Two Anthracene-Based Ir (III) Complexes [Ir (pbt) 2 (aip) ]Cl and [Ir (pbt) 2 (aipm) ]Cl: Relationship between Substituent Group and Photo-oxidation Activity as well as Photo-oxidation-Induced Luminescence
Yuan, Q.-Z.; Fan, Q.; Lv, H.; Chen, W.-W.; Yang, X.-X.; Cao, D.-K.; Wen, J.
Inorganic Chemistry 59(23): 17071-17076
ISSN/ISBN: 1520-510X PMID: 33170668 DOI: 10.1021/acs.inorgchem.0c02279
Two anthracene-based complexes [Ir(pbt)2(aip)]Cl (1) and [Ir(pbt)2(aipm)]Cl (2) have been synthesized based on the ligands aip = 2-(9-anthryl)-1H-imidazo[4,5-f][1,10]phenanthroline, aipm = 2-(9-anthryl)-1-methyl-imidazo[4,5-f][1,10]phenanthroline, and pbtH = 2-phenylbenzothiazole in order to explore both the influence of the substituent group R1 (R1 = H in 1 and CH3 in 2) on photo-oxidation activity and photo-oxidation-induced luminescence. Both 1H NMR spectra and ES mass spectra indicate that the anthracene moiety in complex 1 can be oxidized at room temperature upon irradiation with 365 nm light. Thus, this complex shows photo-oxidation-induced turn-on yellow luminescence. Compared to 1, complex 2 incorporates an R1 = CH3 group, resulting in very weak photo-oxidation activity. On the basis of experimental results and quantum chemical calculation, we report the differences between 1 and 2 in both photo-oxidation behavior and the related luminescence modulation and discuss the relationship between photo-oxidation activity and substituent group R1 in these complexes.