metal-organic compounds
Three alkaline earth metal salts of phenylacetic acid were examined and all were found to have similar structural types to analogous salts of benzoic and halobenzoic acids. Thus, a synchrotron study shows that the cations in catena-poly[[[tetraaquamagnesium(II)]-μ-phenylacetato-κ2O:O′] phenylacetate], {[Mg(C8H7O2)(H2O)4](C8H7O2)}n, form a one-dimensional coordination polymer that propagates through Mg—O—C—O—Mg interactions involving both crystallographically independent Mg centres (Z′ = 2) and through translation along the a axis. The polymeric chains pack to give alternate inorganic layers and organic bilayers. The Ca and Sr species catena-poly[[[diaqua(phenylacetato-κ2O,O′)calcium(II)]-μ3-phenylacetato-1′:1:1′′κ4O:O,O′:O′] monohydrate], {[Ca(C8H7O2)2(H2O)2]·H2O}n, and catena-poly[[[diaqua(phenylacetato-κ2O,O′)strontium(II)]-μ3-phenylacetato-1′:1:1′′κ4O:O,O′:O′] monohydrate], {[Sr(C8H7O2)2(H2O)2]·H2O}n, are essentially isostructural. Both form one-dimensional coordination polymers through a carboxylate group that forms four M—O bonds. The polymeric chains propagate via 21 screw axes parallel to the b axis and are further linked in the bc plane by hydrogen bonding involving the non-metal-bound water molecule. Similarly to the Mg salt, both have inorganic layers that alternate with organic bilayers.