Synthesis and crystal structure of a calcium(II)-basedcoordination polymerconstructed from 1,2,4,5-Benzenetetracarboxylic Acid

Abstract

International audienceThe polymeric compound, [Ca2(btec)(H2O)6]∞ was obtained by slow diffusion of dilute aqueous solutionsof calcium chloride and of the sodium salt of benzene-1,2,4,5-tretracarboxylic acid(H4btec) through an agar-agar gelbridge in a U-shaped tube. This compound crystallizes in the triclinic system, space group P-1 (n° 2) with a = 5.8270 (2)Å, b = 7.7197 (2) Å, c = 9.6763 (3) Å, a = 112,497 (1) °, β = 101.293 (1)°, g = 97.567(2)° and Z = 2. Each Ca2+ ion iscoordinated by three oxygen atoms from coordinated water molecules and five oxygen atoms from three btec4-ligandsthat form a slightly distorted dodecahedron. Ligands also act as μ6-bridging groups between the Ca2+ ions.Thecrystal structure consists of a superimposition of 2D layers that spread parallel to the, plane