Tetraaquabis(3,5‐dicarboxybenzoato‐O)cobalt(II)

The hydro­thermal reaction of cobalt(II) chloride with trimesate (3,5‐di­carboxy­benzoate) ions in aqueous solution gives the novel title complex, [Co(C₉H₅O₆)₂(H₂O)₄]. The Co^II ion lies on an inversion centre and is octahedrally coordinated to two trimesate anions and four water mol­ecules. Hydro­gen bonds ensure the three‐dimensional architecture of the structure.     

Tetraaquabis(2‐methoxybenzaldehyde isonicotinoylhydrazone)cadmium(II) dinitrate

The Cd^II centre in the title complex, [Cd(C₁₄H₁₃N₃O₂)₂(H₂O)₄](NO₃)₂, occupies a crystallographic inversion centre and is coordinated by two donor N atoms from two 2‐methoxybenzldehyde isonicotinoylhydrazone ligands and by four O atoms from four coordinated water molecules, giving a slightly distorted octahedral geometry. There is an extended three‐dimensional network structure resulting from O—H...O hydrogen bonds between coordinated water and nitrate anions, and between coordinated water and carbonyl O atoms, and from N—H...O hydrogen bonds between NH groups and nitrate O atoms.     

Tetraaquabis(carbamoyldicyanomethanido‐κN)manganese(II) dihydrate

The crystal structure of [Mn(C₄H₂N₃O)₂(H₂O)₄]·2H₂O, conventionally abbreviated [Mn(cdm)₂(H₂O)₄]·2H₂O, where cdm is carbamoyldi­cyano­methanide, is described. The bond lengths and distances are comparable to those previously reported for the isomorphous Ni and Co analogs. Molecular units are formed by coordination of the nitrile N atoms of two cdm anions and four water mol­ecules to the manganese(II) cation. Although these mononuclear molecular species are connected via hydrogen bonding, no magnetic ordering was observed down to 1.55 K.     

Tetraaquabis(2,6‐diamine‐7H‐purine‐κN9)cobalt(II) benzene‐1,2,4,5‐tetracarboxylate tetrahydrate

The title compound, [Co(C₅H₇N₆)₂(H₂O)₄](C₁₀H₂O₈)·4H₂O, is an ionic structure comprising a [Co(Hdap)₂(H₂O)₄]⁴⁺ cation (dap is 2,6‐diaminopurine) in a general position, two benzene‐1,2,4,5‐tetracarboxylate (btc⁴⁻) anions straddling two different inversion centres and four solvent water molecules. The structure presents a remarkable degree of pseudosymmetry, with the Co^II cation lying almost exactly on a noncrystallographic pseudo‐inversion centre. The overall spatial arrangement can be described in terms of cationic and anionic chains running along the [111] direction and linked into a three‐dimensional network by a very complex hydrogen‐bonding scheme in which all the available N—H and O—H groups take part.     

Poly[diaquabis(μ3‐2,2‐dimethylpropanedioato)calcium(II)copper(II)]

The title complex, [CaCu(C₅H₆O₄)₂(H₂O)₂]_n, is the first heterobimetallic complex based on a substituted malonate dianion. The Cu^II cation and two independent 2,2‐dimethylmalonate (or 2,2‐dimethylpropanedioate) dianions build up a robust dianionic [Cu(C₅H₆O₄)₂]²⁻ complex, which acts as a building block to coordinate to four Ca²⁺ cations. Each Cu^II centre is in a four‐coordinate square plane of dimethylmalonate O atoms, while each Ca^II atom is in an eight‐coordinate distorted bicapped trigonal–prismatic environment of six O atoms from four different dimethylmalonate groups and two water molecules. This arrangement creates a two‐dimensional layer connectivity of the structure. The dianionic [Cu(C₅H₆O₄)₂]²⁻ units are involved in different intermolecular hydrogen‐bonding interactions with water molecules via the formation of hydrogen‐bonded rings of graph sets R₁²(8) and R(6) within this layer. The crystal was nonmerohedrally twinned by rotation about [011] with a major twin volume fraction of 0.513 (3).     

