Conformational Stability through B···O Triel Bonding: A Computational Investigation of Dioxaborolane-Oxoacetates...

This study computationally investigates the open and locked conformations of substituted 1,3,2-dioxaborol-2-yl-2-oxoacetate (DOBOA) derivatives. The results reveal that the locked conformations, stabilized by B···O triel bonding interactions, are consistently more stable than the corresponding open forms. Systematic substitution with electron-withdrawing groups on the dioxaborolane ring and/or electron-donating groups on the oxoacetate moiety further enhances the strength of the B···O interaction, thereby increasing the stability of the locked conformation. Geometric, energetic, and topological analyses of the electron density reveal that these interactions can be categorized into two regimes: noncovalent and dative. Complementary orbital analysis confirms that this B···O interaction arises due to the O(lp)→B(p-orbital) charge transfer. These findings highlight the role of B···O triel bonding as a conformational locking mechanism, offering a new strategy for rational conformational control in molecular design and functional materials.