Octahedral Building Research Articles

Honeycomb nanoscale-porous material constructed from copper complexes and mixed-addenda Lindqvist-type polyoxoanions

A honeycomb nanoscale-porous material constructed from straight metal–organic chains and octahedral Lindqvist-type polyoxoanion building blocks is solvothermally synthesized, exhibiting a hexagonal array of one-dimensional pores similar with that of MCM-41. The pore sizes are in the range of 16.33 to 23.71 Å and the sorption property of the material is investigated.

Interpenetrating metal-organic frameworks formed by self-assembly of tetrahedral and octahedral building blocks

To investigate the relationship between topological types and molecular building blocks (MBBs), we have designed and synthesized a series of three-dimensional (3D) interpenetrating metal-organic frameworks based on different polygons or polyhedra under hydrothermal conditions, namely [Cd(bpib) 0.5(L 1)] ( 1), [Cd(bpib) 0.5(L 2)]·H 2O ( 2), [Cd(bpib) 0.5(L 3)] ( 3) and [Cd(bib) 0.5(L 1)] ( 4), where bpib=1,4-bis(2-(pyridin-2-yl)-1 H-imidazol-1-yl)butane, bib=1,4-bis(1 H-imidazol-1-yl)butane, H 2L 1=4-(4-carboxybenzyloxy)benzoic acid, H 2L 2=4,4′-(ethane-1,2-diylbis(oxy))dibenzoic acid and H 2L 3=4,4′-(1,4-phenylenebis(methylene))bis(oxy)dibenzoic acid, respectively. Their structures have been determined by single crystal X-ray diffraction analyses and further characterized by elemental analyses, IR spectra, and thermogravimetric (TG) analyses. Compounds 1– 3 display α-Po topological nets with different degrees of interpenetration based on the similar octahedral [Cd 2(–COO) 4] building blocks. Compound 4 is a six-fold interpenetrating diamondoid net based on tetrahedral MBBs. By careful inspection of these structures, we find that various carboxylic ligands and N-donor ligands with different coordination modes and conformations, and metal centers with different geometries are important for the formation of the different MBBs. It is believed that different topological types lie on different MBBs with various polygons or polyhedra. Such as four- and six-connected topologies are formed by tetrahedral and octahedral building blocks. In addition, with the increase of carboxylic ligands’ length, the degrees of interpenetration have been changed in the α-Po topological nets. And the luminescent properties of these compounds have been investigated in detail.

ChemInform Abstract: Functionalization of Hexakis Methanofullerene Malonate Crown‐Ethers: Promising Octahedral Building Blocks for Molecular Networks.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Nature of the Observed Asymmetry in Mössbauer Spectra of Iron (2+) Hexacyanometallates (III)

Abstract The material under study belongs to the Prussian blue analogues family, which are coordination compounds with a porous framework appropriate for the storage of small molecules, among them hydrogen. The porous framework results from systematic vacancies for the octahedral building block, [M(CN)6], in a 3D structure. Mössbauer spectroscopy is a powerful tool to obtain structural information on the local environment for the iron nucleus in these materials. Mössbauer spectra of iron (2+) hexacyanometallates (III) show two slightly asymmetric quadrupole splitting doublets. These two doublets correspond to two non-equivalent structural sites for the iron atom in the framework related with a non-random vacancy distribution. The observed asymmetry was ascribed to a vibrational anisotropy for these iron sites. The asymmetry decreases on the sample cooling and for 7 K it practically disappears. The iron atom is found at the cavities surface with a mixed coordination sphere, Fe(NC)6–x (H2O) x . Such anisotropic coordination environment could explain the presence of certain vibrational anisotropy detected as asymmetric quadrupole splitting doublets.

Lanthanide Metal−Organic Frameworks Based on Octahedral Secondary Building Units: Rare Net Topology and Luminescence

Three isomorphous three-dimensional (3D) lanthanide metal−organic frameworks, [Ln2(DBTDC-O2)3(DMF)4]·3DMF·2H2O (Ln = Nd, Eu, and Gd), have been solvothermally synthesized and characterized, where H2DBTDC-O2 is a sulfone-functionalized bridging ligand, S,S-dioxodibenzothiophen-3,7-dicarboxylic acid. In the structures, two lanthanide(III) ions are bridged by four syn−syn carboxylate groups and chelated by another two carboxylate groups to generate a [Ln2(COO)6] dinuclear moiety, which serves as octahedral secondary building units (SBUs) to produce the rare sxb 3D net (485463), instead of the default primitive cubic (pcu) net. The frameworks possess relatively large solvent-occupied cavities despite the presence of 2-fold interpenetration. The Eu(III) compound displays intense luminescence as a result of the efficient ligand-to-metal energy transfer.

