'Tetol': a stereo-rigid four-strand motif for alkali and alkaline earth metal ion coordination

The tetraalcohol 2,3,5,6-endo,endo,endo,endo-tetrakis(hydroxymethyl]bicyclo [2.2.1]heptane (tetol, 1) has been prepared and crystallises readily as the lithium(I) complex [Li(1)(2)]Cl, forming an oligomeric multi-chain structu re in which pairs of alcohols from two crystallographically independent tet ol molecules bind lithium ions tetrahedrally. However, formation of monomer ic structures in solution is inferred from electrospray mass spectroscopy, which has also shown evidence of exchange of lithium ion in the complexed s pecies by added alkaline earth ions. (C) 2000 Elsevier Science S.A. All rig hts reserved.