Amphiphile Structures in the Solid State: Complex Cations with Lipophilic Substituents

Structural characterisation of hexamine cage complexes, two containing diamagnetic Co III and one containing paramagnetic Cu II , to which both rather short (C 4 ) and relatively long (C 13 ) alkyl substituents have been attached, shows that while the longer “tail” introduces an anticipated bilayer form to the crystalline solid, even the shorter tail can be associated with a form of aggregation of lipophilic entities in the crystal. The short tail at least may also be involved in interactions with anions of a complex type. As surfactants, functionalised cage complexes contain a head group, which is a multi‐site hydrogen‐bonding entity, and which can thus provide a mechanism for further aggregation concomitant with that of any apolar functionality. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)