Anion Encapsulation Research Articles

Encapsulation of halide anions in perhydrogenated silicon fullerene: X −@Si 20H 20 (X = F, Cl, Br, I)

We report the results of a density functional study of the encapsulation of halide anions into the dodecahedral cage of the perhydrogenated silicon fullerene Si 20H 20. The HOMO–LUMO energy gap of the endohedral complexes X −@Si 20H 20 (X = F, Cl, Br, I) is only ∼0.5 eV larger than that computed for the empty fullerene. The amount of charge that is being transferred from the encapsulated anion to the fullerene increases from F − (∼10%) to I − (>70%). Only the encapsulation of Br − does not alter the cage thus indicating that this spherical anion might be employed in the anion-templated synthesis of the elusive Si 20H 20 cluster.

Anion encapsulation by neutral supramolecular assemblies of cyclic CuII complexes: a series of five polymerization isomers, [(cis-CuII(mu-OH)(mu-pz))n], n=6, 8, 9, 12, and 14.

Anion encapsulation by neutral supramolecular assemblies of cyclic CuII complexes: a series of five polymerization isomers, [(cis-CuII(mu-OH)(mu-pz))n], n=6, 8, 9, 12, and 14.

Anion Encapsulation by Neutral Supramolecular Assemblies of Cyclic CuII Complexes: A Series of Five Polymerization Isomers, [{cis‐CuII(μ‐OH)(μ‐pz)}n], n=6, 8, 9, 12, and 14

Konzentrische Kreise: Das Zusammenspiel von Metallkoordination, dipolaren Wechselwirkungen und Wasserstoffbrücken führt zur komplexen supramolekularen Anordnung aus drei oder vier neutralen Metallacyclen [{cis-Cu(μ-OH)(μ-pz)}n], n=6, 8, 9, 12, 14, die Anionen durch mehrere Wasserstoffbrücken einschließen (im Bild SO42−, pz=Pyrazol, Cu blau, O rot, N hellblau, C schwarz, S gelb). In der Natur werden ähnliche Kombinationen chemischer Wechselwirkungen für spezielle Aufgaben eingesetzt.

Molecular encapsulation of anions in a neutral receptor.

Molecular encapsulation of anions in a neutral receptor.

Self-assembly and anion encapsulation properties of cavitand-based coordination cages.

Two novel classes of cavitand-based coordination cages 7a--j and 8a--d have been synthesized via self-assembly procedures. The main factors controlling cage self-assembly (CSA) have been identified in (i) a P--M--P angle close to 90 degrees between the chelating ligand and the metal precursor, (ii) Pd and Pt as metal centers, (iii) a weakly coordinated counterion, and (iv) preorganization of the tetradentate cavitand ligand. Calorimetric measurements and dynamic (1)H and (19)F NMR experiments indicated that CSA is entropy driven. The temperature range of the equilibrium cage-oligomers is determined by the level of preorganization of the cavitand component. The crystal structure of cage 7d revealed the presence of a single triflate anion encapsulated. Guest competition experiments revealed that the encapsulation preference of cages 7b,d follows the order BF(4)(-) > CF(3)SO(3)(-) >> PF(6)(-) at 300 K. ES-MS experiments coupled to molecular modeling provided a rationale for the observed encapsulation selectivities. The basic selectivity pattern, which follows the solvation enthalpy of the guests, is altered by size and shape of the cavity, allowing the entrance of an ancillary solvent molecule only in the case of BF(4)(-).

The First Coordinatively Saturated, Quadruply Stranded Helicate and Its Encapsulation of a Hexafluorophosphate Anion.

Incarcerated in a helical prison: The encapsulation of a PF6- ion within a quadruply stranded helicate (shown schematically) results from the self-assembly of four molecules of 1,4-bis(3-pyridyloxy)benzene and two PdII ions. This represents not only the first example of a coordinatively saturated quadruple helicate, but also the first example of the encapsulation of a complex anion by a helicate.

Molecular Structure of Inclusion Complex with Chloride Anion Eccentrically Bound into the Cavity of a Tetraazamacrotricyclic Receptor Having Asymmetrically Charged Nitrogen Centers

Abstract The crystal structure of [ClL]2+·2Cl−·3CH3OH, where L = (C6H5CH2)3N4((CH2)6)6, shows the complete encapsulation of a chloride anion into the intramolecular cavity of the macrotricyclic cage L3+. The included anion is held eccentrically into the cavity with a distance of about 4.1 Å from the three charged nitrogen cations and 5.7 Å from the uncharged nitrogen atom.

Control of aggregation through anion encapsulation in clusters of the V/O/RPO3 2? system: synthesis and crystal and molecular structures of the tetranuclear clusters [NBun 4][V V 4O6F(PhPO3)4] and [NBun 4]2[V V 3V VI O6F(PhPO3)4

The reaction of [(NBun4)][V5O7(PhPO3)5(OMe)2] with HBF4·Et2O in acetonitrile yields the tetranuclear vanadium(V) cluster [NBun4][V4O6F(PhPO3)4]1 which upon reduction with organohydrazine yields the mixed-valence cluster [NBun4]2[VV3VIVO6F (PhPO3)4]2.

Encapsulation of cations and anions by azacrowns: Thermodynamic and structural aspects

Abstract