Synthesis, Photophysics, Live Cell Imaging, and Aggregation Behavior of Some Structurally Similar Alkyl Chain Containing Bromonaphthalimide Systems: Influence of Alkyl Chain Length on the Aggregation Behavior

Abstract

A series of 4-bromonaphthalimide systems (BNI-C n ; n = 4, 6, 10, 12, and 16) comprising different alkyl side chains have been synthesized and used as the building blocks to fabricate organic fluorescent micro materials. The systems have been developed basically to investigate the effect of alkyl side chains on the aggregation behavior of the systems. The aggregation behavior of these systems has been studied by spectroscopic and microscopic techniques. Microscopic investigation reveals that there is a decrease in the size of the aggregates with an increase in the linear alkyl side chain length. A change in the shape from rod-like to spherical with an increase in the length of alkyl group has also been observed during microscopic investigation. The photophysical properties of these well-characterized aggregates have been studied and compared with those in molecular form. A bathochromic shift both in absorption and in emission spectrum of the aggregates has indicated the formation of J aggregates. A confocal fluorescence microscopic investigation also reveals that the long chain systems (12 and 16 member) are cell permeable and can be used as the imaging probe in live cells.

Enhanced Photocatalytic Activity of a Molybdate‐Intercalated Iron‐Based Layered Double Hydroxide

“…To determine the lifetimes of the charge carriers, we studied the time‐resolved photoluminescence decay (TRPL) spectra (Figure ) . The curves were fitted with biexponential decay response functions, defined by Equation , …”

Fluoride ion sensing in aqueous medium by employing nitrobenzoxadiazole-postgrafted mesoporous silica nanoparticles (MCM-41)

“…34 The effects of aggregation of fluorophores on their photophysical properties has been extensively studied in the solution phase. [35][36][37] Here, aggregation may be a result of p-p stacking interactions among several NBD moieties that are bound to the silica surface. 34 Nevertheless, the overall absorption feature of both bound and unbound NBD indicates that the basic chromophoric properties of NBD are not significantly altered upon covalent attachment to the mesoporous silica surface.…”

Investigating the molecular and aggregated states of a drug molecule rutaecarpine using spectroscopy, microscopy, crystallography and computational studies

“…36,66,67 The blue shift that has been observed for the aggregates can be explained by invoking the molecular exciton theory. 36,43,66,67 According to this theory, two different energy levels for aggregates; higher and lower as compared to monomers, can be possible owing to the interaction between transition dipoles of the molecules that are participating in the self-assembly process. 43,[66][67][68] The blue shift for the aggregates in the present case illustrates that during the self-assembly process, the rutaecarpine molecules are arranged in such a way that favours the formation of H-type aggregates.…”

“…[31][32][33][34][35] The aggregation of organic nanoparticles is generally driven by selfassembly of individual monomers due to the varying nature of intermolecular forces like van der Waals interaction, p-p stacking, hydrogen bonding, hydrophobic interaction and co-ordinate bonding, [36][37][38] leading to a variety of nanostructural designs. [39][40][41][42][43][44] Therefore, it is extremely important to understand the role of intermolecular interactions in determining the structure and optical properties of nanomaterials so as to develop functionally tunable materials with desired optical and electronic properties for future applications.…”