Theoretical studies on the electronic structure and spectroscopic properties of transition metals bis(dipyrrinate)s

ABSTRACT

Density functional theory (DFT) and Time-dependent density functional theory (TD– DFT) computations have been used to reveal structural, molecular, electronic and spectral–luminescent parameters and features of several homoleptic transition metals bis(dipyrrine) complexes. The influence of complexing agent and ligand nature on the regularities in geometric, spectral–luminescent properties, kinetic and thermal stability changes in the [M₂L₂] complexes series were studied. Special attention is paid to the influence of the solvating media (PCM/TD–B3LYP/Def2–SVP) on changing spectral–luminescent properties of d-metals bis(dipyrrinate)s. The interpretation of the dependence between spectral–luminescent properties of the complexes and HOMO–LUMO (highest occupied molecular orbital and lowest unoccupied molecular orbital) energy gap's width was given. It was shown that the regularities in changing the helicates’ quantum yield depending on the nature of complexing agent, ligand and solvent properties, obtained from quantum-chemical calculations, are in the agreement with our previously obtained experimental data. Thus, structural and spectral–luminescent characteristics of new [M₂L₂] luminophors can be evaluated with high reliability, and good forecast prospects for their use as fluorescent dyes for optical devices can be made in terms of the results of theoretical studies (B3LYP/Def2–SVP and TD–B3LYP/Def2–SVP).

KEYWORDS:

• Bis(dipyrrinate)
• geometric characteristics
• frontier molecular orbital
• spectral–luminescent properties
• energy gap

Acknowledgments

The reported study was funded by RFBR according to the research project № 16-33-00852 mol_a and 15-43-03081-p_center_a. We are grateful to the Interdisciplinary Supercomputer Center of the Russian Academy of Sciences (Moscow) for providing MBC 100 K cluster resources.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

The reported study was funded by RFBR according to the research project № 16-33-00852 mol_a and 15-43-03081-p_center_a