Solution and solid-state structures of dibenzylamino calix[4]arene with complexed solvent molecules

The solution and solid state structures of 1,3-dibenzylamino calix[4]arene were investigated via NMR and X-ray crystallography for MeCN, ethanol, hexane, THF, chloroform and toluene solvents. Analysis of the obtained structures show a symmetric flattening/pinching of the calixarene for solvents with a roughly cylindrical shape (MeCN, ethanol, hexane) and an asymmetrical flattening of the cone for more anisotropic, flat solvents, such as THF or toluene. Due to the deviation from planarity of the N2O2 fragment in the latter case, these solvents might be best suited for the preparation of octahedral or tetrahedral metal complexes, while the former would be more suitable for the preparation of square-planar complexes.