Reaktionen des Alumopolysiloxans (Ph2SiO)8[AlO(OH)]4mit 4,4′-Bipyridin und Azobipyridinen

The molecular alumosiloxane (Ph2SiO)8(AlO(OH))4·4Et2O (1) reacts with 4,4′-bipyridine and azobipyridines (4,4′-azobipyridine and 3,3′-azobipyridine) to form polymer adducts. The acidic hydroxygroups of1interfere with the pyridine-nitrogen atoms to form O···H···N hydrogen bridges which are the source of one- and two-dimensional networks. As reaction products we have characterized (Ph2SiO)8[AlO(OH)]4·2p-(C5H4N)2(2), (Ph2SiO)8[AlO(OH)]4·1.5p-(C5H4N)2N2·C4H8O (3) and (Ph2SiO)8[AlO(OH)]4·2m-(C5H4N)2N2(4). In the crystal structure of2, the supramolecular adduct forms a one-dimensional connection. In3and4two-dimensional connections are formed. The azobipyridine ligands in solution show cis-trans-isomerisation by application of light even in the supramolecular state (as base adducts of (Ph2SiO)8[AlO(OH)]4).