Organic Hybrid Structure Research Articles

(C2N2H10)2Mg(HP2O7)2·2H2O synthesis and crystal structure

(C2N2H10)2Mg(HP2O7)2·2H2O, is a new inorganic organic hybrid structure. It has been synthetized using wet chemistry. Its crystal structure consists of cis- and trans-edge sharing [MgO4(H2O)2] octahedra resulting in chains, which are linked via [HP2O7] units to form [Mg(HP2O7)2(H2O)2]4− layers. The Mg2+ cations and the ethylendiammonium cations are located on centers of inversion. The ethylendiammonium cations are alternately located in the interlayer space. The cohesion of the crystal is well ensured by coulombic interactions between anions and cations and by several hydrogen bonds. The diphosphate anion shows an eclipsed conformation.

Fabrication of Hierarchically Ordered Hybrid Structures over Multiple Length Scales via Direct Etching of Self-Organized Polyhedral Oligomeric Silsesquioxane (POSS) Functionalized Block Copolymer Films

A novel fabrication of hierarchically ordered organic and inorganic hybrid structures at length scales ranging from nanometers to micrometers was demonstrated by oxygen plasma treatment of self-organized silicon-containing block copolymer films. The rod-coil type silicon-containing block copolymer, polystyrene-b-polyisoprene with polyhedral oligomeric silsesquioxane (POSS) -modified side chains, was successfully synthesized by hydrosilation of polystyrene-b-poly(1,2-ran-3,4-isoprene) block copolymer with hydrido-heptacyclopentyl substituted POSS. The films were prepared from the polymer solution by casting on silicon wafers under a moist air flow. The self-organized microstructures were investigated by electron microscopy. It was found that the hexagonally packed micropores and phase-separated nanodomains were formed within the films. Oxygen plasma etching of the films provided novel hierarchically ordered hybrid structures.

Inorganic–organic hybrid structure: Synthesis, structure and magnetic properties of a cobalt phosphite–oxalate, [C 4N 2H 12][Co 4(HPO 3) 2(C 2O 4) 3

A hydrothermal reaction of a mixture of cobalt (II) oxalate, phosphorous acid, piperazine and water at 150 °C for 96 h followed by heating at 180 °C for 24 h gave rise to a new inorganic–organic hybrid solid, [C 4N 2H 12][Co 4(HPO 3) 2(C 2O 4) 3], I. The structure consists of edge-shared CoO 6 octahedra forming a [Co 2O 10] dimers that are connected by HPO 3 and C 2O 4 units forming a three-dimensional structure with one-dimensional channels. The amine molecules are positioned within these channels. The oxalate units have a dual role of connecting within the plane of the layer as well as out of the plane. Magnetic susceptibility measurement shows the compound orders antiferromagnetically at low temperature ( T N = 22 K ). Crystal data: I, monoclinic, space group= P2 1/ c (No. 14). a = 7.614 ( 15 ) , b = 7.514 ( 14 ) , c = 17.750 ( 3 ) Å , β = 97.351 ( 3 ) ° , V = 1007.30 ( 3 ) Å 3 , Z = 2 , ρ calc = 2.466 g / cm 3 , μ ( Mo K α ) = 3.496 mm - 1 , R 1 = 0.0310 and w R 2 = 0.0807 data [ I > 2 σ ( I ) ] .

The effect of carboxymethyl chitosan on the precipitation of calcium carbonate

It is believed that chitosan plays an important role on the formation of specific inorganic–organic hybrid structure of shells. In this paper, insoluble chitoan was modified to a water-soluble macromolecule—carboxymethyl chitosan (CMCS), and further used as an additive in the crystallization process of calcium carbonate (CaCO 3). The combination investigation of XRD, Micro FT-IR and SEM on the precipitated crystals shows that the addition of CMCS obviously changed the crystal morphology, but did not induce the transformation of the crystal form, i.e., CaCO 3 keeps calcite form in all the cases no matter whether CMCS exists or not in the precipitation systems. The morphological variation of CaCO 3 strongly depends on the CMCS concentration in the aqueous solutions.

Dendron rodcoils: synthesis of novel organic hybrid structures.

Convergent and divergent syntheses of novel organic hybrid structures termed dendron rodcoils (DRC) containing dendritic, rodlike, and coillike segments are described. The aryl ester dendron masked with 32 trifluoromethyl groups is prepared via a convergent approach using 5-(tert-butyldimethylsiloxy)isophthalic acid as the monomer unit. The activation of the focal point of the dendron allows for successful coupling between the dendron and the diblock rodcoil molecules synthesized separately. In another example, the dendritic block is grown via divergent strategy from the terminus of rodcoil using 3,5-bis(tert-butyldimethylsiloxy)benzoic acid as an AB(2) monomer. A combination of catalyzed esterification reactions and silyl deprotection chemistry proved to be a very efficient method for construction of these nanosized structures with unusual molecular architecture. Both synthetic strategies allowed for the preparation of DRCs with nearly monodisperse dendritic blocks as demonstrated by NMR, MALDI-TOF, and GPC measurements.

Inorganic hybrid open-framework structures: synthesis and structure of a cobalt phosphate-oxalate, [C4N2H12]0.5[Co2(HPO4)(C2O4)1.5

A new open-framework inorganic–organic hybrid structure involving cobalt, [N2C4H12]0.5[Co2(HPO4)(C2O4)1.5], has been synthesized for the first time by hydrothermal methods. The three-dimensional structure is formed by the edge-shared CoO6 and CoO5 polyhedra forming a [Co2O9] dimer, that are connected with the PO4 polyhedra and the oxalate units forming one-dimensional channels. The amine molecules are located within these channels. The oxalate units have a dual functionality of connecting within the plane of the layer as well as out of the plane. The material is thermally stable up to 350°C and orders anti-ferromagnetically at low temperatures. Crystal data: a=7.494(1), b=7.726(1), c=17.852(3) Å, β=97.7(1)°; V=1024.2(2) Å3; space group=P21/c (no. 14); Z=4; M=389.9; Dcalc.=2.529 g cm−3; λ(Mo–Kα)=3.451 mm−1; λ=0.71073 Å; R1=0.04; wR2=0.10 and S=1.13.

A hybrid open‐framework structure: synthesis and structure of an iron phosphate oxalate, [C10N4H28][Fe2(HPO4)3(C2O4)

A new inorganic–organic hybrid structure has been synthesized hydrothermally in the iron phosphate oxalate family using 1,4-bis(3-aminopropyl)piperazine as the structure-directing agent. Crystal data for I, [C10N4H28][Fe2(HPO4)3(C2O4)]2: M = 589.8, monoclinic, space group = P21/n (no. 14), a = 10.829(1), b = 12.747(1), c = 12.397(1) A, β = 95.1(1)°, V = 1704.4(3) A3, Z = 4, R = 0.036 and Rw = 0.083 [1860 observed reflections with I > 2σ(I)]. The structure comprises a network of FeO6 octahedra and PO4 tetrahedra forming inorganic layers which are bridged by the oxalate units forming 8-membered channels in which the amine molecule resides. Magnetic susceptibility studies indicate an antiferromagnetic behavior with TN = ≈40 K, the highest known in an open-framework material.