Rheology of (±)‐camphor‐10‐sulfonic acid doped polyaniline‐m‐cresol conducting gel nanocomposites

The rheological behavior of polyaniline‐(±champhor‐10‐sulfonic acid)_0.5‐m‐cresol [PANI‐CSA_0.5‐m‐cresol] gel nanocomposites (GNCs) with Na‐montmorillonite clay (intercalated tactoids) is studied. The shear viscosity exhibits Newtonian behavior for low shear rate (<2 × 10^?4 s^?1) and power law variation for higher shear rate. The zero shear viscosity (η₀) and the characteristic time (λ) increase but the power law index (n) decrease with increase in clay concentration. In the GNCs storage modulus (G′) and loss modulus (G″) are invariant with frequency in contrast to the pure gel. The G′ and G′ exhibit the gel behavior of the GNCs up to 105 °C in contrast to the melting for the pure gel at 75.7 °C. The percent increase of G′ of GNCs increases dramatically (619% in GNC‐5) with increasing clay concentration. The conductivity values are 10.5, 5.65, 5.51, and 4.75 S/cm for pure gel, GNC‐1, GNC‐3, and GNC‐5, respectively, promising their possible use in soft sensing devices. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 46: 28–40, 2008     

Synthesis and central nervous system stimulant activity of camphor‐1,2,3‐triazine fused with diphenylcyclopropenone and camphor‐1,2,3‐triazine n‐oxides

Reactions of camphor‐1,2,3‐triazine 1 with diphenylcyclopropenone 2 gave two cycloadducts; 6,9‐methanopyrazolo[1,2‐b][1,2,3]benzotriazinones 3–4. Oxidation of 1 with 3‐chloroperbenzoic acid gave 1‐oxide 5 as the major compound along with a trace of 1,2‐dioxide 6.     

Poly[tetra­aquadi‐μ3‐malonato‐cobalt(II)­calcium(II)]

The structure of the polymeric title compound, [CaCo(C₃H₂O₄)₂(H₂O)₄]_n, consists of CaO₈ and CoO₆ polyhedra linked together by malonate groups. The Co atom lies on a centre of symmetry in an octa­hedral arrangement, and is coordinated by four malonate O atoms in a planar arrangement and two water mol­ecules in a trans conformation. The geometry around the Ca atom, which lies on a twofold axis, may be described as a distorted square anti­prism, which involves two water mol­ecules and six malonate O atoms. The Co—O and Ca—O bond lengths are in the ranges 2.0711 (12)–2.1004 (14) and 2.3775 (12)–2.6329 (12) Å, respectively.     

3‐Deoxy‐β‐d‐ribo‐hexopyranose (3‐deoxy‐β‐d‐glucopyranose)

The β‐pyranose form, (III), of 3‐deoxy‐d ‐ribo‐hexose (3‐deoxy‐d ‐glucose), C₆H₁₂O₅, crystallizes from water at 298 K in a slightly distorted ⁴C₁ chair conformation. Structural analyses of (III), β‐d ‐glucopyranose, (IV), and 2‐deoxy‐β‐d ‐arabino‐hexopyranose (2‐deoxy‐β‐d ‐glucopyranose), (V), show significantly different C—O bond torsions involving the anomeric carbon, with the H—C—O—H torsion angle approaching an eclipsed conformation in (III) (−10.9°) compared with 32.8 and 32.5° in (IV) and (V), respectively. Ring carbon deoxygenation significantly affects the endo‐ and exocyclic C—C and C—O bond lengths throughout the pyranose ring, with longer bonds generally observed in the monodeoxygenated species (III) and (V) compared with (IV). These structural changes are attributed to differences in exocyclic C—O bond conformations and/or hydrogen‐bonding patterns superimposed on the direct (intrinsic) effect of monodeoxygenation. The exocyclic hydroxymethyl conformation in (III) (gt) differs from that observed in (IV) and (V) (gg).     

