New Mn12 single-molecule magnets (SMM's) with the composition [Mn12O12(O2CR)16(H2O)4] were prepared and structurally characterized. Complexes of this type can exhibit two out-of-phase ac magnetic susceptibility signals, one in the 4-7 K region and the other in the 2-3 K region. The origin of the two magnetization relaxation processes was systematically examined. The X-ray structures of two isomeric forms of a Mn12 SMM are given. One complex has an abnormal Jahn-Teller distortion axis. The magnetization hysteresis loops for the two isomers are quite different.
@article{arxiv.cond-mat/0109380,
title = {Single-Molecule Magnets: Jahn-Teller Isomerism and the Origin of Two Magnetization Relaxation Processes in Mn12 Complexes},
author = {Sheila M. J. Aubin and Ziming Sun and Hilary J. Eppley and Evan M. Rumberger and Ilia A. Guzei and Kirsten Folting and Peter K. Gantzel and Arnold L. Rheingold and George Christou and David N. Hendrickson},
journal= {arXiv preprint arXiv:cond-mat/0109380},
year = {2007}
}