Are dative and ionic bonds one-electron bonds?

Kimika Teorikoa Seminar

The nature of dative bonding remains one of the most persistent conceptual controversies in chemistry, despite more than a century of theoretical development since Lewis. We demonstrate that this apparent dichotomy largely originates from an overreliance on the electron-pair paradigm. By combining Generalized Valence Bond theory with complementary real-space and wavefunction-based descriptors,[1] we show that a broad class of bonds traditionally labeled as dative or ionic are more naturally and consistently described as one-electron bonds. Our central finding is that, in these interactions, only one electron of the nominal bonding pair actively delocalizes and provides essentially the full bonding stabilization, while its partner remains largely localized as a spectator. This asymmetric, single-electron delocalization motif emerges robustly across prototypical ionic, polar covalent, and donor–acceptor systems, and is revealed independently by orbital-based and orbital-invariant analyses.[2] The resulting picture reconciles long-standing debates concerning the distinctiveness of dative bonding and provides a unified interpretation of bonding, dissociation pathways, and bond strength trends across heteropolar chemistry.

References:
[1] D. Barrena-Espés, E. Francisco, A. Martín Pendás, submitted.
[2] A. Martín Pendás, E. Francisco (2022). Nat. Commun. 13, 3227.