TY - JOUR
T1 - Effect of ligand substitution on the SMM properties of three isostructural families of double-cubane Mn4Ln2 coordination clusters
AU - Akhtar, Muhammad Nadeem
AU - Lan, Yanhua
AU - Aldamen, Murad A.
AU - Zheng, Yan Zhen
AU - Anson, Christopher E.
AU - Powell, Annie K.
N1 - Publisher Copyright:
© The Royal Society of Chemistry.
PY - 2018
Y1 - 2018
N2 - Three isostructural lanthanide series with a core of MnIII2MnII2Ln2 are reported. These three families have the formulae of [MnIII2MnII2Ln2(μ4-O)2(H2edte)2(piv)6(NO3)2] {no crystallization solvent, Ln = La, Ce, Pr, Nd, Eu (1-4, 6); solv = 3MeCN, Ln = Sm, Gd, Tb, Dy, Ho, Er, Tm, Yb, Y (5, 7-13)}, where H2edte = N,N,N′,N'-tetrakis(2-hydroxyethyl)ethylenediamine and piv = pivalate; [MnIII2MnII2Ln2(μ4-O)2(H2edte)2(benz)6(NO3)2], where benz = benzoate, or [MnIII2MnII2Ln2(μ4-O)2(edteH2)2(benz)6(NO3)2]·2MeCN {Ln = Gd, Tb, Dy (14-16); and [MnIII2MnII2Ln2(μ4-O)2(edteH2)2(piv)8].solv {solv = 4MeCN, Ln = La (17); solv = 2MeCN·tol·H2O, Ln = Pr, Nd, Sm, Tb (18-20, 22); solv = 2MeCN·H2O, Ln = Gd (21). These compounds crystallize in two different systems, namely, monoclinic in the space groups P21/n for 1-4, 6, and 14-16 and C2/c for 5, 7-13, 18-20, and 22 and triclinic in the space group P1 for 17 and 21. The crystal structures of these compounds display a face-fused dicubane structure connected by different types of bridged oxygen atoms. Solid-state dc magnetic susceptibility characterization was carried out for 1-22, and fitting showed that MnIII⋯MnIII is antiferromagnetically (AF) coupled and MnII⋯MnIII, MnII⋯Ln and MnIII⋯Ln are weakly ferromagnetically coupled. In addition, ac measurements were carried out and showed that only 7, 15, and 22 for Tb, 8 and 16 for Dy, and 20 for Sm exhibited slow magnetization relaxation. In the case of 15, it was possible to determine the energy barrier of the slow-relaxation behavior by fitting peak temperatures to the Arrhenius law, which gave a value of Ueff = 21.2 K and a pre-exponential factor of τ0 = 4.0 × 10-9 s.
AB - Three isostructural lanthanide series with a core of MnIII2MnII2Ln2 are reported. These three families have the formulae of [MnIII2MnII2Ln2(μ4-O)2(H2edte)2(piv)6(NO3)2] {no crystallization solvent, Ln = La, Ce, Pr, Nd, Eu (1-4, 6); solv = 3MeCN, Ln = Sm, Gd, Tb, Dy, Ho, Er, Tm, Yb, Y (5, 7-13)}, where H2edte = N,N,N′,N'-tetrakis(2-hydroxyethyl)ethylenediamine and piv = pivalate; [MnIII2MnII2Ln2(μ4-O)2(H2edte)2(benz)6(NO3)2], where benz = benzoate, or [MnIII2MnII2Ln2(μ4-O)2(edteH2)2(benz)6(NO3)2]·2MeCN {Ln = Gd, Tb, Dy (14-16); and [MnIII2MnII2Ln2(μ4-O)2(edteH2)2(piv)8].solv {solv = 4MeCN, Ln = La (17); solv = 2MeCN·tol·H2O, Ln = Pr, Nd, Sm, Tb (18-20, 22); solv = 2MeCN·H2O, Ln = Gd (21). These compounds crystallize in two different systems, namely, monoclinic in the space groups P21/n for 1-4, 6, and 14-16 and C2/c for 5, 7-13, 18-20, and 22 and triclinic in the space group P1 for 17 and 21. The crystal structures of these compounds display a face-fused dicubane structure connected by different types of bridged oxygen atoms. Solid-state dc magnetic susceptibility characterization was carried out for 1-22, and fitting showed that MnIII⋯MnIII is antiferromagnetically (AF) coupled and MnII⋯MnIII, MnII⋯Ln and MnIII⋯Ln are weakly ferromagnetically coupled. In addition, ac measurements were carried out and showed that only 7, 15, and 22 for Tb, 8 and 16 for Dy, and 20 for Sm exhibited slow magnetization relaxation. In the case of 15, it was possible to determine the energy barrier of the slow-relaxation behavior by fitting peak temperatures to the Arrhenius law, which gave a value of Ueff = 21.2 K and a pre-exponential factor of τ0 = 4.0 × 10-9 s.
UR - https://www.scopus.com/pages/publications/85043333915
U2 - 10.1039/c7dt04304j
DO - 10.1039/c7dt04304j
M3 - 文章
C2 - 29431788
AN - SCOPUS:85043333915
SN - 1477-9226
VL - 47
SP - 3485
EP - 3495
JO - Dalton Transactions
JF - Dalton Transactions
IS - 10
ER -