Meso-/Microscopic Single Particle Analyses of Vapochromic Solid-State Crystallization in [Pt(CN)2(H2dcbpy)

Abstract

In this study, the vapochromic behavior of the platinum complex, [Pt(CN)2(H2dcbpy)], was investigated using super-resolution microscopy techniques, that is, structured illumination microscopy and confocal laser microscopy. In [Pt(CN)2(H2dcbpy)], the amorphous-to-crystal transition occurs under the influence of methanol vapor, and the meso-/microscopic solid-state crystallization processes of amorphous single particles can be directly traced by their phosphorescence changes. The time evolutions of three-dimensional vapochromic behaviors demonstrated that when the size of single particles exceeded 10 μm, vapochromism initially manifested along the direction of the position of the MeOH reservoir and that the vapor-induced crystallization initiated at the surface, and subsequently, the crystallization-induced voids enabled vapochromism to advance into the interior of the particles. The findings reported herein provide new insights into the mechanisms underlying solid-state crystallization processes, and a novel strategy to sense organic vapor molecules is proposed.