Synthesis, crystal structure, and properties of three lead(II) complexes based on the 1,10-phenanthroline ligand

Three new lead(II) complexes containing the 1,10-phenanthroline ligand, [Pb(phen)(2)(3,5-DNB)(2)] (1), [Pb(phen)(2)(3,5-DNB)(NO3)](2)center dot H2O (2), and [Pb(phen)(HCOO)(NO3)(H2O)]( n ) (3) (phen = 1,10-phenanthroline, 3,5-DNB = 3,5-dinitrobenzoate anion) have been synthesized and characterized by elemental analyses, Fourier transform infrared spectroscopy (FTIR), thermogravimetric analyses (TGA), and single-crystal X-ray diffraction. The complexes 1 and 2 are monomeric species, whereas complex 3 is a one-dimensional polymer. In the three complexes, the ligand phen creates a number of pi center dot center dot center dot pi stacking interactions and hydrogen bonds, which play an important role in extending complexes 1-3 to supramolecular architectures. The Pb(II) ion of complexes 1 and 2 shows hemidirected geometry with noncovalent Pb center dot center dot center dot O/C tetrel bonds formed which further stabilize the supramolecular structures.