A new magnetic metal-organic framework material, [Mn{sub 2}(C{sub 8} H{sub 4}O{sub 4}){sub 2}(C{sub 3}H{sub 7}NO){sub 2}], has been synthesized. The structure consists of chains of carboxylate-bridged Mn atoms interconnected with acid linkers, giving much larger interchain than intrachain Mn...Mn distances. Magnetic susceptibility data fitted to a Curie-Weiss law give {Theta} = -5.7 K and a total magnetic moment of 5.96 {micro}{sub B}. The heat capacity provides no evidence of magnetic ordering down to 2 K. The X-ray charge density was determined from multipole modeling of 16 (1) K single-crystal synchrotron-radiation data. The structural surroundings of the two unique Mn centers are different, but orbital population analysis reveals close to single electron occupation in all 3d orbitals of both Mn sites, in agreement with the magnetic susceptibility measurements. Bader topological analysis shows the presence of direct chemical Mn...Mn interactions only in two out of three intrachain contacts, which suggests a 'broken' chain. The topological measures and approximate energy densities at the metal-ligand bond critical points ({rho}, {del}{sup 2}{rho}, G, V and H) indicate ionic interactions. Formal electron counting suggests mixed-valence Mn sites, but this hypothesis is not supported by the Bader atomic charges [q(Mn) = +2.035 and +2.031].

Two isostructural metal organic framework (MOF) structures have been synthesized by solvothermal methods and examined by single-crystal X-ray diffraction. A microcrystal of 2C4H12N+[Co3(C8H4O4)4]2-.3C5H11NO (1) was investigated at T = 120 K using synchrotron radiation. 2C4H12N+[Zn3(C8H4O4)4]2-.3C5H11NO (2) was investigated at multiple temperatures (T = 30, 100, 200 and 300 K) on a conventional diffractometer. The thermal expansion of the structure of (2) is anisotropic and along the a axis, which corresponds to the metal chain direction. The structures contain anionic frameworks with cations and solvent molecules trapped in the voids. The magnetic susceptibility (chi) and heat capacity (C(p)) have been measured from 1.8 to 350 K. Compound (1) orders ferromagnetically with a broad phase transition observed in C(p) at approximately 6 K. The magnetic moment reaches a value of 3 micro(B) per Co at 2 K in a magnetic field of 9 T, and a Curie-Weiss fit to chi(T) gives an effective moment (mu(eff)) of 4.2 mu(B) and a Weiss temperature (theta) of 23 K. The exchange mechanism for the magnetic coupling is suggested to involve the Co-O-Co bridges in the individual three-metal-atom subchains. The three-dimensional magnetism presumably is due to super-exchange through two out of the three unique C8H4O4 linker molecules, which have the carboxylate and benzene pi systems well aligned.

Two new metal organic framework (MOF) structures have been obtained from the Zn–terephthalic acid (H2BDC)–dimethyl formamide (DMF) system and examined by single-crystal X-ray diffraction: Zn(C8H4O4)(C3H7NO), 1, monoclinic C2/m, a=11.1369(5), b=14.0217(7), c=7.9890(4)Å, β=106.316(1)°, V=1197.3(1)Å3, T=180(2)K, Z=4, R1=0.060, wR2=0.169, S=1.27; Zn(HCO2)3(C2H8N), 2, trigonal R3¯c, a=8.1818(1), c=22.1235(7)Å, V=1282.57(5)Å3, T=180(2)K, Z=6, R1=0.014, wR2=0.039, S=1.11. Contrary to previously published structures in the same system, the crystals were obtained by solvothermal synthesis at 381K. Structure 1 consists of 2-D layers stacked in an offset manner to accommodate DMF moieties coordinated to Zn2+ within voids in adjacent layers. Structure 2 consists of a 3-D network constructed from Zn2+ ions bridged by deprotonated formic acid moieties. Over time, the structure of 1 rearranges to Zn(C8H4O4)(C3H7NO)(H2O) [monoclinic P21/n, a=6.6456(2), b=15.2232(5), c=12.6148(4)Å, β=104.110(2)°, V=1237.70(7)Å3, T=100(2)K, Z=4, R1=0.048, wR2=0.100, S=1.07], which is identical to the known MOF-2 structure, obtained by crystallization at ambient conditions. The three structures were determined from crystals with similar crystal habits picked from a single solvothermal synthesis batch. The study demonstrates that MOF syntheses can give not only multiple crystal structures under different conditions, but also that numerous different structures, including some that are metastable, can be formed under identical conditions.

