The Bonding Nature of Cyclometalated Ru Complex: How DFT Study Revealing the Dewar‐Chatt‐Duncanson Model Relates to the Molecular Properties

Abstract

The new intermediate Ru η3‐allyloxapyridyl complex has been studied aiming to illuminate the Dewar–Chatt–Duncanson (donation/back‐donation (D/BD)) model by calculations. A non‐standard, alternative calculation scheme integrating the density functional theory along with the charge decomposition, natural bond orbital (NBO) analysis and the map of electrostatic potential has provided new insights into the electronic structure of the complex presenting it in a Lewis structure. The donating, accepting contribution of Ru to ligand bonding in BD has been estimated by Weinhold's perturbation theory. This allowed quantifying D and BD contribution to the stabilization of the complex Lewis structure by deletion of selected Fock‐matrix elements from the basis set. Lewis energy gets lowered mainly by BD contribution from Ru d NBOs into the C2 atom of allyl ligand. Finally, the outcomes of calculations reveal: that Ru to ligands is bonded in donor‐acceptor fashion; the complex embodies nucleophilic character accumulated on the lone pairs of O atom in oxabenzyl group. The nucleophilic sides suggested by calculations support the reactivity trends of complex in the catalytic cycle. Calculated properties correlate well with experimental observations. The proposed scheme applied to the complex can be helpful for treatment of new metal complex candidates.

Synthesis and DFT characterisation of 2-arylamino-1,4-benzoquinone derivatives as potential electron transfer mediators

“…The DFT calculations were performed with the B3LYP and 6-311+g(d,p) basis set using the Gaussian 09 program package [23] for BQ and 2a-f, 3b of quinones (Q) and hydroquinones (QH 2 ) (+2e-and +2H+). The use of the B3LYP hybrid functional at the DFT level is the most popular choice for treatment of heteroaromatic derivatives which matches well with the experimental observations [24][25][26][27]. The use of 6-311G, 6-31G basis sets accomplished with additional diffuse and polarized functions for the aromatic heterocycles also provided comparable results [28][29][30][31].…”