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)(H(2)O)(4)], with pyridine yields a Co(II) fumarate, [Co(fum)(H(2)O)(4)], with a chain structure and a chiral pyridylsuccinic acid zwitter ion, (-)OOC-CH(N(+)C(5)H(5))-CH(2)-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) center dot(n/2) H(2)O along with the adduct of fumaric acid with bipyridine.