most likely leading to reduced delocalization and coupling.     

1,2,4-Triazole functionalized adamantanes: a new library of polydentate tectons for designing structures of coordination polymers

A series of functionalized adamantanes: 1,3-bis(1,2,4-triazol-4-yl)(tr(2)ad); 1,3,5-tris(1,2,4-triazol-4-yl)-(tr(3)ad); 1,3,5,7-tetrakis(1,2,4-triazol-4-yl)adamantanes (tr(4)ad) and 3,5,7-tris(1,2,4-triazol-4-yl)-1-azaadamantane (tr(3)ada) were developed as a new family of geometrically rigid polydentate tectons for supramolecular synthesis of framework solids. The coordination compounds were prepared under hydrothermal conditions; their structures reveal a special potential of the triazolyl adamantanes for the generation of highly-connected and open frameworks as well as structures based upon polynuclear metal clusters assembled with short-distance N(1),N(2)-triazole bridges. Complexes [Cd{L}(2)]A·nH(2)O [L = tr(3)ad, A = 2NO(3)(-) (4), CdCl(4)(2-) (5); L = tr(3)ada, A = CdI(4)(2-) (7)] are isomorphous and adopt a layered 3,6-connected structure of CdI(2) type. [{Cu(3)(OH)}(2)(SO(4))(5)(H(2)O)(2){tr(3)ad}(3)]·26H(2)O (6) is a layered polymer based upon Cu(3)(μ(3)-OH) nodes and trigonal tr(3)ad links. In [Cu(3)(OH)(2){tr(3)ada}(2)(H(2)O)(4)](ClO(4))(4) (8), [Cu(2){tr(3)ada}(2)(H(2)O)(3)](SO(4))(2)·7H(2)O (9) and [Cd(2){tr(3)ada}(3)]Cl(4)·28H(2)O (10) (UCl(3)-type net) the organic tripodal ligands bridge polynuclear metal clusters. Complexes [Ag{tr(4)ad}]NO(3)·3.5H(2)O (11) and [Cu{tr(4)ad}(H(2)O)](ClO(4))(2)·3H(2)O (12) have 3D SrAl(2)-type frameworks with the metal ions and adamantane tectons as topologically equivalent tetrahedral nodes, while in [Cd(3)Cl(6){tr(4)ad}(2)]·9H(2)O (13) the ligands bridge trinuclear six-connected Cd(3)Cl(6)(μ-tr)(4)(tr)(2) clusters. In the compounds [Cd(2){tr(2)ad}(4)(H(2)O)(4)](CdBr(4))(2)·2H(2)O (2) and [Cd{tr(2)ad}(4){CdI(3)}(2)]·4H(2)O (3) the bitopic ligands provide simple links between the metal ions, while in [Ag(2){tr(2)ad}(2)](NO(3))(2)·2H(2)O (1) the ligand is tetradentate and generates a 3D framework.     

Structural evolution and magnetic properties of Co(II) coordination polymers varied from 1D to 3D constructed by 1,4-bis(1,2,4-triazol-1-ylmethyl)benzene

Seven Co(II) coordination polymers, [Co(btx)(3)(H(2)O)(2)](ClO(4))(2)·(btx)·2H(2)O (1), [Co(btx)(3)(H(2)O)(2)](BF(4))(2)·(btx)·2H(2)O (2), [Co(btx)(2)(H(2)O)(2)](NO(3))(2)·2H(2)O (3), [Co(btx)(2)Cl(2)] (4), [Co(btx)(BA)(2)(H(2)O)(2)]·2HBA (5), [Co(btx)(IPA)] (6) and [Co(3)(btx)(3)(BTA)(2)(H(2)O)(2)] (7) (btx = (1,4-bis(1,2,4-triazol-1-ylmethyl)benzene), HBA = benzoic acid, H(2)IPA = isophthalic acid, H(3)BTA = benzene-1,3,5-tricarboxylic acid), have been hydrothermally synthesized and characterized. 1 and 2 are isostructural and show a 1D Co-μ(2)-btx-Co chain structure, in which btx acts as both a bridging and terminal ligand. 3 is also a 1D chain structure but different from 1 and 2. The Co(II) ions are bridged by double μ(2)-btx to form Co(2)-btx(2) rings, which were further connected into 1D chains by sharing the Co(II) ions of the rings. 4 exists as a 2D grid with (4,4) topology structure. When aromatic acid was introduced to the synthetic system, three other coordination polymers 5-7 were obtained. In 5, the 1D chain is as that of 1, except that the terminal ligand was replaced by BA(-). 6 shows a two-fold parallel interpenetration framework featuring a 6-c uninodal net with (3(3),4(6),5(5),6) Schlafli topological symbol. 7 is an interesting 3D framework, which contains a 2-nodal net motif with the unprecedented (3(6),4(2),5(6),6)(3(9),4(9),5(3))(2) topology structure. The influence of the varieties of the structures and magnetic properties are studied and discussed in detail.     

