[Mn6] under Pressure:A Combined Crystallographic and Magnetic Study

摘要

While investigating the coordination chemistry of derivatized salicylaldoximes (R-saoH2) in the synthesis of Mn6 single-molecule magnets (SMMs) we found that the exchange between the metal centers was weak and typically only a few wavenumbers (< 1-2 cm~(-1)) in magnitude.Structurally distorting the molecule "internally" by deliberate chemical modification of the magnetic core (the twisting of the Mn-N-O-Mn moiety) allowed us to switch the exchange from antiferromagnetic to ferromagnetic,thus producing SMMs with ground states of S = 12 and greatly enhanced blocking temperatures.An alternative method of achieving such a switch is to exert "external" hydrostatic pressure.This is an attractive proposition since it offers the potential to provide detailed information about the relationship between structure and magnetic properties,especially if the magnetic studies can be coupled with high-pressure crystallography.