Field‐Induced Single‐Ion Magnetism Based on Spin‐Phonon Relaxation in a Distorted Octahedral High‐Spin Cobalt(II) Complex

Abstract

The six‐coordinate mononuclear high‐spin cobalt(II) complex [Co(bpy)2(ClAn)]·EtOH (1; bpy = 2,2′‐bipyridine, ClAn2– = chloranilate) and its magnetically diluted analogue [Co0.1Zn0.9(bpy)2(ClAn)]·EtOH (3), in which the CoII centres of 1 are partially diluted with the magnetically inactive ZnII centres of [Zn(bpy)2(ClAn)]·EtOH (2) as a diamagnetic matrix, exhibited slow magnetic relaxation in applied direct‐current (DC) magnetic fields. Fits of the DC magnetic data indicate that this new field‐induced single‐ion magnet possesses large positive axial and significant rhombic zero‐field splittings. The results of temperature‐dependent and DC‐magnetic‐field‐dependent alternating‐current magnetic measurements on 1 and 3, which is a field‐induced single‐ion magnet, agree with those from theoretical studies, and spin relaxation occurs through two‐phonon Raman and direct spin‐phonon bottleneck processes of Kramers ions.