Slow magnetic relaxation in a pseudotetrahedral cobalt(ii) complex with easy-plane anisotropy

Abstract

A pseudotetrahedral cobalt(II) complex with a positive axial zero-field splitting parameter of D = 12.7 cm(-1), as determined by high-field EPR spectroscopy, is shown to exhibit slow magnetic relaxation under an applied dc field.

Magnetic anisotropy in two- to eight-coordinated transition–metal complexes: Recent developments in molecular magnetism

“…For the tetrahedral Co II complex [(3G)Co II Cl] + (43, Fig. 15), a positive D value was unambiguously determined by HF-EPR spectroscopy with D = 12.7 cm -1 , E = 1.2 cm -1 , g z = 2.17 [64]. Analysis of the magnetization data yielded D = 11.4(1) cm -1 , which was consistent with the EPR set of parameters.…”

Evidence of Slow Magnetic Relaxation in Co(AcO)2(py)2(H2O)2

“…The double well model holds up in the case of monometallic cobalt(II) SMMs with negative D values [9,[11][12][13][14][15][16][17][18][19], but the observation of similar behaviour in monometallic cobalt(II) complexes with positive D values [20][21][22] suggests that the picture is more complex. Indeed, slow relaxation in positive-D compounds is a phenomenon that is not yet fully understood-although attempts have been made to explain it [23,24].…”

Origin of slow magnetic relaxation in Kramers ions with non-uniaxial anisotropy

“…In 2012, Long and colleagues 4 found that a mononuclear pseudo-tetrahedral Co II shows slow magnetic relaxation, that is, it behaves as an SMM, when a small static magnetic field is applied to it. The same or similar behaviour has thereafter been reported for a number of other Co II complexes [5][6][7][8][9] as well as for lineal Fe II complexes 10 .…”