Encapsulated potassium cation in a new calix[4]arene neutral ligand: synthesis and X-ray crystal structure

The X-ray crystal structure of a p-t-butylcalix[4]arene tetra-amide and its 1 : 1 KSCN complex shows the ligand in a fixed cone conformation and the cation completely encapsulated in an eight-oxygen antiprism; the hydrophobic cavity contains a methanol molecule.