摘要
Scientists have synthesized a number of organometallic compounds as substituents for pentadienyl anions. Studies on stability and electronic structures of pentadienyl anions （C<sub>5</sub>H<sub>7</sub><sup>-</sup>） have been carried out from both experimental measurements and theoretical calculations. Up to now the conclusions are quite different. Among them Dewar has performed a complete geometrical optimization of C<sub>5</sub>H<sub>7</sub><sup>-</sup> by MNDO method and pointed out that relative stability order of C<sub>5</sub>H<sub>7</sub><sup>-</sup> isomers was W】S】 U.Using a MONSTERGAUSS program we have performed STO-3G geometrical op-
