Molecular and Crystal Structure of Hexazocyclane based on 4,4′-Diaminodiphenyl Ether
Bulletin of the Academy of Sciences of the USSR, Division of Chemical Science
Experimental confirmation of the macrocyclic structure of hexazocyclane molecules has been obtained for the first time.
In the crystal of the hexazocyclane that has been investigated, the tautomeric structure that is realized is centrosymmetric with the H atoms at the nitrogen atoms bonding the isoindole and ether parts of the molecule. The factors favoring realization of this tautomeric form have been examined.
The basic features in the solvation of hexazocyclane molecules have been established: The crystal solvate molecules form H-bonds with the H-groups of the macroring and are located in its semiopen void spaces.
The data that we have obtained on the relative constancy of the dihedral angle between the planes of the benzene rings of the diphenyl oxide fragment of the hexazocyclane molecule can provide an explanation for the features of intramolecular cyclization of the hexazocyclane with additional nitrile groups in these fragments, specifically, the actual exclusive formation of the “trans” isomer.