Neue Koordinationspolymere auf der Basis der Naphthalin-1,4,5,8- tetracarboxylat-hydrate von Ca, Sr und Ba / New Coordination Polymers Based on Naphthalene-1,4,5,8-tetracarboxylate Hydrates of Ca, Sr, and Ba

Abstract

Crystals of [Ca(NTC)(H2O)2]·H2O (1) (NTC = naphthalene-1,4,5,8-tetracarboxylate-1,8-monoanhydride) and [Sr2(NTC)2(H2O)8]·H2O (3) were obtained by layering an aqueous solution of sodium naphthalene-1,4,5,8-tetracarboxylate with an aqueous solution of CaCl2 or SrCl2, respectively. Crystals of [Sr(NTC)(H2O)2]·2H2O (2) and [Ba(NTC)(H2O)2] (4) were obtained by gel crystallisation. The NTC in 1 and 2 is tridentate, and in 4 pentadentate, forming bonds to the cations using the oxygen atoms of the carboxylate and one oxygen atom of anhydride groups. In 3 the cations are associated only via the oxygen atoms of carboxylate groups. 1 and 2 have layer structures, 3 has a chain structure, and 4 forms a three-dimensional coordination network. The number of O atoms around the cations is eight for 1, 2 and 4, and nine for 3.