Two of the present authors recently put forward a novel approach to resonance energy which is based on a similar topological reasoning as a previously elaborated resonance energy concept. It is shown that these two ap...Two of the present authors recently put forward a novel approach to resonance energy which is based on a similar topological reasoning as a previously elaborated resonance energy concept. It is shown that these two approaches are not completely equivalent. Several other properties of the new resonance energy are pointed out.展开更多
The stability of C36H2 isomers and selection rules for choosing position in addition reactions based on symmetrical C36（D6h and D2d） fullerene have been studied by means of Aihara＇s topological resonance energy （...The stability of C36H2 isomers and selection rules for choosing position in addition reactions based on symmetrical C36（D6h and D2d） fullerene have been studied by means of Aihara＇s topological resonance energy （TRE） and bond resonance energy （BRE） methods. The relation between the addition pattern and BREs is established, showing high antiaromatic bonds are preferred for addition. These results show that TRE and BRE methods can be used to predict and interpret addition sites for these systems.展开更多
The aromaticity of all possible substituted fullerene isomers of C18N2, C18B2, C18BN, and their molecular ions which originate from the C20 （Ih） cage were studied by the topological resonance energy （TRE） and the ...The aromaticity of all possible substituted fullerene isomers of C18N2, C18B2, C18BN, and their molecular ions which originate from the C20 （Ih） cage were studied by the topological resonance energy （TRE） and the percentage topological resonance energy methods. The relationship between the aromaticity of C18BxNy isomers and the sites where the heteroatoms dope at the C20 （Ih） cage is discussed. Calculation results show that at the neutral and cationic states all the isomers are predicted to be antiaromatic with negative TREs, but their polyvalent anions are predicted to be aromatic with positive TREs. The most stable isomer is formed by heteroatom doping at the 1,11-sites in C18N2. C18B2, and C18BN. Heterofullerenes are more aromatic than C20. The stability order in the neutral states is C18N2〉C18BN〉C18B2〉C20. The stability order in closed-shell is C18B2^8- 〉C20^6- 〉C18BN^6- 〉C18N2^4-. This predicts theoretically that their polyvalent anions have high aromaticity.展开更多
文摘Two of the present authors recently put forward a novel approach to resonance energy which is based on a similar topological reasoning as a previously elaborated resonance energy concept. It is shown that these two approaches are not completely equivalent. Several other properties of the new resonance energy are pointed out.
基金The project was sponsored by the Scientific Research Foundation for the Returned Overseas Chinese Scholars, State Education Ministry (No. [2005]383)
文摘The stability of C36H2 isomers and selection rules for choosing position in addition reactions based on symmetrical C36（D6h and D2d） fullerene have been studied by means of Aihara＇s topological resonance energy （TRE） and bond resonance energy （BRE） methods. The relation between the addition pattern and BREs is established, showing high antiaromatic bonds are preferred for addition. These results show that TRE and BRE methods can be used to predict and interpret addition sites for these systems.
文摘The aromaticity of all possible substituted fullerene isomers of C18N2, C18B2, C18BN, and their molecular ions which originate from the C20 （Ih） cage were studied by the topological resonance energy （TRE） and the percentage topological resonance energy methods. The relationship between the aromaticity of C18BxNy isomers and the sites where the heteroatoms dope at the C20 （Ih） cage is discussed. Calculation results show that at the neutral and cationic states all the isomers are predicted to be antiaromatic with negative TREs, but their polyvalent anions are predicted to be aromatic with positive TREs. The most stable isomer is formed by heteroatom doping at the 1,11-sites in C18N2. C18B2, and C18BN. Heterofullerenes are more aromatic than C20. The stability order in the neutral states is C18N2〉C18BN〉C18B2〉C20. The stability order in closed-shell is C18B2^8- 〉C20^6- 〉C18BN^6- 〉C18N2^4-. This predicts theoretically that their polyvalent anions have high aromaticity.
