Crystal Engineering Using Trisphenols. Three-Dimensional Hydrogen-Bonding Networks in 1,1,1-Tris(4-hydroxyphenyl)ethane, its Hydrated Adduct with 1,4-Diazabicyclo[2.2.2]octane (1/1/1) and its Adduct with Piperazine (4/3)

Abstract

In 1,1,1-tris(4-hydroxyphenyl)ethane, C20H18O3 (1), monoclinic la, a = 7.9781 (10), b = 18.558 (3), c = 11.1995 (13) Å, \beta–101.668 (9)°, with Z = 4, each of the hydroxyl groups acts as both a donor and an acceptor of hydrogen bonds of the type O—H...O. The molecules are thus connected into square nets, graph set R^4_4(38), pairs of which are then interwoven; the nets are themselves interconnected by further hydrogen bonds to give a continuous three-dimensional network. In 1,1,1-tris(4-hydroxyphenyl)ethane-l,4-diazabicyclo[2.2.2]octane–water (1/1/1), C20H18O3.C6H12N2.H2O (2), triclinic P\overline 1, a = 10.421 (2), b = 10.734 (2), c = 10.9756 (13) Å, \alpha = 76.645 (12), \beta 74.513 (11), \gamma = 89.305 (13)°, with Z = 2, the water molecules are linked to the trisphenol and the diamine units by O—H...O and O—H...N hydrogen bonds, respectively, to form a linear aggregate. These aggregates are linked into chains by the formation of O—H...N hydrogen bonds between the trisphenol and the neighbouring diamine; however, alongside hydrogen-bond formation between the trisphenol and the diamine, there is also partial transfer of a proton, so that the intra-chain links between trisphenol and diamine units are in fact a mixture of O—H...N and N—H...O hydrogen bonds. These chains in the [101] direction are cross-linked by further O—H...O hydrogen bonds, involving only trisphenol O atoms, which form chains in both the [010] and [001] directions, thus generating a continuous three-dimensional network. Adduct (3), 1,1,1-tris(4-hydroxyphenyl)ethane–piperazine (4/3), (C20H18O3)4.(C4H10N2)3, triclinic P\overline 1, a = 12.5049 (11), b = 12.7046 (10), c = 14.6226 (9) Å, \alpha = 113.738 (6), \beta = 100.839 (6), \gamma = 102.438 (7)°, with Z = 1, has two independent trisphenol molecules in general positions and three independent piperazine molecules lying about centres of inversion. The five independent components of the asymmetric unit are linked together by means of three O—H...N and one O—H...O hydrogen bonds to form an open aggregate containing no hydrogen-bonded rings. These aggregates are connected into three sets of interlinked chains in the [010], [001] and [\overline 110] directions: the [010] and [\overline 110] chains employ only O—H...O hydrogen bonds, while the [001] chains employ both O—H...N and N—H...O hydrogen bonds. Additionally, the inversion symmetry at each piperazine unit gives rise to further interlinks.