Search results for "Oct"
showing 10 items of 3052 documents
Coordination compounds of methazolamide. Synthesis, spectroscopic studies and crystal structures of [M(Methazolamidato)2(py)2(OH2)2] (M CoII, NiII …
1992
Abstract The synthesis and X-ray crystallographic characterization of three monomeric transition-metal coordination compounds with the ligand methazolamide {[N(4-methyl-2- sulphamoyl-Δ21,3,4-thiodiazolin-5-ylidene)],acetamide} (abbreviated as Hmacm) are described, via [M(macm)2(py)2(OH2)2] [M Co(1), Ni(2) and Cu(3)]. In all the compounds the metal ion, lying on the centre of symmetry, is surrounded by two sulphonamidato nitrogen atoms and two pyridine nitrogen atoms in equatorial sites and two oxygen water molecules in axial positions. The coordination geometry of the metal is an almost regular octahedron around the cobalt(II) and nickel(II) ions. In contrast, the copper(II) ion has a sig…
Cobalt(II), nickel(II) and copper(II) complexes withN-cyano-N?-methyl-N?(2-[(5-methyl-1H-imidazol-4-yl)methylthio]ethyl)guanidine
1985
N-Cyano-N′-methyl-N″(2-[(5-methyl-1H-imidazol-4-yl)-methylthio] ethyl) guanidine cimetidine (CM), complexes with CoII, NiII and CuII are described. The compounds are of stoichiometry [M(CM)2]SO4 · nH2O [M = CoII, NiII or CuII; n = 3,3 or 4, respectively], [M(CM)2](ClO4)2 [M = CoII or NiII], [M(CM)2]Cl2 · nH2O [M=CoII, NiII or CuII; n = 1, 2, or 2, respectively] and [Cu(CM)SO4] · 2H2O. The electronic spectra of the compounds in solid state, magnetic susceptibilities and i.r. and e.p.r. spectra were studied. Octahedral environments are proposed for the complexes: [M(CM)2]SO4·nH2O, [M(CM)2](ClO4)2, [Ni(CM)2]Cl2 · 2H2O, [Cu(CM)2]Cl2 · 2H2O and [Cu(CM)SO4] · 2H2O and a tetrahedral structure for …
Simultaneous gas chromatographic determination of aliphatic C2−C20 n-carboxylic acids and their methyl esters using SE-30 and OV-351 quartz capillary…
1983
Simultaneous determination of aliphatic C2−C20 carboxylic acids and their methyl esters was carried out using SE-30 and OV-351 quartz capillary columns with temperature programming. Complete resolution of all 36 components was achieved. On SE-30 the methyl ester and the corresponding free acid are eluted in turn, whereas on OV-351 acetic acid eluted after methyl octanoate, after which the Cn methyl ester and Cn-6 carboxylic acid (n>9) are eluted one after the other. A non-polar SE-30 column is better for long-chain acids giving sharp peaks without tailing, the analysis time of the mixture being less than 16 minutes. The weight response correction factors for compounds under optimum operatin…
1-{2-[4-(4-Nitrophenyl)piperazin-1-yl]ethyl}-4-aza-1-azoniabicyclo[2.2.2]octane iodide
2012
The title compound, C18H28N5O2+·I−, was observed as a main product in an intended 1:1 reaction between 4-iodonitrobenzene and 1,4-diazabicyclo[2.2.2]octane (DABCO). In the reaction, DABCO undergoes a ring opening to yield a quaternary salt of DABCO and 1-ethyl-4-(4-nitrophenyl)piperazine with an iodide anion. The crystal structure determination was carried out as no crystal structure had been previously reported in the investigations describing the corresponding reaction with 4-chloronitrobenze. Indeed, the crystal structure of the title compound confirms the molecular composition proposed earlier for the analogous chloride salt. The cation conformation is similar to the …
Synthesis, Crystal Structure and Magnetic Properties of [Fe(bpe)4(H2O)2](TCNQ)2 (bpe = trans-1,2-bis(4-pyridyl)ethane and TCNQ = tetracyanoquinodimet…
2005
The synthesis, structure and magnetic properties of [Fe(bpe)4(H2O)2](TCNQ)2 (1) are reported. 1 crystallizes in the triclinic P space group, a = 13.481(5), b = 14.887(3), c = 16.663(4) A, α = 101.048(18), β = 112.84(2), γ = 90.92(2)°, V = 3009.6(14) A3, Z = 2. The iron atom defines a compressed octahedron with the equatorial positions occupied by the bpe molecules which act as monodentate ligands and the two axial positions occupied by water molecules. The TCNQ− radical counterions are uncoordinated and interact by pairs defining (TCNQ)22− units strongly coupled antiferromagnetically. The iron(II) atoms are in the high spin state and its magnetic behaviour indicates the occurrence of zero-f…
In vitro evaluation of leishmanicidal properties of a new family of monodimensional coordination polymers based on diclofenac ligand
2020
Some series of isostructural chains with general formula [M(diclof)(HO)]·(EtOH) have been obtained from reaction between diclofenac ligand (diclof) and first row transition salts (M = Mn (1),Ni (2) and Co (3)). These monodimensional coordination polymers have been characterized and their crystal structures have been solved by X-ray diffraction methods, elucidating isostructural compounds that are chains with water molecules acting as bridge between different metallic centers, while diclofenac ligands are coordinated to the octahedral coordination environment of the same. Magnetic studies of these complexes have revealed the existence of moderate ferromagnetic interactions among manganese, n…
ChemInform Abstract: New Conditions for the Generation of Dianions of Carboxylic Acids.
