Structure and property variations of lead iodide–organic coordination polymers tuned by substituted groups on phenanthroline

Abstract

Three lead iodide–organic coordination polymers with different substituents on 1,10-phenanthroline, [(5-S-phen)PbI₂]_n (S = –NO₂(1), –Cl(2) and –NH₂(3)) have been synthesized in polar organic solvent under nearly the same conditions. 1 and 2 are structurally similar to each other, and exhibit 3-D networks based on inter-layer hydrogen bond interactions. 3 also gives 3-D arrangement viahydrogen bonds among 1-D chains. To our interest, we found that the ligand's electronic nature is the dominant factor in the dimension extending behavior; EWGs (electron-withdrawing group) on the phenanthroline ring will lead to larger electron mobility in a coordinated skeleton, but EDGs (electron-donating group) will give a smaller charge carrier mobility. Consequently, from EWGs to EDGs, an enlarged band gap can be observed. Their luminescences were also discussed.