TY - JOUR
T1 - Ferromagnetic Exchange Coupling in a Family of MnIII Salen-Type Schiff-Base Out-of-Plane Dimers
AU - Kachi-Terajima, Chihiro
AU - Ishii, Rikako
AU - Tojo, Yoshiaki
AU - Fukuda, Masato
AU - Kitagawa, Yasutaka
AU - Asaoka, Mizuki
AU - Miyasaka, Hitoshi
N1 - Publisher Copyright:
© 2017 American Chemical Society.
PY - 2017/6/8
Y1 - 2017/6/8
N2 - A series of MnIII saltmen dimers, [Mn2(5-Rsaltmen)2(X)2](A)2n (saltmen2- = N,N′-(1,1,2,2-tetramethylethylene)bis(salicylideneiminate); R = H, Cl, Br, MeO, Me; X = H2O, ReO4-, NO3-, N3-, NCS-, A- = ClO4-, PF6-, CF3SO3- for X = H2O) were synthesized and structurally and magnetically investigated to understand the correlation between their intradimer ferromagnetic (FM) interaction and single-molecule magnet (SMM) behavior. All complexes had a similar di-μ-phenolate-bridged out-of-plane dimer structure but displayed different bridging Mn-Oph∗ distances depending on the R substituents of the saltmen ligand and axial X ligand. Magnetic susceptibility studies revealed intradimer FM coupling (JMn-Mn∗), resulting in an ST = 4 ground state for all dimers. However, the magnitude of FM coupling strongly depended on R and X. JMn-Mn∗ increased with decreasing Mn-Oph∗ distance but decreased with decreasing Mn-X distance with a relation of H2O ≈ ReO4- > NO3- > N3- ≈ NCS- with a linear trend for R = H, Cl, Me but not for R = Br, MeO. Theoretical investigations revealed that a larger orbital overlap stabilized a FM spin configuration through competition between the orbital degeneracy and on-site Coulomb repulsion of out-of-phase and in-phase orbitals. Most dimers showed typical SMM behavior. The dimers with larger JMn-Mn∗ tended to have higher blocking temperatures.
AB - A series of MnIII saltmen dimers, [Mn2(5-Rsaltmen)2(X)2](A)2n (saltmen2- = N,N′-(1,1,2,2-tetramethylethylene)bis(salicylideneiminate); R = H, Cl, Br, MeO, Me; X = H2O, ReO4-, NO3-, N3-, NCS-, A- = ClO4-, PF6-, CF3SO3- for X = H2O) were synthesized and structurally and magnetically investigated to understand the correlation between their intradimer ferromagnetic (FM) interaction and single-molecule magnet (SMM) behavior. All complexes had a similar di-μ-phenolate-bridged out-of-plane dimer structure but displayed different bridging Mn-Oph∗ distances depending on the R substituents of the saltmen ligand and axial X ligand. Magnetic susceptibility studies revealed intradimer FM coupling (JMn-Mn∗), resulting in an ST = 4 ground state for all dimers. However, the magnitude of FM coupling strongly depended on R and X. JMn-Mn∗ increased with decreasing Mn-Oph∗ distance but decreased with decreasing Mn-X distance with a relation of H2O ≈ ReO4- > NO3- > N3- ≈ NCS- with a linear trend for R = H, Cl, Me but not for R = Br, MeO. Theoretical investigations revealed that a larger orbital overlap stabilized a FM spin configuration through competition between the orbital degeneracy and on-site Coulomb repulsion of out-of-phase and in-phase orbitals. Most dimers showed typical SMM behavior. The dimers with larger JMn-Mn∗ tended to have higher blocking temperatures.
UR - http://www.scopus.com/inward/record.url?scp=85021410543&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85021410543&partnerID=8YFLogxK
U2 - 10.1021/acs.jpcc.7b03336
DO - 10.1021/acs.jpcc.7b03336
M3 - Article
AN - SCOPUS:85021410543
VL - 121
SP - 12454
EP - 12468
JO - Journal of Physical Chemistry C
JF - Journal of Physical Chemistry C
SN - 1932-7447
IS - 22
ER -