Synthesis of isoniazid-substituted tetraphenylethylene stereoisomers with dramatic differences on aggregate morphologies, optical and mechanocharomic properties

Abstract

Stereoisomers play an irreplaceable prominent role in life sciences. In molecular engineering, the isomers have been continuously designed and synthesized, and their interrelationships among structure-property-function have also been explored. However, the difficulties in purification and structural confirmation of tetraphenylethene (TPE) derivatives' stereoisomers hinder their structural diversity and scope of functions. Meanwhile, there were few researches on the macroscopic optical differences about TPE derivatives isomers. Herein, isoniazid-substituted TPE derivatives stereoisomers have been synthesized, as confirmed by single crystal data, mass spectrometry and NMR spectroscopy. The different photophysical properties were caused by the introduction of functional group isoniazid on the periphery of TPE. These isomers possessed dramatic differences in fluorescent properties, and exhibited diverse changes in response to stimuli. They also have distinct aggregated self-assembly morphologies because of different intermolecular hydrogen bonding, and they can be used as efficient fluorescent probes for detecting copper. Based on the coordination-driven sensing system, the morphologies of isomers aggregates changed significantly after interaction with copper, and the stoichiometry between them is 2:1. The theoretical calculation demonstrated that they have obvious intramolecular charge transfer behavior. Our research provided a good strategy for designing different substituted groups that can produce various functions and have more potential applications.