Semiconductive donor promoted photochromism of iodoplumbate hybrids

Two iodoplumbate hybrids, [MNH]2[Pb2I6]2·H2O (1) and [MINH][PbI3]·OH (2) (MNH2+ = methylated nicotinohydrazide, MINH2+ = methylated isonicotinohydrazide), have been synthesized by employing positional isomeric MNH2+ and MINH2+ cations as electron acceptors and semiconductive iodoplumbate anions as electron donors, and they exhibit entirely different photochromic behaviors. 1 displays high photosensitivity and a wide responsive range from UV to blue and green light, indicating the driving role of excitation of the PbI3− chain donor in photoinduced electron transfer (PET) and photochromism. The nonphotochromic behavior of 2 shows that efficient PET is hindered by the intermolecular charge transfer (CT) interaction between acceptor and donor.