Molecular structure of bis[(1,3)2-oxaadamantano]-18-crown-6 and its potassium picrato complex

The structure of bis[(1,3)2-oxaadamantano]-18-crown-6 (1) and its potassium picrato complex ([1-K](+)(C6H2N3O7)(-);) have been studied by means of NMR -spectroscopy, X-ray structure analysis and molecular mechanics calculation s. In the gas phase and in the CDCl3 solution, in both 1 and [1-K](+) the m ost stable conformation of C-2h symmetry is found. However, in the solid st ate 1 adopts crystallographic C-i symmetry while its potassium picrato comp lex exhibits C-l symmetry. (C) 2000 Elsevier Science B.V. All rights reserv ed.