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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Straightforward synthesis of photoactive chalcogen functionalized benzimidazo[1,2-a]quinolines

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Author(s):
da Silva, Rodrigo Borges [1] ; Coelho, Felipe Lange [1] ; Rodembusch, Fabiano Severo [1] ; Schwab, Ricardo Samuel [2] ; Forain Miolo Schneider, Juliana Maria [3] ; Rampon, Daniel da Silveira [4] ; Schneider, Paulo Henrique [1]
Total Authors: 7
Affiliation:
[1] Univ Fed Rio Grande do Sul, Inst Quim, Dept Quim Organ, Av Bento Goncalves 9500, BR-91501970 Porto Alegre, RS - Brazil
[2] Univ Fed Sao Carlos UFSCar, Dept Quim, Rodovia Washington Luis, Km 235 SP 310, BR-13565905 Sao Carlos, SP - Brazil
[3] UFCSPA, Dept Farmacociencias, Rua Sarmento Leite 245, BR-90050170 Porto Alegre, RS - Brazil
[4] Fed Univ Pararui UFPR, Dept Chem, Lab Polymers & Mol Catalysis LAPOCA, POB 19032, BR-81531990 Curitiba, Parana - Brazil
Total Affiliations: 4
Document type: Journal article
Source: NEW JOURNAL OF CHEMISTRY; v. 43, n. 29, p. 11596-11603, AUG 7 2019.
Web of Science Citations: 0
Abstract

A series of new organochalcogen derivatives of benzimidazo{[}1,2-a]quinolines were synthesized in moderate to excellent yields and in short reaction times from chalcogen benzimidazoles, in a straightforward synthetic procedure, through transition-metal-free cascade reactions involving a sequential intermolecular aromatic nucleophilic substitution (SNAr), followed by an intramolecular Knoevenagel condensation. Both the sulfur and selenium derivatives presented similar photophysical properties, with absorption maxima located in the UV region (similar to 355 nm) related to spin and symmetry allowed electronic p-p{*} transitions, and fluorescence emission located in the violet-blue region (similar to 440 nm) with a relatively large Stokes shift (similar to 90 nm). The fluorescence quantum yields were slightly influenced by the chalcogen, with the sulfur derivatives presenting higher values than the selenium analogues, probably due to the intersystem crossing allowed by the selenium atom. Moreover no clear evidence for charge transfer in either compound in the ground and excited states was observed. (AU)

FAPESP's process: 13/06558-3 - Asymmetric catalysis: preparation of chiral alcohols and their derivatives from highly functionalized organozinc reagents and application of new chiral ligands supported on magnetic nanoparticles
Grantee:Ricardo Samuel Schwab
Support type: Regular Research Grants