Royal Society of Chemistry, CrystEngComm, 45(15), p. 9722, 2013
DOI: 10.1039/c3ce41253a
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Three new metal-organic frameworks (MOFs) have been synthesised from alkali earth metal ions of increasing ionic radii (Mg, Ca and Sr) and 2,2’-dihydroxybiphenyl-4,4’-dicarboxylic acid (H4diol). The distinct coordination environments, framework topologies and the non-coordinated diol moieties accessed are a result of using differently sized metal ions for MOF synthesis which affects the ability of the diol moieties to chelate the metal. Detailed structural analysis of [Sr3(H2diol)3(DMF)5], [Ca3.5(Hdiol)(H2diol)2(DMF)5] and [Mg(H2diol)(DMF)2] show distinctive variations in variable temperature expansion/contraction properties and porosity. In addition, [Sr3(H2diol)3(DMF)5] and [Ca3.5(Hdiol)(H2diol)2(DMF)5] display a broad fluorescence emission (λmax = ~435 nm) under ultraviolet light due to the presence of non-coordinated biphenyl-diol moieties within the structures, while chelation of Mg by the diol pocket in [Mg(H2diol)(DMF)2] leads to quenching of the ligand fluorescence. ; Damien Rankine, Tony D. Keene, Christopher J. Sumby and Christian J. Doonan ; First published online 04 Sep 2013