Two New Lead(II) Coordination Polymers with (Substituted) Bipyridine and Auxiliary Nitrate Ligands

The reaction of lead(II) nitrate with 4,4′‐bipyridine (4,4′‐bpy) and 4,4′‐dimethyl‐2,2′‐bipyridine (4,4′‐dm‐2,2′‐bpy) or 5,5′‐dimethyl‐2,2′‐bipyridine (5,5′‐dm‐2,2′‐bpy) resulted in the fomation of single crystals of [Pb 2 (4,4′‐bpy)(5,5′‐dm‐2,2′‐bpy) 2 (NO 3 ) 4 ] ( 1 ) and [Pb 3 (4,4′‐bpy) 2 (4,4′‐dm‐2,2′‐bpy) 2 (NO 3 ) 6 ] ( 2 ). The new compounds have been characterized by single‐crystal X‐ray diffraction structure analysis as well as through elemental analysis, IR, 1 H‐NMR and 13 C‐NMR spectroscopy and their stability has been studied by thermal analysis. In the crystal structure of ( 1 ) formula‐like dimers are further connected to a 2‐D network through the auxiliary nitrate ligands. The crystal structure of ( 2 ) exhibits two crystallographically independent Pb II central atoms (in a ratio of 1:2). With the aid of the 4,4′‐bpy and the nitrate ions, a 3‐D polymeric structure is achieved.