Pressure-driven high-to-low spin transition in the bimetallic quantum magnet[Ru2(O2CMe)4]3

Abstract

Synchrotron-based infrared and Raman spectroscopies were brought together with diamond anvil cell techniques and an analysis of the magnetic properties to investigate the pressure-induced high → low spin transition in [Ru2(O2CMe)4]3[Cr(CN)6]. The extended nature of the diruthenium wavefunction combined with coupling to chromium-related local lattice distortions changes the relative energies of the π * and δ * orbitals and drives the high → low spin transition on the mixed-valence diruthenium complex. This is a rare example of an externally controlled metamagnetic transition in which both spin-orbit and spin-lattice interactions contribute to the mechanism.

Realization of the orbital-selective Mott state at the molecular level in Ba$_3$LaRu$_2$O$_9$

“…(IV) Structural and spin state transitions under pressure One way to gain additional insight into mechanisms leading to the S tot = 3/2 molecular ground state in Ba 3 LaRu 2 O 9 is to apply external stimuli [51,52]. Since orbital hybridization should increase with decreasing intradimer Ru-Ru distance, our hypothesis is that a small amount of pressure may induce a spin state transition from S tot = 3/2 to S tot = 1/2 [52]. Such a transition is expected to take place with a reduction in the Ru ordered moment from 3 µ B to 1 µ B per cluster.…”

Spatially resolved multimodal vibrational spectroscopy under high pressures

“…Pressure is a unique tuning parameter in that it directly changes bond lengths and angles, which in turn can alter the intrinsic properties of a material leading to structural transitions, 17,51 changes in polarization, 52 spin crossovers, 53 and even metallization. 51,54,55 The coupling of pressure measurements with the O-PTIR + Raman system is an interesting and unexplored avenue, allowing for spatially resolved simultaneous IR and Raman studies.…”

New insights into progressive ligand replacement from [Ru2Cl(O2CCH3)4]: synthetic strategies and variation in redox potentials and paramagnetic shifts

“…Since then, many diruthenium complexes with a large variety of donor bridging ligands, such as other O , O ′-donors (carboxylates), 3 O , N -donors (amidates 4 or hydroxypyridinates 5 ) or N , N ′-donors (such as amidinates 6 or anilinopyridinates 7 ), have been investigated. In this regard, it is worth mentioning the high stability of these formally mixed-valence species (actually, they are average valence species) and the variety of structural arrangements, 8 which provides these compounds with exceptional magnetic, 9–12 electronic, 13,14 and electrochemical 15–17 behaviours. These properties, as well as the ability of the diruthenium core to coordinate different chemical species through their axial, 13,18,19 equatorial 6,20–23 or peripheral positions, 24,25 make these compounds suitable for many potential applications, such as catalysis, 26–29 biological chemistry (anticancer activity and 30,31 interaction with proteins 27,32 ), or electronics (as electronic wires 33 ).…”