Joselyn Albanez

Supramolecular Structure, Thermal and Spectroscopic Properties of a New Coordination Polymer: Catena-Bis(μ2-4,4′-dipyridyldisulfide-κ2N,N′)-Bis(AQUO)-Copper(II)di-trifluoromethanesulfonate

A new supramolecular network of copper (II), [{Cu(bpds)2(H2O)2}] • 2CF3SO3]n, (I), (bpds = 4,4′-bipyridildisulfide) has been synthesized and characterized by elemental analysis and Fourier transform infrared (FT-IR) and its structure determined using X-ray crystallography. The thermal decomposition mechanism of the complex was studied by using thermogravimetry-derivative thermogravimetry (TG-DTG) techniques. X-ray structural analysis revealed that the coordination polymer displays 1D chains. The octahedral O2N4 chromophore surrounding the metal ion forms via two trans located water oxygen and four nitrogen from four bpds ligand. The structure consists of Cu(H2O)2 fragments linked by pairs of bpds ligand to form a double-stranded chain. The thermogravimetric analysis indicates sequential loss of adsorbed and coordinated water and triflate counter ion, prior to more comprehensive ligand fragmentation at elevated temperatures.

Diaqua-bis-(5-methyl-pyrazine-2-carboxyl-ato-κN,O)cadmium.

In the title compound, [Cd(C6H5N2O2)2(H2O)2], the CdII ion is coordinated in a severely distorted octahedral geometry. The N atoms are cis to each other, while the water O atoms and ligand O atoms are mutually trans. The crystal structure is stabilized by a network of O—H⋯O, O—H⋯N and C—H⋯O hydrogen bonds and π–π stacking interactions [centroid–centroid distances = 3.730 (3) and 3.652 (3) Å] between the 5-methylpyrazine-2-carboxylate ligands. The structure is isotypic with the manganese analog.

SYNTHESIS AND THERMAL PROPERTIES OF TWO NEW DICATIONIC IONIC LIQUIDS

abStract Two new dicationic ionic liquids 1,7-bis(3-methylimidazolium-1-yl)heptane bromide (I) and 1,8-bis(3-methylimidazolium-1-yl)octane bromide (II) have been synthesized and characterized by elemental analysis, FT-IR, 1 H and 13 C NMR, and TG-DSC techniques. The compound (I) is liquid at room temperature, whereas (II) is liquid at 42.7oC. Keywords : Dicationic Ionic liquids, thermal properties, synthesis. introduction Ionic liquids (ILs) have been recognized as potential new green alternatives to conventional organic solvents in a wide range of synthetic, catalytic, separation and electrochemical applications. They are characterized by their unique physicochemical properties, including low melting points, low inflammability, and tunable hydrophobicities. They are stable in a wide range of temperature, and have great chemical and electrochemical stability. In addition, they have negligible vapor pressures so there is no loss of solvent through evaporation, avoiding environmental problems due to volatilization

2-Phenyl-ethyl 1-thio-β-d-galactopyran-oside hemihydrate.

The title compound, C14H20O5S·0.5H2O, crystallizes with two organic molecules and a solvent water molecule in the asymmetric unit. In both molecules, the hexapyranosyl rings adopt a slightly distorted chair conformation (5 C 2) with four substituents in equatorial positions and one substituent in an axial position. The main difference between the organic molecules is the dihedral angle between the phenyl ring and the best plane defined by the O—C1—C2—C3 atoms (r.m.s deviations = 0.003 and 0.043 Å) of the hexapyranosyl rings [47.4 (4) and 86.5 (4)°]. In the asymmetric unit, molecules are linked by two strong O—H⋯O hydrogen bonds. In the crystal, the components are linked by a total of 10 distinct O—H⋯O hydrogen bonds, resulting in the formation of a two-dimensional network parallel to the ab plane.

Trithia­cyanuric acid: a second triclinic polymorph

The title compound, C3H3N3S3, is a triclinic modification. The other reported modification crystallizes with just one molecule in the asymmetric unit, [Guo et al. (2006 ▶). Cryst. Growth Des. 6, 846–848] and was solved by power X-ray diffraction data. The present modification has Z′ = 2. In the crystal, molecules are linked by strong intramolecular N—H⋯S hydrogen bonds with set graph-motif R 2 2(8). In both molecules, all of the N atoms and two of the S atoms are involved in hydrogen bonding, with an average H⋯S distance of 2.58 Å and N—H⋯S angles in the range 163–167°. π–π stacking interactions are not observed. In the solid state, the molecules exist in the thione form. The molecular and supramolecular properties are similar in both polymorphs.

Disorder in the anionic part of catena-poly[[(pyrazine-2-carboxyl­ato)copper(II)]-μ-pyrazine-2-carboxyl­ato]

The title compound, [Cu(C5H3N2O2)0.88(C6H4NO2)1.12]n, is characterized by disorder of the anion, resulting from a statistical occupation in a 0.44 (3):0.56 (3) ratio of pyrazine-2-carboxylate and pyridine-2-carboxylate. The compound was isolated during attempts to synthesize a mixed-ligand coordination polymer by solvothermal reaction between copper(II) nitrate and equimolar mixtures of pyrazine-2-carboxylic acid and pyridine-2-carboxylic acid in a mixture of water and EtOH. The difference in the two components of the compound is due to substitutional disorder of a CH group for one of the N atoms of the pyrazine ring which share the same site in the structure. In the crystal structure, the CuII atom lies on an inversion centre and is six-coordinated in a distorted N2O4 geometry. The carboxylate group carbonyl O atoms are weakly coordinated to an equivalent CuII atom that is translated one unit cell in the a-axis direction, thus forming a polymeric chain through carboxylate bridges.

