Theoretical and experimental investigations on hypoelectronic heterodimetallaboranes of group 6 transition metals.

Density functional theory (DFT) has been used to probe the bonding and electronic properties of dimolybdaborane ((Cp*Mo)2B5H9), 1 (Cp* = η 5 -C5Me5), and several other hetero- dimolybdaborane clusters, such as ((Cp*Mo)2B5(μ3-OEt)H7 )( 2), ((Cp*Mo)2B5(μ3-OEt)(n-BuO)H6 )( 3), ((η 5 -C5H5W)2B4H4S2 )( 4), and ((Cp*Mo)2B4H4E2 )( 5−7, where, for 5, E = S, for 6, E = Se, and for 7, E = Te). The DFT results were also used to address some key points such as (i) the metal−metal bond length, (ii) the location and number of bridging and terminal hydrogen atoms, (iii) the molecular orbital analysis, and (iv) the assignment of 11 B and 1 H NMR chemical shifts. These studies further provide meticulous insight into similarities and differences between various dimetallaborane clusters 1−7 .I n addition, the crystal structures of 5 and 7 are reported, which come on top of the already existing literature of dimetallaboranes and support the theoretical findings.