Manganese(II) D-gluconate dihydrate

Mn(C6HllO7) 2. 2H20, 2C6HllO 7.Mn2+. - 2H20, triclinic, P1, a = 7.205 (5), b = 8.184 (4), c = 11.157 (6) A, ,t = 90.96(4), fl = 94.40(5), y = 137.34 (4) °, M r = 481.3, V = 441.9 (5)/~3, Z = 1, D m = 1.79, D x = 1.81 Mg m -a,/t(Cu Kct, 2 = 1.5418 A) = 7.24 mm -~, final R = 0.033 and R w = 0-045. The Mn atom is octahedrally coordinated by one carboxyl- ate O atom and one hydroxyl O atom from both gluconate ligands and two water O atoms in cis positions. Mn--O distances range between 2.091 (5) and 2.275 (5) /~. The independent gluconate ions assume different bent-chain conformations and one is bonded to two adjacent Mn atoms forming polymeric chains parallel to b. There is extensive intermolecular hydrogen bonding (and one intramolecular hydrogen bond) involving all the hydroxyl and water H atoms and holding the polymeric units together.