Structural preferences and multiple bonding interactions in hetero-closo-dodecaborates of group-14 elements - A...

The geometric and electronic structural features of group-14 hetero-closo-dodecaborates such as monomers [HEB₁₁H₁₁]^-, [EB₁₁H₁₁]^2- [E = C (1a), Si (2a), Ge (3a), Sn (4a) and Pb (5a)] and dimers [(EB₁₁H₁₁)₂]^2- [E = C (1), Si (2), Ge (3), Sn (4) and Pb (5)] analyzed using density functional theory (DFT) method at BP86/Def2-TZVP level of theory. The structural features such as the geometry, metrical parameters and bonding interactions are theoretically studied. The dispersion correction method has been used to get more insight which improves the metrical parameter of group-14 elements towards experimental parameters. The electronic structure of the clusters has been studied using frontier molecular orbital analysis (FMO). It shows the group-14 elements electronic contribution and possible electron delocalization between the cages to stabilize the dimeric clusters. DFT (BP86/Def2-TZVP) calculations on the clusters confirm the thermal stability of the newly modelled dimeric clusters (2-5) which could have diverse applications. The ¹³C, ¹H, ²⁹Si, and ¹¹B nmr chemical shift values computed at DFT (BP86/Def2-TZVP) level are highly useful in identifying and assigning the individual atoms of the monomeric and dimeric clusters. From the global reactivity descriptors and local descriptors analysis, an identification of reactive sites with respect to electrophilic and nucleophilic centers of the reactant has been reported.