Silirenyl anion

The geometries of the ground states and of the first excited singlet and triplet states of 150 with X = SiH-, CH-, NH, O, PH and S were calculated by the Cl version of the semi-empirical SINDOl method167. We will discuss here only the silirenyl anion (150, X = SiH-) and compare the properties of this anion to those of the analogous cyclopropenyl anion (150, X = CH-). The calculated optimized geometries and bond orders for 150, X = SiH- and CH- are given in Table 15. 

TABLE 15. Calculated geometries and bond orders of the silirenyl anion (150, X = SiH ) and the cyclopropenyl anion (150, X = ( II ) in their ground and first excited singlet and triplet states"... 

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