Establishing an Active Descriptor in the Binding of Alkanes to Osmium Complexes

Within the realm of alkane functionalization, transition metal σ-alkane complexes have emerged as pivotal intermediates, offering new pathways for efficient C-H bond activation. To obtain the long-lived osmium σ-alkane intermediates, active descriptors for estimating the strength of the σ-Os···H-C interaction were developed using principal component analysis (PCA) in this study. Our results indicate that the Os σ-alkane complex could be stabilized by an introduced electron-withdrawing group, and the Os σ-methane complex was demonstrated to be the most unstable σ-alkane complex. Furthermore, the Os···H_(N)-C angle, the computed eigenvalues of natural adaptive orbitals (NAdOs), and the contribution of Os 5d orbital in the NAdO can be selected as active descriptors for estimating the stability of Os σ-alkane complexes. This approach provides a practical strategy for observing long-lived σ-alkane intermediates in alkane functionalization.