DFT of Homometallic TM ₂ B _n ⁻ (TM = Ni, Cu, Zn; <i>n</i> = 5, 7) Clusters: Bonding, Aromaticity, and Fluxionality

Abstract Transition metal‐boron (TM‐B) clusters have emerged as a frontier in materials science, garnering extensive attention due to their unique bonding configurations and potential applications in catalysis, electronics, and nanotechnology. Despite the progress in single‐atom doping studies, the systematic exploration of dual TM doping remains limited, particularly regarding the synergistic effects on structural dynamics and electronic properties. This work employs density functional theory (DFT) calculations to investigate the geometric structures, electronic characteristics, and bonding mechanisms of B n − ( n = 5, 7) clusters co‐doped with homometallic diatomic pairs of Ni 2 , Cu 2 , or Zn 2 . The results reveal that dual TM doping induces significant charge transfer from TM atoms to boron frameworks, with boron atoms serving as critical scaffolds for orbital hybridization. Notably, the B ring in Ni 2 B 7 − exhibits aromaticity, while Zn 2 B 7 − demonstrates exceptional molecular rheological behavior at room temperature, positioning it as a promising candidate for molecular motor design. This study not only uncovers the distinct synergistic effects of dual TM doping but also provides a theoretical framework for rationally designing functional TM‐B materials with tailored properties.