The use of hydrothermal methods in the synthesis of novel open-framework materials

The preparation of inorganic compounds, exhibiting open-framework structures, by hydrothermal methods has been presented. To illustrate the efficacy of this approach, few select examples encompassing a wide variety and diversity in the structures have been provided. In all the cases, good quality single crystals were obtained, which were used for the elucidation of the structure. In the first example, simple inorganic network compounds based on phosphite and arsenate are described. In the second example, inorganic-organic hybrid compounds involving phosphite/arsenate along with oxalate units are presented. In the third example, new coordination polymers with interesting structures are given. The examples presented are representative of the type and variety of compounds one can prepare by careful choice of the reaction conditions

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176 p.Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1978.U of I OnlyRestricted to the U of I community idenfinitely during batch ingest of legacy ETD

Amine-intercalated layered Sn<SUP>II</SUP> phosphates with open-framework structures

Three new SnII phosphate materials, [NH3(CH2)3 NH2(CH2)2NH2(CH2)3 NH3]&#183;2[Sn2P2O8] (I), [(N2C5H14)2][Sn4P4 O16]&#183;3H2O (II) and [(N2C5H14)] [Sn2P2O8]&#183;H2O (III), have been synthesised by means of hydrothermal methods using N,N'-bis(3-aminopropyl)ethylenediamine (BAPEN; for I) and homopiperazine (H-PIP; for II and III), respectively, as the structure-directing organic amines. The solids I-III have layered architectures. The structures of all three compounds consist of strictly alternating vertex-sharing trigonal-pyramidal SnO3 and tetrahedral PO4 moieties forming infinite layers possessing apertures bound by 4- and 8-T atoms (T = Sn, P). The distorted 4- and 8-membered apertures within the layers suggest the subtle influence of the lone-pair of electrons of SnII on the structure. The interlamellar space is occupied by the protonated organic amine molecules which interact with the framework through N-H&#183;&#183;&#183;O hydrogen bonding. The compounds I-III bear some structural relationship to the layered zinc phosphite phases

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  Congenital long QT syndrome (LQTS), referred to as a ticking time-bomb is a cause of sudden death in young infants, children and adults.1 Its prevalence is estimated to be 1 in 2500 to 1 in 10,000 individuals internationally, with no racial predilection.2 It should be viewed as an unrecognized rather than a rare condition.1 This is a descriptive report of eight children diagnosed to have congenital LQTS from 2000 to 2007 (Table 1), in Sarawak General Hospital, Kuching, Sarawak, Malaysia, the main tertiary referral hospital for Sarawak. The population of Sarawak (2006 Census) was 2,357,500 and that of Kuching, 435,000

Amine-Intercalated Layered SnIISn^{II} Phosphates with Open-Framework Structures

Three new $Sn^{II}$ phosphate materials, $[NH_3(CH_2)_3NH_2(CH_2)_2-NH_2(CH_2)_3NH_3]·2[Sn_2P_2O_8]$ (I), $[(N_2C_5H_{14})_2][Sn_4P_4O_{16}]·3H_2O$ (II) and $[(N_2C_5H_{14})][Sn_2P_2O_8]·H_2O$ (III), have been synthesised by means of hydrothermal methods using N,N'-bis(3-aminopropyl)ethylenediamine (BAPEN; for I) and homopiperazine (H-PIP; for II and III), respectively, as the structure-directing organic amines. The solids I–III have layered architectures. The structures of all three compounds consist of strictly alternating vertex-sharing trigonal-pyramidal $SnO_3$ and tetrahedral $PO_4$ moieties forming infinite layers possessing apertures bound by 4- and 8-T atoms (T = Sn, P). The distorted 4- and 8-membered apertures within the layers suggest the subtle influence of the lone-pair of electrons of SnII on the structure. The interlamellar space is occupied by the protonated organic amine molecules which interact with the framework through N–H···O hydrogen bonding. The compounds I–III bear some structural relationship to the layered zinc phosphite phases

Synthesis, structure and magnetic behavior of a new three-dimensional Manganese phosphite-oxalate: [C2N2H10][Mn-2(II)(OH2)(2)(HPO3)(2)(C2O4)]

A novel manganese phosphite-oxalate, [C2N2H10][Mn-2(II)(OH2)(2)(HPO3)(2)(C2O4)] has been hydothermally synthesized and its structure determined by single-crystal X-ray diffraction. The structure consists of neutral manganese phosphite layers, [Mn(HPO3)](infinity), formed by MnO6 octahedra and HPO3 units, cross-linked by the oxalate moieties. The organic cations occupy the middle of the 8-membered one dimensional channels. Magnetic studies indicate weak antiferromagnetic interactions between the Mn2+ ions. (C) 2009 Elsevier Inc. All rights reserved

