Search results for "single-molecule"
showing 7 items of 77 documents
Rare‐earth cyclobutadienyl sandwich complexes: Synthesis, structure and dynamic magnetic properties
2018
The potassium cyclobutadienyl [K2{η4‐C4(SiMe3)4}] (1) reacts with MCl3(THF)3.5 (M=Y, Dy) to give the first rare‐earth cyclobutadienyl complexes, that is, the complex anions [M{η4‐C4(SiMe3)4}{η4‐C4(SiMe3)3‐κ‐(CH2SiMe2}]2−, (2M), as their dipotassium salts. The tuck‐in alkyl ligand in 2M is thought to form through deprotonation of the “squarocene” complexes [M{η4‐C4(SiMe3)4}2]− by 1. Complex 2Dy is a single‐molecule magnet, but with prominent quantum tunneling. An anisotropy barrier of 323(22) cm−1 was determined for 2Dy in an applied field of 1 kOe, and magnetic hysteresis loops were observed up to 7 K. nonPeerReviewed
Asymmetric Ring Opening in Tetrazine‐based Ligand Affording a Tetranuclear Opto‐Magnetic Ytterbium Complex
2021
We report the formation of a tetranuclear lanthanide cluster, [Yb 4 (bpzch) 2 (fod) 10 ] ( 1 ), which occurs from a serendipitous ring opening of the functionalized tetrazine bridging ligand, bpztz (3,6‐dipyrazin‐2‐yl‐1,2,4,5‐tetrazine) upon reacting with Yb(fod) 3 (fod ‐ = 6,6,7,7,8,8,8‐heptafluoro‐2,2‐dimethyl‐3,5‐octandionate). Compound 1 was structurally elucidated via single‐crystal X‐ray crystallography and subsequently magnetically and spectroscopically characterized to analyse its magnetisation dynamics and its luminescence behaviour. Computational studies validate the observed M J energy levels attained by spectroscopy and provides a clearer picture of the slow relaxation of the ma…
Triplet-State Position and Crystal-Field Tuning in Opto‐Magnetic Lanthanide Complexes : Two Sides of the Same Coin
2019
Lanthanide complex‐based luminescence thermometry and single‐molecule magnetism are two effervescent research fields, owing to the great promise they hold from an application standpoint. The high thermal sensitivity achievable, their contactless nature, along with sub‐micrometric spatial resolution make these luminescent thermometers appealing for accurate temperature probing in miniaturized electronics. To that end, single‐molecule magnets (SMMs) are expected to revolutionize the field of spintronics, thanks to the improvements made in terms of their working temperature – now surpassing that of liquid nitrogen – and manipulation of their spin state. Hence, the combination of such opto‐magn…
Dynamic Magnetic and Optical Insight into a High Performance Pentagonal Bipyramidal Dy(III) Single-Ion Magnet
2017
The pentagonal bipyramidal single-ion magnets (SIMs) are among the most attractive prototypes of high-performance single-molecule magnets (SMMs). Here, a fluorescence-active phosphine oxide ligand CyPh2PO (=cyclohexyl(diphenyl)phosphine oxide) was introduced into [Dy(CyPh2PO)2(H2O)5]Br3⋅2 (CyPh2PO)⋅EtOH⋅3 H2O, and combined dynamic magnetic measurement, optical characterization, ab initio calculation, and magneto-optical correlation of this high-performance pseudo-D5h DyIII SIM with large Ueff (508(2) K) and high magnetic hysteresis temperature (19 K) were performed. This work provides a deeper insight into the rational design of promising molecular magnets. peerReviewed
Spin crossover cobalt(II) molecular nanomagnets as dynamic molecular systems
2022
Los complejos mononucleares de iones metálicos paramagnéticos de la primera serie de transición con ligandos "no-inocentes" hechos a medida han surgido recientemente como prototípicos de sistemas moleculares dinámicos (DMSs, del inglés “dynamic molecular systems”). El enorme impacto de los DMSs en varios dominios de la nanociencia y nanotecnología molecular se debe a su capacidad para ejecutar funciones específicas y selectivas bajo el control de un estímulo externo que modula adecuadamente sus propiedades estructurales y electrónicas (ópticas, redox y magnéticas). En esta Tesis Doctoral, a lo largo de siete capítulos describimos la química y las propiedades físicas de una clase única de na…
Theoretical and computational studies of magnetic anisotropy and exchange coupling in molecular systems
2018
The field of molecular magnetism studies the magnetic properties of molecular systems as opposed to conventional metal-based magnets. The high chemical modifiability of the constituting molecules makes such materials highly versatile, and the small size of the building blocks leads to the rise of various quantum mechanical phenomena, such as tunneling and entanglement. These phenomena can then be further utilized in the construction of nanoscale quantum devices. This dissertation describes computational and theoretical studies in the field of molecular magnetism using state-of-the-art quantum chemical methods based on ab initio multireference approaches and broken symmetry density functional t…
Conformational Dynamics of the Dengue Virus Protease Revealed by Fluorescence Correlation and Single-Molecule FRET Studies.
2021
The dengue virus protease (DENV-PR) represents an attractive target for counteracting DENV infections. It is generally assumed that DENV-PR can exist in an open and a closed conformation and that active site directed ligands stabilize the closed state. While crystal structures of both the open and the closed conformation were successfully resolved, information about the prevalence of these conformations in solution remains elusive. Herein, we address the question of whether there is an equilibrium between different conformations in solution which can be influenced by addition of a competitive inhibitor. To this end, DENV-PR was statistically labeled by two dye molecules constituting a FRET …