Synthesis of New Copper(II) and Iron(III) Malonates with Barium Cations

Barium–copper(II) and barium–iron(III) coordination polymers with malonic acid dianions [BaCu II (Mal) 2 (H 2 O) 4 ] n ( 1 ) (CCDC No. 2239603) and {[Ba_2Fe_2^III(OH)_2(Mal)_4(H_2O)_6]·4H_2O}_n ( 2 ) (CCDC No. 2239902) are prepared for the first time. The complexes are built by bischelate fragments of 3 d metals M (Mal) 2 x – ( x = 2 for 1 , x = 1 for 2 ) forming layers ( 1) or fragments coupled by OH bridges ( 2 ) in the crystal. The barium atoms coordinate O atoms of chelate-bridging malonate anions and bridging water molecules that are additionally H-bonded to the M (Mal) 2 x – fragments in 1 and 2 , thus forming complex Ba–O–H… M (Mal) 2 bridges suitable for the formation of 3D and 2D polymers, respectively. The new compounds are characterized by single-crystal XRD, IR spectroscopy, CHN analysis, and powder XRD methods.