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

CHARGE, SPIN AND MOMENTUM DENSITY C428single crystal X-ray diffraction and by DFT calculations.The X-ray crystal structure of C 10 H 12 S 3 was studied both at 295 K and at 100 K.The Space group is C2/m at 295 K, which is transformed to P2 1 /n at 100 K.The mirror symmetry perpendicular to 2-fold axis disappears at low temperature.Such reduction of symmetry elements was also found in a previous study on the 2,5-dimethyl-6a-thiathiophthene [1].The bond lengths of two S-S bonds are crystallographically the same [2.3341(8)Å] at 295K, but are significantly different [2.3274(5) and 2.3393( 5) Å] at low temperature.The experimental electron density is produced according to multipole model.The theoretical electron density is calculated by DFT calculation, where the basis set of 6-31G** is used for all the atoms but an additional diffuse function is added for S atom.Results on the electron density distribution will be presented in terms of deformation density, Laplacian maps and the topological properties.Sulfur K-edge X-ray absorption spectroscopy (XAS) is also undertaken to further our knowledge on the electronic configuration of S atom.

The crystal structure of the title compound, [Gd(C14H8O4) 1.5(C5H11NO)](n), comprises chains of Gd atoms intraconnected by the carboxylate groups of the biphenyl-4,4'-dicarboxylate (BPDC) linkers, one of which is disposed about a twofold axis. The Gd atom chains are aligned along the b axis and are interconnected by BPDC linkers, creating a three-dimensional framework. A single diethylformamide (DEF) molecule is bonded to each Gd atom. This molecule is positioned in the cavities formed by the interconnection of the Gd atom chains via the BPDC linkers. Due to the steric constraints of the carboxylate groups, the square antiprismatic coordination geometry of eight O atoms (one from the DEF molecule and seven from carboxylate groups) around Gd is distorted.

The crystal structure of the title compound, {[Gd-2(C8H4O4)(3)(C5H11NO)(2)].H2O}(n), consists of chains of Gd atoms interconnected by a benzene-1,4-dicarboxylate (BDC) linker. The chains are also intraconnected by carboxylate groups from the BDC linker, thus generating a three-dimensional framework with large cavities. The coordination of the eight carboxylate O atoms around the Gd-III ion is distorted dodecahedral, due to the steric constraints of the carboxylate groups. The large anisotropic displacement parameters of the atoms of the coordinated diethylformamide (DEF) and the disorder in their positions indicate loose bonding to the framework, and hence solvent exchange may be possible. Additionally, one water molecule is located in the cavity.

A new magnetic metal organic framework material has been synthesized, Mn3(C8O4H4)3(C5H11ON)2, 1. Magnetic susceptibility measurements from 2 to 400 K reveal anti-ferromagnetic ordering at approximately 4 K and a total magnetic moment of 6.0 micro(B). The magnetic phase transition is confirmed by heat capacity data (2-300 K). The crystal structure is studied by conventional single-crystal X-ray diffraction data at 300, 275, 250, 225, 200, 175, 150, 125, and 100 K, and synchrotron data at 20 K. There is a phase transition between 100 and 20 K due to ordering of the diethylformamide molecules. The X-ray charge density is determined based on multipole modeling of a second 20 K single-crystal synchrotron radiation data set. The electron distributions around the two unique Mn centers are different, and both have substantial anisotropy. Orbital population analysis reveals large electron donation (1.7 e) to each Mn atom and the maximum possible number of unpaired electrons is 3.2 for both Mn sites. Thus, there is a considerable orbital component to the magnetic moment. Bader topological analysis shows an absence of Mn-Mn bonding, and the magnetic ordering is via super-exchange through the oxygen bridges. Formal electron counting suggests Mn2+ sites, but this is not supported by the Bader atomic charges, Mn1 = +0.11 e, Mn2 = +0.17 e. The topological measures show the dominant metal-ligand interactions to be electrostatic, and a simple exponential correlation is derived between Mn-O bond lengths and the values of nabla2rho at the bond critical points.

