Novel hydrogen-bonded two- and three-dimensional networks generated from the reaction of metal nitrate hydrates (M = Cd, Co) with the bidentate linear ligand 4,4 '-bipyridine

Two new hydrogen-bonded coordination polymers have been prepared using the transition metal nitrate hydrates Cd(NO3)(2). 4H(2)O and Co(NO3)(2). 6H(2)O in combination with the organic bidentate ligand 4,4'-bipyridine: Cd-2(H2O )(4)(bipy)(5)(NO3)(2)(PF6)(2) (1) (bipy = 4,4'-bipyridine) and [Co(H2O)(4)( bipy)][PF6](2). 3bipy (2). The compounds were characterized by single cryst al X-ray diffraction, IR spectroscopy, and thermogravimetric analysis. Comp ound 1 shows a novel hydrogen bonded brick wall motif assembled from unprec edented dimeric "H-shaped" [Cd-2(bipy)(5)] building blocks via a new comple mentary binary hydrogen bonding bridge. Compound 2 forms a novel three-dime nsional network based on [Co(H2O)(4)(bipy)](n) linear polymer chains which are cross-linked to each other by a new type of Co-H2O(2)... bipy ... H2O(1 )... bipy ... H2O(1)... bipy ... H2O(2)-Co hydrogen bonding linkage.