Measurement of the Quantum Tunneling Gap in a Dysprosocenium Single-Molecule Magnet
William J. A. Blackmore, Andrea Mattioni, Sophie C. Corner, Peter Evans, Gemma K. Gransbury, David P. Mills, Nicholas F. Chilton
Abstract
High Resolution Image Download MS PowerPoint Slide We perform magnetization sweeps on the high-performing single-molecule magnet [Dy(Cp ttt ) 2 ][B(C 6 F 5 ) 4 ] (Cp ttt = C 5 H 2 t Bu 3 -1,2,4; t Bu = C(CH 3 ) 3 ) to determine the quantum tunneling gap of the ground-state avoided crossing at zero-field, finding a value on the order of 10 –7 cm –1 . In addition to the pure crystalline material, we also measure the tunnel splitting of [Dy(Cp ttt ) 2 ][B(C 6 F 5 ) 4 ] dissolved in dichloromethane (DCM) and 1,2-difluorobenzene (DFB). We find that concentrations of 200 or 100 mM [Dy(Cp ttt ) 2 ][B(C 6 F 5 ) 4 ] in these solvents increases the size of the tunneling gap compared to the pure sample, despite a similarity in the strength of the dipolar fields, indicating that either a structural or vibrational change due to the environment increases quantum tunneling rates.