A series of octanuclear-nickel(II) complexes supported by thiacalix[4]arenes

A series of discrete complexes, [Ni(8)(BTC4A)(2)(μ(6)-CO(3))(2)(μ-CH(3)COO)(4)(dma)(4)]·H(2)O (1), [Ni(8)(BTC4A)(2)(μ(6)-CO(3))(2)(μ-Cl)(2)(μ-HCOO)(2)(dma)(4)]·2DMF·2CH(3)CN (2), [Ni(8)(PTC4A)(2) (μ(6)-CO(3))(2)(μ-CH(3)COO)(4)(dma)(4)]·DMF (3), and [Ni(8)(PTC4A)(2)(μ(6)-CO(3))(2)(μ-OH)(μ-HCOO)(3) (dma)(4)] (4) (p-tert-butylthiacalix[4]arene = H(4)BTC4A, p-phenylthiacalix[4]arene = H(4)PTC4A, dma = dimethylamine, and DMF = N,N'-dimethylformamide), have been prepared under solvothermal conditions and structurally characterized by single-crystal X-ray diffraction analyses, powder XRD, and IR spectroscopy. These four complexes are stacked by dumbbell-like building blocks with one chairlike octanuclear-nickel(II) core, which is capped by two thiacalix[4]arene molecules and connected by two in situ generated carbonato anions and different auxiliary anions. This work implied that not only the solvent molecules but also the upper-rim groups of thiacalix[4]arenes have significant effects on the self-assembly of the dumbbell-like building blocks. The magnetic properties of complexes 1-4 were examined, indicating strong antiferromagnetic interactions between the nickel(II) ions in the temperature range of 50-300 K.     

One pot-synthesis of chiral Ni6 clusters involving Ni3 subunits: a combined structural, magnetic and DFT study

Ni(6) clusters of the general formula [{Ni(3)L(n)(OAc)(OH)}(2)(X)(OAc)(H(2)O)(2)] (n = 1, 2; X = Cl(-) or N(3)(-), (L(n))(3-) = hexadentate tritopic ligands) can be isolated by spontaneous self-assembly, from mixtures of Ni(OAc)(2), H(3)L(n), NMe(4)OH·5H(2)O and NaX in adequate molar ratios. Thus, four new hexanuclear complexes [{Ni(3)L(1)(OAc)(OH)}(2)Cl(OAc)(H(2)O)(2)]·7.5H(2)O (1·7.5H(2)O), [{Ni(3)L(2)(OAc)(OH)}(2)Cl(OAc)(H(2)O)(2)]·2H(2)O·7.5MeOH (2·2H(2)O·7.5MeOH), [{Ni(3)L(1)(OAc)(OH)}(2)(N(3))(OAc)(H(2)O)(2)]·6H(2)O (3·6H(2)O) and [{Ni(3)L(2)(OAc)(OH)}(2)(N(3))(OAc)(H(2)O)(2)]·4H(2)O (4·4H(2)O) were obtained and fully characterised. 1·7.5H(2)O and 2·2H(2)O·7.5MeOH were isolated in the form of single crystals, the latter losing solvate on drying, to yield 2·2H(2)O. Recrystallisation of 3·6H(2)O in MeCN/MeOH also generates single crystals of 3·H(2)O·2MeOH·2MeCN. Their X-ray characterisation shows that these Ni(6) clusters can be considered to be built from two triangular trinuclear [Ni(3)L(n)(OAc)(OH)](+) subunits with different connectors. In addition, these studies demonstrate that the (L(n))(3-) ligands behave as trinucleating, adopting such a conformation that induces chirality in the isolated compounds. In this way, 3·H(2)O·2MeOH·2MeCN appears particularly interesting, since it emerges as homochiral after undergoing spontaneous resolution upon crystallisation. The magnetic characterisation of 1·7.5H(2)O to 3·6H(2)O reveals that the three compounds present an overall antiferromagnetic coupling. The intricate magnetic behaviour of these clusters, mediated by a total of 14 bridges of different kinds, was analysed and satisfactorily interpreted in light of DFT calculations.     

Novel hexagonal {V=O}6-containing sandwich-type cluster accompanied by in situ carbon-carbon bond formation of organic cations

Two novel sandwich-type polyanions containing hexagonal {V=O}(6) group (H(2)tpy)(Hbpe)(3)H[(VO)(6)(SbW(9)O(33))(2)]·2H(2)O (1) and (H(2)tcy)(6)(Hbpp)(6)H(4)[VW(12)O(40)][(VO)(6)(SbW(9)O(33))(2)](3)·30H(2)O (2) (tpy = 4-(2,3,4-tri(pyridin-4-yl)butyl)pyridine, bpe = 1,2-(4-pyridyl)ethene, tcy = 1,2,4,5-tetra(pyridin-4-yl)cyclohexanol, bpp = 1,3-bis-(4-pyridyl)propane), were reported. Both compounds are built upon the complex hydrogen bonding networks of C-H···O and N-H···O occurred among inorganic anions and organic cations. Unusual in situ organic reactions involving C-C coupling are also observed in 1 and 2 regardless of the rigid bpe or flexible bpp. Compound 2 represents a rare case in which nano-sized α-Keggin [VW(12)O(40)](4-) and sandwich-type [(VO)(6)(SbW(9)O(33))(2)](6-) anionic clusters are present in a common crystal framework.