Showing papers on "Coordination polymer published in 1990"

π‐Complexes of p‐Block Elements: Planar Dihydroanthracene in a Menshutkin Complex. Crystal Structure of Br3Sb · C6H4(CH2)2C6H4 · SbBr3

Abstract: Crystals of a 1:2 complex of 9,10-dihydroanthracene and antimony tribromide are obtained from toluene solutions of the components. In the crystal the complex forms corrugated sheets of an inorganic (SbBr3)n coordination polymer, which are cross-linked by antimony coordination to the benzene rings of the dihydroanthracene molecules are also arranged in folded layers. The dihydroanthracene molecules reside on centers of inversion and their carbon skeleton is planar within the limits of the experiment. With contacts from opposite sides of the molecular plane, the dihydroanthracene is η6,(η6)'-coordinated to the Sb(III) centers at distances of 3.25 A. In a very irregular geometry the coordination sphere of the crystallographically equivalent antimony atoms contains bromine neighbours at different distances. – Antimony trichloride and dihydroanthracene form a complex of ambiguous stoichiometry, while bismuth trichloride again gives a 2;1 complex, the structure of which has not yet been determined.

π‐Complexes of p‐block elements: (η6‐Mesitylene)tin(II) chloride tetrachloroaluminate(III), a coordination polymer

Abstract: (η6-1,3,5-Trimethylbenzene)tin(II) chloride tetrachloroaluminate(III), (η6-1,3,5-C6H3Me3)SnCl (AlCl4), has been obtained from the reaction of anhydrous SnCl2 and AlCl3 in the molar ratio 1 : 2 in excess mesitylene as a solvent. The compound crystallizes in monoclinic needles, space group P21/n, containing a coordination polymer with planar four-membered rings Sn-Cl-Sn-Cl as the fundamental structural units. Each tin(II) atom of these rings is η6-bonded to a mesitylene ring, with the metal approximately centered over the aromatic hydrocarbon at a distance of 2.71 A. Each of the tin(II) atoms is further connected to two tetrachloroaluminate counter ions, one of these monodentate and one bidentate. Through this mono/bidentate contacts a one-dimensional coordination polymer is generated with crystallographic centers of inversion in the middle of the Sn(Cl)2Sn and Sn(AlCl4)2Sn rings. The structure is similar to that of the analogous benzene complex, but not identical owing to a different connectivity pattern. Also, the arene-Sn(II) distance is much shorter in the mesitylene complex (2.71 A) than in the benzene complex (2.90 A), indicating that the trimethylbenzene molecule is a much better donor than benzene.

Metal Tetrahydroborates and Tetrahydroborato Metalates, 15 [1]. An 11B and 113Cd NMR Study of MBH4–CdCl2 Systems in Dimethylformamide and the X-Ray Structure of CdCl2 · 2 DMF

Abstract: CdCl₂ dissociates in dimethylformamide into the species Cd(DMF)₆²⁺, CdCl(DMF)₅⁺ and CdCl₃⁻ as determined by ¹¹³Cd NMR spectroscopy. ¹¹B and ¹¹³Cd NMR spectra of MBH₄/CdCl₂ solutions in this solvent show the presence of complexes [CdCl₂₋ₙ(BH₄)ₙ₊₁]⁻ with rapid exchange of BH₄⁻ and Cl⁻ at ambient temperature. There is no evidence that Cd(BH₄)₂ is formed in a metathetical reaction.The crystal structure of CdCl₂ · 2 DMF has been determined. It is a coordination polymer containing hexacoordinated Cd atoms with the DMF molecules in cis-position. Coordination of DMF occurs via the carbonyl oxygen atoms.

Coupling to metal surface

Abstract: PURPOSE: To bond an active chemical seed onto the metal surface of an artificial object positively and permanently and to use it as the component of a biological sensor by enabling a plurality of functional groups to contain atoms with electrons to the surface of a metal. CONSTITUTION: A first set of functional groups that can be bound to the surface of a metal, and a second set of functional groups that can be bound to a chemical seed are included, the first set of functional groups form pendants from polymer chain or its forming part, and each functional group includes an electron to be fed to the metal surface for forming binding with the metal surface. With the second set, the functional group is not bonded to the metal surface and bonds coordination polymer onto the metal surface. Also, the chemical seed is bound to the coordination polymer by the second set of functional groups. The metal belongs to the II family of a periodic table, and the coordination polymer is polyimine or polythiol.

Metal Coordination Polymers: Eight-Coordinate Cerium(IV) and Zirconium(IV) Polymers with Varied Flexibility, Conjugation, and Stability Through Ligand Variation

Abstract: Tractable (soluble) linear transition metal coordination polymers in which the metal ions are a necessary part of the backbone (and without which the polymer will stay intact) have proven difficult to synthesize.1-6 Bis(tetradentate) Schiff-base ligands coupled with zirconium(IV) ions large enough for eight- coordination can be used to overcome this insolubility,7-8 and recently an analogous soluble cerium(IV) Schiff-base polymer has been prepared.9 Although a number of reports had appeared regarding polymeric systems in which lanthanide metal ions are attached to a branch of a polymer chain10-14 or solid state species that either remain insoluble in all solvents or fall apart into small molecules when dissolved,15-17 soluble linear polymers with lanthanide ions in their backbone had been lacking prior to our study of catena-poly [cerium(IV)-µ-N,N′,N″,N‴-tetrasalicylidene(3,3′-diaminobenzidinato)-O,-N,N′,O′:O″,N″,N‴ ,O‴], [Ce(tsdb)]n.9