Theoretical studies on the spectroscopic properties and the substituent effects of pyridyl triazole Os(II) complexes

To explore the spectroscopic properties of pyridyl triazole Os(II) complexes and how the substituent effects affect the spectroscopic properties of [Os(ptz)₂L₂] (L=PH₃; ptzH=(2-pyridyl)-1,2,4- triazole) (1), [Os(bptz)₂L₂] (bptzH=3-tert-butyl-5-(2- pyridyl)-1,2,4-triazole) (2), [Os(fptz)₂L₂] (fptzH=3-(trifluoreomethyl)-5-(2-pyridyl)-1,2,4-triazole) (3), and [Os(fbtz)₂L₂] (fbtzH=3-(trifluoreomethyl)-5-(4-tert-butyl- 2-pyridyl)-1,2, 4-triazole) (4), the density functional theory (DFT) method at the B3LYP level was used to optimize the geometrical structures in the ground and excited state. The absorption and emission properties of the dichloromethane solution were predicted at the time-dependent density functional theory (TD-DFT, B3LYP) level associated with the PCM solvent effect model, the transitions characters of them were assigned. Important correlations between substituent effects and emission spectra and the quantum yield have been obtained by comparing and analyzing the calculated results.