Functionalization of hexakis methanofullerene malonate crown-ethers: promising octahedral building blocks for molecular networks

Hexaazido and hexaiodo macrocyclic methanofullerenes undergo high-yielding sixfold click reactions or sixfold Heck, Sonogashira and Suzuki cross-coupling reactions, respectively, to yield all organic building blocks for higher molecular architectures.

Synthesis, structure and luminescent property of a new 3D porous metal–organic framework with rutile topology

A new 3D porous metal–organic framework (MOF), Cd(CTC)(HPDA)·(H 2O) ( 1) (CTC = cis, cis-1,3,5-cyclohexanetricarboxylate and PDA = 1,3-propanediamine) has been synthesized by using an organic amine, PDA, as a template. X-ray crystallography reveals that two cadmium centers are coordinated by six different carboxylate groups to construct a dinuclear octahedral secondary building unit (SBU), and these octahedral SBUs are further interconnected by the cyclohexane rings of CTC to generate a 3D network with quadrangular channel dimensions of ca. 10 × 17 Å 2. In this structure, the dinuclear octahedral SBU can be defined as a 6-connected node, and CTC ligating with three SBUs can act as a 3-connected node. So the resulting structure of 1 is a binodal (3,6)-connected net with rutile topology. Additionally, polymer 1 exhibits intense fluorescence at 364 nm with the excitation peak at 240 nm in the solid state at room temperature.

Behavior of transition metals ferricyanides as microporous materials

The properties of divalent transition metal ferricyanides as microporous materials remain poorly documented. This family of compounds crystallizes with a cubic cell (Mn, Co, Ni, Cu, Zn, Cd) and also in a rhombohedral (R-3c) modification (Zn). The porous nature of the cubic complexes is related to the occurrence of systematic vacancies of the octahedral building unit [Fe(CN) 6]. The system of vacancies forms a porous framework with polar surface. The rhombohedral modification for the zinc complex salt also has a porous structure but free of vacancy and with a practically non-polar surface. Such structural information was complemented with adsorption isotherms of H 2O, N 2 and CO 2, which were evaluated according to Dubinin model for the volume pore filling. For CO 2 the maximum adsorbed amount was calculated using the Langmuir–Freundlich isotherm. From these adsorption data, a characterization of the studied ferricyanides according to pore volume, pore accessibility and guest–host interactions is given. Information on the guest–host interaction was also derived from Mössbauer spectra recorded on samples with N 2, CO 2, ethanol, methanol and water as adsorbed species. The quadrupole splitting ( Δ) of the Mössbauer spectrum appears as an excellent sensor for the interaction between the adsorbed species and the metal at the pore surface. The Mössbauer spectra were also used as sensor for the pore accessibility to light hydrocarbons. The surface properties of the studied ferricyanides result modulated by the metal used to form the 3D structure from the octahedral block. In this sense, the studied materials behave as tunable zeolites. The materials behavior during the dehydration process and their thermal stability were evaluated from X-ray powder patterns, thermogravimetric and spectroscopic (IR and Mössbauer) data. For all the studied compositions the crystal structure was refined from the corresponding X-ray powder patterns using the Rietveld method.

General Route to Three-Dimensional Framework Uranyl Transition Metal Phosphates with Atypical Structural Motifs: The Case Examples of Cs2{(UO2)4[Co(H2O)2]2(HPO4)(PO4)4} and Cs3+x[(UO2)3CuH4-x(PO4)5]·H2O

