Structure and stability of carboxylate complexes. Part VII. Crystal and molecular structures of copper(II)meso-tartrate trihydrate and copper(II)d-tartrate trihydrate

The crystal and moelcular structure of copper(II)meso-tartrate trihydrate and copper(II)d-tartrate trihydrate have been determined by three-dimensional X-ray analysis. The former complex is orthorhombic Pbca, a= 11·46, b= 11·74, and c= 12·13 Å. Diffractometer data refined to R= 0·035. The meso-tartrate ligands from two chelate rings which link distorted octahedral copper ions of two crystallographically different types into chains. The chains are linked to form sheets by weak interactions between one type of copper ion and non-chelating tartrate carboxy-oxygen atoms. Water molecules complete the co-ordination sphere of the second type of copper ion. The sheets are hydrogen bonded together into a three-dimensional network.The latter is monoclinic, P21, a= 12·13, b= 8·37, c= 8·47 Å, and γ= 104·6° and twinned on the (100) plane. Photographic data refined to R= 0·100. The crystals are formed from dimeric groups similar to those found in the vanadyl and antimony salts. Each copper atom is surrounded by six oxygen atoms, four from two cis chelate rings of two tartrate ions, one from a water molecule, and one from the carboxy-group of a related dimeric unit.