Theoretical Design of High-spin Organic Molecules with -·N-N- as a Spin-containing Fragment and Heterocycles as an End Group  

作　　者：储德清 王立敏 张景萍 王荣顺 

机构地区：[1]Faculty of Material and Chemical Engineering, Tianjin Polytechnic University, Tianjin 300160, China [2]Faculty of Chemistry, Northeast Normal University, Changchun, Jilin 130024, China

出　　处：《Chinese Journal of Chemistry》2006年第11期1648-1652,共5页中国化学（英文版）

摘　　要：Novel stable high spin molecules possessing three different arranged fashions are designed with -·N-N〈 as a spin-containing （SC） fragment, various aromatic, such as benzene （1）, pyridine （2）, pyridazine （3）, pyrimidine （4）, pyrazine （5）, triazine （6） as end groups （EG） and phenyl as a ferromagnetic coupling （FC） unit. The effects of a different end groups on the spin multiplicities of the ground states and their stabilities were investigated by means of AM1-CI approach. It has been found that the spin densities on the two atoms of the SC fragment are different from delocalization resulting in the specific stability of -·N-N〈. In these molecules, the stabilities of the triplet states decrease when the distance between the atoms of central SC （-N-） increases. The orders of the stability of triplet states for 1an, 1bn, 1cn [They are isomers in which SC is connected with FC in different way （1an, N1NNN1; 1bn, N1N N1N; 1cn, NN1N1N） and six heterocycles are EG] show that the stability of triplet states with heterocycles as end groups is higher than that with phenyl as end groups, and in the order： triazine （EG） 〉 pyrimidine, pyrazine 〉 pyridine, pyridazine.Novel stable high spin molecules possessing three different arranged fashions are designed with -·N-N〈 as a spin-containing （SC） fragment, various aromatic, such as benzene （1）, pyridine （2）, pyridazine （3）, pyrimidine （4）, pyrazine （5）, triazine （6） as end groups （EG） and phenyl as a ferromagnetic coupling （FC） unit. The effects of a different end groups on the spin multiplicities of the ground states and their stabilities were investigated by means of AM1-CI approach. It has been found that the spin densities on the two atoms of the SC fragment are different from delocalization resulting in the specific stability of -·N-N〈. In these molecules, the stabilities of the triplet states decrease when the distance between the atoms of central SC （-N-） increases. The orders of the stability of triplet states for 1an, 1bn, 1cn [They are isomers in which SC is connected with FC in different way （1an, N1NNN1; 1bn, N1N N1N; 1cn, NN1N1N） and six heterocycles are EG] show that the stability of triplet states with heterocycles as end groups is higher than that with phenyl as end groups, and in the order： triazine （EG） 〉 pyrimidine, pyrazine 〉 pyridine, pyridazine.

关 键 词：HETEROCYCLE end group BIRADICAL HIGH-SPIN AM1-CI 

分 类 号：O626[理学—有机化学] O641.3[理学—化学]