Crystals and Aggregates of a Molecular Tetrarotor with Multiple Trityl Embraces Derived from Tetraphenyladamantane

Abstract

Samples of tetrakis-1,3,5,7-(4′-(3″,3″,3″-triphenylpropynyl)-phenylene)­adamantane and its trityl-deuterated isotopologue were synthesized and their crystallization and packing properties were analyzed within the context of formation of 4- or 6-fold phenyl embraces. The tetrahedral shape of these molecules with four propeller-like triphenylmethyl moieties generates several edge-to-face intermolecular interactions in the solid state that result in the formation of infinite chains of molecules that are tightly interlocked. The formation of analogous edge-to-face intermolecular interactions leading to aggregation in solution was also suggested by NMR experiments carried out in different solvents as a function of concentration. The formation of interdigitated chains was also manifested in fibrils and thin needles, which were documented by scanning electron microscopy (SEM). Single crystal X-ray diffraction studies revealed the presence of multiple 4-fold phenyl embraces and edge-to-face interactions as the leading motifs behind the formation of tightly interlocked molecular chains