Crystal structure of a heterometallic coordination polymer: poly[di-aqua-bis-(μ7-benzene-1,3,5-tri-carboxyl-ato)dicalcium(II)copper(II)]

摘要

In the title complex, [Ca2Cu(C9H3O6)2(H2O)2]n, the CaII and CuII cations are bridged by the benzene-1,3,5-tri-carboxyl-ate anions (BTC3?) to form the coordination polymer, in which each BTC3? anion bridges two CuII and five CaII cations with a μ7 coordination mode. The CuII cation, located at an inversion centre, is in a nearly square-planar geometry defined by four O atoms from four bridging BTC3? anions, while the CaII cation is in a distorted octa-hedral geometry defined by five O atoms from bridging BTC3? anions and one water mol-ecule. O—H?O hydrogen bonds between coordinating water mol-ecules and carboxyl groups further stabilize the structure; π–π stacking is also observed between parallel benzene rings, the centroid-to-centroid distance being 3.357?(2)??.