Exchange coupling and magnetic anisotropy in a family of bipyrimidyl radical-bridged dilanthanide complexes: Density functional theory and ab initio calculations
Article first published online: 19 FEB 2014
Copyright © 2014 Wiley Periodicals, Inc.
Journal of Computational Chemistry
Volume 35, Issue 12, pages 904–909, 5 May 2014
How to Cite
How to cite this article: 2014. J. Comput. Chem., 35, 904–909. DOI: 10.1002/jcc.23565, , .
- Issue published online: 2 APR 2014
- Article first published online: 19 FEB 2014
- Manuscript Accepted: 31 JAN 2014
- Manuscript Revised: 30 JAN 2014
- Manuscript Received: 14 NOV 2013
- Natural Science Foundation of Jiangsu Province of China . Grant Number: BK2011778
- China Postdoctoral Science Foundation funded project . Grant Number: 2012M520104
- single-molecule magnet;
- energy barrier;
- exchange coupling;
- complete-active-space self-consistent field;
The origin of the magnetic anisotropy energy barriers in a series of bpym− (bpym = 2,2′-bipyrimidine) radical-bridged dilanthanide complexes [(Cp*2Ln)2(μ-bpym)]+ [Cp* = pentamethylcyclopentadienyl; Ln = GdIII (1), TbIII (2), DyIII (3), HoIII (4), ErIII (5)] has been explored using density functional theory (DFT) and ab initio methods. DFT calculations show that the exchange coupling between the two lanthanide ions for each complex is very weak, but the antiferromagnetic Ln-bpym− couplings are strong. Ab initio calculations show that the effective energy barrier of 2 or 3 mainly comes from the contribution of a single TbIII or DyIII fragment, which is only about one third of a single Ln energy barrier. For 4 or 5, however, both of the two HoIII or ErIII fragments contribute to the total energy barrier. Thus, it is insufficient to only increase the magnetic anisotropy energy barrier of a single Ln ion, while enhancing the Ln-bpym− couplings is also very important. © 2014 Wiley Periodicals, Inc.