nke Li

3D Coordination Framework with Uncommon Two‐Fold Interpenetrated {33⋅59⋅63}‐lcy Net and Coordinated Anion Exchange

Unusual {3(3)5(9)6(3)}-lcy topology has been found in an uncommon 3D six-connected, two-fold interpenetrated {3(3)5(9)6(3)}-lcy net (illustrated). The coordinated SO(4) (2-) anions in this framework can undergo a full exchange with Cl(-) anions, in the course of which the crystals change color as shown. The process has a solvent-mediated rather than a solid-state mechanism.Reaction of tetrazole-1-acetic acid with CuSO(4)5H(2)O produces two novel 3D coordination frameworks: ([Cu(3)(mu(3)-OH)(eta(1):eta(1):eta(1):mu(3)-SO(4))(tza)(3)]3 CH(3)OHH(2)O}(n) (1; Htza=tetrazole-1-acetic acid) and {[Cu(4)(mu(2)-OH)(eta(2):eta(2):mu(4)-SO(4))(tta)(5)]3 H(2)O}(n) (2; Htta=tetrazole). Framework 1 is constructed from a trinuclear copper cluster [Cu(3)(mu(3)-OH)(eta(1):eta(1):eta(1):mu(3)-SO(4))] and displays a six-connected framework with uncommon {3(3)5(9)6(3)}-lcy topology. Framework 2 presents a complicated five-nodal (3,4,6)-connected net with (4(2)6)(34(2)5(2)7)(4(3)6(2)8)(3(2)4(8)5(3)6(2))(4(6)8(6)10(3)) topology. The eta(2):eta(2):mu(4)-SO(4) bridging mode in 2 has not been found in the reported coordination polymers. The coordinated SO(4) (2-) anions in 1 can be replaced completely when the solid polymer is treated with an aqueous methanolic solution containing Cl(-) anions. Detailed atomic force microscopy studies indicate a solvent-mediated rather than a solid-state mechanism for the exchange process.

Two novel two-dimensional double-sheet layered manganese(II) coordination polymers: synthesis, crystal structures and third-order nonlinear optical properties

Two novel Mn(II) coordination polymers [Mn(N3)2(bbp)2]n1 and {[Mn(NCS)2(bbp)2]·0.25H2O}n2 (bbp = 4,4′-trimethylenedipyridine) with 2D double-sheet layered structures were obtained by a normal synthesis method at room temperature. Interestingly, each layer contains two sheets; the double-sheet layer is formed around an octahedral coordination center, Mn(II), with bbp ligands knitted into each other. The structures both contain channels with dimensions of about 6.5 × 6.5 A for 1 and 6.7 × 6.0 A for 2. Both compounds have a similar construction, giving the same third-order nonlinear optical (NLO) behavior and weak antiferromagnetic properties. Their third-order NLO refractive indexes n2 are 1.21 × 10−18 m2 W−1 for 1 and 6.71 × 10−19 m2 W−1 for 2. The NLO susceptibilities χ(3) were calculated to be 4.78 × 10−12 esu and 2.40 × 10−12 esu, respectively.

Tuning the functional substituent group and guest of metal–organic frameworks in hybrid membranes for improved interface compatibility and proton conduction

The incorporation of metal–organic frameworks (MOFs) into polymers would be a very promising strategy for overcoming the disadvantage of MOF brittleness and for extending the application of MOFs in proton-conducting materials. Here, we prepare a series of hybrid membranes composed of MOFs and chitosan (CS, very cheap polymer), and systemically study the effect of the incorporation of pure MIL-101 ([Cr3O(H2O)3(bdc)3], bdc = terephthalic acid), the ligand-modified MIL-101, namely S-MIL-101 ([Cr3O(H2O)3(STA)3]·nH2O, STA = 2-sulfoterephthalic acid), and the non-volatile acid-loaded MIL-101, namely acids@MIL-101 (acids = H2SO4, H3PO4 or CF3SO3H), on the interface compatibility and proton conduction of the hybrid membrane. The experimental results revealed the well compatible interfaces between MOF-based materials and the CS matrix because of the hydrogen bond interaction between them, which greatly improved the proton conductivity, activation energy, thermal and mechanical stability, and swelling property of the hybrid membranes. The functionality of MIL-101 is less than that of S-MIL-101 and acids@MIL-101 because of the presence of more hydrogen-bonding sites, proton hopping sites and proton carriers in the latter two types of materials. All MOF-based materials tested (MIL-101, S-MIL-101, and acids@MIL-101) and their hybrid membranes with CS are characterized using field emission scanning electron microscopy (FE-SEM), TEM, EDS, Fourier transform infrared (FT-IR) spectroscopy, thermogravimetric analysis (TGA), and DSC. Fuel cell performances based on these hybrid membranes have been measured. The investigation provides important information for the design of hybrid membranes containing MOFs and polymers.

Synthesis, Crystal Structure and Thermal Properties of a Novel Ferrocenecarboxylato-Bridged Zinc(II) Dimer [Zn2(µ-OOCFc)4(3-PyCOOCH3)2]

A novel ferrocenyl dimer [Zn2(μ-OOCFc)4(3-PyCOOCH3)2] (Fc=(η5-C5H5)Fe(η5-C5H4)), 1, was obtained by the reaction of Zn(OAc)2·2H2O with sodium ferrocenecarboxylate and 1,4-butanediol dinicotinate in methanol solution. X-ray structural analysis reveals that the compound contains two zinc(II) centers symmetrically bridged by four ferrocenecarboxylate anions as O,O′-bridging ligands, leading to a dimeric tetrabridged [Zn2(μ-OOCFc)4] core. The zinc(II) ion is in a distorted octahedral environment with four oxygen atoms from four distinct ferrocenecarboxylates, a nitrogen atom from the ligand NC5H4CO2CH3, and another zinc atom. The symmetry of the complex in the paddle-wheel structure brings the metal centers close, the Zn … Zn intradimer distance being 2.934(11) Å. It is the first example of a zinc(II) dimer with ferrocenecarboxylate anion ligands. Its thermal properties were measured in air.

