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Secondary Building Units (secondary + building_unit)
Selected AbstractsChemInform Abstract: A New Organic,Inorganic Molybdenum Arsenate Complex Based on [(CuO6) (As3O3)2Mo6O18] 4- Cluster as Secondary Building Units.CHEMINFORM, Issue 23 2009Fangyong Su Abstract ChemInform 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. [source] BaSm5[Si9Al3N20]O , A Nitridoaluminosilicate Oxide with a New Structure Type Composed of "Star-Shaped" [N[4]((Si,Al)N3)4] Units as Secondary Building Units.CHEMINFORM, Issue 20 2006Alexandra Lieb Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source] A novel threefold-interpenetrating primitive cubic network based on a dinuclear Zn2 nodeACTA CRYSTALLOGRAPHICA SECTION C, Issue 2 2009Yun-Peng Diao In the mixed-ligand metal,organic polymeric compound poly[[,2 -1,4-bis(imidazol-1-yl)benzene](,2 -terephthalato)dizinc(II)], [Zn2(C8H4O4)2(C12H10N4)]n or [Zn2(bdc)2(bib)]n [H2bdc is terephthalic acid and bib is 1,4-bis(imidazol-1-yl)benzene], the asymmetric unit contains one ZnII ion, with two half bdc anions and one half bib molecule lying around inversion centers. The ZnII ion is in a slightly distorted tetrahedral environment, coordinated by three carboxylate O atoms from three different bdc anions and by one bib N atom. The crystal structure is constructed from the secondary building unit (SBU) [Zn2(CO2)2N2O2], in which the two metal centers are held together by two bdc linkers with bis(syn,syn -bridging bidentate) bonding modes. The SBU is connected by bdc bridges to form a two-dimensional grid-like (4,4)-layer, which is further pillared by the bib ligand. Topologically, the dinuclear SBU can be considered to be a six-connected node, and the extended structure exhibits an elongated primitive approximately cubic framework. The three-dimensional framework possesses a large cavity with dimensions of approximately 10 × 13 × 17,Å in cross-section. The potential porosity is filled with mutual interpenetration of two identical equivalent frameworks, generating a novel threefold interpenetrating network with an ,-polonium topology [Abrahams, Hoskins, Robson & Slizys (2002). CrystEngComm, 4, 478,482]. [source] Inorganic,Organic Hybrid Structures: Open-Framework Iron Phosphite,Oxalates of Varying DimensionalityCHEMISTRY - A EUROPEAN JOURNAL, Issue 3 2007Sukhendu Mandal Abstract Inorganic,organic hybrid structures belonging to the family of iron phosphite,oxalates have been prepared by employing hydrothermal methods. Their structures, determined by single-crystal X-ray diffraction, show a hierarchy within the family. While compounds I and II are low dimensional, III,VI have three-dimensional structures. Compound I has edge-shared ladders of iron phosphite with oxalate units hanging from the iron centers. Compound II has a layer structure with a honeycomb-like arrangement. The three-dimensional hybrid structures have the oxalate units connected in both in-plane and out-of-plane modes. A newly identified secondary building unit (SBU-7) and the oxalate units satisfying the valence and coordination requirements in the structure of V are novel and noteworthy structural features. Magnetic studies show that the dominant interactions between the iron centers are antiferromagnetic. Similar to other known hybrid structures, the phosphite,oxalate structures appear to show wide compositional and structural diversity. [source] Rarely Decorated Rutile Frameworks Built from Triangular Organic Spacers and Distorted Octahedral Co3 Building BlocksEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 24 2007Feng Luo Abstract Under mild temperatures, the self-assembly of CoCl2 and H3BTC in a solution of dmso generates a guest-free metal,organic polymer, namely Co3(BTC)2(,1 -dmso)2(,2 -dmso)2(1: dmso = dimethylsulfoxide, H3BTC = 1,3,5-benzenetricarboxylic acid). In 1, the CoII ions show the six-coordinate octahedral geometry completed by the BTC3, ions and the dmso oxygen atoms; remarkably, the coordinated dmso ligands not only act as terminal ligands to complete the octahedral geometry of the CoII ions, but also play an important role in bridging CoII ions together to give the Co3 secondary building units (SBUs). From a topological viewpoint, this novel polymer is classified to be the decorated (3,6)-connected rutile net with the (4.62)2(42.610.83) topology, where BTC3, ligands and Co3 SBUs are viewed to be the 3- and 6-connected nodes, respectively. In addition, the magnetic properties of 1 are explored by using a linear trinuclear cobalt mode, thusleading to g = 2.41, J = ,34.92 cm,1, TIP = 340,×,10,6 cm3,mol,1,, = ,6 K (a , parameter was included to take into account intertrinuclear interactions).