Both bulk crystals and nanocrystals of two helical complexes, [Cu(mu(2)center dot L)(H2O)](n) (1) and {[Cu(mu(2)-L)(H2O)]center dot 2H(2)O}(n) (2) (H2L = thiazolidine-2,4-dicarboxylic acid), have been synthesized with the chiralities of right-handedness (1) and left-handedness (2), respectively. 4-Cyanopyridine and poly(vinylpyrrolidone) (PVP) have been applied to control the synthesis of complexes with different helicities in bulk-crystal and nanocrystal forms, respectively. 2 can be irreversibly transformed to 1 under heating. Associated with the conformation changing, the symmetry alters between nonpolar and polar space groups.