物理化学学报Issue(9)：1683-1689,7.DOI:10.3866/PKU.WHXB201506031
金属串配合物[Ni3（L）4（NCS）2]（L=dpa-，mpta-，mdpa-，mppa-）结构和磁性的理论研究
Theoretical Study on the Structures and Magnetic Properties of Metal String Complexes [Ni3(L)4(NCS)2] (L=dpa-, mpta-, mdpa-, mppa-)
摘要
Abstract
¾ ¾ ¾nb ¾¤ Density functional theory at the BP86 level and natural bond orbital theory were used to investigate the influence of bridging ligands on the Ni―Ni interactions and magnetic coupling properties of metal string complexes [Ni3(L)4(NCS)2] (L =1: dpa– (dipyridylamine),2: mpta– (4-methylpyridyl-thiazolylamine),3: mdpa– (4-methyl-dipyridylamine),4: mppa– (4-methylpyridyl-3H-pyrrolylamine)) with potential applications in molecular wires. The folowing conclusions can be drawn. (1) The ground states of the complexes are antiferromagnetic (AF) singlet states, which correspond to the quintet state (HS). The energy and structure of HS is similar to AF. There are three-center-four-electron bonds ( ) along the chains. (2) The Ni―Ni and Ni―N distances are unaffected by methyl substituents on the pyridine ring of dpa– ligands. However, substitution of the 3H-pyrrole ring or thiazole ring by the pyridine ring in mdpa– lengthens the N1―N2 and Ni―Ni distances but shortens the Ni2―N2 distance. These effects of the thiazole ring are weaker than those of the 3H-pyrrole ring. Therefore, the strength of the Ni―Ni interaction is1 ≈3 >2 >4. (3) The predictedJab values of3 and4 ¾ are –103 and –88 cm–1, respectively. The AF magnetic coupling effects of the complexes increase with increasing Ni―Ni interaction strength: the stronger the Ni―Ni interaction, the greater the direct magnetic coupling in the orbitals along the chains. In addition, the stronger the Ni2―N2 interaction, the larger the indirect magnetic coupling involving the bridging ligand. The direct magnetic coupling is stronger than the indirect magnetic coupling.关键词
金属串配合物/桥联配体/密度泛函理论/磁耦合/分子导线Key words
Metal string complex/Bridging ligand/Density functional theory/Magnetic coupling/Molecular wire分类
化学化工引用本文复制引用
陈蓉,周沃华,吴子文,许旋,徐志广..金属串配合物[Ni3（L）4（NCS）2]（L=dpa-，mpta-，mdpa-，mppa-）结构和磁性的理论研究[J].物理化学学报,2015,(9):1683-1689,7.基金项目
The project was supported by the Natural Science Foundation of Guangdong Province, China (S2012010008763), Ministry of Education and Guangdong Province, China (2010B090400184), and Science and Technology Program of Guangzhou City, China (2011J4300063).广东省自然科学基金(S2012010008763),广东省教育部产学研项目(2010B090400184)和广州市科技攻关项目(2011J4300063)资助 （S2012010008763）
