TY - JOUR
T1 - Role of the orbitally degenerate Mn(III) ions in the single-molecule magnet behavior of the cyanide cluster {[MnII(tmphen)2] 3[MnIII(CN)6]2} (tmphen = 3,4,7,8-tetramethyl-1,10-phenanthroline)
AU - Palii, Andrei V.
AU - Ostrovsky, Sergei M.
AU - Klokishner, Sophia I.
AU - Tsukerblat, Boris S.
AU - Berlinguette, Curtis P.
AU - Dunbar, Kim R.
AU - Galán-Mascarós, José Ramón
PY - 2004/12/29
Y1 - 2004/12/29
N2 - We report a new theoretical model that accounts for the unusual magnetic properties of the cyanide cluster {[MnII(tmphen)2] 3MnIII(CN)6]2} (tmphen = 3,4,7,8-tetramethyl-1,10-phenanthroline). The model takes into account (1) the spin-orbit interaction, (2) the trigonal component of the crystal field acting on the ground-state cubic 3T1(t24) terms of the apical Mn(III) ions, and (3) the isotropic contribution to the exchange interaction between Mn(III) and Mn(II) ions. The ground state of the cluster was shown to be the state with the total angular momentum projection |M J| = 15/2; the energies of the low-lying levels obtained from this treatment increase with decreasing |MJ| values, a situation that leads to a barrier for the reversal of magnetization (Ueff ≈ 30 cm -1). The new model explains the recently discovered single-molecule magnet behavior of the {[MnII(tmphen)2] 3[MnIII(CN)6]2] in contrast to the traditional approach that takes into account only the ground-state spin (S) and a negative zero-field splitting parameter (DS < 0).
AB - We report a new theoretical model that accounts for the unusual magnetic properties of the cyanide cluster {[MnII(tmphen)2] 3MnIII(CN)6]2} (tmphen = 3,4,7,8-tetramethyl-1,10-phenanthroline). The model takes into account (1) the spin-orbit interaction, (2) the trigonal component of the crystal field acting on the ground-state cubic 3T1(t24) terms of the apical Mn(III) ions, and (3) the isotropic contribution to the exchange interaction between Mn(III) and Mn(II) ions. The ground state of the cluster was shown to be the state with the total angular momentum projection |M J| = 15/2; the energies of the low-lying levels obtained from this treatment increase with decreasing |MJ| values, a situation that leads to a barrier for the reversal of magnetization (Ueff ≈ 30 cm -1). The new model explains the recently discovered single-molecule magnet behavior of the {[MnII(tmphen)2] 3[MnIII(CN)6]2] in contrast to the traditional approach that takes into account only the ground-state spin (S) and a negative zero-field splitting parameter (DS < 0).
UR - http://www.scopus.com/inward/record.url?scp=11244317214&partnerID=8YFLogxK
U2 - 10.1021/ja046771a
DO - 10.1021/ja046771a
M3 - Article
AN - SCOPUS:11244317214
SN - 0002-7863
VL - 126
SP - 16860
EP - 16867
JO - Journal of the American Chemical Society
JF - Journal of the American Chemical Society
IS - 51
ER -