ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

A DFT, TDDFT and QTAIM study of the acridine pincer ligand-based Ru(II) and Rh(III) complexes: detailed analysis of the metal-F bonding

Gayani N. Pallewela and Ryan P. A. Bettens

Yale-NUS College, National University of Singapore, Singapore, Singapore

E-mail: gayaninp@nus.edu.sg

Received: 2 January 2022  Accepted: 22 June 2022

Abstract:

Abstract

A series of acridine-based PNP and PNF pincer containing Ru and Rh transition metal complexes have been explored. A theoretical investigation has been performed to examine the electronic structure, absorption and possible remote interaction of the fluorine atom connected to the acridine ligand with the metal centre employing DFT and TDDFT calculation. Bader’s Atoms in Molecules Theory is additionally applied for the studied complexes to evaluate the bonding nature between metal and F. For all the studied complexes, the LUMOs mainly consist of the acridine π* orbitals. HOMOs primarily consist of metal d orbitals. On that account, a metal-to-ligand charge transfer transition is possible in these complexes. The analysis of UV–Vis absorption spectra demonstrates how attached ligands affect electronic transitions. All of the complexes display two main transitions. The lowest energy band is due to the HOMO–LUMO MLCT transition between metal d orbitals and acridine π* orbitals. The topological analysis demonstrates a strong interaction between the metal atom and the F atom. Even so, positive Laplacian of electron density observed at the bond critical point between metal and F denied the possibility of covalent-type interaction.

Graphical abstract

Keywords: PNP and PNF pincer complexes; Ru and Rh transition metal complexes; Density functional theory; Time-dependent density functional theory; Absorption spectra; Quantum theory of atoms in molecules

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-022-02340-8

Chemical Papers 77 (1) 47–61 (2023)