THE CRYSTAL-STRUCTURE OF CALCIUM SUCCINATE MONOHYDRATE

The crystal structure of calcium succinate monohydrate, Ca(C4H4O4).H2O , has been determined by single crystal X ray diffraction. The crystal s are monoclinic with a = 11.952(2), b = 9.698(2), c = 11.606(2) Angst rom, beta = 108.81(1)degrees, space group C2/c, Z = 8, V = 1272.49 Ang strom(3), d, = 1.80, and d(c) = 1.818 Mg m(-3). The structure was refi ned by full-matrix least-squares techniques to R = 0.027, R(w) = 0.040 , for 829 reflections with I greater than or equal to 3 sigma(I). Ca i s coordinated to seven oxygen atoms, and the coordination polyhedron i s best described as a pentagonal bipyramid. One carboxylate group in t he succinate ion is bonded to three different Ca ions, forming a four- membered chelate ring with one Ca ion and unidentate bridge bonds to t wo other Ca ions. The other carboxylate group is bonded to two Ca ions through unidentate bonds. The structure is highly polymeric. The gene ral structural features are nearly identical to those of calcium adipa te monohydrate.