Time-dependent solid-state molecular motion and colour tuning of host-guest systems by organic solvents.

Yang, Yu-Dong; Ji, Xiaofan; Lu, Zhi-Hao; Yang, Jian; Gao, Chao; Zhang, Haoke; Tang, Ben Zhong; Sessler, Jonathan L et al. · Nat Commun · 2020

basic_science · Level V

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Abstract

Host-guest complex solid state molecular motion is a critical but underexplored phenomenon. In principle, it can be used to control molecular machines that function in the solid state. Here we describe a solid state system that operates on the basis of complexation between an all-hydrocarbon macrocycle, D<sub>4d</sub>-CDMB-8, and perylene. Molecular motion in this solid state machine is induced by exposure to organic solvents or grinding and gives rise to different co-crystalline, mixed crystalline, or amorphous forms. Distinct time-dependent emissive responses are seen for different organic solvents as their respective vapours or when the solid forms are subject to grinding. This temporal feature allows the present D<sub>4d</sub>-CDMB-8⊃perylene-based system to be used as a time-dependent, colour-based 4th dimension response element in pattern-based information codes. This work highlights how dynamic control over solid-state host-guest molecular motion may be used to induce a tuneable temporal response and provide materials with information storage capability.