17-Acet­oxy­mulinic acid

The title compound, [systematic name: 5a-acetoxymethyl-3-isopropyl-8-methyl-1,2,3,3a,4,5,5a,6,7,10,10a,10b-dodecahydro-7,10-endo-epidioxycyclohepta[e]indene-3a-carboxylic acid], C22H32O6 (I), is closely related to methyl 5a-acetoxymethyl-3-isopropyl-8-methyl-1,2,3,3a,4,5,5a,6,7,10,10a,10b-dodecahydro-7,10-endo-epidioxycyclohepta[e]indene-3a-carboxylate, (II) [Brito et al., (2008 ▶). Acta Cryst. E64, o1209]. There are two molecules in the asymmetric unit, which are linked by two strong intramolecular O—H⋯O hydrogen bonds with graph-set motif R 2 2(8). In both (I) and (II), the conformation of the three fused rings are almost identical. The five-membered ring has an envelope conformation, the six-membered ring has a chair conformation and the seven-membered ring has a boat conformation. The most obvious differences between the two compounds is the observed disorder of the acetoxymethyl fragments in both molecules of the asymmetric unit of (I). This disorder is not observed in (II). The crystal structure and the molecular conformation is stabilized by intermolecular C—H⋯O hydrogen bonds. The ability to form hydrogen bonds is different in the two compounds. The crystal studied was a non-merohedral twin, the ratio of the twin components being 0.28 (1):0.72 (1)

(1R,3aR,5aS,6S,8aR,8bR,9aS)-1-Hydr-oxy-6-isopropyl-1,3a,5a-trimethyl-perhydro-cyclo-penta-[a]cyclo-propa[i]naphthalen-4-one.

The title compound (also know as azorellanone), C20H32O2, is built up from three fused carbocycles, one five-membered ring and two six-membered rings. The five membered-ring has an envelope conformation, whereas the six-membered rings have a distorted half-chair and a twist–boat conformation. In the crystal, molecules are linked by O—H⋯O interactions into zigzag chains with graph-set notation C(8) along [010]. The absolute configuration was assigned on the basis of earlier chemical studies.

S-(4-Nitrophenyl) 4-nitrobenzenethiosulfonate.

The title compound, C(12)H(8)N(2)O(6)S(2), (I), is a positional isomer of S-(2-nitrophenyl) 2-nitrobenzenethiosulfonate [Glidewell, Low & Wardell (2000). Acta Cryst. B56, 893-905], (II). The most obvious difference between the two isomers is the rotation of the nitro groups with respect to the planes of the adjacent aryl rings. In (I), the nitro groups are only slightly rotated out of the plane of the adjacent aryl ring [2.4 (6) and 6.7 (7) degrees ], while in (II) the nitro groups are rotated by between 37 and 52 degrees , in every case associated with S-S-C-C torsion angles close to 90 degrees . Other important differences between the isomers are the C-S-S(O(2))-C torsion angle [78.39 (2) degrees for (I) and 69.8 (3) degrees for (II) (mean)] and the dihedral angles between the aromatic rings [12.3 (3) degrees for (I) and 28.6 (3) degrees for (II) (mean)]. There are two types of C-H...O hydrogen bond in the structure [C...O = 3.262 (7) A and C-H...O = 144 degrees ; C...O = 3.447 (7) A and C-H...O = 166 degrees ] and these link the molecules into a two-dimensional framework. The hydrogen-bond-acceptor properties differ between the two isomers.

X-RAY CRYSTALLOGRAPHIC STRUCTURAL STUDY ON A NEW COORDINATION POLYMER: CATENA-di-μCHLORO-BIS[(di-2-PYRIDYLDISULFIDE- k² N, N') COPPER(I)]

abSTraCT In title compound, [CuCl(C 10 H 8 N 2 S 2 )] n , (I) each Cu(I) ion coordinates to two nitrogen atoms from two different ligands and to two chloro ions which bridge to another Cu(I) to complete a planar four-membered Cu 2 Cl 2 ring.The Cu + coordination geometry is best described as a slightly distorted tetrahedron. The structure consists of CuCl cores connected by 2, 2’-dypyridyldisulfide ligand and form a two-dimensional extended polymeric network in which the 2, 2’-dipyridyldisulfide ligand bridges Cu atoms. The title compound is isostructural with di-µ-chlorido-bis[(di-2-pyridyldisulfide-κ 2 N, N’) copper(I)], (II) 1 , which is a zero-dimensional binuclear compound. The two structures differ due conformational flexibility of ligand, which have axial conformation in (I) and equatorial conformation in (II), torsion angles S-S-C-N (axial ring) 168.8(4)o; for (I) and 72.0(3)o for (II) respectively. Keywords: Coordination polymes, disulfides, x-ray diffraction. INTrODuCTION