title: Single-molecule-magnet behavior and spin changes affected by crystal packing effects.
abstract: Five Mn 3Zn 2 heterometallic complexes have been synthesized and structurally and magnetically characterized. Spin ground states up to S = 6 have been observed for these complexes and are shown to depend on the cocrystallizing cation and on the terminal ligand. Large axial zero-field interactions ( D = -1.16 K) are the result of near-parallel alignment of the Mn (III) Jahn-Teller axes. High-frequency electron paramagnetic resonance, single-crystal magnetization hysteresis, and alternating current susceptibility measurements are presented to characterize [NEt 4] 3[Mn 3Zn 2(salox) 3O(N 3) 6X 2] [X (-) = Cl (-) ( 1), Br (-) ( 2)] and [AsPh 4] 3[Mn 3Zn 2(salox) 3O(N 3) 6Cl 2] ( 3) and reveal that 1 and 2 are single-molecule magnets ( U eff = 44 K), while 3 is not.
authors.affiliation: Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, California 92093-0358, USA.
authors.forename: Patrick L
authors.initials: PL
authors.lastname: Feng
authors.forename: Changhyun
authors.initials: C
authors.lastname: Koo
authors.forename: John J
authors.initials: JJ
authors.lastname: Henderson
authors.forename: Motohiro
authors.initials: M
authors.lastname: Nakano
authors.forename: Stephen
authors.initials: S
authors.lastname: Hill
authors.forename: Enrique
authors.initials: E
authors.lastname: del Barco
authors.forename: David N
authors.initials: DN
authors.lastname: Hendrickson