A heterospin pressure sensor

Abstract

The spin transition temperature of the Cu(ii)-nitroxide complex was found to shift by approximately 100 K toward higher temperatures when the hydrostatic pressure increased to ∼0.04 GPa.

Hypersensitive pressure-dependence of the conversion temperature of hysteretic valence tautomeric manganese–nitronyl nitroxide radical 2D-frameworks

“…This behavior is occasionally observed for compounds immersed in oil as a pressure-transmitting medium. 20,21 It is ascribed to liquid oil medium/matrix effect toward the dispersed powder as may be also found for nanoparticle of SCO. 22 Here this illustrates the exceptionally high pressure sensitivity of compound 1.…”

Ligand Structure Effects on Molecular Assembly and Magnetic Properties of Copper(II) Complexes with 3-Pyridyl-Substituted Nitronyl Nitroxide Derivatives

“…This strongly affects the parameters of magnetic transitions and can result in the assembly of phases that cannot exhibit any magnetostructural anomalies. 5,[7][8][9][10][11][12][13]23,24 Cu(hfac) 2 complexes with various derivatives of 3-pyridyl-substituted nitronyl nitroxide (L) are of particular interest due to the diversity of molecular species and their magnetic properties (Scheme 1). 4,7,12,[16][17][18]25,26 Introduction of a Me group in the 4th position of the pyridine ring for L 4-Me nitronyl nitroxide has led to the formation of Cu(II) complexes with structure and magnetic properties completely different from those of the [{Cu(hfac) 2 } 4 L 2 ] compound based on the unsubstituted ligand.…”

“…Steric factors and intermolecular interactions between uncoordinated NO groups can favor both axial and equatorial coordination types, depending on the molecular structure and crystal packing of the resulting compounds. In some cases, the energy gap between equatorial and axial coordination is very weak, which allows the magnetic exchange interactions to be switched by changing the temperature, pressure, or light irradiation. − …”

“…However, only a few Cu­(II) complexes with nitroxides exhibit structural-magnetic anomalies under external stimuli. − Even a minor modification of a ligand leads to significant changes in the molecular and crystal structures of the resulting Cu­(II) complexes. This strongly affects the parameters of magnetic transitions and can result in the assembly of phases that cannot exhibit any magnetostructural anomalies. ,− ,, Cu­(hfac) 2 complexes with various derivatives of 3-pyridyl-substituted nitronyl nitroxide (L) are of particular interest due to the diversity of molecular species and their magnetic properties (Scheme ).…”

“…However, only a few Cu­(II) complexes with nitroxides exhibit structural-magnetic anomalies under external stimuli. − Even a minor modification of a ligand leads to significant changes in the molecular and crystal structures of the resulting Cu­(II) complexes. This strongly affects the parameters of magnetic transitions and can result in the assembly of phases that cannot exhibit any magnetostructural anomalies. ,− ,, Cu­(hfac) 2 complexes with various derivatives of 3-pyridyl-substituted nitronyl nitroxide (L) are of particular interest due to the diversity of molecular species and their magnetic properties (Scheme ). ,,,− ,, Introduction of a Me group in the 4th position of the pyridine ring for L 4‑Me nitronyl nitroxide has led to the formation of Cu­(II) complexes with structure and magnetic properties completely different from those of the [{Cu­(hfac) 2 } 4 L 2 ] compound based on the unsubstituted ligand. , Recently described copper­(II) and mixed-metal copper­(II)-lanthanide complexes with L 5‑Br and L 6‑OMe nitronyl nitroxides have demonstrated various topological structures and different magnetic behaviors in the absence of structural and magnetic transitions. − ,, However, the effect of substituents at different positions of the pyridine ring on the coordination ability of 3-pyridyl nitronyl nitroxide ligand, structure, and magnetic behaviors of the resulting Cu­(II) complexes has not been studied systematically.…”