中文摘要：

研究了以杂环做端基的高自旋分子对自旋稳定性的影响，用UB3LYP／6—31G^＊方法计算得到分子构型与自旋交换的性质．结果表明：以-·N-O做自旋中心，苯做耦合单元，吡啶、嘧啶、三嗪为端基的分子，-·N-O自由基的体系非常稳定性，同时分子中三重态以三嗪为端基的稳定性最稳定，以嘧啶为端基的稳定性最低；以-·N-S，-·N-O，-·N-NH做自旋中心，苯为耦合单元，吡啶为端基的分子，分子中三重态稳定以-·N-S为自旋中心的最稳定，以-·C-O为自旋中心的稳定性最低．

英文摘要：

The effect of heterocycles can be studied on the spin multiplicity in high-spin molecules and selected the molecules possessing stable high-spin ground state coordinated by metals. The geometry and charac- ter of the spin exchange interaction are obtained by means of UB3LYP/6-31G^＊ . It is shown that molecules with-·N-O as spin-containing （SC） fragment, pyridine, pyrimidine and triazine as end groups （EG） and phenyl as a ferromagnetic coupling （FC） unit are designed, the spin densities on the two atoms of the SC fragment are different from delocalization results in the specific stability of-·N-O, the stability of triplet states for the molecule with triazine as EG is highest, and that for the molecule with pyrimidine as EG is lowest. Molecules with-·N-S,-·N-O,-·N-NH as SC fragment , pyridine as EG and phenyl as FC are designed, the stability of triplet states for the molecule with-·N-S as SC is highest, that for the molecule with-·N-O as SC is lowest.