5,5'-Diamino-2,2'-bipyridin-1,1'-diium bis(5,5'-diamino-2,2'-bipyridin-1-ium) tetrakis(rac-1,1'-binaphthalene-2,2'-diyl phosphate) hexahydrate: a two-dimensional supramolecular hydrogen-bonded network
Abstract
In the title compound, C10H12N42+.2C10H11N4+.4C20H12O4P-.6H2O, the 1,1'-binaphthalene-2,2'-diyl phosphate anion and 5,5'-diamino-2,2'-bipyridine as hydrogen-acceptor and -donor building blocks, respectively, are combined in a supramolecular two-dimensional hydrogen-bonding network of one centrosymmetric diprotonated diaminobipyridin-1,1'-ium dication, two monoprotonated diaminobipyridinium cations, four phosphate counter-anions and six water molecules of crystallization. Protonation of diaminobipyridine to the bipyridinium mono- or dication enhances the hydrogen bonding due to the primary electrostatic attraction with the anion. The packing can be rationalized by a separation of the hydrophobic binaphthyl backbone from the hydrophilic (RO)2PO2- phosphate groups, bipyridinium cation and water components. The binaphthyl tail-to-tail packing in the hydrophobic lamellae as well as the diaminobipyridinium packing is governed by - and C-H interactions.