Crystal and molecular structure of two calix[6]arenes:p-Isopropylcalix[6]arene andp-tert-butylcalix[6]arene?benzene(1?3) complex

Abstract

The isopropyl derivative crystallizes from a mixture of carbon disulfide and benzene in the orthorhombic system: Space groupP21nb, a=17.420(3),b=17.708(3),c=18.972(3) A,V=5852(3) A,Z=4. Thet-butyl derivative crystallizes from benzene, but the crystal is a complex (1∶3), space groupPĪ,a=15,065(5),b=19.103(3),c=13.878(3) A, α=106.95(2), β=102.72(2), γ=80.61(2),V=3703(2) A3,Z=2. Refinement led toR=0.185 for 1512 reflections for the isopropyl derivative, a sufficiently high number to establish the conformation of the molecule; for thet-butyl complexR=0.12 for 7340 reflections. Intramolecular hydrogen bonds are given as well as comparison of the conformation of both compounds. Thet-butyl groups and the benzene molecules are disordered but the isopropyl groups are not.