The rod-like bis-monodentate N,N'-type ligands, are a type of most widely used
organic ligands in the field of supramolecular coordination chemistry because of their redox
stability and easy modification. The infinite 1D chain structure is the simplest topology of
coordination polymers, however, the complicated crystal packing modes of the 1D chains
make their solid-state structures diversified thereof endow different potential applications. For
instance, the 1D chains can stack in the crystal lattice in a parallel fashion which is the most
common packing mode, but in many cases, the 1D chains were found to stack in a nonparallel
fashion. In addition, if the 1D chains are not straightly linear, they can entangle with
each other to form even complicated crystal structure [1].
We have long been interested in study of coordination polymers constructed from the
ditopic rigid or flexible N,N'-type ligands which comprise the Py (pyridyl), terminal donor
groups. We report a two 1D coordination polymers constructed from the rigid Schiff-base
N,N'-type ligands (R–C=N–N=C–R) 1,4-bis(3-pyridyl)-2,3-diaza-1,3-butadiene (N3Py) and
1,4-bis(4-pyridyl)-2,3-diaza-1,3-butadiene (N4Py) namely [Cd(3-bphz)I2]n (1) and
[Cd(4-bphz)(CH3COO)2(H2O)]n (2). The structures of compounds were determined using Xray
diffraction method (Fig.1).

Fig.1. Molecular structures of compound 1 and 2.
Single-crystal analysis reveals that complexe 1, 2 crystallized in the orthorhombic
crystal system. Complexe 1 display one-dimensional zig-zag chain structure, and the complex
2 display one-liniar chain structure. The node of compound 1 consists of a tetracoordinate
CdII center bonded to two I–ligands and two 3-bphz ligands. In the second compound, the
cadmium ion is heptacoordinated by two CH3COO–ligands, two 4-bphz ligands and a water
molecule.
[1] Qing Wanga, Bing Liangb, Jian-Yong Zhanga, Mei Pana, Bei-Sheng Kanga, and Cheng-Yong Su, Z. Anorg.
Allg. Chem. 2007, 05, 2463-2469.