The reaction of UO2(NO3)2.6H2O with Co or Cu metal, phosphoric acid, and CsCl under mild hydrothermal conditions results in the formation of Cs2{(UO2)4[Co(H2O)2(HPO4)(PO4)4} (1) or Cs(3+x)[(UO2)3CuH(4-x)(PO4)5].H2O (2). The structure of 1 contains uranium atoms in pentagonal bipyramidal and hexagonal bipyramidal environments. The interaction of the uranyl cations and phosphate anions creates layers in the [ab] plane. The uranyl phosphate layers are joined together by octahedral Co centers wherein the Co is bound by phosphate and two cis water molecules. In addition, the Co ions are also ligated by a uranyl oxo atom. The presence of these octahedral building units stitches the structure together into a three-dimensional framework where void spaces are filled by Cs+ cations. The structure of 2 contains uranium centers in UO6 tetragonal bipyramidal and UO7 pentagonal bipyramidal geometries. The uranyl moieties are bridged by phosphate anions into sinusoidal sheets that extend into the [bc] plane and are linked into a three-dimensional structure by Cu(II). The Cu centers reside in square planar environments. Charge balance is maintained by Cs+ cations. Both the overall structures and the uranyl phosphate layers in 1 and 2 are novel.

A scandium coordination polymer constructed from trimeric octahedral building blocks and 2,5-dihydroxyterephthalate

Scandium chloride and nitrate react with 2,5-dihydroxyterephthalic acid to form three-dimensional framework compounds in which hexagonally-closed packed inorganic building blocks are linked by the carboxylate groups of the organic ligand. The inorganic moieties consist of three scandium oxygen octahedra that are joined by a common mu3-oxygen atom; the pores in the structure account for 60% of the volume, but the framework decomposes upon removal of the solvent molecules.

A Three‐Dimensional Metal–Organic Framework with an Unprecedented Octahedral Building Unit

A Three‐Dimensional Metal–Organic Framework with an Unprecedented Octahedral Building Unit

A Three‐Dimensional Metal–Organic Framework with an Unprecedented Octahedral Building Unit

A Three‐Dimensional Metal–Organic Framework with an Unprecedented Octahedral Building Unit

A three-dimensional porous metal–organic framework with the rutile topology constructed from triangular and distorted octahedral building blocks

The solvothermal reaction of zinc acetate dihydrate with 1,3,5-benzenetricarboxylic acid yields a three-dimensional porous metal-organic framework constructed from triangular and distorted octahedral building blocks, the framework of which can be described as a decorated rutile net.

KCu0.9Bi2.7S5: New Semiconducting Quaternary Bismuth Sulfide

Bismuth chalcogenides are quite interesting due to their potential as useful thermoelectric materials. Recently, many new ternary and quaternary compounds have been discovered that possess promising thermoelectric property. Furthermore, fundamental interest in these compounds is growing due to their structural diversity they exhibit. For example, the compounds of a general formula of ABi3Q5 (A=K, Rb, Cs; Q=S, Se, Te) are known to have six different structure types. The polymorphism is made possible by subtle changes in the edge-sharing modes between the infinite BiQ6 (Q=S, Se) octahedral chains found in the frameworks. Various edge-sharing modes between the octahedral chains can form many types of building units, resulting in a large number of new bismuth chalcogenide frameworks. This is because each BiQ6 octahedron in one chain has maximum 10 edges available for edge-sharing with others in the neighboring chains. If all the 10 edges are shared with ten other BiQ6 octahedra in six neighboring chains, then NaCl-type structure is formed. If fewer edges of an octahedron are to be shared, there are many possible ways of edge-sharing modes to be imagined. For example, (1 × 3) building bar units, formed by sharing edges of BiQ6 octahedra between three chains, are found in α-RbBi3Se5. (2 × 3) building bar units, formed by the two (1 × 3) building bar units, are found in α-RbBi3Se5, γ-RbBi3S5, γ-RbBi3Se5, CsBi3S5, K2Bi6.33S10, and K2Bi8S13. Furthermore, (1 × 2) building bar units in Bi2S3, (2 × 2) units in αRbBi3S5, (1 × 4) units in CsBi3Se5, and even (1 × 8) units in KBi3S5 are found. This suggests that proper utilization of various types of building bar units in well designed reactions will lead to many new compounds with open frameworks or low-dimensional characteristics. Recently, quaternary A/Bi/M/Q (M=Zn, Cd, Mn, Cu; Q=S, Se) systems have been explored and many new compounds of Cs2Bi2MS5 (M=Zn, Cd, Mn), K3Bi5Cu2S10, RbBi2.66CuSe5, ABi2CuS4 (A=K, Cs), and A3Bi5Cu2S10 (A=Rb, Cs) are prepared. They contain infinite linear chains of BiQ6 octahedra as well as MQ4 tetrahedra. Once again, (1 × 3) octahedral building bar units in RbBi2.66CuSe5 and (1 × 2) building bar units in Cs2Bi2MS5 (M=Zn, Cd, Mn), K3Bi5Cu2S10, ABi2CuS4 (A=K, Cs), and A3Bi5Cu2S10 (A=Rb, Cs) are found. Furthermore, the presence of additional MQ4 tetrahedral infinite chains complicates the connectivity between them. The tetrahedral metal ion plays an important role as a binder in connecting the octahedral BiQ6 building bar units enriching the structural diversity of bismuth chalcogenides. Here, we report on the synthesis, structural, and optical characterization of the new quaternary bismuth chalcogenide compound of KCu0.9Bi2.7S5. The structure of KCu0.9Bi2.7S5 is isostructural with that of RbBi2.66CuSe5. It has a three-dimensional framework with tunnels running parallel to a-axis as shown in Figure 1. Its unique three-dimensional structure is built from the linear infinite BiS6 octahedral chains and CuS4 tetrahedral chains. The linear infinite BiS6 octahedral chain is formed by edgesharing along the crystallographic a-axis. The linear CuS4 tetrahedral chain is formed via vertex-sharing of tetrahedrons along the crystallographic a-axis. The (1 × 3) octahedral building bar unit (see Figure 1) is formed by sharing edges of each BiS6 octahedron in the central chain with 4 neighboring octahedra in two adjacent chains. These (1 × 3) building bar units are then sharing edges of their terminal octahedra with the neighboring ones to form 2-D stepwise layers as shown in Figure 2. These layers are interconnected with each other by sharing S(1) vertex of terminal octahedra in (1 × 3) building bar units to form a 3-D framework with tunnels. Cu ion is sitting in a tetrahedron of

