TY - JOUR
T1 - Magnetic and optical studies on an S=6 ground-state cluster [Cr12O9(OH)3(O2CCMe3)15]
T2 - Determination of, and the relationship between, single-ion and cluster spin Hamiltonian parameters
AU - Collison, David
AU - Murrie, Mark
AU - Oganesyan, Vasily S.
AU - Piligkos, Stergios
AU - Poolton, Nigel R. J.
AU - Rajaraman, Gopalan
AU - Smith, Graham M.
AU - Thomson, Andrew J.
AU - Timko, Grigore A.
AU - Wernsdorfer, Wolfgang
AU - Winpenny, Richard E. P.
AU - McInnes, Eric J. L.
PY - 2003/8/25
Y1 - 2003/8/25
N2 - The dodecametallic Cr(III) cluster [Cr12O9(OH) 3(O2CCMe3)15] has a ground spin state of S = 6 characterized by the spin Hamiltonian parameters gzz = 1.965, gxx = gyy = 1.960, DS=6 = +0.088 cm-1, and E S=6 = 0 (where D and E are the axial and rhombic zero-field splitting parameters, respectively) as determined by multifrequency EPR spectroscopy and magnetization studies. Micro-SQUID magnetization studies reveal steps due to the fine structure of the ground state, with the spacing between the steps in excellent agreement with the DS=6 value determined by EPR. Analysis of high-resolution optical data (MCD) allows us to determine the single-ion g values and D value (= -1.035 cm-1) of the constituent Cr(III) ions directly. A vector coupling analysis demonstrates that the cluster ZFS is almost entirely due to the single-ion component. Thus, the relative orientations of the local and cluster magnetic axes can lead to a cluster ZFS of opposite sign to the single-ion value, even when this is the only significant contribution.
AB - The dodecametallic Cr(III) cluster [Cr12O9(OH) 3(O2CCMe3)15] has a ground spin state of S = 6 characterized by the spin Hamiltonian parameters gzz = 1.965, gxx = gyy = 1.960, DS=6 = +0.088 cm-1, and E S=6 = 0 (where D and E are the axial and rhombic zero-field splitting parameters, respectively) as determined by multifrequency EPR spectroscopy and magnetization studies. Micro-SQUID magnetization studies reveal steps due to the fine structure of the ground state, with the spacing between the steps in excellent agreement with the DS=6 value determined by EPR. Analysis of high-resolution optical data (MCD) allows us to determine the single-ion g values and D value (= -1.035 cm-1) of the constituent Cr(III) ions directly. A vector coupling analysis demonstrates that the cluster ZFS is almost entirely due to the single-ion component. Thus, the relative orientations of the local and cluster magnetic axes can lead to a cluster ZFS of opposite sign to the single-ion value, even when this is the only significant contribution.
UR - https://www.scopus.com/pages/publications/0041508227
U2 - 10.1021/ic034541b
DO - 10.1021/ic034541b
M3 - Article
AN - SCOPUS:0041508227
SN - 0020-1669
VL - 42
SP - 5293
EP - 5303
JO - Inorganic Chemistry
JF - Inorganic Chemistry
IS - 17
ER -