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 = 896.67 Angstrom(3), Z = 4. The Sr atom is surrounded by nine oxygen atoms which come from four different maleate anions and three water molecules. 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 1.258(3) Angstrom). In the maleate anion, the planes that contain the carboxylate groups form an angle of 74.44(9)degrees. Both carboxylate groups deviate significantly from planarity. The different coordination modes of the carboxylate group and the extensive hydrogen bonding present are responsible for the polymeric nature of the structure.