The two title compounds, di-mu-bromo-bis{[2,6-bis(pyrazol-1-yl-kappaN(2))pyridine-kappaN](perchlorato-kappaO)copper(II)}, [Cu(2)Br(2)(ClO(4))(2)(C(11)H(9)N(5))(2)], (I), and [2,6-bis(pyrazol-1-yl)pyridine]dibromocopper(II), [CuBr(2)(C(11)H(9)N(5))], (II), were synthesized by only slight modifications of the same reaction; compound (II) was formed by adding one molar equivalent of pyrazole (C(3)N(2)H(4)) to the reaction mixture of (I). Compound (I) is a bromo-bridged dinuclear copper(II) compound stabilized by weak interactions with the perchlorate anions (ClO(4)(-)), while (II) is a related mononuclear species, which has a distorted square-pyramidal geometry.

A new magnetic metal-organic framework material, [Mn(2)(C(8)OH(4)(4))(2)(C(3)H(7)NO)(2)], has been synthesized. The structure consists of chains of carboxylate-bridged Mn atoms interconnected with acid linkers, giving much larger interchain than intrachain Mn...Mn distances. Magnetic susceptibility data fitted to a Curie-Weiss law give Theta = -5.7 K and a total magnetic moment of 5.96 micro(B). The heat capacity provides no evidence of magnetic ordering down to 2 K. The X-ray charge density was determined from multipole modeling of 16 (1) K single-crystal synchrotron-radiation data. The structural surroundings of the two unique Mn centers are different, but orbital population analysis reveals close to single electron occupation in all 3d orbitals of both Mn sites, in agreement with the magnetic susceptibility measurements. Bader topological analysis shows the presence of direct chemical Mn...Mn interactions only in two out of three intrachain contacts, which suggests a 'broken' chain. The topological measures and approximate energy densities at the metal-ligand bond critical points (rho, nabla(2)rho, G, V and H) indicate ionic interactions. Formal electron counting suggests mixed-valence Mn sites, but this hypothesis is not supported by the Bader atomic charges [q(Mn) = +2.035 and +2.031].

Zone melting purification experiments have been carried out on the clathrate, Ba8Ga16Ge30. The impurities present have been identified and their approximate concentrations measured. Trace impurities were determined to be approximately 240 parts per million (ppm) in the most impure sample to 17 ppm in the most pure sample. The temperature-dependent Seebeck coefficient, thermal conductivity, and electrical conductivity are reported as a function of sample purity as well as the room-temperature Hall coefficient. Microprobe analysis suggests that the samples are nonstoichiometric with excess Ge relative to Ga, and there are indications of the presence of defects. Single-crystal x-ray investigations as well as synchrotron powder diffraction measurements support the presence of defects, but the x-ray data cannot accurately determine the relative amounts of Ga and Ge. Band-structure calculations in the generalized gradient approximation show that the measured Hall and Seebeck coefficients are consistent with a defect lattice of approximate stoichiometry Ba8Ga14Ge31. Although the figure of merit (ZT) is found to be the highest for the purest sample, the dominant contribution to transport is conjectured to arise from deviations from the ideal stoichiometry and not impurities.

