Crystal structure of a p-tert-butylcalix[8]arene - N-methyl-morpholine complex

p-tert-Butyl-calix[8]arene crystallizes with six molecules of N-methyl-morpholine in a triclinic lattice, space group P1 with a = 12.142(3) Å, b = 16.596(4) Å, c = 17.211(2) Å, ? = 83.72(2)°, ? = 80.66(2)°, ? = 69.55(2)°, Z = 1. The formation of hydrogen bonds with two molecules of N-methyl-morpholine, induces the calix[8]arene skeleton to adopt a chair-like conformation in which two 3/4-cone moieties are oriented above and below the mean molecular plane, respectively. The other four solvent molecules per unit cell simply fill the interstitial voids in a "like-tubular" solid state assembly built by p-tert-butylcalix[8]arene molecules piled along the a-axis direction.