Isomeric naphthalimides bearing pyran units: Insight into mutual relation between structure and photochromic properties

Controlling photophysics of styrylnaphthalimides through TICT, fluorescence and E,Z-photoisomerization interplay

“…1,8-Naphthalimide derivatives are famous organic fluorophores which generally exhibit high thermo-and photostability and are known to act as fluorescent brighteners and dyes for polymer fibers, 10,11 laser active media, 12,13 electroluminescent materials [14][15][16] and optical memory devices. [17][18][19] Because of their intense fluorescence, large Stokes shifts along with the relative ease of synthetic operations for targeted modification of the molecular structure, these types of compounds have found application in the construction of fluorescent chemosensors for biologically relevant cations and anions, [20][21][22] labels or probes for proteins, cells, lysosomes and other acidic organelles. [23][24][25] However, the emission bands of most naphthalimides are in blue and green-yellow regions, which is a characteristic of 4-amino-, 4-amido-and 4-alkoxy-substituted derivatives.…”

A novel bacteriochlorin–styrylnaphthalimide conjugate for simultaneous photodynamic therapy and fluorescence imaging

“…1,8-Naphthalimide derivatives are famous organic fluorophores which generally exhibit high thermo-and photostability and are known to act as fluorescent brighteners and dyes for polymer fibers, 28,29 laser active media, 30,31 electroluminescent materials [32][33][34] and optical memory devices. [35][36][37] Because of its intense fluorescence, large Stokes shifts along with the relative ease of synthetic operations for targeted modification of the molecular structure, these types of compounds have found application in the construction of fluorescent chemosensors for biologically relevant cations and anions, [38][39][40] labels or probes for proteins, cells, lysosomes and other acidic organelles. [41][42][43] In our recent papers, [44][45][46] we have described photophysical properties of naphthalimides containing a substituted styryl fragment as an electron releasing group at the 4 th position of a naphthalene ring.…”

Recent Developments on Catalyst‐Free, Visible‐Light‐Triggered Synthesis of Heterocyclic Scaffolds and Their Mechanistic Study

“…Dihydropyrano [2,3-c]pyrazole and its derivatives are attractive and fruitful scaffolds in the field of synthetic as well as medicinal chemistry having diverse biological activities such as anti-inflammatory, anti-microbial activity, anti-cancer, analgesic and anti-oxidant etc. [62] Tripathi et al reported an eco-friendly and metal-free procedure for the synthesis of pyrano [2,3-c]pyrazoles (73) via a four-component reaction of ethylacetoacetate (69), hydrazine hydrate (70), aromatic aldehydes (71) and malononitrile (72) at room temperature (Scheme 38). [63] The reaction was carried out in solvent-free and catalyst-free conditions exploiting visible light as a promoter.…”

“…They also found that in the absence of visible light, the yield of the product was noticeably decreased to 30 % which specified the importance of light. The authors proposed that ethyl acetoacetate (69) and hydrazine hydrate (70) underwent nucleophilic addition reaction to form 39 A, which through keto-enol tautomerism led to 39 B. Then, malononitrile (72) tautomerized in presence of visible light and reacted with benzaldehyde (71) to form benzylidene malononitrile adduct 39 D which formed a radical 39 E by photochemical activation.…”