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

The Fe atom of the title compound, [Fe(bipy) 2 (CN) 2 ](NO 3 ) (bipy is 2,2′-bi­pyridine, C 10 H 8 N 2 ), is octahedrally coordinated to the N atoms of the bi­pyridines and to the C atoms of the cyanide groups which are cis to each other. The Fe—C distances are 1.922 (3) and 1.923 (2) Å, and the Fe—N bonds trans to CN are 1.972 (2) and 1.973 (2) Å and are longer than those cis to the CN groups, viz . 1.955 (2) and 1.962 (2) Å. The bi­pyridine groups are close to being planar, with N—C—C—N torsion angles of −2.4 (3) and 1.6 (3)°, and bite angles of 81.43 (8) and 81.74 (8)°.

The Fe atom of the title compound, [Fe(bipy)(2)(CN)(2)O](NO3) (bipy is 2,2'-bipyridine, C10H8N2), is octahedrally coordinated to the N atoms of the bipyridines and to the C atoms of the cyanide groups which are cis to each other. The Fe-C distances are 1.922 (3) and 1.923 (2) Angstrom, and the Fe-N bonds trans to CN are 1.972 (2) and 1.973 (2) Angstrom and are longer than those cis to the CN groups, viz. 1.955 (2) and 1.962 (2) Angstrom. The bipyridine groups are close to being planar, with N-C-C-N torsion angles of -2.4 (3) and 1.6 (3)degrees, and bite angles of 81.43 (8) and 81.74 (8)degrees.

The reaction between tris(ethylenediamine)nickel(II) cations and hexacyanometallate(III) anions (M = Fe, Co) yields ordered bimetallic assemblies, catena-poly[[tris(ethylenediamine)nickel-bis(mu-hexacyanoiron-N,N')] trihydrate] and catena-poly[[tris(ethylenediamine)nickel-bis(mu-hexacyano-cobalt-N,N')] trihydrate], [{Ni(C2H8N2)(2)}(3){M(CN)(6)}(2)]. 3H(2)O, in which both cis and trans [Ni(en)(2)] and [M(CN)(6)] moieties are linked to give S-shaped Ni-NC-M-CN-Ni-NC-M-CN-Ni units which are crosslinked to give ribbons parallel to the b axis. The two compounds are isomorphous with mean metal-ligand distances Fe-C = 1.940 (3), Co-C = 1.844 (3) and Ni-N = 2.102 (2) Angstrom for the iron, and 2.105 (3) Angstrom for the cobalt compound. These compounds appear to be identical with those formulated as [Ni(en)(2)](3)[M(CN)(6)](2). 2H(2)O [Ohba, Maruona, Okawa, Enoki & Latour (1994). J. Am. Chem. Soc. 116, 11566-11567; Ohba, Fukita & Okawa (1997). J. Chem. Soc. Dalton Trans. pp. 1733-1737] which were indexed on a smaller unit cell and described as disordered.

The reaction between tris(ethyl­enedi­amine)­nickel(II) cations and hexa­cyanometallate(III) anions (M = Fe, Co) yields ordered bimetallic assemblies, catena-poly­[[tris­(ethyl­enedi­amine)­nickel-bis(μ-hexa­cyano­iron-N,N′)] trihydrate] and catena-poly­[[tris­(ethyl­enedi­amine)­nickel-bis(μ-hexa­cyano­cobalt-N,N′)] trihydrate], [{Ni(C2H8N2)2}3{M(CN)6}2]·3H2O, in which both cis and trans [Ni(en)2] and [M(CN)6] moieties are linked to give S-shaped Ni–NC–M–CN–Ni–NC–M–CN–Ni units which are cross­linked to give ribbons parallel to the b axis. The two compounds are isomorphous with mean metal–ligand distances Fe—C = 1.940 (3), Co—C = 1.844 (3) and Ni—N = 2.102 (2) Å for the iron, and 2.105 (3) Å for the cobalt compound. These compounds appear to be identical with those formulated as [Ni(en)2]3[M(CN)6]2·2H2O [Ohba, Maruona, Okawa, Enoki & Latour (1994). J. Am. Chem. Soc. 116, 11566–11567; Ohba, Fukita & Okawa (1997). J. Chem. Soc. Dalton Trans. pp. 1733–1737] which were indexed on a smaller unit cell and described as disordered.