SUPRAMOLECULES OF CROWN-ETHERS WITH GEMIN AL SULFONES - SYNTHESIS OF 4 BINARY COMPLEXES AND CRYSTAL-STRUCTURE OF (CH2CH2O)(4)CENTER-DOT-2H(2)C(SO2C2H5)(2)

In a systematic search for supramolecular complexes involving all comb inations of the cyclic polyethers 12-crown-4 (12C4), 15-crown-5 (15C5) , 18-crown-6 (18C6) and dibenzo-18-crown-6 (DB-18C6), and the geminal di- or trisulfones H2C(SO(2)Me)(2), H2C(SO(2)Et)(2) and HC(SO(2)Me)(3- n)(SO(2)Et)(n) (n = 0-3), only the following four complexes could be i solated and unequivocally characterized by elemental analysis and H-1 NMR spectroscopy: [(12C4){H2C(SO(2)Et)(2)}(2)] (3), [(18CG){H2C(SO(2)M e)(2)}] (4), [(DB-18CG){H2C(SO(2)Et)(2)}] (5) and [(DB-18C6)(2){HC(SO( 2)Me)(SO(2)Et)(2)}(3)] (6). The structure of 3 (triclinic, space group P1) consists of crystallographically centrosymmetric formula units, i n which the disulfone molecules are bonded on each side of the ring by two C-H ... O(crown) interactions originating from the central methyl ene group (H ... O 213 pm) and from the methylene group of one EtSO(2) moiety (H ... O 237 pm). Formula units related by translation are con nected into parallel strands by a third type of reciprocal C-H ... O b ond (H ... O 232 pm) between the second H atom of the central methylen e group and a sulfonyl oxygen atom of the adjacent unit. The structure of 4 (monoclinic, space group C2/c) showed severe disorder of the cro wn ether and could not be refined satisfactorily. Compounds 5 and 6 cr ystallized as long and extremely thin fibres, indicative of linear-pol ymeric supramolecular structures; single crystals for X-ray crystallog raphy were not available.