Mononuclear Dysprosium(III) Complexes with Triphenylphosphine Oxide Ligands: Controlling the Coordination Environment and Magnetic Anisotropy

Inorganics

Kuduva R. Vignesh¹  Gopalan Rajaraman¹  Wasinee Phonsri²  Keith S. Murray²  Boujemaa Moubaraki²  Sophie Benjamin³  Kerey Holton⁴  Stuart K. Langley⁴  Gary B. Hix⁵ 

[1] Department of Chemistry, IIT Bombay, Mumbai 400076, India;School of Chemistry, Monash University, Clayton, VIC 3800, Australia;School of Science and Technology, Nottingham Trent University, Nottingham NG11 8NS, UK;School of Science and the Environment, Division of Chemistry, Manchester Metropolitan University, Manchester M15 6BH, UK;School of Sciences, University of Wolverhampton, Wolverhampton WV1 1LY, UK;

关键词: single molecule magnets;    single ion magnets;    phosphine oxide complexes;    lanthanide SMMs;    magnetic anisotropy;    ab initio calculations;   

DOI  :  10.3390/inorganics6020061

来源: DOAJ

【 摘 要 】

We report the synthesis, structural and magnetic characterization of five mononuclear DyIII ion complexes using triphenylphosphine oxide as a monodentate ligand. They have formulae [DyIII(OPPh3)3(NO3)3] (1), [DyIII(OPPh3)4(NO3)2](NO3) (2), [DyIII(OPPh3)3Cl3] (3), [DyIII(OPPh3)4Cl2]Cl (4) and [DyIII(OPPh3)4Cl2](FeCl4) (5). These complexes are characterized using single crystal X-ray diffraction, which revealed that each complex has a unique coordination environment around the DyIII ion, which results in varying dynamic magnetic behavior. Ab initio calculations are performed to rationalize the observed magnetic behavior and to understand the effect that the ligand and coordination geometry around the DyIII ion has on the single-molecule magnet (SMM) behavior. In recent years, seven coordinate DyIII complexes possessing pseudo ~D5h symmetry are found to yield attractive blocking temperatures for the development of new SMM complexes. However, here we show that the strength of the donor ligand plays a critical role in determining the effective energy barrier and is not simply dependent on the geometry and the symmetry around the DyIII ion. Seven coordinate molecules possessing pseudo D5h symmetry with strong equatorial ligation and weak axial ligation are found to be inferior, exhibiting no SMM characteristics under zero-field conditions. Thus, this comprehensive study offers insight on improving the blocking temperature of mononuclear SMMs.

【 授权许可】

Unknown