Maleate-fumarate conversion and other novel aspects of the reaction of a Co(II) maleate with pyridine and bipyridine.

Reaction of a molecular Co(II) maleate, [Co(Hmal)2(H2O)4], with pyridine yields a Co(II) fumarate, [Co(fum)(H2O)4], with a chain structure and a chiral pyridylsuccinic acid zwitter ion, (-)OOC-CH(N+C5H5)-CH2-COOH, in almost quantitative yields, while the reaction of 4,4'-bipyridine (bipy) with the Co(II) maleate, on the other hand, almost quantitatively generates a polylmeric Co(II) maleate, [Co(mal)(bipy)]n.(n/2)H2O along with the adduct of fumaric acid with bipyridine.

catena-Poly[[[aqua-(propane-1,3-diamine-κN,N')copper(II)]-μ-fumarato-κO:O'] monohydrate].

The asymmetric unit of the title compound, {[Cu(C(4)H(2)O(4))(C(3)H(10)N(2))(H(2)O)]·H(2)O}(n), consists of two Cu(II) atoms, half each of two propane-1,3-diamine ligands and two coordinated water mol-ecules, all lying on crystallographic mirror planes, also one fumarate dianion and one uncoordinated water mol-ecule in a general position. The Cu(C(3)H(10)N(2))(H(2)O) units are linked via fumarate dianions into a zigzag chain running along the a axis. A longer Cu-O distance [2.