Self-assembly synthesis of precursors to potential open framework alkali earth metal–organic complexes

The synthesis and crystal structures of a series of six magnesium pyridinecarboxylic and dicarboxylic acid complexes are reported. These complexes have been prepared to establish the nature of the hydrogen-bonding within this series and to investigate the potential of using these complexes as precursors in the self-assembly of network materials. Two Mg picolinic acid complexes ( Mg1 , Mg2 ) display a 1 : 2 metal : ligand ratio and are polymorphic. A Mg isonicotinic acid complex ( Mg3 ) is a constitutional isomer of Mg1 and Mg2 , while a 1 : 1 Mg picolinic acid complex ( Mg4 ) is also reported and compared to the other members of the series. The set of complexes reported is completed by the synthesis and structural characterisation of two complexes containing the 2,4-pyridinedicarboxylic acid (2,4pdca) ligand, both a 1 : 1 ( Mg5 ) and 1 : 2 ( Mg6 ) Mg 2,4pdca acid complex, in which the presence of the additional carboxylate functionality provides clearer potential to form materials with extended network structures.