Actinide Single‐Molecule Magnets

Facile N-functionalization and strong magnetic communication in a diuranium(v) bis-nitride complex

“…The greater radial extension of 5f orbitals compared to 4f orbitals may provide enough orbital overlap with ligand orbitals to implement magnetic communication between two metal centers through multiply bound bridging atoms 10b,14. However, clear cut examples of magnetic communications in uranium chemistry remain limited and magnetic exchange is usually quite weak in chalcogenide or nitride bridged diuranium complexes 9b,15.…”

Future Directions for Transuranic Single Molecule Magnets

“…SMM behaviour has actually been observed in several monometallic U III [13] and U V [14] complexes and in heterometallic coordination compounds containing U V and either Mn II or Dy III cations [15][16][17]. The results obtained on these systems have been the subject of recent reviews [12,[18][19][20]. Here, we will critically summarize the attempts to obtain SMMs based on transuranic elements, mainly Np and Pu, focusing on the reasons for the limited success obtained so far and trying to indicate a possible direction for future research.…”

“…The results obtained on these systems have been the subject of recent reviews [12,[18][19][20]. Here, we will critically summarize the attempts to obtain SMMs based on transuranic elements, mainly Np and Pu, focusing on the reasons for the limited success obtained so far and trying to indicate a possible direction for future research.…”

“…In truth, calculations have shown that the leading exchange interaction within the complex is the one between the Np VI and each of the Np V centers and is antiferromagnetic; however, the magnetic moment carried by the former ion is smaller than those on the latter, which turn out to be parallel as if there were an effective ferromagnetic interaction between them. The magnetization dynamics of the system have been studied by ac susceptibility measurements, and fitting the experimentally deduced T-dependence of the relaxation time τ shown in Figure 2b leads to an energy barrier U eff = 140 K, surprisingly high given that the expected exchange gap for the system is around 25 K. The reason for this discrepancy might be that the steepness of the curve makes the accessible temperature range relatively narrow, so that the actual relaxation process is more complicated than a simple Orbach model [20]. This would also explain why the prefactor τ 0 seems significantly smaller compared to other systems.…”

Electronic g Tensors in UV Complexes–A Computational Study

“…The inherent difficulties associated with experimental work involving the actinides has recently led to an increased interest in the use of computational studies to complement and enhance our fundamental understanding of f-element chemistry. [1] The range of applications is considerable and varies: from studies of geometrically simple systems where the intention is to understand the fundamental electronic structure and bonding in actinide molecules; [2] to the use of fluorescence spectroscopy to correlate between the molecular structure (ligand species and type) with the observed spectral lineshape; [3] to studying the potential for designing actinide molecular magnets; [4] to predicting and controlling the behaviour of actinide elements in solution. [5] Understanding the origin of actinide metal to ligand selectivity is key in developing nuclear waste reprocessing techniques that separate the lanthanides from the actinides and also in facilitating the design of new extractants.…”