Design of frameworks with mixed triangular and octahedral building blocks exemplified by the structure of [Zn4O(TCA)2] having the pyrite topology.

A prerequisite to the design of crystalline materials is the knowledge of the possible structures that potentially may form by linking together specific molecular shapes. In this context, we recently argued that, from the large number of possible structures that could in principle be assembled from various molecular shapes, those with the highest symmetry are most likely to form in practice. Thus it is particularly important to identify these special structures since they represent the default structures for the assembly of shapes. This approach has been useful in the chemistry of extended metal–organic frameworks (MOFs) in which 3D structures assembled entirely from triangles, squares, tetrahedra, or octahedra usually form structures based on the SrSi2, NbO, diamond and primitive cubic nets, respectively. Indeed, these have the highest possible symmetry for their respective building block shapes and have become as important to crystal designers as the Platonic solids are to molecular chemists. Herein we point out that the FeS2 (pyrite) net found in [Zn4O(TCA)2]·(DMF)3(H2O)3 (hereafter MOF-150; TCA= 4,4’,4’’-Tricarboxytriphenylamine, DMF=N,N’-dimethylforamide), is the most regular net (and the most likely to form) for linking together triangles and octahedra and that it has some additional net properties that lead to its classification as a default net. We use TCA and [Zn4O(CO2)6] as secondary building units (SBUs) (Figure 1a) to provide threeand six-coordinated vertices, respectively. The SBUs are produced by employing previously determined reaction parameters to effect their formation in situ. Thus, the reaction of zinc nitrate and TCA in DMF/EtOH/H2O resulted in the formation of light brown truncated crystals, which were formulated by elemental microanalysis and single crystal X-ray diffraction studies. The structure consists of two identical interpenetrating nets, one of which is shown in Figure 1b. In this structure, the basic zinc acetate octahedral SBUs, each composed of four ZnO4 tetrahedra sharing a common corner, are linked by the tritopic TCA to form a 6,3-coordinated net shown in stylized form in Figure 1c. The two interpenetrating frameworks are depicted in Figure 1d. The underlying 6,3-coordinated framework has symmetry Pa3, and the two interpenetrating frameworks have symmetry Ia3 (as found in the crystal, Figure 1d). The topology of each framework is related to the structure of the pyrite form of FeS2; it has the same topology if the S S bonding in pyrite is ignored, so we call it the pyrite net. It has been observed, not interpenetrating, in a [Hg(TPT)3] 3+

