(4NPEA)2PbI4 (4NPEA = 4‑Nitrophenylethylammonium): Structural, NMR, and Optical Properties of a 3 × 3 Corrugated 2D Hybrid Perovskite

(4NPEA)2PbI4 (4NPEA = 4-nitrophenylethylammonium) is the first 3 × 3 corrugated 2D organic-Pb/I perovskite. The nitro groups are involved in cation–cation and cation-iodide interactions. The structure contains both highly distorted and near-ideal PbI6 octahedra, consistent with the observation of two 207Pb NMR resonances, while the optical properties resemble those of other 2D perovskites with distorted PbI6 octahedra.