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应用密度泛函理论 Ｂ３ＬＹＰ方法对金属串配合物［ＣｏＭＣｏ（ｄｐａ）４（ＮＣＳ）２］（１：Ｍ＝Ｃｏ，２：Ｍ＝Ｎｉ，３：Ｍ＝Ｐｄ，４：Ｍ＝Ｐｔ；ｄｐａ＝二吡啶胺）的成键性质和自旋过滤效应进行了研究，结果表明：配合物 １的基态为二重态，Ｃｏ６＋３金属链形成三中心三电子 σ键（σ２σ１ｎｂσ０）；而配合物 ２～４的基态均为反铁磁耦合单重态（ＡＦ态），对应的最低能量高自旋态（ＨＳ态）分别为三重态、七重态和七重态，单电子分布在两端 Ｃｏ原子上，［ＣｏＭＣｏ］６＋链具有三中心四电子 σ键（σ２σ１ｎｂσ１）．配合物 １～４均具有自旋过滤效应，电子传输通道主要为 β－自旋 σｎｂ轨道，与费米能级的距离大小为１＜２＜３≈４．电场作用下，１～４的高电势端 Ｃｏ２—Ｎ４键增长而低电势端 Ｃｏ３—Ｎ７键缩短，Ｃｏ—Ｍ平均键长略为缩短，Ｃｏ—Ｍ键增强；电场作用下金属原子的自旋密度和电荷密度变化很小，电磁性质稳定；电场作用下 σｎｂ轨道分布仍保持沿金属轴方向离域，ＬＵＭＯＨＯＭＯ能隙减小，有利于电子输运．
The metal chain complex [CoMCo (dpa) 4 (NCS) 2] (1: M = Co, 2: M = Ni, 3: M = Pd, 4: M = Pt; dpa = Dipyridyl amine) were studied. The results showed that the ground state of complex 1 was in doublet state, and the three-center three-electron σ bond (σ2σ1nbσ0) was formed in Co6 + 3 metal chain. Complex 2 The ground states of ~ 4 are all antiferromagnetic coupled singlet states (AF states), and the corresponding lowest energy high spin states (HS states) are triplet, CoMCo] 6+ chains have three central four-electron sigma bonds (σ2σ1nbσ1). The complexes 1 ~ 4 all have spin-filtering effect. The electron transport channels are mainly β-spin σnb orbitals, and the distance from the Fermi level is 1 <2 <3≈4. Under the action of electric field, Co2-N4 bonds on the high potential side of 1 ~ 4 increase and Co3-N7 bond decrease on the low potential side, the average bond length of Co-M is shortened and the Co-M bond is enhanced. The spin density of metal atoms And the change of charge density is very small and the electromagnetic property is stable. The distribution of σnb orbital remains away from the metal axis along the metal axis due to the electric field, and the LUMO-HOMO gap decreases, which is in favor of electron transport.