Manipulating and quantifying spin states in solution as a function of pressure and temperature.

Ross W Hogue,Sally Brooker,Geoffrey B Jameson,Christopher P Lepper

doi:10.1039/c7cc08104a

Abstract

Monitoring the spin states of species in solution is a crucial aspect of understanding magnetic properties as well as spin-labile sensing, supramolecular, catalytic and biochemical processes. Herein, we describe the first quantitative variable-pressure and variable-temperature method of determining spin states in solution, demonstrate that it is accurate, and identify a simultaneous T and P sensor system.

Highlights

Monitoring the spin states of species in solution is a crucial aspect of understanding magnetic properties as well as spin-labile sensing, supramolecular, catalytic and biochemical processes
Measurements of spin states in the solution phase are of particular importance, especially for the study of biologically relevant processes, including photosynthesis[4] and iron-containing enzyme activity,[5] noting that life persists at pressures in excess of 100 MPa (B1000 atmospheres)
While this has been observed in pressure-induced solution spin crossover (SCO), by the Gouy method,[7] and UV-vis[8] and 1H NMR9 spectroscopies, these have all been qualitative measures of spin states

Summary

Introduction

Monitoring the spin states of species in solution is a crucial aspect of understanding magnetic properties as well as spin-labile sensing, supramolecular, catalytic and biochemical processes. The frequency shift of the solvent signal, Df, in the outer tube compared to the pure solvent (to which the NMR spectrum is locked), is dependent on the magnetic susceptibility of the paramagnetic material, and wMT can be calculated from Df (Hz), the concentration m (g cmÀ3), and the spectrometer frequency f (Hz) using the Evans method (eqn (1)) to obtain the mass susceptibility wg (cm[3] gÀ1).[10,15] wg = 3Df/(4pmf)

Results

Conclusion