Synthesis, Structure, and Solid-State Transformation Studies of Phosphonoacetate Based Hybrid Compounds of Uranium and Thorium

Three new phosphonoacetate hybrid frameworks based on the actinide elements uranium and thorium have been synthesized. The compounds [C4N2H14][(UO2)(2)(O3PCH2COO)(2)]center dot H2O, I,[C4N2H14][(UO2)(2)(C2O4)(O3PCH2COOH)(2)], II, and Th(H2O)(2)(O3PCH2COO)(C2O4)(0.5). H2O, III, are built up from the connectivity between the metal polyhedra and the phosphonoacetate/oxalate units. Compound II has been prepared using a solvent-free approach, by a solid state reaction at 150 degrees C. It has been shown that II can also be prepared through a room temperature mechanochemical (grinding) route. The layer arrangement in III closely resembles to that observed in I. The compounds have been characterized by powder X-ray diffraction, IR spectroscopy, thermogravimetric analysis, and fluorescence studies

Synthesis, structure and magnetic behavior of a new three-dimensional Manganese phosphite-oxalate: [C2N2H10][Mn-2(II)(OH2)(2)(HPO3)(2)(C2O4)]

A novel manganese phosphite-oxalate, [C2N2H10][Mn-2(II)(OH2)(2)(HPO3)(2)(C2O4)] has been hydothermally synthesized and its structure determined by single-crystal X-ray diffraction. The structure consists of neutral manganese phosphite layers, [Mn(HPO3)](infinity), formed by MnO6 octahedra and HPO3 units, cross-linked by the oxalate moieties. The organic cations occupy the middle of the 8-membered one dimensional channels. Magnetic studies indicate weak antiferromagnetic interactions between the Mn2+ ions. (C) 2009 Elsevier Inc. All rights reserved

Hierarchical Structures in Tin(II) Oxalates

Six new $Sn^{II}$ oxalates exhibiting a hierarchy of structures have been prepared employing hydrothermal methods. The compounds I $[C_{10}N_2H_{10}][Sn(C_2O_4)_2]$, II $[C_{10}N_2H_{10}][Sn_2(C_2O_4)_3]$, and III $[C_8N_4H_{26}][Sn(C_2O_4)_2]_2.2H_2O$ possess zero-dimensional molecular structures; IV $[C_{10}N_2H_8]_2[Sn(C_2O_4)]_2$ and V $[C_{12}N_2H_8][SnC_2O_4]$ have one-dimensional chain structures; and compound VI $[C_5N_2H_{14}]_2[Sn_4(C_2O_4)_6]·7H_2O$ has a two-dimensional layer structure. The SnII ions have 4- and 6-coordination with square-pyramidal or pentagonal-bipyramidal geometry, in which the lone pair of electrons also occupies one of the vertices. Weak intermolecular forces such as hydrogen-bond interactions, \pi ... \pi interactions, and lone-pair- \pi interactions have been observed and appear to lendstructural stability. Theoretical studies indicate that the \pi ... \pi interaction energy between the bound 1,10-phenanthroline molecules is of the order of 5-6 kcal mol-1 in V. Natural bond orbital (NBO) analysis on two model compounds, II and IV, indicates reasonable lone-pair- \pi interactions. The close structural relationship between all the compounds indicates that a building-up process from the zero-dimensional monomer can be considered. The present structures provide opportunities for evaluating the structure-directing role of the lone pair of electrons of $Sn^{II}

New open-framework phosphate and phosphite compounds of gallium

Five new open-framework compounds of gallium have been synthesized by hydrothermal methods and their structures determined by single crystal X-ray diffraction studies. The compounds, C8N4H26]Ga6F4(PO4)(6)], I, C5N3H11]Ga3F2(PO4)(3)]center dot H2O, II, C6N3H19]Ga-4(C2O4)(PO4)(4)(H2PO4)]center dot 2H(2)O, III, Ga2F3(HPO4)(PO4)]center dot 2H(3)O, IV, and C3N2H5](2)Ga-4(H2O)(3)(HPO3)(7)], V, possess three-dimensional structures. All the compounds are formed by the connectivity between the Ga polyhedra and phosphite/phosphate units. The observation of SBU-6 (I and II) and spiro-5 (IV) secondary building units (SBUs) are noteworthy. The flexibility of the formation of gallium phosphate frameworks has been established by the isolation of two related structures (I and II) from the same SBU units but different organic amines. Some of the present structures have close resemblance to the gallium phosphate phases known earlier. The compounds have been characterized by CHN analysis, powder XRD, IR, and TGA. (C) 2011 Elsevier B. V. All rights reserved