EDA-NOCV analyses of M−E2 bond: E2 binding and activation [E2 = N2, H2].

Autor: Karnamkkott, Harsha S, Gorantla, Sai Manoj N V T, Mondal, Kartik Chandra
Zdroj: Journal of Chemical Sciences; Sep2024, Vol. 136 Issue 3, p1-16, 16p
Abstrakt: Dinitrogen and dihydrogen ligated metal complexes [(L)nM−H2/N2] have been known to chemists for nearly four decades. These species are captivating for their unusual bonding interactions between transition metal atoms and closed-shell diatomic molecules like H2/N2. Some of these complexes are part of the textbook, with emphasis given to their surprising stability, often without the formation of an electron-sharing M−H2/N2 bond. The nature of chemical bonding in these complexes is speculated due to M−H2/N2 bond distances and mode of binding (side-on or end-on). In the past, spectroscopic and other tools have studied the nature of the chemical bonds. We report on the energy decomposition analysis coupled with natural orbital for chemical valence (EDA-NOCV) calculations to shed light on the deeper insight of the quantitative pairwise bonding interactions in previously isolated/reported (L)Co−N2 and (L)Co−H2 complexes [L = three P- and one E-donor ligand; E = Si, B; Co is either Co(I) or Co(0)]. A comparative EDA-NOCV analysis shows that N2 is a better π-acceptor while, in contrast, H2 is a superior σ-donor although both ligands (H2, N2) are σ-donor and σ/π-acceptor. The extent of backdonation from Co to H2/N2 also depends on E atoms of the chelating ligands (L). The overall intrinsic interaction energy of the Co−N2 bond is significantly higher by 5–10 kcal/mol than that of the Co−H2 bond. EDA-NOCV analyses have also studied two Fe−H2 complexes. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index
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