Komplexe mit substituierten 2,5-Dihydroxy-p-benzochinonen: Die Schichtverbindung Ca[C6(i-C3H7)2O4H]2·2/3H2O / Complexes with Substituted 2,5-Dihydroxy-p-benzoquinones: The Layer Compound Ca[C6(i-C3H7)2O4H]2·2/3H2O
Dark, hydrophobic single crystals of Ca[C6(i-C3H7)2O4H]2·2/3H2O were grown in aqueous silica gel. Infinite layers parallel to (001) formed by Ca2+ and [C6(i-C3H7)2O4H]- are the main feature of the crystal structure. Ca2+ is coordinated in two different manners. Ca(1) has CN7: the coordination polyhedron is a slightly distorted capped trigonal antiprism made up by one water molecule and six oxygen atoms (O(1), O(2)) of the anions which chelate Ca(1). The mean Ca(1)-O distance is 238.9 pm. The coordination polyhedron of Ca(2) is a distorted octahedron formed by six anions acting as monodentate ligands via O(3): Ca(2)-O(3) 227.3 pm. In one half of the [C6(/-C3H7)204H] anion the bonding geometry resembles that of the corresponding dianions, but in the other half the bond lengths are very similar to those observed in free 2,5-dihydroxy-p-benzoquinones. The remaining H atom of the anion is involved in strong intramolecular hydrogen bonding as well as in an intermolecular hydrogen bond.