The role of terminal ligands in the slow relaxation of magnetisation and luminescence thermometry of dinuclear Nd-III complexes

Author(s)

Bispo-Jr, Airton G. ; Galico, Diogo A. ; Diaz-Rodriguez, Roberto M. ; Ovens, Jeffrey S. ; Sigoli, Fernando A. ; Murugesu, Muralee

• Document type: Journal article
• Source: INORGANIC CHEMISTRY FRONTIERS; v. 10, n. 13, p. 11-pg., 2023-06-06.

Abstract

Single-molecule magnets (SMMs) are promising candidates as components for the next generation of molecule-based electronics. As the state-of-the-art in this field is mainly focused on heavy lanthanide(III) (Ln(III)) ions, examples of light lanthanide-based systems, e.g., those based on Nd-III, have fallen far behind. Besides the slow relaxation of magnetisation, the luminescence of multifunctional Ln(III) complexes can be leveraged for in situ temperature monitoring via luminescence thermometry. To help understand how both magnetic and luminescence performance can be improved through structural modifications in Nd-III-based SMMs, two dinuclear Nd-III complexes, [Nd-2(III)(valdien)(2)(X)(2)] (X = acac(-){1-Nd-2} or NO3- {2-Nd-2}), are herein reported, and we discuss opto- and magneto-structural correlations depending on the terminal ligand. The Nd-III complexes display field-induced slow relaxation of magnetization, but for {2-Nd-2}, QTM has a lower contribution because the longer Nd-III-O-terminal distances induce a weaker equatorial crystal field component. The systems were further used to develop luminescent temperature probes featuring a maximum thermal sensitivity of 0.52% K-1 at 40 K for {2-Nd-2}, confirming its multifunctional slow relaxation of magnetisation and temperature readout features. (AU)

• FAPESP's process: 21/08111-2 - Development of rare earth based light converters: luminescent markers, optical sensors, and amplifiers
• Grantee: Hermi Felinto de Brito
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 12/11382-9 - Optical modulation of semiconductor nanostructures using surface acoustic waves
• Grantee: Odilon Divino Damasceno Couto Júnior
• Support Opportunities: Research Grants - Young Investigators Grants
• FAPESP's process: 21/06326-1 - Luminescence of lanthanide ions: an optical tool against counterfeiting
• Grantee: Fernando Aparecido Sigoli
• Support Opportunities: Regular Research Grants
• FAPESP's process: 19/23763-6 - Triplet state direct excitation on trivalent lanthanide complexes
• Grantee: Airton Germano Bispo Júnior
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 21/09755-0 - Multifunctional LnIII complexes featuring magneto-chiral dichroism and direct excitation of triplet state
• Grantee: Airton Germano Bispo Júnior
• Support Opportunities: Scholarships abroad - Research Internship - Post-doctor