| Abstract
| - A theoretical study of the SiC3+ isomershas been carried out, characterizing six different structures.Predictionsfor their geometries and vibrational frequencies have been made at boththe MP2/6-31G* and B3LYP/cc-pVTZ levels. The nature of bonding in these isomers has beencharacterized by using Bader's topologicalanalysis of the electronic charge density. According to ourcalculations, which range up to the CCSD(T)/cc-pVTZ level, the lowest-lying species is a rhombic structure, with thelinear isomer and another rhomboidalisomer lying about 9.1 and 12.2 kcal/mol, respectively, higher inenergy. Therefore, although SiC3+ ispredictedto have a cyclic ground state, the linear isomer, and perhaps a secondcyclic state, could be accessible toexperimental detection. Both cyclic species are shown to befour-membered rings with only peripheral bonding,since there are no transannular Si−C or C−C bonds.
|
