784-03-2Relevant articles and documents
Effect of molecular structure and hydrogen bonding on the fluorescence of hydroxy-substituted naphthalimides
Biczok, Laszlo,Valat, Pierre,Wintgens, Veronique
, p. 4759 - 4766 (1999)
Fluorescence properties of hydroxy-naphthalimides were studied in methylene chloride in the absence and the presence of hydrogen-bonding additives. The position of the HO-substituent only slightly affects the radiative rate, however, the triplet yield and the rate of the radiationless processes are considerably higher for the 3-hydroxy derivative. Addition of nitrogen-heterocyclic compounds leads not only to hydrogen-bonding in the ground state but also fluorescence quenching. The parallel change through of the series of the hydrogen-bond acceptors between the proton affinity and the rate constants of dynamic quenching indicates that proton displacement plays a crucial role in the excited hydrogen-bonded complexes. Interaction of hydroxy-naphthalimides with pyridine arid benzoxazole results in rapid radiationless deactivation from the singlet excited state, whereas intense emission as well as long fluorescence lifetime characterize imidazole and pyrazole complexes. The dual emission of the imidazole complexes observed in solvents of medium polarity is assigned to two conformers which differ in the extent of the proton shift along the hydrogen-bond.
Naphthalimide/benzimide-based excited-state intramolecular proton transfer active luminogens: Aggregation-induced enhanced emission and potential for chemical modification
Wang, Rong,Ding, Ju,Zhang, Yanrong
, p. 9152 - 9161 (2019/06/17)
Fluorescent organic particles are important in a number of areas, including medical imaging; hence, the development of organic materials that exhibit aggregation-induced emissions is an important objective. To that end, we report the synthesis of naphthalimide- and benzimide-based 2-(2-hydroxyphenyl)benzothiazole (HBT) derivatives (HNIBT and HPIBT, respectively) that exhibit aggregation-induced emission enhancement (AIEE), in contrast to most naphthalimide- or benzimide-based derivatives that are prone to aggregation-induced quenching. Experimental studies like single-crystal X-ray diffraction analysis and theoretical calculations demonstrate that the ability to undergo excited-state intramolecular proton transfer is pivotal for AIEE. Further studies revealed that a terminal alkynyl chain at the N-imide site of HPIBT has little impact on the emission behavior of the resultant compound (HPIBT-yl). HPIBT-Pe, an amphiphilic molecule obtained through the click reaction of HPIBT-yl and a tetraethylene-glycol-derived azide, self-assembled to form highly photostable particles that have long-term fluorescence imaging potential in cellular environments.
Synthesis and Photooxygenation of 2,3,6-Trimethylfuronaphthopyrida-5,7-dione, A Potential Chemiluminescent Probe for Singlet Oxygen
Adam, Waldemar,Qian, Xuhong,Saha-Moeller, Chantu R.
, p. 417 - 422 (2007/10/02)
As potential chemiluminescent probe for singlet oxygen, the furonaphthalimide 4 was synthesized in five steps (ca. 25percent overall yield), by starting from commercially available 4-chloro-1,8-naphthalic anhydride; its photooxygenation at -10 deg C gave the cleavage product 6 of the intermediary dioxetane 5, which is thermally too labile for isolation and could not be detected even by low temperature NMR spectroscopy.The new 1,8-naphthalimide derivatives 3,4 and 6 were fully characterized and their absorption and fluorescence spectral properties were determined.
