Bioinspired Nanoarchitectonics of Naphthalene Diimide to Access 2D Sheets of Tunable Size, Shape, and Optoelectronic Properties

Abstract

A bioinspired nanoarchitectonics design strategy is adapted to construct 2D sheets of promising n-type organic semiconductor naphthalene diimide (NDI) with tunable size, shape and optoelectronic properties. Modulation of noncovalent interactions such as intermolecular NDI-NDI aromatic and hydrogen bonding interactions among the molecules within the self-assembled 2D sheets is achieved by the minute structural mutations on the NDI imide substitutions in the form of glycine derivatives (carboxylic acid, amide and ester). Microscopy studies (FESEM and AFM) showed the formation of flat, smooth and large 2D nanosheets with distinct lateral and height profiles. Photophysical studies revealed unique solid state optoelectronic properties with promising temperature responsive fluorescence behavior with quite longer life time values which are useful as temperature sensor materials. The concentration and temperature dependent H-1 NMR and IR studies provided the insights into distinct noncovalent interactions responsible for the observed NDI 2D sheets with variable size and shape. Furthermore, PXRD studies revealed highly crystalline molecular organization within the 2D sheets. On account of these tunable unique properties, the 2D sheets derived from NDI-conjugates might find a wide range of future interdisciplinary applications from materials to biomedicine.