The new ditopic ligand LH (L = 3-(pyridin-4-ylmethyl)acetylacetonate) has been prepared. The crystal structure of the aluminium(III) complex AlL3·H2O is reported and shows three pendant pyridyl groups available for bridging metal ions. With square planar ions (Cu(II), Pd(II)) the formation of a symmetric cage complex [M6(AlL3)8]12+ is proposed. With Co(NCS)2 an extended structure [{Co(NCS)2}(AlL3)(OH2)]n is found. Factors favouring cage or extended structures are briefly discussed.
