Observation of symmetry lowering and electron localization in the doublet-states of a spin-frustrated equilateral triangular lattice:: Cu3(O2C16H23)•1.2C6H12

被引:95
作者
Cage, B
Cotton, FA [1 ]
Dalal, NS
Hillard, EA
Rakvin, B
Ramsey, CM
机构
[1] Texas A&M Univ, Dept Chem, College Stn, TX 77842 USA
[2] Texas A&M Univ, Mol Struct & Bonding Lab, College Stn, TX 77842 USA
[3] Florida State Univ, Dept Chem & Biochem, Tallahassee, FL 32306 USA
关键词
D O I
10.1021/ja0286829
中图分类号
O6 [化学];
学科分类号
0703 ;
摘要
Cu3(O2C16H23)6·1.2C6H12, containing a Cu36+ core in an equilateral triangle geometry, has been found to be a versatile model system for investigating the spin-frustration phenomenon in a triangular lattice. It affords well-resolved EPR spectra from both of the two possible (Stotal = 1/2 and 3/2) spin states of the Cu36+ core. From 295 to 100 K, the spectra consist of a triplet, but with the central line overlapped by an additional, sharp peak, which replaces the triplet at 30 K and below. The triplet was thus assigned to the excited state with Stotal = 3/2, located at 324 ± 5 K (∼225 cm-1), with the zero-field parameters D = -535 G, E = 0, g∥ = 2.209 and g⊥ = 2.057. The singlet was attributed to the Stotal = 1/2 state, with gxx = 2.005, gyy = 2.050, gzz = 2.282, and, surprisingly, a hyperfine splitting arising from a single Cu2+ nucleus, with Azz = 157 G. The detailed magnetic measurements on a three-electron, equilateral triangular system, and the observation of symmetry lowering in the doublet ground state, should be of broad theoretical and experimental interest in molecular magnetism. Copyright © 2003 American Chemical Society.
引用
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页码:5270 / 5271
页数:2
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