title: Two unprecedented decanuclear heterometallic [MnMnLn] (Ln = Dy, Tb) complexes displaying relaxation of magnetization.
abstract: We report the syntheses, crystal structures, and magnetic properties of two 3d-4f heterometallic compounds; namely, [Mn8Ln2O2(OH)2{(py)2CO2}4(teaH)4(CH3COO)6]·6CH3CN·2H2O (LnIII= Dy (1), Tb (2); (py)2CO2H2= the gem-diol form of di-2-pyridyl ketone, teaH3= triethanolamine). Both compounds were prepared by the reaction of Mn(OAc)2·4H2O, Ln(NO3)3·5H2O (Ln = Dy and Tb) with the ligands di-2-pyridyl ketone and triethanolamine in MeCN, and they crystallize in the monoclinic space group C2/c. [Mn8Ln2] complexes have not been reported before, and the metallic cores of both complexes were unprecedented. In these cores, two Dy or Tb and two Mn ions comprised a well-known butterfly topology, with three of the remaining six Mn atoms each being situated on either side of the butterfly, linked through two μ3-O2-ions. Six MnIIIand two MnIIwere in six-coordinated distorted octahedrons and two LnIIIions were in nine-coordinated distorted muffins. Interestingly, the coordination sites of LnIIIions are occupied by six O and two N atoms from two teaH2-ligands and one μ3-O2-atom, without the presence of coordinated solvent molecules such as H2O and small anions such as NO3-ions, which is rare in 3d-4f complexes. Remarkably, alternating current (ac) magnetic susceptibility measurements revealed that both complexes displayed dynamic anisotropic magnetic behaviour. The effective energy barrier (Ueff) of complex 2 was estimated to be 18.97 K through high frequency (111-9111 Hz) ac susceptibility measurements. The low symmetry of the coordination configuration of Ln3+in 1 and 2 may be responsible for the small energy barriers of these two compounds.
authors: School of Chemistry and Environmental Engineering, Wuhan Institute of Technology, Key Laboratory for Green Chemical Process of Ministry of Education, Wuhan 430074, P. R. China. wangch198201@163.com.
authors: Hui-Sheng
authors: HS
authors: Wang
authors: School of Chemistry and Environmental Engineering, Wuhan Institute of Technology, Key Laboratory for Green Chemical Process of Ministry of Education, Wuhan 430074, P. R. China. wangch198201@163.com.
authors: Feng-Jun
authors: FJ
authors: Yang
authors: School of Chemistry and Environmental Engineering, Wuhan Institute of Technology, Key Laboratory for Green Chemical Process of Ministry of Education, Wuhan 430074, P. R. China. wangch198201@163.com.
authors: Qiao-Qiao
authors: QQ
authors: Long
authors: School of Chemistry and Environmental Engineering, Wuhan Institute of Technology, Key Laboratory for Green Chemical Process of Ministry of Education, Wuhan 430074, P. R. China. wangch198201@163.com.
authors: Zhi-Yong
authors: ZY
authors: Huang
authors: School of Chemistry and Environmental Engineering, Wuhan Institute of Technology, Key Laboratory for Green Chemical Process of Ministry of Education, Wuhan 430074, P. R. China. wangch198201@163.com.
authors: Wei
authors: W
authors: Chen
authors: School of Chemistry and Environmental Engineering, Wuhan Institute of Technology, Key Laboratory for Green Chemical Process of Ministry of Education, Wuhan 430074, P. R. China. wangch198201@163.com.
authors: Zhi-Quan
authors: ZQ
authors: Pan
authors: State Key Laboratory of Coordinate Chemistry, Nanjing National Laboratory of Microstructures, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, P. R. China. yousong@nju.edu.cn.
authors: You
authors: Y
authors: Song