SIMULTANEOUS ELECTROPHILE-NUCLEOPHILE CL-CENTER-DOT-CENTER-DOT-CENTER-DOT-PI INTERACTIONS STABILIZING SOLID-STATE INCLUSIONS - A NEW TOOL FOR SUPRAMOLECULAR CRYSTAL ENGINEERING

The crystalline inclusions of the host compound chlorophenyl)hydroxyme thyl]-9,10-ethanoanthracene, with guests such as pentan-2-ol [1 . pent an-2-ol (1:1), 1a], 1,4-dioxane [1 . 1,4-dioxane (2:5), 1b] and o-xyle ne [1 . o-xylene (1:2), 1c] were shown by X-ray analysis to have host matrices mainly determined by directional 'electrophile-nucleophile pa iring' interactions, involving a chloro substituent and the adjacent a ryl pi electrons of a neighbouring molecule, The observed shorter Cl . .. centroid distances in 1a-c are between 3.33 and 3.75 Angstrom. On t he other hand, the versatility of host-guest interactions due to the d ifferent proton donor-acceptor abilities and polarities of the guests yielded various packing relations with different symmetries and confor mations of the host hydroxy functions, Although compounds 1a and 1b co ntain H-bonded 1 . pentanol and 1 . dioxane aggregates, respectively, the realized packing arrangements seem to be a compromise between clos e packing on the one hand and hydrogen bonding on the other. Compound 1c is a lattice-type inclusion in which the o-xylene guests are trappe d in tunnels formed by the bulky host molecules.