Chiral coordination polymers with amino acids: (2)(infinity)[Cu-2(mu-L-tryptophanato)(2)(mu-4,4 '-bipyridine)(H2O)(2)](NO3)(2)

The two-dimensional mixed-ligand network catena-[(mu-4,4'-bipyridine)-bis(mu-L-tryptophanato-kappa N-3,O,O')-diaqua-dicopper(II) dinitrate] is constructed through the bridging action of both the tridentate amino carboxylato and the bidentate 4,4'-bipyridine ligand. The enantiomeric L-tryptophanato ligand acts as an N,O chelate towards one copper atom and bridges through the second carboxylate oxygen atom to the adjacent copper ion. Stacking of the corrugated nets creates channels which are occupied by the hydrogen-bonded and very weakly Cu-coordinating nitrate ions.