Semiconductive donor promoted photochromism of iodoplumbate hybrids

Abstract

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.