Structures of alkyl-substituted Troger's base derivatives illustrate the importance of Z ' for packing in the absence of strong crystal synthons
Faculty of Sciences. Chemistry
Acta crystallographica: section B: structural science. - Copenhagen
, p. 472-481
University of Antwerp
Crystal structures of Troger's base (5,11-methano-2,8-dimethyl-5,6,11,12-tetrahydrodibenzo[b, f][1,5] diazocine) analogues with the methyl groups replaced by ethyl, iso-propyl and tert-butyl groups were studied. The incidence of Z' > 1 structures increases to rather conspicuous levels. The reasons behind this trend are expanded upon, and a possible explanation is given in the flexibility of the alkyl substituents and van der Waals stabilization. In combination these effects allow for an additional stabilization of the packing by small changes in the molecular conformations, thus expanding the size of the asymmetric unit.