The development of coordination polymers (CPs) in materials science, crystal engineering and
supramolecular chemistry are areas of research undergoing significant growth. The infinite 1D chain
structure is the simplest topology of CPs; however, the complicated crystal packing modes of the 1D chains
make their solid-state structures diversified thereof endow different potential applications 1. It is reported
that 2-thiophenecarboxylic acid possesses biological properties being used in hypercalcemic treatment 2,
while Schiff bases are known to be used to design medicinal compounds. Herein we report crystal
structures of two 1D CPs, [Zn2(4-bphz)(2-tpca)4]n(1) and [Cd2(4-bphz)3(2-tpca)4]n (2) constructed from the
rigid 1,2-bis(pyridin-4-ylmethylene)hydrazine (4-pbhz) ligand and 2-thiophenecarboxylic acid (2-tpca). 1
crystallizes in the triclinic P-1 sp. gr.: a=9.1359(9), b=10.2173(9), c=11.2253(9) Å, α= 98.526(7), β=
108.158(8), =115.093(9)°, V =852.44 Å3 (Fig., left). 2 crystallizes in the monoclinic P21/n sp.gr.:
a=10.6084(3), b=20.3823(5), c=16.1527(5) Å, β=106.643(3)°, .V = 3346.27 Å3 (Fig., right).

The metal coordination nodes represent the binuclear Chinese lantern moiety Zn2(μ2RCOO)4 in 1, and
mononuclear pentagonal bipyramid CdN3O4 in 2. The coordination of extra 4-pbhz ligand to the metal
centers in 2 reveals the most likely pathway to the structure’s extension.
1. W. L. Leong, J. J. Vittal,Chem. Rev., 2011, 111 (2), 688–764.
2. W. Lloyd, V.S. Fang, H. Wells, A.H. Tashjian Jr., Endocrinology 85 (1969) 763–768.