50365-37-2Relevant articles and documents
Two Emissive Long-Lived Excited States of an Imidazole-Functionalized Ruthenium Dipyridophenazine Complex
Isakov, Dajana,Giereth, Robin,Nauroozi, Djawed,Tschierlei, Stefanie,Rau, Sven
, p. 12646 - 12653 (2019)
A ruthenium(II) polypyridine-type complex based on the dipyridophenazine ligand with a directly fused imidazole unit (L1, dipyrido[3,2-a:2′,3′-c]phenazine-10,11-imidazole) has been synthesized, and its electrochemical and photophysical properties have been studied. The cyclic voltammogram of [Ru(tbbpy)2(L1)]2+ (C1) (tbbpy is 4,4′-tert-butyl-2,2′-bipyridine) shows a cathodic shift of the phenazine-based reduction process compared to similar molecules, while the first detected reduction wave (-1.34 V vs Fc/Fc+) is assigned to the imidazole unit within the molecule. On the basis of the TD-DFT calculations, the strong visible absorption band exhibited by C1 is assigned to a metal-to-ligand charge transfer (MLCT) transition with a concurrent ligand-centered (LC) transition. At room-temperature, C1 features emission (φ = 0.04) from its lowest excited states with time constants of 1.2 and 18.3 μs. These lifetimes are assigned to emission processes from the 3MLCT and 3LC state, respectively. This is the first time that a long-lived dual emission has been observed for a ruthenium(II) complex bearing a directly fused extended π-system. Furthermore, the emission of C1 is quenched upon water addition. In contrast to related compounds based on a dipyridophenazine ligand, the excited state energy is not shifted, and the lifetime is drastically decreased to 169 ns.
NHC-Ir(I) complexes derived from 5,6-dinitrobenzimidazole. Synthesis, characterization and preliminary evaluation of their in vitro anticancer activity
Sánchez-Mora, Arturo,Valdés, Hugo,Ramírez-Apan, María Teresa,Nieto-Camacho, Antonio,Hernández-Ortega, Simón,Canseco-González, Daniel,Morales-Morales, David
, (2019)
The design, synthesis, characterization and in vitro anticancer activity of a series of Ir(I) NHC complexes derived from 5,6-dinitrobenzimidazole is reported. The evaluation was performed in five human cancer cell-lines, namely glioblastoma (U-251), prostatic adenocarcinoma (PC-3), colorectal adenocarcinoma (HCT-15), mammary adenocarcinoma (MCF-7) and lung adenocarcinoma (SKLU-7), including healthy cells of African green monkey kidney (COS-7) for comparative purposes. The complexes exhibited better activity in comparison with the corresponding NHC ligand precursors. In particular, complex (4a) exhibited a good performance against PC-3 and SKLU-1 with IC50 values of 10.6 ± 0.9 μM and 10.4 ± 1.5 μM, respectively.
Reaction of substituted pyrido[1,2-a]benzimidazoles with electrophilic agents
Begunov, Roman S.,Sokolov, Alexandr A.,Belova, Valeria O.,Fakhrutdinov, Artem N.,Shashkov, Alexander S.,Fedyanin, Ivan V.
, p. 5701 - 5704 (2015/09/29)
The reactivity of substituted pyrido[1,2-a]benzimidazoles toward electrophilic aromatic substitution has been studied. An unusual introduction of an electrophilic species at the ortho position with respect to an electron-withdrawing group was found, and investigated. Changing the substituent nature from a meta director to an ortho/para director did not alter the selectivity of electrophilic substitution. Assignment of the proton and carbon spectra for the products of SEAr reactions were carried out using 1D and 2D NMR and the structures of selected nitro- and dinitropyrido[1,2-a]benzimidazoles were confirmed by single crystal X-ray diffraction.
