Synthesis and Photophysical Properties of α‐Pyrone‐fused‐pyrido[3, 2,1‐jk]carbazolone Derivatives : DFT/TD‐DFT Insights

Abstract

The present paper discloses an interesting microwave‐assisted solvent‐free protocol for the synthesis of thermally stable, highly fluorescent pyrano[2′, 3′:4,5]pyrido[3, 2,1‐jk]carbazole‐5,8‐diones in good to high yields with good quantum yields (Ø ≥ 0.70) through a [3+3] annulation reaction of aryl‐substituted Morita‐Baylis‐Hillman acetates with a 4‐hydroxy‐6H‐pyrido[3, 2,1‐jk]carbazol‐6‐one in the presence of Hünig's base. The solvatochromic properties of synthesized compounds have been determined which showed blue shifts in absorption and emission spectra with increasing the polarity of solvents. Similarly, the higher quantum yields were also observed in case of non‐polar solvents as compared to polar ones. Interestingly, the experimental results of photophysical properties were in good agreement with theoretical data obtained using B3LYP/6‐311G++(d,p) level of theory. Furthermore, the synthesized chromophoric scaffolds exhibited good thermal stability (342‐387 °C) and average fluorescence lifetime in the range of 2.011‐2.139 ns for 408 nm, 2.268‐2.277 ns for 428 nm.

Diverse Architectures and Luminescence Properties of Group 11 Complexes Containing Pyrimidine-Based Phosphine, N-((Diphenylphosphine)methyl)pyrimidin-2-amine

“…82 The difference in emission pattern is due to the different polarities of the solvents, and the details are available in the literature. 83,84…”

“…Compounds 2 – 7 showed blue shifts of 65, 68, 62, 56, 57, and 8 nm, respectively, relative to 1 , which is in contrast to the trend observed in acetonitrile, where red shift for 2 and no change for 3 were observed . The difference in emission pattern is due to the different polarities of the solvents, and the details are available in the literature. , …”

“…In addition to the high-energy absorption bands, low-energy shoulder bands are observed around 291− 82 The difference in emission pattern is due to the different polarities of the solvents, and the details are available in the literature. 83,84 The disparity in the emissive behavior of 2−4 can also be attributed to (i) the effects of different Cu−Cu bond lengths in these complexes and (ii) the rigid coordination environment enforced by the bidentate P∩N ligand that stabilizes the molecular geometry in the 3 XLCT state. 13 Absorptions, emissions, and relative quantum yields of 1−7 are summarized in Table 2.…”