ABSTRACT
[This retracts the article DOI: 10.1039/C6RA01980C.].
ABSTRACT
[This retracts the article DOI: 10.1039/C4RA04000G.].
ABSTRACT
[This corrects the article DOI: 10.1039/C4RA04000G.].
ABSTRACT
A series of new unsymmetrically substituted naphthalenediimide (NDI) moieties NDI-1 to NDI-6 were synthesized. The structures of these compounds were confirmed by means of FT-IR, 1Hâ NMR, 13Câ NMR, ESI-mass and HRMS spectroscopic measurements. UV/Vis and fluorescence spectroscopy were employed to investigate the photophysical properties of the prepared compounds in solution and in the solid state. Using the onset of UV/Vis absorption, the optical band gaps were calculated. Cyclic voltammetry measurements were performed to study the electrochemical behavior and to calculate the LUMO energy levels. The thermal properties of NDI derivatives were studied by differential scanning calorimetry. The mesomorphic birefringent behavior of the NDI derivatives was investigated with polarizing optical microscopy. Among all of the studied NDI derivatives, only NDI-1, NDI-2, and NDI-3 showed liquid crystalline texture, owing to the presence of an amide linkage for H-bonding along with aromatic moieties for π-π-stacking.
ABSTRACT
In the present work, two new naphthalene diimide (NDI) amphiphiles, NDI-N and NDI-NA, were successfully synthesized and employed to investigate their self-assembly and optical properties. For NDI-NA, which contains an amide group, aggregation-induced emission enhancement (AIEE) was demonstrated in the presence of various ratios of methylcyclohexane (MCH) in chloroform, which led to the visual color changes. This new amide-containing NDI-NA amphiphile formed nanobelt structures in chloroform/MCH (10:90, v/v) and microcup-like morphologies in chloroform/MCH (5:95, v/v). The closure of these microcups led to the formation of vesicles and microcapsules. The structural morphologies gained from the solvophobic control of NDI-NA were confirmed by various complementary techniques such as infrared spectroscopy, X-ray diffraction, and scanning and transmission electron microscopy. In the absence of the amide moiety in NDI-N, no self-assembly was observed, indicating the fundamental role of H-bonding in the self-association process.
ABSTRACT
An amino-core-substituted naphthalenediimide (NDI) derivative has been synthesized in good yield in two steps. The NDI bearing a diamine moiety undergoes a reversible protonation-deprotonation process, which results in intensity changes in the absorption and emission spectra. This derivative exhibits good photostability, good selectivity, high sensitivity, and is employed to exhibit the pH within the rough endoplasmic reticulum of living cells.
ABSTRACT
Construction of thermodynamically stable nanostructures on the nano- to millimeter scales through noncovalent bonding plays an important role in material science. The self-assembly of tetra-alkylamino core-substituted naphthalene diimides (cNDIs) with variable alkyl chains (C8H17, C12H25, and C16H33) added on to the core leads to the formation of a variety of controlled morphologies and well-defined nanostructures. Such structures include nanorods, vesicular, belts, twisted ribbons, and donutlike morphologies (formed in CHCl3/MeOH and CHCl3/hexane mixtures) generated through solvophobic control. UV/Vis absorption and fluorescence spectroscopy demonstrate molecular aggregation in solution. Furthermore, SEM was employed to visualize the supramolecular self-assembled nanostructures. The growth of these structures is mainly due to packing of hydrophobic alkyl chains and π-π stacking of the cNDI core. The present study paves the way to rational and controlled designs of nanostructures made of optically active dyes (naphthalene diimide); this may open a new avenue towards tuning nanodimensional morphology.
