Synthesis, NMR and X-ray structure of phosphorylated tetrameric metacyclophanes

The synthesis of mesitylene-derived 1,3 alternate [1.1.1.1] metacyclophanes functionalized with pendant methylene-phosphonic acid diethyl ester groups is described. The compounds were fully characterized by H-1, C-13 and P-31 -NMR spectra and by FAB-MS spectroscopy. The preferred conformation in solution was established by NMR methods, wher eas the solid state conformation of one of them, solved by X-ray diffractio n techniques, is also reported. The macrocycle forms a lattice clathrate wi th cyclohexane in the ratio 1:2 (macrocycle over guest) and alternates with an additional molecule of water in a hydrogen-bonded 1D array.