3,6‐Bis(dimethylamino)‐10‐(10‐iododecyl)acridinium iodide

In the title compound, C₂₇H₃₉IN₃⁺·I^?, the acridinium system shows the usual approximate mirror symmetry about the central C?N line, and the corresponding bond lengths and angles in the two halves agree within experimental error. The alkyl chain at the ring N atom is initially perpendicular to the ring plane and then bends sharply at the fourth C atom. Pairs of centrosymmetrically related cations overlap two of their rings and the di­methyl­amino groups are also partly involved in the overlap. Each I^? ion is involved in short‐range interactions with two cations. These interactions give rise to a 14‐membered cyclic structure, which involves pairs of cations and anions across an inversion centre.     

Tetraaquabis[5‐(3‐pyridyl‐κN)pyrimidine]zinc(II) bis(trifluoromethanesulfonate): a novel cationic complex and three‐dimensional hydrogen‐bonded network

The title compound, [Zn(C₉H₇N₃)₂(H₂O)₄](CF₃O₃S)₂, contains an octahedral [ZnL₂(H₂O)₄]²⁺ cationic complex with trans geometry (Zn site symmetry ), and each 5‐(3‐pyridyl)pyrimidine (L) ligand is coordinated in a monodentate fashion through the pyridine N atom. In the extended structure, these complexes, with both hydrogen‐bond acceptor (pyrimidine) and donor (H₂O) functions, are linked to each other by intermolecular water–pyrimidine O—H...N hydrogen‐bonding interactions, resulting in a double chain along the crystallographic a axis. The trifluoromethanesulfonate anions are integrated into the chains via O—H...O hydrogen bonds between the coordinated water and sulfonate O atoms. These double chains are associated into a novel three‐dimensional network through interchain water–pyrimidine O—H...N hydrogen bonds. The asymmetric ligand plays an important role in constructing this unusual supramolecular structure.     

Diaqua[methyl 4‐O‐benzyl‐2,3,6‐tri‐O‐(2‐picolyl)‐α‐d‐mannopyranoside]cobalt(II) bis(perchlorate) monohydrate: partial coordination of a ligand derived from d‐mannose

The title compound, [Co(C₃₂H₃₅N₃O₆)(H₂O)₂](ClO₄)₂·H₂O, contains a cationic complex with a novel facultative hexadentate sugar‐derived ligand coordinated in a tetradentate fashion to give a CoN₂O₄ coordination. The partial coordination is imposed by the rigid conformation of the sugar. The pyridine group that is not bound to the metal is free to participate in intermolecular hydrogen bonding and π–π stacking interactions.     

Supramolecular networks of 10‐(2‐hydroxyethyl)acridin‐9(10H)‐one and 10‐(2‐chloroethyl)acridin‐9(10H)‐one

Both 10‐(2‐hydroxyethyl)acridin‐9(10H)‐one, C₁₅H₁₃NO₂, and 10‐(2‐chloroethyl)acridin‐9(10H)‐one, C₁₅H₁₂ClNO, have monoclinic (P2₁/c) symmetry and supramolecular three‐dimensional networks. But the differences in the intermolecular interactions displayed by the hydroxy group and the chlorine substituent lead to stronger intermolecular π‐stacking interactions and hydrogen bonding, and hence a significantly higher melting point for the former.     

Poly[hexaaquabis(μ4‐4‐carboxybenzenesulfonato)bis(μ3‐4‐carboxybenzenesulfonato)calcium(II)dipotassium(I)]

This study presents the coordination modes and crystal organization of a calcium–potassium coordination polymer, poly[hexaaquabis(μ₄‐4‐carboxybenzenesulfonato‐κ⁴O¹:O^1′:O^1′′:O⁴)bis(μ₃‐4‐carboxybenzenesulfonato‐κ²O¹:O^1′)calcium(II)dipotassium(I)], [CaK₂(C₇H₅O₅S)₄(H₂O)₆]_n, displaying a novel two‐dimensional framework. The potassium ion is seven‐coordinated by four sulfonate and one carboxyl O atom located on five different acid ligands, two of which are unique, and by two symmetry‐independent water O atoms. A pair of close potassium ions share two inversion‐related sulfonate O‐atom sites to form a dimeric K₂O₁₂ unit, which is extended into a one‐dimensional array along the a‐axis direction. The six‐coordinate Ca²⁺ ion occupies a special position () at (0, , ) and is surrounded by four sulfonate O atoms from two inversion‐related pairs of unique acid monoanions and by two O atoms from aqua ligands. The compound displays a layered structure, with K₂O₁₂ and CaO₆ polyhedra in the layers and aromatic linkers between the layers. The three‐dimensional scaffold is open, with nano‐sized channels along the c axis.     