2010
Abstract Lithium carboxylic acid enediolates are generated efficiently using lithium amides prepared from thienyllithium or butyllithium and either diethylamine, piperazine, N,N′-dibenzylethylenediamine, N-benzylpiperazine or 1,3,3-trimethyl-6-azabicyclo[3.2.1]octane, even in catalytic amounts.
Synthesis, infrared and M�ssbauer characterization and X-ray crystal structure of 1,10-phenanthrolinium tetrachloromethoxy phenylantimonate(V)
1991
The compound has been characterized by X-ray crystal structure determination, Mossbauer and i.r. spectroscopy. It crystallizes in the monoclinic space groupP21/c (No. 14) witha=24.228(4),b=8.335(2),c=23.975(4) A,β=117.83(3)° andZ=8. Least-squares refinement on 3749 observed reflections gave finalR=0.034 (Rw=0.037). The compound is constituted by [(C6H5)SbCl4OMe]− anions andphenH+cations. The coordination polyhedron about Sb is an octahedron (Sb-Cl 2.416(3), Sb-O 1.962(7) and Sb-C 2.138(9) A). The whole structure is characterized by two short contacts (O(1)⋯N(2) 2.76(1) O(2)⋯N(4) 2.75(1) A) involving the methoxy oxygens of the two independent anionic units [(C6H5)SbCl4OMe]− and two nitrogens…
Halogen Bonding Based “Catch and Release”: Reversible Solid State Entrapment of Elemental Iodine with Mono-Alkylated DABCO Salts
2012
The halogen bonding (XB) between elemental iodine (I2) and neutral 1,4-diazabicyclo[2.2.2]octane (DABCO) and its monoalkylated PF6– salts was studied by X-ray crystallographic, thermoanalytical, and computational methods. DABCO was found to form both 1:1 and 1:2 complexes with I2 showing an exceptionally strong halogen bond (ΔEcp = −73.0 kJ/mol) with extremely short N···I distance (2.37 A) in the 1:1 complex (1a). In the more favored 1:2 complex (1b), the XB interaction was found to be slightly weaker [ΔEcp = −64.4 kJ/mol and d(N···I) = 2.42 A] as compared to 1a. The monoalkylated DABCO salts (2PF6–7PF6) form corresponding 1:1 XB complexes with I2 {[2···I2]PF6–([7···I2]PF6} similarly to the…
C-Methyl resorcin[4]arene packing motifs with alkyl ammonium salts: From molecular capsules to channels and tubes
2005
A variety of packing motifs of C-methyl resorcinarene were obtained when complexed with small alkyl ammonium salts of different size and shape. Using bromide and chloride salts of the small quaternary alkyl ammonium cations, tetramethyl ammonium and dimethyldiethyl ammonium, leads to a grid-like packing of solvent mediated dimeric capsules while the use of salts of larger diquaternary cations bearing a 1,4-diazabicyclo[2.2.2]octane (DABCO) scaffold produces solvent/anion mediated chains and channels or tubular structures. The connecting interactions between resorcinarenes in each structure are hydrogen bonding and/or π⋯π interactions.