Utilisation of the static Evans method to measure magnetic susceptibilities of transition metal acetylacetonate complexes as part of an undergraduate inorganic laboratory class

Abstract

The Evans method is routinely utilised to collect paramagnetic susceptibility data via the employment of relevant Nuclear Magnetic Resonance (NMR) methods. As the sample is normally spun, the lack of such a function on benchtop NMR instrumentation required a “static” approach to be employed. We have utilised the static Evan’s method approach to measure the magnetic susceptibilities, and subsequently the effective magnetic moment, of a series of synthesised transition metal acetylacetonate complexes in order to appraise the d-electron configuration. The obtained values were compared to those obtained using a Guoy balance and theoretical calculations. The collection of T1 relaxation data further exemplifies the effect of the paramagnetic centre in terms of aiding relaxation, and therefore links to Magnetic Resonance Imaging (MRI) contrast agents, thus providing students with real-world perspective of the experiment conducted