Syntheses and structures of 1D and 2D coordination polymers derived from pyridine-2,4,6-tricarboxylic acid

The reactions of pyridine-2,4,6-tricarboxylic acid (ptcH3) and FeSO4 · 7H2O, CoCl2 · 6H2O or Cu(ClO4)2 · 6H2O gave rise to three novel coordination polymers {[M(H2O)6][M(ptc)(H2O)2]2 · 2H2O}n (M = Fe(II) (1), Co(II) (2)) and {[Cu3(ptc)2(H2O)8] · 4H2O}n (3). 1 and 2 are one-dimensional (1D) polymers while 3 exhibits two-dimensional (2D) coordination network, which are due to the different bonding modes of ptcH3 with metal(II) ions in 1–3.