Two Cd(II) complexes derived from mercapto-triazole ligands: syntheses, crystal structures, and luminescent properties

Two cadmium complexes, {[Cd(a-ptt)(ptt)]·H2O} n (1) and [Cd(a-Hmtt)2(SO4)H2O]·CH3OH (2), have been prepared based on 4-amino-3-(4-pyridine)-5-mercapto-1,2,4-triazole (a-Hptt) and 4-amino-3-methyl-5-mercapto-1,2,4-triazole (a-Hmtt), respectively. In 1, amino-triazole ligand a-Hptt can partly be deaminated and transformed into 3-(4-pyridine)-5-mercapto-triazole (Hptt) under hydrothermal conditions. X-ray diffraction analysis reveals that 1 exhibits an unusual 2-D lampshade-type layer structure in which the amino ligand a-ptt and the deamination ligand ptt display exo-tridentate bridging and bidentate bridging, respectively. Complex 2 is mononuclear and further assembled into a 3-D supramolecular architecture via non-covalent interactions. Complexes 1 and 2 were characterized by elemental analyses, IR, and thermogravimetric analyses. Furthermore, solid-state luminescent properties of 1 and 2 have also been investigated.

Syntheses, Crystal Structures, and Properties of Six Coordination Complexes Based on a Newly Designed Mercapto-thiadiazole Ligand

Six coordination complexes were solvothermally synthesised: a 3D framework [Cd(tmtt)2]n (1), 2D architectures [Zn(tmtt)2]n (2) and [Pb(tmtt)2]n (3), 1D chain structures [Ni(tmtt)2·(H2O)2]n (4) and [Co(tmtt)2·(H2O)2]n (5), and a mononuclear structure [Hg(tmtt)2] (6). The complexes, based on self-assembly of different metal ions with a newly designed mercapto-thiadiazole ligand tmttH (tmttH = 5-[(1H-1,2,4-triazol-1-yl)methyl]-1,3,4-thiadiazole-2(3H)-thione), were characterised by single crystal X-ray diffraction analyses. Crystal structure analyses reveal that complex 1 exhibits a four-fold interpenetrating 3D framework with {64.82} topology based on two kinds of right-handed single-helical chains, 2 displays a bilayer structure, 3 presents a crown-shaped network, 4 and 5 show 1D double–helical chain structures, and 6 is a mononuclear structure. Moreover, the thermal stabilities of crystalline samples 1–6 have been investigated, and the luminescent properties of complexes 1, 2, 3, 6, and the free ligand have been studied. The results of photoluminescent measurements illustrate that 2 and 3 may serve as excellent candidates for potential photoactive materials.

A substitution product generated from a Mn- p -ferrocenylbenzoate precursor: synthesis, crystal structure and properties

A one-dimensional linear chain polymer {[Mn(OOCC6H4Fc)2(μ 2-OH2)(DMF)2]} n (1) was obtained by substitution from a precursor polymer {[Mn(OOCC6H4Fc)2(μ 2-OH2)(H2O)2](H2O)} n (P1), in which the terminal coordinated H2O molecules are substituted by DMF, while the bridging aqua molecules are intact, so product 1 and precursor P1 are isomorphous. Polymer 1 behaves as a 1D Heisenberg Mn(II) chain with weak intrachain antiferromagnetic interaction between the local high-spin Mn(II) ions; the exchange coupling parameters J = −5.00 cm−1 are larger than most of the reported di-Mn(II) complexes containing μ 2-aqua and μ 2-carboxylato units and some one-dimensional Mn(II) carboxylic polymers.

Three New Hg(II) Complexes Constructed From Mercapto- and Amino-Containing Triazole Ligands: Syntheses, Crystal Structures, and Luminescent Properties

Three new mercury(II) complexes [HgI2(3-aptt)2] (1), [Hg(4-aptt)2] (2), and [Hg(a-mtt)2]·H2O (3) were synthesized based on three structurally related ligands: 4-amino-3-(3-pyridyl)-1H-1,2,4-triazole-5-thione (3-Haptt), 4-amino-3-(4-pyridyl)-5-mercapto-1,2,4-triazole (4-Haptt), and 4-amino-3-methyl-1,2,4-triazoline-5-thiadone (a-Hmtt). The structures of complexes 1–3 were determined by single-crystal X-ray diffraction techniques and further characterized by elemental analyses and IR spectra. The results reveal that these three complexes take mononuclear structures. And although various weak interactions, including N‒H···I and N···H‒O H-bondings as well as Ntrz···Npy and π···π stacking, play significant roles in crystal structures, just these weak interactions link the mononuclear units into higher dimensional supramolecular networks. Their thermal stabilities and the solid state luminescent properties have also been discussed.

CCDC 855733: Experimental Crystal Structure Determination

Related Article: Chunying Xu, Linke Li, Yinping Wang, Qianqian Guo, Xianjuan Wang, Hongwei Hou, Yaoting Fan|2011|Cryst.Growth Des.|11|4667|doi:10.1021/cg200961a