Molecule-based magnetism

MULTIPLE SCATTERING THEORY APPLIED TO XMCD SPECTRA IN MOLECULE-BASED MAGNETS. 

Concerning molecule-based magnets, the first spin-ladder was synthesized (/ -EPYNN)[Ni (dmit)2] (/ -EPYNN = / -7V-ethylpyridinium o-nitronyl nitroxide). Within the crystal lattice, the radical cation /7-EPYNN units are arranged in ID chains with ferromagnetic interactions. The chains of [Ni(dmit)2] moieties in the ladder formation exhibit coexistent antiferromagnetic interactions.1031,1032... 

Raebiger J, Miller W (2002) Magnetic ordering in the rare earth molecule-based magnets, Ln (TCNE)3 (Ln = Gd, Dy TCNE = tetracyanoethylene). J S Inorg Chem 41(12) 3308-3312... 

Following the idea of McConnell [44] who proposed in 1967 that a stacking arrangement such as.., D+ A D+ A D+ A-... of donor and acceptor could lead to molecule-based magnets, the combination between metal bis-dithiolene complexes and metalloceniums was performed originally only to promote cooperative ferromagnetic interactions [45]. 

Kahn 0, Codjovi E, Garcia Y, van Koningsbruggen PJ, Lapouyade R, Sommier L (1996) Molecule-Based Magnetic Materials. In Turnbull MM, Sugimoto T, Thompson LK (eds) Symposium Series No. 644, American Chemical Society, Washington, DC, p 298... 

In Turnbull MM, Sugimoto T, Thompson LK (eds) Molecule Based Magnetic Materials. ACS Symposium Series 644, p 298... 

Zerara M, Hauser A (2002) Abstracts of VUIth International Conference on Molecule-based Magnets C31, Valencia, Spain... 

The molecule-based magnet V(TCNE)(CH2Cl2)3 sealed in ampoules with an inert gas, can deflect the magnetic field of another magnet. Regrettably, widespread application of this vanadium-TCNE compound will have to wait. It reacts with water readily and explosively with oxygen. Therefore, it is impossible to exploit it in ambient conditions of air and atmospheric moisture. 

C. J. O Connor, in Molecule-Based Magnetic Materials, M. M. Turnbull, T. Sugimoto, and L. K. Thompson, Eds., American Chemical Society, Washington, DC, 1996, 644 44ff. 

Soft and Hard Molecule-Based Magnets with a Fully Interlocked Three-Dimensional Structure... 

In this contribution, we would like to show how such an approach allowed us to synthesize both soft and very hard molecule-based magnets. This contribution is organized as follows first, we define briefly the field of molecular magnetism, then we indicate the successive steps which led us to three-dimensional molecule-based magnets with fully interlocked structures. We describe these original structures in detail. Finally, we focus on the physical properties of these objects, with special emphasis on the huge coercivity of one of the compounds, which confers a memory effect on this compound. 

The design of molecule-based magnets requires the assembly of magnetic bricks in a controlled fashion. The bricks we play with are characterized by three factors, namely shape, chemical functionality, and spin distribution. The first two factors are common to all bricks (or building blocks) used in molecular chemistry. The third is specific to molecular magnetism. Spin distribution is a new dimension. Let us consider the brick [Cu(opba)]2- (where opba stands for ortho-pheny-lenebis(oxamato)) this is shown below as a typical example [6, 7]. 

Structure of Molecule-Based Magnets Containing Three Spin Carriers, with a Fully Interlocked Structure... 

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