Ferrocene analogues of sandwich B12·Cr·B12: a theoretical study

The bowl B(12) cluster was previously reported to be analogous to benzene and predicted to be one of the best candidates to be new inorganic ligands. The structural stability and electronic properties of a new sandwich compound Cr(B(12))(2) (D(3d)) have been investigated by using density functional theory. It is found that the sandwich Cr(B(12))(2) (D(3d)) is a stable complex with large binding energy (-5.93 eV) and HOMO-LUMO gap (2.37 eV), as well as Fe(C(5)H(5))(2) and Cr(C(6)H(6))(2), following the 18-electron principle. The detailed molecular orbitals and aromaticity analyses indicate that the sandwich compound Cr(B(12))(2) (D(3d)) is electronically very stable. The natural bond orbital analysis suggests that spd-π interaction plays an important role in the sandwich compounds.