(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007) [source] Two-dimensional metal-organic frameworks containing linear dicarboxylatesACTA CRYSTALLOGRAPHICA SECTION B, Issue 5 2006Samuel M. Hawxwell The solvothermal synthesis of four two-dimensional metal-organic frameworks containing linear dicarboxylic acids as ligands for ZnII centres is described. Zn(BDC)(DMF) [(1) where BDC = benzene-1,4-dicarboxylic acid; DMF = N,N -dimethylformamide] adopts a common paddlewheel motif leading to a 44 grid network, whereas Zn3(BDC)3(EtOH)2 (2), Zn3(BDC)3(H2O)2·4DMF (3) and Zn3(BPDC)3(DMF)2·4DMF (4) each form networks with the relatively uncommon 36 topology based upon Zn3(O2CR)6 secondary building units. All contain coordinated solvent molecules, namely DMF [(1) and (4)], ethanol (2) or H2O (3). Comparison of structures (2) and (3) illustrates a clay-like flexibility in interplanar spacing which sheds light on the ability of the Zn3(BDC)3 framework to undergo desolvation and uptake of small solvent and gas molecules. [source] A monoclinic pseudopolymorph of manganese squarate dihydrate, Mn(,-C4O4)(H2O)2, built from cubic unitsACTA CRYSTALLOGRAPHICA SECTION C, Issue 4 2009Elisabeth Gavilan The structure of poly[[[hexaaquatrimanganese(II)]-tri-,-squarato] monohydrate], {[Mn3(C4O4)3(H2O)6]·H2O}n, synthesized hydrothermally, consists of a new three-dimensional framework described by secondary building units (SBUs) containing two MnO6 octahedra and three squarate groups in a cube-shaped arrangement. In the asymmetric unit, one squarate group is located around an inversion centre (4a; 0, 0, 0), two Mn atoms [4d (, , 0) and 4c (, , 0)] are located on inversion centres and the third Mn atom is on a twofold axis (4e; 0, y, ). This report illustrates the concept of the SBU and the flexibility of the squarate spacer in the design of new porous topologies. [source] Synthesis and Properties of (Triptycenedicarboxylatio)zinc Coordination NetworksCHEMISTRY - A EUROPEAN JOURNAL, Issue 23 2009Sergei Abstract Paddle wheels and pillars: Layered 3D metal,organic frameworks comprised of paddle-wheel coordination units are constructed under a variety of conditions to incorporate bridging ligands (as illustrated) that impart desired properties, such as guest-exchange behavior, luminescence, microporosity, and stability, to the material. (Triptycenedicarboxylato)zinc metal,organic frameworks (MOFs) based on paddle wheel secondary building units (SBUs) with different axial ligands have been prepared. The reproducible formation of the layered paddle-wheel structures from triptycenedicarboxylic acid (H2TDC) and zinc nitrate under various conditions seems to be characteristic of this acid and is utilized for the construction of 3D frameworks by a pillaring approach. We attempted to bring additional functionalities into MOFs by employing the appropriate pillaring ligands, for example, bis(4-pyridyl)- s -tetrazine and bis(4-pyridyl)-dimethoxy- p -phenylenedivinylene, and investigated certain properties of some MOF materials, such as guest-exchange behavior, luminescence, microporosity, and stability. [source] Linking Two Distinct Layered Networks of Nanosized {Ln18} and {Cu24} Wheels through Isonicotinate LigandsCHEMISTRY - A EUROPEAN JOURNAL, Issue 1 2008Jian-Wen Cheng Abstract A new series of heterolanthanide(III)-copper(I) wheel-cluster complexes [Ln6(,3 -O)2](IN)18[Cu8(,4 -I)2(,2 -I)3],H3O (IN=isonicotinate; Ln=Y 1, Nd 2, Dy 3, Gd 4, Sm 5, Eu 6, Tb 7) were prepared by hydrothermal reaction at low pH. X-ray crystallographic studies reveal that two unusual trinuclear [Ln3(,3 -O)] and tetranuclear [Cu4(,4 -I)] cores are successfully used as secondary building units to make two different nanosized wheels [Ln18(,3 -O)6(CO2)48]6,, {Ln18}, and [Cu24(,4 -I)6(,2 -I)12]6+, {Cu24}, with 12-rings and a diameter of 26.7 and 26.4,Å, respectively. The wheels are further assembled into two-dimensional (2D) {Ln18} and {Cu24} networks, the linkages between two distinct layered networks of {Ln18} and {Cu24} wheels by IN pillars along the c axis giving a series of unprecedented three-dimensional (3D) sandwich frameworks. To our knowledge, compounds 1,7 are the first examples containing two different layered networks of nanosized Ln and transition metal (TM) wheels in wheel-cluster chemistry. The IR, UV/Vis, thermogravimetric analysis (TGA), luminescent, and magnetic properties of these complexes were also studied. [source] | ||||||||||