Hydrothermal syntheses and crystal structures of three zinc succinates: Zn(C<inf>4</inf>H<inf>4</inf>O<inf>4</inf>)-α, Zn(C<inf>4</inf>H <inf>4</inf>O<inf>4</inf>)-β and K<inf>2</inf>Zn(C<inf>4</inf>H <inf>4</inf>O<inf>4</inf>)<inf>2</inf>
Bowden TA., Milton HL., Slawin AMZ., Lightfoot P.
Three zinc succinate coordination polymers have been synthesised hydrothermally. Two polymorphs of Zn(C4H4O4) adopt three-dimensional structures consisting of tetrahedral Zn atoms isolated from each other via bis-bidentate succinate moieties. The polymorphs differ in the conformation of the succinate group, the a form (I) having syn-periplanar geometry whereas the β form (II) has anti-periplanar geometry. K 2Zn(C4H4O4)2 (III) has a layered structure also composed of isolated tetrahedral Zn units. In this case the two crystallographically distinct succinate groups, one of each conformer, have bis-monodentate coordination, acting as both inter- and intra-layer bridges between neighbouring Zn-containing layers. The 'double' zinc succinate layers are separated along the b-axis by interlayer potassium ions. © The Royal Society of Chemistry 2003.