A method to predict the relaxation time of quantum tunneling of magnetization and the magnetic reversal barrier with efficiency and reliability.

A systematic theoretical study is performed in a group of 16 square antiprism dysprosium single-ion magnets. Based on ab initio calculations, quantum tunneling of magnetization (QTM) time, i.e., tQTM, and...

Single-molecule magnet (SMM) is a fascinating system holding the potential of being revolutionary micro-electronic device in information technology. However current SMMs are still far away from real-life application due to...

Three new rhodamine-based probes Y1-Y3 were synthesized as "off-on" chemosensors for Fe(3+) imaging in living cells. The recognizing behaviors were investigated both experimentally and computationally. The crystal structure of the complex Y3-Fe(3+) revealed that Fe(3+) preferred to coordinate with the N atom of benzothiazole moiety rather than the O atom of carboxyl group.

A theoretical method, taking into account the anisotropy of the internal magnetic field (B⃑int), is proposed to predict the rate of quantum tunneling of magnetization (QTM), i.e., τQTM−1, for Kramers single-ion magnets (SIMs).

Two DyIII complexes, [Dy­(bbpen-F)­X] [X = Cl (1), Br (2); H2bbpen-F = N,N′-bis­(2-hydroxybenzyl)-N,N′-bis­(5-fluoro-2-methylpyridyl)­ethylenediamine], have been synthesized that show remarkable single-molecule-magnet behavior with effective barriers of magnetic reversal of 837.7 K for 1 and 1149.7 K for 2 under zero direct-current field and hysteresis loops up to 20 K for 1 and 30 K for 2, as confirmed by magnetic properties and ab initio calculations.

Taking advantage of the steric hindrance and charge-driving effects, four air-stable pentagonal bipyramidal mononuclear Dy compounds were hydrothermally synthesized. With a tetradentate ligand, N,N'-bis(2-methylenepyridinyl)ethylenediamine (Bpen), invariably coordinates to Dy in an equatorial plan, 1-3 achieve an orderly transformation of the ligand field by sequentially replacing the remaining sites of the Dy ion. Compound 4 possesses the same coordination atoms but a different peripheral coordination sphere with 3. Magnetic characterizations display that the compounds are field-induced single-ion magnets (SIM) with actually low barriers, even though 2 has both the same atoms and a similar geometry of the first sphere compared with [Dy(bbpen)Cl] (2', H bbpen=N,N'-bis(2-hydroxybenzyl)-N,N'-bis(2-methylpyridyl)ethylenediamin), a high-performance SIM previously reported. Detailed ab initio calculations have been employed to further elucidate the electronic and magnetic structure of the low-lying energy levels of compounds 1-4 and 2'. The theoretical results indicate there is an apparent difference in the electronic structure for these compounds. The analysis on the electrostatic potential further demonstrates that although the pentagonal bipyramidal D is one of the ideal configurations expected, the electron density of the donor atoms from the different hybridizations and other functional groups, outside the first sphere, should also be considered in the rational design of promising molecular magnets.

In this work, a large excess of electrostatic repulsion, arising from the axial ligands, over that from the equatorial ligands is taken as the design strategy for high performance pentagonal bipyramidal (PBP) DyIII single-ion magnets (SIMs).