Reactions of the Alumopolysiloxane (Ph 2 SiO) 8 [AlO(OH)] 4 with 4,4′‐Bipyridine and Azobipyridines

The molecular alumosiloxane (Ph 2 SiO) 8 (AlO(OH)) 4 · 4Et 2 O ( 1 ) reacts with 4,4′‐bipyridine and azobipyridines (4,4′‐azobipyridine and 3,3′‐azobipyridine) to form polymer adducts. The acidic hydroxygroups of 1 interfere 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 (Ph 2 SiO) 8 [AlO(OH)] 4 · 2p‐(C 5 H 4 N) 2 ( 2 ), (Ph 2 SiO) 8 [AlO(OH)] 4 · 1.5p‐(C 5 H 4 N) 2 N 2 · C 4 H 8 O ( 3 ) and (Ph 2 SiO) 8 [AlO(OH)] 4 · 2m‐(C 5 H 4 N) 2 N 2 ( 4 ). In the crystal structure of 2 , the supramolecular adduct forms a one‐dimensional connection. In 3 and 4 two‐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 (Ph 2 SiO) 8 [AlO(OH)] 4 ).