Synthesis, structural characterization and magnetic behaviour of a family of [CoIII2LnIII2] butterfly compounds

We have successfully prepared and structurally characterized a family of butterfly-like [Co2 IIILn2 III] complexes where all magnetic properties are due to the Ln(iii) ions. The complexes with Ln = Tb(1), Dy(2), Ho(3), Er(4) and Yb(5) are iso-structural. An exception is the complex with Ln = Gd(6) which strings in a one dimensional chain. The structural similarity together with the high tendency of the crystallites to align under an applied magnetic field allowed an overall DC magnetic data treatment to extract phenomenological crystal field parameters and hence to determine the ground state multiplet energy level splitting. The Dy(iii) member is the only one showing slow relaxation of magn…

Bimetallic MnIII–FeII hybrid complexes formed by a functionalized MnIII Anderson polyoxometalate coordinated to FeII: observation of a field-induced slow relaxation of magnetization in the MnIII centres and a photoinduced spin-crossover in the FeII centres

The synthesis and crystal structure of an Anderson POM functionalized with two 2,6-di(pyrazol-1-yl)-pyridine (1-bpp) ligands are reported (compound 1). High-frequency electron paramagnetic resonance (HF-EPR) and magnetic measurements show that it presents a significant negative axial zero-field splitting and field-induced slow relaxation of magnetization due to the presence of isolated MnIII anisotropic magnetic ions. Complexation of 1 with FeII gives rise to a 2D cationic network formed by Anderson POMs coordinated to two FeII ions through the two tridentate 1-bpp ligands and to other two FeII ions through two oxo ligands in compound 2, and to an anionic polymeric network formed by Anderso…

Spin Crossover and Long-Lived Excited States in a Reduced Molecular Ruby.

Abstract The chromium(III) complex [CrIII(ddpd)2]3+ (molecular ruby; ddpd=N,N′‐dimethyl‐N,N′‐dipyridine‐2‐yl‐pyridine‐2,6‐diamine) is reduced to the genuine chromium(II) complex [CrII(ddpd)2]2+ with d4 electron configuration. This reduced molecular ruby represents one of the very few chromium(II) complexes showing spin crossover (SCO). The reversible SCO is gradual with T 1/2 around room temperature. The low‐spin and high‐spin chromium(II) isomers exhibit distinct spectroscopic and structural properties (UV/Vis/NIR, IR, EPR spectroscopies, single‐crystal XRD). Excitation of [CrII(ddpd)2]2+ with UV light at 20 and 290 K generates electronically excited states with microsecond lifetimes. This…

Chromium(iii)-based potential molecular quantum bits with long coherence times

Molecular quantum bits based on copper(ii) or vanadium(iv) have been shown to possess long coherence times on multiple occasions. In contrast, studies in which non-spin-½ ions are employed are relatively scarce. High-spin ions provide additional states that can be used to encode further quantum bits. Furthermore, an optical rather than a microwave readout of molecular quantum bits is highly desirable, because in principle it could allow addressing at the single quantum bit level. The chromium(iii) complex [Cr(ddpd)2]3+ (ddpd = N,N'-dimethyl-N,N'-dipyridine-2-yl-pyridine-2,6-diamine) combines both the large spin (S = 3/2) and optical activity (strong, long lived luminescence). Here we demons…

Encapsulation of single-molecule magnets in carbon nanotubes

Next-generation electronic, photonic or spintronic devices will be based on nanoscale functional units, such as quantum dots, isolated spin centres or single-molecule magnets. The key challenge is the coupling of the nanoscale units to the macroscopic world, which is essential for read and write purposes. Carbon nanotubes with one macroscopic and two nanoscopic dimensions provide an excellent means to achieve this coupling. Although the dimensions of nanotube internal cavities are suitable for hosting a wide range of different molecules, to our knowledge, no examples of molecular magnets inserted in nanotubes have been reported to date. Here we report the successful encapsulation of single-…

Single Molecule Magnet Features in the Butterfly [Co III 2 Ln III 2 ] Pivalate Family with Alcohol‐Amine Ligands

CCDC 1489635: Experimental Crystal Structure Determination

Related Article: Alejandro V. Funes, Luca Carrella, Yvonne Rechkemmer, Joris van Slageren, Eva Rentschler, Pablo Alborés|2017|Dalton Trans.|46|3400|doi:10.1039/C6DT04713K

CCDC 1489636: Experimental Crystal Structure Determination

Related Article: Alejandro V. Funes, Luca Carrella, Yvonne Rechkemmer, Joris van Slageren, Eva Rentschler, Pablo Alborés|2017|Dalton Trans.|46|3400|doi:10.1039/C6DT04713K

CCDC 1058520: Experimental Crystal Structure Determination

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CCDC 1958093: Experimental Crystal Structure Determination

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CCDC 1058519: Experimental Crystal Structure Determination

Related Article: Alexandre Abhervé, Mario Palacios-Corella, Juan Modesto Clemente-Juan, Raphael Marx, Petr Neugebauer, Joris van Slageren, Miguel Clemente-León, Eugenio Coronado|2015|J.Mater.Chem.C|3|7936|doi:10.1039/C5TC01089F

CCDC 1489634: Experimental Crystal Structure Determination

Related Article: Alejandro V. Funes, Luca Carrella, Yvonne Rechkemmer, Joris van Slageren, Eva Rentschler, Pablo Alborés|2017|Dalton Trans.|46|3400|doi:10.1039/C6DT04713K

CCDC 1489637: Experimental Crystal Structure Determination

Related Article: Alejandro V. Funes, Luca Carrella, Yvonne Rechkemmer, Joris van Slageren, Eva Rentschler, Pablo Alborés|2017|Dalton Trans.|46|3400|doi:10.1039/C6DT04713K

CCDC 1489638: Experimental Crystal Structure Determination

Related Article: Alejandro V. Funes, Luca Carrella, Yvonne Rechkemmer, Joris van Slageren, Eva Rentschler, Pablo Alborés|2017|Dalton Trans.|46|3400|doi:10.1039/C6DT04713K