1,3-DIMETHOXY-2,4-DIDEHYDROXY-P-TERT -BUTYLCALIX[4]ARENE Gerrit J. van Hummel*, Paul J. A. Kenis**, Yuhua Ting** and Sybolt Harkema* Laboratories of Supramolecular Chemistry and Technology** and Chemical Physics, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands.

The title compound is an example of the rare 1,2-alternate conformation one of the four basic conformations kown in calix-[4]arenes (Groenen et al, 1991). In this compound two phenolic hydroxy groups have been replaced by H atoms. The asymmetric unit contains half a molecule; the other half being generated by an inversion centre. Due to the point symmetry the OH-depleted phenyl rings as well as the methoxy phenyl rings are positioned anti-parallel with respect to each other. One of the two phenyl rings is planar, the other shows a small boat-like deformation (max. deviation 0.011(2)Å), which was also previously found (Ting et al., 1995). Space Group: P1. a= 8.919(4), b=10.394(2), c= 10.544(3)Å, [[alpha]]= 90.38(1)deg., [[beta]]= 103.9l(2)deg. and [[gamma]]= 98.84(1)deg., Z= 1, D_calc= 1.14 g/cm³, T= 140 K, radiation: Mo_K[[alpha]]= 0.7107 Å, Number of reflections measured= 5401, refined(I>3[[sigma]](I))= 4198; R= 0.058, Rw= 0.084.

Ting, Y., Verboom, W., Reinhoudt, DN. and Harkema, S., (1995) Acta C'ryst. C51, 1465-1467.

Groenen, L.C., van Loon, J.D., Verboom, W., Harkema, S., Casnati, A., Ungaro, R., Pochini, A., Ugozolli, F. And D.N. (1991), J.Am.Chem.Soc., 113, 2385-2392.