Syntheses and photoluminescence properties of rhenium(I) complexes based on dipyrido[3,2-a:2′,3′-c]phenazine derivatives with carbazole moiety

Abstract

Four rhenium(I) complexes ReL1–ReL4 based on dipyrido[3,2-a:2′,3′-c]phenazine (L1) and derivatives L2-L4 ligands (L2: 10,13-dibromodipyrido[3,2-a:2′,3′-c]phenazine, L3: 10-bromo-13-carbazolyl-dipyrido[3,2-a:2′,3′-c]phenazine, L4: 10,13-dicarbazolyldipyrido[3,2-a:2′,3′-c]phenazine) were synthesized and characterized. The Re(I) complexes ReL1–ReL4 show photoluminescent emissions at 556, 582, 637 and 662 nm, respectively, assigned to d (Re)→ ∗ (diimine) MLCT phosphorescence in CH2Cl2 solution. The carbazole containing complexes ReL3 and ReL4, as compared to ReL1, exhibit higher luminescence. These observations imply that modification of diimine rhenium(I) carbonyl complexes with carbazole moiety would lead to efficient phosphorescent properties.