Design of Frameworks with Mixed Triangular and Octahedral Building Blocks Exemplified by the Structure of [Zn4O(TCA)2] Having the Pyrite Topology

Design of Frameworks with Mixed Triangular and Octahedral Building Blocks Exemplified by the Structure of [Zn₄O(TCA)₂] Having the Pyrite Topology

Self‐Assembly of a Polar Open‐Framework Uranyl Vanadyl Hexaoxoiodate(VII) Constructed Entirely from Distorted Octahedral Building Units in the First Uranium Hexaoxoiodate: K2 [(UO2)2(VO)2(IO6)2O] ×H2O.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Self-assembly of a polar open-framework uranyl vanadyl hexaoxoiodate(VII) constructed entirely from distorted octahedral building units in the first uranium hexaoxoiodate: K2[(UO2)2(VO)2(IO6)2O].H2O.

The reaction of UO(3) with V(2)O(5) and KIO(4) under mild hydrothermal conditions produces K(2)[(UO(2))(2)(VO)(2)(IO(6))(2)O].H(2)O (1) in the form of orange acicular crystals. The structure of 1 consists of UO(6), VO(6), and IO(6) distorted octahedra that are assembled into a polar, open-framework structure. The distorted VO(6) and IO(6) octahedra edge-share to form chains that run down the c-axis. Each VO(6) octahedron also shares a vertex with an adjacent vanadium atom to link the chains together into a ribbon. The IO(6) units also partake in corner-sharing with the UO(6) units to create interconnected elliptical tubes. The major channels in 1 are filled with K(+) cations and water molecules. The polarity of this compound is caused by alignment of distorted vanadyl hexaoxoiodate ribbons and UO(6) trapezoidal bipyramids resulting in a large second-harmonic generation response of 300 times that of alpha-quartz. Crystallographic data: 1, orthorhombic, space group Pba2, a = 9.984(2) A, b = 16.763(3) A, c = 4.977(1) A, Z = 4 (T = 193 K).

Structure cristalline d'un nouvel hydroxyphosphate naturel de strontium, fer et aluminium (lulzacite), Sr2Fe(Fe0,63Mg0,37)2Al4(PO4)4(OH)10

Abstract Crystal structure of a new natural strontium, iron and aluminium hydroxyphosphate (lulzacite): Sr2Fe(Fe0.63Mg0.37)2Al4(PO4)4(OH)10. The crystal structure of a new natural strontium, iron and aluminium hydroxyphosphate (lulzacite) has been solved through an X-ray study of a single crystal: – symmetry: triclinic (P1); – unit cell parameters: a=5.457(1) A, b=9.131(2) A, c=9.769(2) A, α=108.47(3)°, β=91.72(3)° and γ=97.44(3); – structural formula: (Sr0.96Ba0.04)2Fe(Fe0.63Mg0.37)2Al4[(P0.98V0.02)O4]4(OH)10 (Z=1). The structure presents along the b axis the alternation, on one hand of infinite chains of edge sharing octahedra (one Fe2+O6 and an AlO6 pair), and, on the other hand, of trimers with a central AlO6 octahedron framed by two mixed (Fe2+,Mg)O6 octahedra. Trimers and chains are linked by the corners of one AlO6 octahedron and two PO4 tetrahedra. Strontium ions are located in the channels of the structure. This structure is isotypic with that of jamesite, a lead arsenate. Similar octahedral building blocks are present in other mineral species: trimers in ludlamite (iron phosphate), chains in various hydroxysalts. © 2000 Academie des sciences / Editions scientifiques et medicales Elsevier SAS lulzacite / hydroxyphosphate / phosphate / strontium / iron / aluminium

Dodecaindane (tBu3Si)8In12—A Compound with an In12 Deltapolyhedron Framework

A unique feature among polyhedron frameworks of boron group elements is exhibited by the In12 framework of the black-violet dodecaindane R*8In12 (R*=SitBu3), which can be obtained by the thermolysis of R*2In−InR*2. The molecular structure of R*8In12 (tBu groups omitted in picture shown) can be described as a combination of two R*4In6 octahedral building blocks and can thus be classified as a conjuncto dodecaindane.