A Novel Multi-helical Polymer: Pyridine-2,6-dicarboxylato Plumbum(II) Complex [Pb(dipic)]n

Self-assembly of pyridine-2, 6-dicarboxylato dianion (dipic)2- and plumbous nitrate affords a coordination polymer of [Pb(dipic)]n (1). Its structure was determined by elemental analyzer, IR spectroscopy and single crystal X-ray diffraction, and further characterized by thermal gravity (TG) analysis. Interestingly, this polymer exhibits a novel 2D framework which contains three-type of helical chains with the highest-stranded number of three in the entangled system. The reticular 2D framework is connected through oxo-bridges. When the strong hydrogen bonds in the structure are taken into account, Pb(dipic)]n forms a 3D layer structure. The hydrogen bonds between these helical chains play important roles in constituting a 3-dimension layer structure from its 2-dimension network.