James H. Gall

Perchlorocoronene: a novel host precursor

The title compound (1b), a new non-planar chlorocarbon possessing approximate D3d symmetry, has been prepared by chlorination of coronene (1a); complete substitution of (1b) by arenethiolate nucleophiles in the dipolar aprotic solvent DMEU (1,3-dimethylimidazolidin-2-one) yields the dodecathioethers (2a) and (2b), members of a new prospective host series.

Engineering robust polar chiral clathrate crystals

The R-(+)-enantiomeric form of Dianins compound and the S-(+)-enantiomeric form of its direct thiachroman analogue both obtained chromatographically employing a cellulose tris(3,5-dimethylphenylcarbamate) column, are shown to undergo supramolecular assembly to form a polar clathrate lattice which is stable even in the absence of a consolidating guest component.

Discovery and crystal structure of a novel chlorocarbon host: perchlorofluorene-9-spirocyclohexa-2',5'-diene

Chlorination of triphenylene (1a) employing a mixture of aluminium trichloride and sulphur monochloride in sulphuryl chloride leads to rearrangement with formation of the title chlorocarbon (2), a new host, as main product. X-ray crystal structure analyses of the unsolvated spirocycle (2) as well as of its inclusion compounds with guests benzene and cyclohexa-1,4-diene are described.

The first members of the octasubstituted naphthalene spider-host series with type I (abababab) conformation: gateway to new nano-host gas storage materials

Octakis(m-tolyloxymethyl)naphthalene, the first Type I spider host produced, crystallises from tetraglyme forming a novel channel structure with the host molecule attaining exact D(2) symmetry. The (flexible) channel structure is retained for guest CS(2), the host now only having exact C(2) symmetry. The octa-sulfone octakis(m-tolylsulfonylmethyl)naphthalene is also of Type I in its triclinic DMSO clathrate. DNMR establishes a substantial difference in molecular flexibilities in solution.

An unprecedented Dianin clathrate structure with Z′(host) = 16

Financial support from the Malaysia HIR MOHE, Grant No:F000009-21001 is gratefully acknowledged. We also wish to thank Dr Alex. R. Eberlin, Johnson-Matthey (Pharmorphix), Cambridge (UK), for assistance with the DSC experiments.

1,2,4,5-Tetrakis(phenylsulfonyl)benzene: a novel quadruped host with D2 symmetry having ordered sulfolane and cycloheptanone guests

The title tetrasulfone 1, in common with higher members of the multi-armed aromatic hosts, forms host-guest complexes with polar guest molecules. In the sulfolane and cycloheptanone complexes the host molecule possesses an abab conformation with exact C(2,) and approximate D(2) symmetry with deviations owing to crystal packing forces. The conformation of the well-ordered cycloheptanone molecule, which normally undergoes facile pseudorotation, is unambiguously defined in the voids of the crystalline inclusion compound.

4-(2,4-dihydroxyphenyl)-2,2,4-trimethylchroman: A diol counterpart of Dianin’s compound

The title resorcinol forms true clathrates analogous to those formed by Dianin’s compound itself; the ethyl acetate clathrate has space group R3, with a = 27.222(3), c = 10.727(2) å, and Z = 18 (host). One of the diol host’s OH groups participates in a hydrogen-bonded [OH]6 unit, whilst the other forms an 0H...0 (ether) hydrogen bond to an adjacent hexameric unit stacked (infinitely) along the c axis. In contrast to Dianin’s compound, sublimation in vacuo does not give the stable “empty” cage form, but leads to spontaneous resolution, the unsolvated crystal being orthorhombic, space group P212121 with a = 9.9031(15), b = 10.599(3), c= 13.501(4) Å, and Z = 4. Molecules are now linked head- to- tail by OH...0 (ether) hydrogen bonds to form infinite chains translationally propagated along a. Two such adjacent, parallel chains, related by a 21 screw axis along a, form a pair consolidated by intemwlecular hydrogen bonds of OH...O(H) type, involving both hydroxyl groups of the diol.

An X-ray crystallographic study of the inclusion properties of additionally dimethylated members of the 2′-hydroxy-2,2,4-trimethylflavan host series

AbstractConsideration of the shape and hydrogen bonding pattern of anentire guest unit, in the known 2:1:2 complex of 2′-hydroxy-2,4,4,7,4′-pentamethylflavan (1) with 1,4-dioxan and water, has indicated a structurally compatible guest,trans-1,4-bis(hydroxymethyl)cyclohexane (3b) which is selectively clathrated from a mixture with itscis isomer (3a). The new complex is triclinic, space group,P

A study of the reaction of bicyclo[5.1.0]octa-2,5-diene with sulphur dioxide

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