title: Triimidosulfonates as Acute Bite-Angle Chelates: Slow Relaxation of the Magnetization in Zero Field and Hysteresis Loop of a Co(II) Complex.
abstract: Starting from a polyimido sulfonate the four-coordinate, N,N'-chelated Co(II) complex [Co{(NtBu)3 SMe}2 ] (1) was synthesized, and its molecular structure was elucidated by single-crystal X-ray structural analysis. The acute N-Co-N bite angle imposed by the N,N'-chelating ligand (NtBu)3 SMe(-) leads to pronounced C2v distortion of the tetrahedral coordination environment and thus to high anisotropy of the Co(II) ion (D≈-58 cm(-1) ), favorable for single-molecule-magnet (SMM) properties. Magnetic measurements revealed a high barrier to spin reversal (Ueff =75 cm(-1) ) that gives rise to the observation of slow relaxation of the magnetization in zero field and a hysteresis loop at 2 K for this unique complex.
authors.affiliation: Institut für Anorganische Chemie, Universität Göttingen, Tammannstrasse 4, 37077 Göttingen (Germany).
authors.forename: Elena
authors.initials: E
authors.lastname: Carl
authors.affiliation: Institut für Anorganische Chemie, Universität Göttingen, Tammannstrasse 4, 37077 Göttingen (Germany).
authors.forename: Serhiy
authors.initials: S
authors.lastname: Demeshko
authors.affiliation: Institut für Anorganische Chemie, Universität Göttingen, Tammannstrasse 4, 37077 Göttingen (Germany). franc.meyer@chemie.uni-goettingen.de.
authors.forename: Franc
authors.initials: F
authors.lastname: Meyer
authors.affiliation: Institut für Anorganische Chemie, Universität Göttingen, Tammannstrasse 4, 37077 Göttingen (Germany). dstalke@chemie.uni-goettingen.de.
authors.forename: Dietmar
authors.initials: D
authors.lastname: Stalke
keywords: X-ray diffraction; cobalt; magnetic properties; polyimidosulfonate; single-molecule magnets