Sotaro Kusumoto, Kazuki Nakahama, Kouta Karube, Yuudai Iwai, Ryo Ohtani, Fumiya Kobayashi, Kosaku Ohishi, Teruki Motohashi, Yang Kim, Yoshihiro Koide
A Zn(II) hydrazone complex undergoes reversible, coordination-driven pyridine capture in the solid state, producing rapid vapochromic and turn-on vapoluminescent responses. Interconversion between ZnL2 and ZnL2(Py) increases the photoluminescence quantum yield from 5.86% to 25.4% by inducing rigidity and suppressing nonradiative decay. This work demonstrates that reversible guest coordination is a powerful strategy for controlling solid-state luminescence and for designing VOC-responsive sensing materials.