Poly[tetra­aqua­di‐μ3‐malonato‐calcium(II)­zinc(II)]

The title complex, [CaZn(C₃H₂O₄)₂(H₂O)₄]_n, is a two‐dimensional polymer and consists of CaO₈ and ZnO₆ polyhedra linked together by malonate ligands. The Ca^II cation, lying on a twofold axis, is coordinated by two water mol­ecules and six malonate O atoms. The Zn^II cation, which lies on an inversion center in an octa­hedral environment, is coordinated by four malonate O atoms in an equatorial arrangement and two water mol­ecules in axial positions. The Zn—O and Ca—O bond lengths are in the ranges 2.0445 (12)–2.1346 (16) and 2.3831 (13)–2.6630 (13) Å, respectively. The structure comprises alternating layers along the [101] plane, the shortest Zn⋯Zn distance being 6.8172 (8) Å. The whole three‐dimensional structure is maintained and stabilized by the presence of hydrogen bonds.     

Poly[[diaqua(μ3‐3‐nitrophthalato)calcium(II)] monohydrate]

The title 3‐nitrophthalate–calcium coordination polymer, {[Ca(C₈H₃NO₆)(H₂O)₂]·H₂O}_n, crystallizes as a one‐dimensional framework. The Ca^II centre has a distorted pentagonal–bipyramidal geometry, being seven‐coordinated by five O atoms from three different 3‐nitrophthalate groups and by two water molecules, resulting in a one‐dimensional zigzag chain along the a‐axis direction by the interconnection of the four O atoms from the two carboxylate groups. There is a D3 water cluster composed of the coordinated and the solvent water molecules within such chains. Adjacent chains are aggregated into two‐dimensional layers via hydrogen bonds in the c‐axis direction. The whole three‐dimensional structure is further stabilized by weak O—H...O hydrogen bonds between the O atoms of the nitro group and the water molecules.     

Monomere und polymere Dimethylaminothioquadratato‐Komplexe: Die Kristallstrukturen von Nickel(II)‐, Cobalt(II)‐, Silber(I)‐, Platin(II)‐, Gold(I)‐, Quecksilber(II)‐ und Blei(II)‐Dimethylaminothioquadrataten

Monomeric and Polymeric Dimethylaminothiosquarato Complexes: The Crystal Structures of Nickel(II), Cobalt(II), Silver(I), Platinum(II), Gold(I), Mercury(II) and Lead(II) Dimethylaminothiosquarates The ligand 2‐dimethylamino‐3, 4‐dioxo‐cyclobut‐1‐en‐thiolate, Me₂N‐C₄O₂S⁻ (L) forms neutral and anionic complexes with nickel(II), cobalt(II)‐, silver(I)‐, platinum(II)‐, gold(I)‐, mercury(II)‐ and lead(II). According to the crystal structures of seven complexes the ligand is O, S‐chelating in [Ni(L)₂(H₂O)₂]·2 H₂O, [Co(L)₂(CH₃OH)₂] and (with limitations) in [Pb(L)₂·DMF]. In the remaining compounds the ligand behaves essentially as a thiolate ligand. The platinum, gold and mercury complexes [TMA]₂[Pt(L)₄], [TMA] [Au(L)₂] and [Hg(L)₂] are monomeric. In [TMA][Ag₂(L)₃]·5.5 H₂O a chain‐like structure was found. In the asymmetric unit of this structure eight silver ions, with mutual distances in the range 2.8949(4) to 3.1660(3)Å, are coordinated by twelve thiosquarato ligands. [Pb(L)₂·DMF] has also a polymeric structure. It contains a core of edge‐bridged, irregular PbS₄ polyhedra. TMA[Au(H₂NC₄O₂S)₂] has also been prepared and its structure elucidated.