CRYSTAL-STRUCTURE OF TRIAQUAMALEATOSTRONTIUM(II) MONOHYDRATE, [SR(C4H2O4)(OH2)(3)]CENTER-DOT-H2O

[ST(C4H2O4)(OH2)(3)] . H2O is monoclinic, P2(1)/n, with a = 11.476(2), b = 7.027(1), c = 12.344(2) Angstrom, beta = 115.74(3)degrees, V = 89 6.67 Angstrom(3), Z = 4. The Sr atom is surrounded by nine oxygen atom s which come from four different maleate anions and three water molecu les. The Sr-O distances range from 2.546(2) to 2.808(2) Angstrom. The C-O distances are equal within the standard deviation 1.263(3) to 1.25 8(3) Angstrom). In the maleate anion, the planes that contain the carb oxylate groups form an angle of 74.44(9)degrees. Both carboxylate grou ps deviate significantly from planarity. The different coordination mo des of the carboxylate group and the extensive hydrogen bonding presen t are responsible for the polymeric nature of the structure.