An Ab initio theoretical investigation on the geometrical and electronic structures of BAu_n-/0 (n = 1-4) clusters

摘要

An ab initio theoretical investigation on the geometrical and electronic structures and photoelectron spectroscopies (PES) of BAu_n~(-/0) (n = 1-4) auroboranes has been performed in this work. Density functional theory and coupled cluster method (CCSD(T)) calculations indicate that BAu n-/0 (n = 1-4) clusters with n-Au terminals possess similar geometrical structures and bonding patterns with the corresponding boron hydrides BH n-/0. The PES spectra of BAu n- (n = 1-4) anions have been simulated computationally to facilitate their future experimental characterizations. In this series, the T_d BAu 4- anion appears to be unique and particularly interesting: it possesses a perfect tetrahedral geometry and has the highest vertical electron detachment energy (VDE = 3.69 eV), largest HOMO-LUMO gap (ΔE_(gap) = 3.0 eV), and the highest first excitation energy (E_(ex) = 2.18 eV). The possibility to use the tetrahedral BAu 4- unit as the building block of Li~+[BAu_4]~- ion-pair and other [BAu _4]~--containing inorganic solids is discussed.