Home About us Contact
|
Home About us Contact | ||
|
|
||
One-dimensional Chain Structure (one-dimensional + chain_structure)
Selected AbstractsMono-, Di- and Polymeric Calcium and Gadolinium Complexes of the Tripodal Ligand 2,2,,2,,-Nitrilotribenzoic AcidEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 4 2005Stefan Wörl Abstract Three novel carboxylate-bridged complexes incorporating the tripodal N,O ligand 2,2,,2,,-nitrilotribenzoic acid H3L of formula [CaII(H2L)(OH2)4][(H2L)]·4H2O (1), [CaII(OH2)4]-[CaII(L)(OH2)2]2·7H2O (2) and [GdIII(L)(OH2)3]2[GdIII(L)-(OH2)4]2·13H2O (3) were synthesized and characterized by X-ray crystallography. In all three complexes, the ligand H3L binds to the metal centre only by its three carboxylate donors, leaving the bridgehead nitrogen atom nonbonding. The calcium(II) ion in the monomeric complex 1 is distorted pentagonal-bipyramidal coordinated, the +1 charge of the complex cation [CaII(H2L)(OH2)4]+ is balanced by an H2L, anion and both units are connected by hydrogen bonds. The polymeric compound 2 displays a one-dimensional chain structure, in which two [CaII(L)]2, units form a dimeric structure and are connected by hydrated CaII ions. 3 contains two different [GdIII(L)(OH2)n] dimers. In one of them the two GdIII ions are linked by two monoatomic carboxylate O-bridges showing a short Gd···Gd distance of 3.99 Å. In the second, a syn - anti carboxylate 1,3-bridge with a longer Gd···Gd distance of 4.96 Å is observed. Magnetic measurements of 3 show paramagnetic behaviour with weak antiferromagnetic coupling. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005) [source] Proton transfer versus nontransfer in compounds of the diazo-dye precursor 4-(phenyldiazenyl)aniline (aniline yellow) with strong organic acids: the 5-sulfosalicylate and the dichroic benzenesulfonate salts, and the 1:2 adduct with 3,5-dinitrobenzoic acidACTA CRYSTALLOGRAPHICA SECTION C, Issue 10 2009Graham Smith The structures of two 1:1 proton-transfer red,black dye compounds formed by reaction of aniline yellow [4-(phenyldiazenyl)aniline] with 5-sulfosalicylic acid and benzenesulfonic acid, and a 1:2 nontransfer adduct compound with 3,5-dinitrobenzoic acid have been determined at either 130 or 200,K. The compounds are 2-(4-aminophenyl)-1-phenylhydrazin-1-ium 3-carboxy-4-hydroxybenzenesulfonate methanol solvate, C12H12N3+·C7H5O6S,·CH3OH, (I), 2-(4-aminophenyl)-1-phenylhydrazin-1-ium 4-(phenyldiazenyl)anilinium bis(benzenesulfonate), 2C12H12N3+·2C6H5O3S,, (II), and 4-(phenyldiazenyl)aniline,3,5-dinitrobenzoic acid (1/2), C12H11N3·2C7H4N2O6, (III). In compound (I), the diazenyl rather than the aniline group of aniline yellow is protonated, and this group subsequently takes part in a primary hydrogen-bonding interaction with a sulfonate O-atom acceptor, producing overall a three-dimensional framework structure. A feature of the hydrogen bonding in (I) is a peripheral edge-on cation,anion association also involving aromatic C,H...O hydrogen bonds, giving a conjoint R12(6)R12(7)R21(4) motif. In the dichroic crystals of (II), one of the two aniline yellow species in the asymmetric unit is diazenyl-group protonated, while in the other the aniline group is protonated. Both of these groups form hydrogen bonds with sulfonate O-atom acceptors and these, together with other associations, give a one-dimensional chain structure. In compound (III), rather than proton transfer, there is preferential formation of a classic R22(8) cyclic head-to-head hydrogen-bonded carboxylic acid homodimer between the two 3,5-dinitrobenzoic acid molecules, which, in association with the aniline yellow molecule that is disordered across a crystallographic inversion centre, results in an overall two-dimensional ribbon structure. This work has shown the correlation between structure and observed colour in crystalline aniline yellow compounds, illustrated graphically in the dichroic benzenesulfonate