High-Field EPR Study of the Spin-Crossover Transitions in a Mn(III) Schiff-Base Complex

Brittany Grimm; Peter Schauss; Peter Schauss; Peter Schauss; Peter Schauss

High-Field EPR Study of the Spin-Crossover Transitions in a Mn(III) Schiff-Base Complex

POSTER

Abstract

Spin crossover (SCO) transitions from a high-spin (HS) to a low-spin (LS) state occur in certain molecular complexes of octahedrally coordinated 3d$^{\mathrm{4}}$ to 3d$^{\mathrm{7}}$ transition metals and can be induced using temperature, pressure, or optical perturbations.$^{\mathrm{[1]}}$ It has been observed that not all SCO complexes exhibit a complete transition, resulting in mixed LS/HS phases.$^{\mathrm{[2]}}$ Such situations are difficult to characterize experimentally due to the inhomogeneous nature of the mixed phase.$^{\mathrm{[2]}}$ The Mn(III) Schiff-base complex considered in this investigation, [Mn((3-MeO-5-NO$_{\mathrm{2}}$-sal)$_{\mathrm{2}}$323)]PF$_{\mathrm{6}}$, exhibits a complete transition from a pure HS ($S$~$=$~2) to a pure LS ($S$~$=$~1) state below a relatively sharp transition (T$_{\mathrm{1/2}} \quad =$ 51~K, with \textless 10~K hysteresis). Using continuous-wave high-field (0 to 14.5~T) EPR spectroscopy on a powder sample, the zero-field splitting parameters were characterized for both the LS ($D \quad =$ $+$20.8~cm$^{\mathrm{-1}})$ and HS states ($D \quad =$ -4.80 cm$^{\mathrm{-1}}$, $E \quad =$ 2.175 cm$^{\mathrm{-1}})$. References: 1. Kahn, O., and C. Jay Martinez. ``Spin-Transition Polymers: From Molecular Materials Toward Memory Devices.'' \textit{Science}, vol. 279, no. 5347, 2 Jan. 1998, pp. 44--48., doi:10.1126/science.279.5347.44. 2. Capel Berdiell, Izar, et al. ``Frontispiece: An Incomplete Spin Transition Associated with a Z$\prime =$1$\to $Z$\prime =$24 Crystallographic Symmetry Breaking.'' \textit{Chemistry - A European Journal}, vol. 24, no. 20, 7 Nov. 2017, pp. 1--5., doi:10.1002/chem.201882065.

Authors

Brittany Grimm

Florida State University, NHMFL
Peter Schauss

University of Notre Dame, Los Alamos National Laboratory, North Carolina State University, University of Notre dame, Columbia University, Mississippi State Univ, University of Pennsylvania, Carnegie Mellon University, University of Puerto Rico at Humacao, JLAB, MIT, University of Alabama at Birmingham, Florida State University, NHMFL, University College Dublin, Department of Physics, Florida State University; National High Magnetic Field Laboratory, CNR-Instituto Nanoscienze, Karlsruhe Institute of Technology (KIT), Institute of Nanotechnology, Department of Chemistry, Florida State University, University of Alabama at Birmingham, Department of Physics, Birmingham, AL 35294-1170,USA, Department of Chemistry, Virginia Polytechnic Institute and State University, Francis Marion University, University of Richmond, Valdosta State University, University of Pittsburgh, Fermi National Lab, university of minnesota, Univ of Virginia, Joint Quantum Institute, University of Maryland, Georgetown University, IonQ Inc.
Peter Schauss

University of Notre Dame, Los Alamos National Laboratory, North Carolina State University, University of Notre dame, Columbia University, Mississippi State Univ, University of Pennsylvania, Carnegie Mellon University, University of Puerto Rico at Humacao, JLAB, MIT, University of Alabama at Birmingham, Florida State University, NHMFL, University College Dublin, Department of Physics, Florida State University; National High Magnetic Field Laboratory, CNR-Instituto Nanoscienze, Karlsruhe Institute of Technology (KIT), Institute of Nanotechnology, Department of Chemistry, Florida State University, University of Alabama at Birmingham, Department of Physics, Birmingham, AL 35294-1170,USA, Department of Chemistry, Virginia Polytechnic Institute and State University, Francis Marion University, University of Richmond, Valdosta State University, University of Pittsburgh, Fermi National Lab, university of minnesota, Univ of Virginia, Joint Quantum Institute, University of Maryland, Georgetown University, IonQ Inc.
Peter Schauss

University of Notre Dame, Los Alamos National Laboratory, North Carolina State University, University of Notre dame, Columbia University, Mississippi State Univ, University of Pennsylvania, Carnegie Mellon University, University of Puerto Rico at Humacao, JLAB, MIT, University of Alabama at Birmingham, Florida State University, NHMFL, University College Dublin, Department of Physics, Florida State University; National High Magnetic Field Laboratory, CNR-Instituto Nanoscienze, Karlsruhe Institute of Technology (KIT), Institute of Nanotechnology, Department of Chemistry, Florida State University, University of Alabama at Birmingham, Department of Physics, Birmingham, AL 35294-1170,USA, Department of Chemistry, Virginia Polytechnic Institute and State University, Francis Marion University, University of Richmond, Valdosta State University, University of Pittsburgh, Fermi National Lab, university of minnesota, Univ of Virginia, Joint Quantum Institute, University of Maryland, Georgetown University, IonQ Inc.
Peter Schauss

University of Notre Dame, Los Alamos National Laboratory, North Carolina State University, University of Notre dame, Columbia University, Mississippi State Univ, University of Pennsylvania, Carnegie Mellon University, University of Puerto Rico at Humacao, JLAB, MIT, University of Alabama at Birmingham, Florida State University, NHMFL, University College Dublin, Department of Physics, Florida State University; National High Magnetic Field Laboratory, CNR-Instituto Nanoscienze, Karlsruhe Institute of Technology (KIT), Institute of Nanotechnology, Department of Chemistry, Florida State University, University of Alabama at Birmingham, Department of Physics, Birmingham, AL 35294-1170,USA, Department of Chemistry, Virginia Polytechnic Institute and State University, Francis Marion University, University of Richmond, Valdosta State University, University of Pittsburgh, Fermi National Lab, university of minnesota, Univ of Virginia, Joint Quantum Institute, University of Maryland, Georgetown University, IonQ Inc.