Design of luminescent and magnetic coordination compounds based on 3d and lanthanide(III) ions for application as qubits of quantum computers

• Grant number: 25/08634-6
• Support Opportunities: Research Grants - Initial Project
• Start date: March 01, 2026
• End date: February 28, 2031
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Inorganic Chemistry
• Principal Investigator: Airton Germano Bispo Júnior
• Grantee: Airton Germano Bispo Júnior
• Host Institution: Instituto de Química (IQ). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• City of the host institution: São Paulo
• Associated researchers: Andrea Simone Stucchi de Camargo Alvarez Bernardez ; Eva Hemmer ; Fernando Aparecido Sigoli ; Fiorenzo Vetrone ; Hermi Felinto de Brito ; Luís António Ferreira Martins Dias Carlos ; Marcelo Nalin ; Muralee Murugesu ; Sidney José Lima Ribeiro

Abstract

Inspired by the rapid evolution of the digital era, magnetic molecules have been considered over the past thirty years as potential candidates for the fabrication of ultracompact molecular information storage devices. Among such systems, lanthanide(III) (LnIII)-based single-molecule magnets (SMMs), in special DyIII, and 3d4-7 coordination compounds presenting spin-crossover (SCO) have been widely investigated. In addition to the goal of controlling magnetic features at the molecular level, various multifunctionalities have been pursued in these systems to facilitate their application. Luminescence thermometry have been considered among such multifunctionalities since it enables monitoring temperature at the molecular level. However, synergistically combining the magnetic and luminescence performance in coordination compounds is an open challenge. Moreover, understanding how the processing of coordination compounds affects the magnetic performance, and the thermal behavior are also challenges to be addressed to fabricate surfaces or molecular junctions. To tackle these exciting dilemmas, this proposal focuses on the synthesis of polymeric films containing high-performing multifunctional luminescent and magnetic coordination compounds, monitoring their temperature by luminescence thermometry. To achieve such goal, the first strategy is to synthesize SMMs based on DyIII by compartmentalizing the luminescent and magnetic properties in two different DyIII centers in the coordination compound with formula [Dy(LN6)(OL)2][Dy(acac)4] (OL = MeO-, EtO-,ou tBuO-; acac- = acetylacetonate). In these complexes, the cation presents a DyIII center inserted in a high-symmetry coordination environment, ideal for the magnetic performance, while DyIII in the anion counterpart is inserted in a local environment with low symmetry, ideal for luminescence thermometry. To synthesize coordination compounds presenting SCO and luminescence thermometry, the [Fe{Ln(bpm)(acac)3}3]Cl2 (bpm = 2,2'- bipyrimidine, Ln = Eu, Tb, Dy, or Yb) composition is targeted to combine the SCO of FeII and the luminescence dependency on the temperature of the LnIII. The coordination compounds will be dispersed in polymeric matrices to synthesize films containing magnetic molecules, which can be used as models to understand how the dispersion affects the magnetic performance and the thermal behaviour of the films. Such a methodology has never been reported for these types of materials and has the potential to help understand the thermal behavior of the films at the sub-micrometric level, facilitating the development of strategies to optimize the fabrication of devices containing magnetic coordination compounds for application in ultracompact molecular information storage devices. (AU)