WATER DIMERS AND WATER MONOMERS AS LINKS IN 18-CROWN-6 COMPLEXES WITH UNCHARGED ACIDIC MOLECULES - SYNTHESES AND CRYSTAL-STRUCTURES OF (CH2CH(2)O)(6)CENTER-DOT-4H(2)O-CENTER-DOT-2HN(SO(2)PH)(2) AND (CH2CH2O)(6)CENTER-DOT-2H(2)O-CENTER-DOT-2HN(SO2C6H4-4-F)(2) AND STRUCTURE OF FREE HN(SO2C6H4-4-F)(2)

The ternary complexes 18C6 . 4H(2)O . 2HN(SO(2)Ph)(2) (3) and 18C6 . 2H(2)O . 2HN(SO2C6H4-4-F)(2) (4) were obtained by co-crystallization of 18-crown-6 (18C6) with the appropriate di(arenesulfonyl)amine from aqueous solutions and characterized by low-temperature X-ray diffraction. The crystal structures consist of monomeric formula units displaying crystallographic C-i symmetry for 3 (monoclinic, space group C2/c) and approximate C-i symmetry for 4 (monoclinic, space group P2(1)/c). In 3, hydrogen-bonded water dimers H2O...H-O'H (H...O 182 pm) act as links between the two di(benzenesulfonyl)amine molecules and the crown ring. Each dimer accepts an N-H...O' bond (H...O' 194 pm) and is attached by its remaining protons to a set of three alternate crown oxygen atoms O-c (O'H...O-c 202, OH...O-c 207 and 208 pm). The overall topological features of 3 strongly resemble those of the known supramolecule 18C6 . 2MeOH . 2HN(SO(2)Ph)(2). In 4, each amine molecule is N-H...O bonded to a water monomer (H...O 184 and 187 pm) that is connected to two O-c atoms of the crown (OH...O-c 202-210 pm). The crown rings of both complexes adopt the frequently observed pseudo D-3d symmetry. In the crystal of the pure compound HN(SO2C6H4-4-F)(2) (5; monoclinic, space group C2/c), the molecules are associated into chains in the z direction through a relatively weak N-H...O' bond (H...O' 215 pm). The conformations of the HN(SO(2)R)(2) entities in 3, 4, 5 and some related solids are compared and discussed.