Paul R. Mallinson

Design and synthesis of rhombohedral clathrates for containment of small, reactive guest species

Abstract The new hexa-hosts hexakis( p -phenoxyphenoxy)benzene 2 and its p -benzylphenoxy analogue 3, targetted at rhombohedral clathrate packing, have been prepared. X-ray measurements have established that 2 and 3 form very similar rhombohedral closed-cage structures with common trigonal space group R 3 . The cavities of these clathrates are potentially useful for the handling of reactive reagents, examples for 2 being phosgene, thiophosgene, thionyl chloride, and methyl iodide.

Experimental charge-density study on the nickel(II) coordination complex [Ni(H3L)][NO3][PF6] [H3L = N,N′,N′′-tris(2-hydroxy-3-methylbutyl)-1,4,7-triazacyclononane]: a reappraisal

The experimental charge density in the title complex has been re-examined. The original work, reported some 8 years ago [Smith et al. (1997). J. Am. Chem. Soc. 119, 5028-5034], was undertaken using a very early version of the XD software, which contained serious programming errors. A re-refinement, using the original data and a recent version of the XD software, shows that many of the unusual aspects of this earlier study are artefacts due to these programming errors. The topological properties of the newly obtained experimental density compare well with those calculated from a theoretical DFT (density-functional theory) UHF-SCF (unrestricted Hartree Fock-self-consistent field) density. This report corrects several erroneous conclusions regarding the charge density in the title complex--in particular, the highly unusual diffuse Laplacian distribution about the Ni atom, and the trifurcated bond path from the Ni atom to the alcohol oxygen donor atoms are no longer observed. An examination of a range of topological properties of the metal-ligand bonds leads to the conclusion that the Ni-N and Ni-O bonds have an intermediate character, with a significant shared interaction, but with a substantial ionic component. This new study also reveals a previously unrecognized intramolecular H...H interaction in the macrocyclic ligand.

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.

Synthesis and structure of the first per-substituted anthracene host: Decakis(cyclopentylthio)anthracene

Abstract The title compound, a novel host molecule, has been prepared both from mixtures of unsaturated fluorocarbons related to perfluoro-perhydroanthracene and, in an extension of a remarkable new reaction, perfluoroperhydroanthracene itself. The 1,4-dioxane inclusion compound of this anthracene-based host is triclinic, space group P 1, with a = 11.826(1), b = 15.297(1), c = 20.280(1) A, α = 98.77(1), β = 99.85(1), and γ = 95.83(1)°, with two host, and ca. three 1,4-dioxane guest molecules per unit cell. The host molecule occupies a general position in the unit cell and its anthracene core is markedly non-planar; each of the three crystallographically independent six-membered rings possesses a shallow twist-boat conformation. The hosts side-chain moieties display an asymmetrical conformational distribution of the abbabaabab type (a = above, b = below, mean core plane).

Structurally dissimilar clathrates from isomeric spider hosts: octakis(m-tolylthio)naphthalene and its p-tolylthio analogue

The title isomeric hosts (1) and (2), adopting different molecular conformations, form distinct types of closed cage accommodating the common guest 1,4-dioxane; it is remarkable that the symmetrical multimolecular cage structure of (1), not consolidated by hydrogen bonding, can exist even in the absence of guest.

2,4,6-Tris[4-(1-naphthyl)phenoxy]-1,3,5-triazine: formation of a unique piedfort-based host lattice with trigonal symmetry

Abstract X-Ray crystal structure analysis of the isopropanol clathrate of the title compound 1 has revealed a trigonal lattice, space group R°c with a=24.760(3), c=87.644(14)A, Z=48 (host), in which selfassembly of host molecules, in the form of three crystallographically independent Piedfort units of symmetry C 3i, C 3 and D 3 located along c, has led to the formation of two types of trigonal cage, each occupied by an isopropanol guest molecule.

Crystal structure of theβ-clathrate form of 4-p-hydroxyphenyl-2,2,4-trimethylselenachroman

AbstractIn contrast top-hydroxyphenyl-2,2,4-trimethylchroman, Dianins compound (1), or itsthia analogue2, the title seleno-ether has been found to form two crystallographically distinct types of clathrate. In the first-discovered form, the α-modification of as yet undefined structure, the rhombohedral unit cell (R

Charge densities from high-resolution synchrotron X-ray diffraction experiments

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