Crystal structure of the molecular inclusion complex tetra-p-nitro-tetra-O-butyl calix[4]arene with acetone (1 : 2)

The crystal structure of the inclusion complex of tetra-p-nitro-tetra-O-but yl calix[4]arene 1 with acetone, [(C44H52N4O12). 2CH(3)COCH(3)], was measur ed by X-ray crystallographic analysis with an "imaging plate" method. It be longs to the space group C2/c, with a = 13.131(3), b = 21.480(4), c = 19.64 5(4)Angstrom, beta = 105.69(3)degrees and D-cale, = 1.177 mg/m(3) for Z = 4 . Crystal data indicate that the host molecule 1 exist in a pinched-cone co nformation, and the action of one molecule of host upon two molecules of ac etone forms a channel type intermolecular inclusion complex.