Unusual hydrogen bonded (OH)4 tetrahedral nests organize zinc(II)coordination complexes in a non covalent diamondoid network

The crystal organization of Zn(LOH)2X2 (LOH = a-(4-pyridyl)benzhydrol) shows an abrupt change on passing from X = Cl (1) and X = Br (2) to X = I (3). The smaller and more electronegative halides (1, 2) participate in –OH…X hydrogen bonds giving an overall arrangement of the structures in bidimensional sheets where the zinc atoms behave as distorted square nodes in the network topology. In 3 the iodine atom switches the basic supramolecular synthon from –OH…X to a tetrahedral –(OH)4 nest assembled by –OH…OH hydrogen bonds, giving a non-covalent diamondoid network where the metal acts as a spacer. This (OH)4 nest constitutes a relatively robust supramolecular synthon whose tetrahedral topology arises from self recognition between the molecules, without the need of a central templating element.