Near-Infrared Magnetic Circularly Polarized Luminescence and Slow Magnetic Relaxation in a Tetrazinyl-Bridged Erbium Metallocene.

The magnetic and magneto-optical properties of a tetrazinyl radical-bridged Er metallocene, [(Cp*Er)(bpytz)][BPh] (; Cp* = pentamethylcyclopentadienyl, bpytz = 3,6-bis(3,5-dimethyl-pyrazolyl)-1,2,4,5-tetrazine), are reported. As confirmed by these studies strong Ln-rad coupling is achieved, with exhibiting slow magnetic relaxation under a 1000 Oe dc field. The optical and magneto-optical profile of is completed by both near-infrared (NIR) luminescence and magnetic circularly polarized luminescence (MCPL), representing the first example of NIR MCPL with Er.

Ligand Effects on the Emission Characteristics of Molecular Eu(II) Luminescence Thermometers.

Discrete molecular organometallic europium(II) complexes are promising functional materials due to their ability to behave as highly sensitive band-shift luminescence thermometers. Furthering our understanding of the design principles salient to the emission behavior of such systems is important for developing them in this emerging application. To this end, a series of pseudo--symmetric organometallic europium(II) complexes bearing systematically varying ligand sets were synthesized and characterized to probe the influence of subtle structural modification on their optical properties.

Confining single Er ions in sub-3 nm NaYF nanoparticles to induce slow relaxation of the magnetisation.

Molecular systems known as single-molecule magnets (SMMs) exhibit magnet-like behaviour of slow relaxation of the magnetisation and magnetic hysteresis and have potential application in high-density memory storage or quantum computing. Often, their intrinsic magnetic properties are plagued by low-energy molecular vibrations that lead to phonon-induced relaxation processes, however, there is no straightforward synthetic approach for molecular systems that would lead to a small amount of low-energy vibrations and low phonon density of states at the spin-resonance energies. In this work, we apply knowledge accumulated over the last decade in molecular magnetism to nanoparticles, incorporating Er ions in an ultrasmall sub-3 nm diamagnetic NaYF nanoparticle (NP) and probing the slow relaxation dynamics intrinsic to the Er ion.

Slow magnetic relaxation in a europium(II) complex.

Single-ion anisotropy is vital for the observation of Single-Molecule Magnet (SMM) properties (i.e., a slow dynamics of the magnetization) in lanthanide-based systems.

Dual-signalled magneto-optical barcodes with lanthanide-based molecular cluster-aggregates.

A proof-of-concept for magneto-optical barcodes is demonstrated for the first time. The dual-signalled spectrum observed magnetic circular dichroism spectroscopy can be used to develop anti-counterfeiting materials with extra layers of security when compared with the widely studied luminescent barcodes.