Organic Acid Regulated Self-Assembly and Photophysical Properties of Perylene Bisimide Derivatives

Abstract

In this work, perylene bisimide derivatives (PBI-1 and PBI-2) with tertiary amine groups were designed and synthesized. To control the final morphologies and properties of their aggregates, seven kinds of organic acids were used to alter the self-assembly environment. The influence of organic acids on the morphology of the aggregates was investigated. Photophysical properties of the aggregates were markedly affected by the kind and concentration of the organic acid. The thermal and gas sensitivities of the PBI-1 aggregates were studied with the use of UV–visible spectroscopy and digital imaging. The shift of the UV–visible spectra varied with time, temperature, acid type and acid concentration. Furthermore, PBI-1 aggregates showed a red-to-blue color change after addition of seven organic acids, whereas the color of the PBI-2 aggregates remained red. These changes of morphologies, photophysical properties and their thermal and gas sensitivities make these aggregates potentially useful in the fields of optoelectronics or sensors.

Multi-controlled ternary emission of platinum(ii) switches as a visual optical sensor for enzyme and pH detection

“…In general, supramolecular assembly systems are often affected by the microenvironment, including factors like temperature, pH and solvents. [40][41][42][43][44][45][46][47] Based on our previous work about alcohol-selective NIR luminescent sensors and molecular hinges with distinct mechano-and piezochromic responses in the NIR region 48 as well as the visual distinction of the enantiomers due to drastic spectroscopic regulation, 49 herein, we report a water-soluble cationic cyclometalated platinum complex with double-armed ammonium ions (1) exhibiting emission color changes from green to dual NIR due to switching between the monomer, excimer, and aggregated ground states (Scheme 1). It is designed as an optical probe to accurately detect pH values in a small range.…”