The silicon analog of benzene–hexasilabenzene (Si6H6)

Abstract

A b initio molecular electronic structure theory has been applied to the D6h- symmetry isomer of Si6H6. Self-consistent-field (SCF) theory has been applied in conjunction with double zeta (DZ) and double zeta plus silicon 3d (DZ+d) basis sets. The DZ+d basis set may be designated Si(11s 7p 1d/6s 4p 1d), H (4s/2s). The structure of hexasilabenzene is predicted to be: re(Si–Si) =2.223 Å, re(Si–H) =1.476 Å (DZ SCF); re(Si–Si) =2.205 Å, re(Si–H) =1.463 Å (DZ+d SCF). Vibrational frequencies have been predicted at the DZ SCF level, at which the DZ SCF structure is a true minimum. However, the lowest vibrational frequency is predicted to be only 10 cm−1.