IntroductionCrystal structures possessing the tetrahedral connectivity of diamond are described as diamondoid, and occur as two types, non­molecular and supramolecular. In the non­molecular structure type there are strongly bonding connectors between tetrahedral sites — often ditopic ligands binding tetrahedrally coordinated metal atoms1–3— and thus three­dimensionally extended coordination networks. In contrast, in the supramolecular structure type there are identifiable molecules and weak intermolecular interactions. Supramolecular diamondoid lattices, less numerous than non­molecular diamondoid lattices, are known mainly with hydrogen bond linkages. The tetrahedral molecules methane tetracarboxylic acid and adamantane­1,3,5,7­tetracarboxylic acid use the classic carboxylate hydrogen bonded pair as the intermolecular connector:4other tetrahedral molecules use pyridone arms for hydrogen bonding.4,5The cubanoid cluster (μ3-OH)4M4(CO)12forms diamondoid nets by hydrogen bonding involving the OH groups and additional ditopic linker molecules, including diamines and arenes (which form OH⋯arene⋯HO hydrogen bonds).61,3,5,7­Tetraiodoadamantane forms a diamondoid net maintained by I⋯I intermolecular interactions.7Both classes of diamondoid structure commonly occur as interpentrating non­connected nets.8This is because diamond lattices are comprised of fused adamantanoid cages, and the adamantanoid cage is characterised by a large central space relative to the edge length. Guest inclusion is an alternative mechanism for filling this space in diamondoid lattices. An example of the combination of interpenetrating diamondoid lattices held together by hydrogen bonding, and guest inclusion, is exhibited in the lattice formed by 2,7­dimethyltricyclo[4.3.1.13,8]undecane­syn­2,syn­7­diol with guests such as benzene, acetonitrile or dichloromethane.9