Zinc(II) and fin(II) derivatives of maltol (Hmalt), ethylmaltol (HEtmalt), tropolone (Htrop), hinokitiol (Hhino), and kojic acid (Hkoj) have been prepared and characterized, and the crystal structures of M(trop)(2) (M = Zn, Sri) Zn(hino)(2). EtOH, and Sn(malt)2 have been determined. The Zn(trop)2 is a polymeric structure in which tropolone has both a bridging And chelating role; zinc(hino) crystallizes as an ethanol adduct of which the structure is a dimeric fragment of the Zn(trop)2 polymer and in which each metal,is "capped" by a molecule of alcohol, The in complexes are notably air-stable despite adopting monomeric pseudo-tricronal-bipyramidal structures (SnO4E; E is a stereochemically active lone electron pair) in, which the ligands only chelate a single metal center.
Barret, M. C., Mahon, M. F., Molloy, K. C., Steed, J. W., & Wright, P. (2001). Synthesis and structural characterization of tin(II) and zinc(II) derivatives of cyclic alpha-hydroxyketones, including the structures of Sn(maltol)(2), Sn(tropolone)(2), Zn(tropolone)(2), and Zn(hinokitiol)(2). Inorganic Chemistry, 40(17), 4384-4388. https://doi.org/10.1021/ic0100368