Targeted replacement: systematic studies of dodecanuclear {MIII6LnIII6} coordination clusters (M = Cr, Co; Ln = Dy, Y)

Autor: Valeriu Mereacre, Mengsi Zhang, Zhiying Zhao, Wanwan Zhang, Zhangzhen He, Sihuai Chen
Rok vydání: 2018
Předmět:
Zdroj: Dalton Transactions. 47:7456-7462
ISSN: 1477-9234
1477-9226
Popis: Three dodecanuclear 3d–4f coordination clusters, [CrIII6LnIII6(μ3-OH)8(tbdea)6(C6H5COO)16]·2H2O (Ln = Dy (1), Y (2)) and [CoIII6DyIII6(μ3-OH)8(nbdea)6(m-CH3C6H4COO)16]·2H2O·2CH3CN (3), have been synthesized under solvothermal conditions and characterized. Single-crystal X-ray diffraction analysis revealed that all three compounds possess an analogous {MIII6LnIII6} core (M = Cr, Co; Ln = Dy, Y) and dc magnetic susceptibility studies indicated that the magnetic exchange couplings between DyIII ions are dominant antiferromagnetic, while the CrIII–DyIII interactions are weakly ferromagnetic. Furthermore, the ac magnetic susceptibility measurements showed that both CrIII6DyIII6 compound 1 and CoIIi6DyIII6 compound 3 containing highly anisotropic DyIII ions displayed single-molecule magnetic (SMM) behavior with the energy barrier Ueff increasing from 12.8 K (for 1) to 20.8 K (for 3), indicating that weak 3d–4f exchange couplings enhance the QTM and reduce the energy barrier.
Databáze: OpenAIRE