Field-Induced Slow Magnetic Relaxation of a Six-Coordinate Mononuclear Manganese(II) and Cobalt(II) Oxamate Complexes

Abstract

Two air-stable, isostructural, mononuclear six-coordinate manganese(II) and cobalt(II) oxamate complexes, [<b>M</b>(4-HOpa)₂(H₂O)₂] [4-HOpa = <i>N</i>-4-hydroxyphenyloxamate; <b>M</b>= Mn²⁺ (<b>1</b>) or Co²⁺ (<b>2</b>)], exhibit field-induced slow magnetic relaxation. A bottleneck process is observed throughout the temperature range of 2-20 K for <b>1</b>, while for <b>2</b>, it dominates only at low temperatures (2-4 K). Additionally, the Raman process [<i>n</i> = 6.9(2)] is responsible for an increase in the relaxation time at higher temperatures to <b>2</b>.