Comparative study on effects of bridging and terminal ligands on   magnetic exchange interaction in [(NH3)(5)Cr((mu-X)Cr(NH3)(4)L](n+)   (X=O, OH; L=OH, OH2, NH3; n=4, 5): density functional theory study

doi:10.1016/j.theochem.2004.11.043

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	Comparative study on effects of bridging and terminal ligands on magnetic exchange interaction in [(NH3)(5)Cr((mu-X)Cr(NH3)(4)L](n+) (X=O, OH; L=OH, OH2, NH3; n=4, 5): density functional theory study
	Ren, QH ; Chen, ZD
刊名	journal of molecular structure theochem
	2005
关键词	magnetic coupling density functional theory broken symmetry approach Cr(III) dimer TRANSITION-METAL-COMPLEXES ELECTRONIC-STRUCTURE NUMERICAL-INTEGRATION CHROMIUM(III) DIMERS BINUCLEAR COMPLEXES CRYSTAL-STRUCTURE HYDROXO OXO APPROXIMATION TITANIUM(III)
DOI	10.1016/j.theochem.2004.11.043
英文摘要	The magneto-structural correlations for the model molecules of the rhodo, and erythro series of binuclear ammine complexes of Chromium (III), [(NH3)(5)Cr(mu-X)Cr(NH3)(4)L](n+) (X = O, OH; L = OH, OH2, NH3; n = 4, 5) are investigated by using density functional theory combined with the broken-symmetry approach. Comparative studies on effects of bridging and terminal ligands demonstrated that the bridging ligand plays a significant role in magnetic exchange interaction between Cr(III) ions. The substitution of the bridging ligand mu-hydroxo by mu-oxo atom leads a remarkable effect on magnetic exchange interaction, while the magnetic coupling constant J decreases exponentially with the increase of the bridging Cr-O distance and increases exponentially with the increase of the bridging Cr-O-Cr angle. In comparison with the bridging ligand, the terminal ligands behave a minor effect in the magnetic exchange interaction. The substitution of the single terminal ligand t-OH by t-OH2 and t-NH3, and the variation of the terminal coordinate bond distances, Cr-(t-OH), Cr-(t-OH2) and Cr-(t-NH3) all exhibit a limited effect on the magnetic exchange interaction between Cr(III) ions. It is unexpected that the variation of the terminal ligands conformation significantly effects on the magnetic exchange interaction. The stronger magnetic exchange interactions are involved in the staggered conformational isomer, where the direction of N11-Cr2-O13 is in either perpendicular or overlapped one of O3-Cr2-N9. On the other hand, the eclipsed conformational isomer of the terminal ligands results in the weaker magnetic exchange interactions. Finally, molecular orbital analyses reveal a significant magnetic molecular orbital effect, consisting with HTH model. Spin population analyses show that. the polarization mechanism occurs in magnetic super-exchange interaction of model 1a, leading a weaker coupling between the two Cr(III) centers. (c) 2005 Elsevier B.V. All rights reserved.; Chemistry, Physical; SCI(E); 3; ARTICLE; 1-3; 159-168; 719
语种	英语
内容类型	期刊论文
源URL	[http://ir.pku.edu.cn/handle/20.500.11897/253831]
专题	化学与分子工程学院
推荐引用方式 GB/T 7714	Ren, QH,Chen, ZD. Comparative study on effects of bridging and terminal ligands on magnetic exchange interaction in [(NH3)(5)Cr((mu-X)Cr(NH3)(4)L](n+) (X=O, OH; L=OH, OH2, NH3; n=4, 5): density functional theory study[J]. journal of molecular structure theochem,2005.
APA	Ren, QH,&Chen, ZD.(2005).Comparative study on effects of bridging and terminal ligands on magnetic exchange interaction in [(NH3)(5)Cr((mu-X)Cr(NH3)(4)L](n+) (X=O, OH; L=OH, OH2, NH3; n=4, 5): density functional theory study.journal of molecular structure theochem.
MLA	Ren, QH,et al."Comparative study on effects of bridging and terminal ligands on magnetic exchange interaction in [(NH3)(5)Cr((mu-X)Cr(NH3)(4)L](n+) (X=O, OH; L=OH, OH2, NH3; n=4, 5): density functional theory study".journal of molecular structure theochem (2005).