C22 BxNy(x+y=2)全部异构体和分子离子芳香性的研究

用拓扑共振能(TRE)和百分拓扑共振能(%TRE)方法,研究从富勒烯C24(D6)产生异质富勒烯C22N2,C22B2和C22BN的所有异构体,研究阳离子和阴离子的芳香性.分析C22BxNy中杂原子取代位置和稳定性之间的关系.结果,中性状态和阳离子状态中,各异构体的TRE都为负数具有反芳香性.但它们的高价阴离子的TRE都为正数则有芳香性.中性状态中,稳定性顺序为:C22N2(1-19)>C22BN(39-64)>C24>C22B2(20-38).形成闭壳层结构时稳定性顺序为:C22B8-2(20-38>C6-24>C22BN6-(39-64)>C22N4-2(1-19).无论在中性状态还是闭壳层结构,当N原子取代C2类碳原子,B原子取代C1类碳原子时最稳定.理论上,预测C22BxNy的高价阴离子有合成的可能性.

The study on the aromaticity of all possible C22BxNy(x+y=2) isomers and their molecular ions

The aromaticity of all possible C_(22)N_2,C_(22)B_2 and C_(22)BN isomers which are originate from C_(24)(D_6)and their molecular ions have been studied by the topological resonance energy(TRE)and the percentage topological resonance energy(% TRE)methods.The relationship between aromaticity and substitution positions of heteroatoms doped at the C_(24)cage has been discussed.According to the calculation results,the neutrals and cationic states of all isomers are predicted to be antiaromatic with negative TREs.But their polyva- lent anions are predicted to be aromatic with positive TREs.In neutral states,their stability order is:C_(22)N_2(1-19)>C_(22)BN(39- 64)>C_(24)>C_(22)B_2(20-38).When all the isomers achieved closed-shell structures,their stability order is :C_(22)B_2~(8-)(20-38)>C_(24)~(6-)>C_(22)BN~(6-)(39-64)>C_(22)N_2~(4-)(1-19).Both in neutral and closed-shell states,N atom substitute C2 type carbon atom,and B atom substitute C1 type carbon atom are more energetically favorable.It was theoretically predicted that their polyvalent anions would be pre- pared in suitable conditions.