POLYSILA ANALOGS OF AROMATIC HYDROCARBON IONS - STRUCTURES AND ENERGIES OF SI3H3(+), SI4H4(2+), AND SI5H5(-)

Silicon analogs of aromatic monocyclic ions, (SiH)3+ (4), (SiH)42+ (5), and (SiH)5- (6) have been studied ab initio at MP2(full)/6-31G*. The D3h structure Of Si3H3+ is the global minimum, whereas other two ions are nonplanar. The D2d structure of (SiH)42+ is less folded than the carbon analog and possesses a higher stabilization energy. Stabilization energies for the monocharged ions are diminished with respect to the corresponding carbons.