compound. [source] Crystallographic report: Bis(isonicotinonitrile)cadmium diselencyanate, [Cd(SeCN)2(pyCN)2] (pyCN = isonicotinonitrile)APPLIED ORGANOMETALLIC CHEMISTRY, Issue 5 2003Dacheng Li Abstract The title compound, [Cd(SeCN)2(pyCN)2],, adopts an extended one-dimensional chain structure in which the neighboring cadmium atoms are bridged by two selenocyanate ions. The central cadmium atom has a distorted octahedral geometry defined by two isonicotinonitrile and four selenocyanate ions in a 4N2Se fashion. Copyright © 2003 John Wiley & Sons, Ltd. [source] Crystal structure, thermal analysis and theoretical calculation of a one-dimensional chain complex [zn(dafo)2(H2O)2](NO3)2CHINESE JOURNAL OF CHEMISTRY, Issue 8 2004Rong-Lan Zhang Abstract A novel one-dimensional chain complex [Zn(dafo)2(H2O)2](NO3)2 was obtained when we tried synthesizing a mixed ligand supramolecular compound of Zinc(II) with dafo and o -phthalic acid. Its structure was determined by single-crystal X-ray diffraction analysis. The crystal belongs to triclinic system, P -1 space group. The crystallographic data: a=0.6989(4) nm, b=0.8281(5) nm, c=1.0231(5) nm, ,=94.934(5)°, ,=91.366(7)°, ,=99.820(7)°, V=0.5809(5) nm3, Z= 1, F(000)=300, Mr=589.78, Dc=1.686 g/cm3, ,(Mo K,)=1.130 mm,1, R1=0.0521, wR2=0.1096. The analysis of the crystal structure indicates that the compound has a one-dimensional chain structure which is formed by hydrogen bonds. The constitutes of the title complex were proved by elemental analysis, IR spectra and thermal analysis. On the basis of the experimentation, the complex was calculated by DFT-B3LW/LANL2DZ in Gaussian-98w also. [source] Hierarchical Structures in Tin(II) OxalatesEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 9 2008Padmini Ramaswamy Abstract Six new SnII oxalates exhibiting a hierarchy of structures have been prepared employing hydrothermal methods. The compounds I [C10N2H10][Sn(C2O4)2], II [C10N2H10][Sn2(C2O4)3], and III [C8N4H26][Sn(C2O4)2]2·2H2O possess zero-dimensional molecular structures; IV [C10N2H8]2[Sn(C2O4)]2 and V [C12N2H8][SnC2O4] have one-dimensional chain structures; and compound VI [C5N2H14]2[Sn4(C2O4)6]·7H2O 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, ,···, interactions, and lone-pair,, interactions have been observed and appear to lendstructural stability. Theoretical studies indicate that the ,···, 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,, 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 SnII.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008) [source] Metal Aminocarboxylate Coordination Polymers with Chain and Layered StructuresCHEMISTRY - A EUROPEAN JOURNAL, Issue 23 2005Meenakshi Dan Abstract The synthesis and structures of metal aminocarboxylates prepared in acidic, neutral, or alkaline media have been explored with the purpose of isolating coordination polymers with linear chain and two-dimensional layered structures. Metal glycinates of the formulae [CoCl2(H2O)2(CO2CH2NH3)] (I), [MnCl2(CO2CH2NH3)2] (II), and [Cd3Cl6(CO2CH2NH3)4] (III) with one-dimensional chain structures have been obtained by the reaction of the metal salts with glycine in an acidic medium under hydro/solvothermal conditions. These chain compounds contain glycine in the zwitterionic form. 4-Aminobutyric acid transforms to a cyclic amide under such reaction conditions, and the amide forms a chain compound of the formula [CdBr2(C4H7NO)2] (IV). Glycine in the zwitterionic form also forms a two-dimensional layered compound of the formula [Mn(H2O)2(CO2CH2NH3)2]Br2 (V). 6-Aminocaproic acid under alkaline conditions forms layered compounds with metals at room temperature, the metal being coordinated both by the amino nitrogen and the carboxyl oxygen atoms. Of the two layered compounds [Cd{CO2(CH2)5NH2}2],2,H2O (VI) and [Cu{CO2(CH2)5NH2}2],2,H2O (VII), the latter has voids in which water molecules reside. [source] | ||||||||||