Theoretical Study on the Regioselectivity of Leapfrog B 18 and B 30 Boron Sheets in Electrophilic and Nucleophilic Reactions Using DFT-Based Reactivity Indices.

A combined computational and interpretational DFT study is performed to investigate the regioselectivity of B 18 and B 30 leapfrog boron sheets upon reaction with XH 3 -type electrophiles and nucleophiles (X = N, P, As, B, Al). The M062X, B3LYP, and B3LYP-D3 functionals are used combined with the 6-31+G(d,p) basis. The molecular electrostatic potential (MEP), Fukui functions, and the dual descriptor are employed to predict the local reactivity of B 18 and B 30 . Our results reveal that both clusters are hard and prefer to react with hard bases and acids, such as NH 3 and BH 3 . Further, these leapfrog B 6n clusters can play the role of catalysts as they break B-H and Al-H bonds of BH 3 and AlH 3 in s -BH 3 -B 6n and s -AlH 3 -B 6 n complexes, respectively. Leapfrog B 6 n -XH 3 complexes (X = B and Al) can be considered as an interaction between two electron-deficient systems. Therefore, the chemical reactivity between these systems cannot be interpreted in terms of the Hard-Soft-Acid-Base principle.