THE NATURE OF THE GALLIUM-GALLIUM TRIPLE BOND

To simulate and help interpret the nature of the newly synthesized Ga2 R2Na2 molecule with bulky groups, ab initio and density functional qua ntum mechanical methods were applied to study the structures and bondi ng of the model [HGaGaH](2-), [H2GaGaH2](2-), and [H3CGaGaCH3](2-) dia nions, as well as the neutral Na-2[H2GaGaH2], Na-2[H3CGaGaCH3], Ga2H2, and Ga2H3 species. Basis sets of triple-zeta plus double polarization quality augmented with diffuse functions were employed. No general bo nd length-bond order relationship is found. Bending from linearity of the acetylene analogues increases the GaGa separation more than the bo nd order is decreased. The GaGa bonding in the experimental molecule i s concluded to be between triple and double in character despite the r elatively long bond length.