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.