Magnetism, single molecular

Ishikawa, N., Sugita, M., Ishikawa, T., Koshihara, S.Y. and Kaizu, Y. (2003) Lanthanide double-decker complexes functioning as magnets at the single-molecular level. J. Am. Chem. Soc., 125, 8694-8695. 

J., van Slageren, J., Coronado, E. and Luis, F. (2012) Gd-based single-ion magnets with tunable magnetic anisotropy molecular design of spin qubits. Phys. Rev. Lett., 108, 247213. 

Figure 9.33 The structure configurations of [Pc2Ln] TBA+, where Ln = Tb, Dy, Ho, Er, Tm, Yb and Arrhenius analysis for [Pc2Ln] TBA+, where Ln = Tb (top right), Dy (bottom) [108]. (Reprinted with permission from N. Ishrkawa, etal., "Mononuclear lanthanide complexes with a long magnetization relaxation time at high temperatures a new category of magnets at the single-molecular level, Journal of Physical Chemistry B, 108, 11265-11271, 2004. 2004 American Chemical Society.)...

Photon Antibunching and Magnetic Resonance of Single Molecular Spins... 

Another class of physical phenomena demonstrated for single molecules involves magnetic resonance of a single molecular spin. Historically, the... 

Fig. 2.7. (A) Measured distribution of time delays between successive detected fluorescence photons for a single molecule of pentacene in p-terphenyl showing antibunching at r = 0. For details, see [53]. (B) Magnetic resonance of a single molecular spin. Reductions in fluorescence as a function of microwave frequency for four different single molecules of pentacene in p-terphenyl. For details, see [59]...

Fig. 3.1.1 Anisotropic spin interactions, (a) Quadrupole coupling of nucleus to the electric field gradient of a C- H bond, (b) Dipole-dipole coupling between C and H. (c) Anisotropic magnetic shielding of C nuclei. Left Geometry of the interaction and principal axes of the coupling tensor. Middle NMR spectrum for a single molecular orientation. Right The average over all orientations is the powder spectrum. The parameters A>, denote the anisotropy of the interaction k. S is the chemical shift. Adapted from [Blii3] with permission from Wiley-VCH.

NMR of solids differs from solution-state NMR in several important ways. First, the solution-state tumbling of molecules is, of course, restricted in the solid phase. In the absence of rapid isotropic motion, magnetic dipolar interaction between neighboring spins affects the NMR line shape. Second, the chemical shift interaction is not just a simple scalar, but is a tensor quantity. In solution-state NMR, only the scalar average is seen while in solid-state NMR, the tensor elements are observed. In the solid state, the chemical shift tensor yields a variety of possible NMR line shapes. Likewise, the quadrupolar interaction also creates a variety of line shapes. Third, a single molecular motion can dominate the process of thermal equilibration of the NMR spin system with its environment... 

Two different experimental arrangements have been successfully utilized for magnetic resonance experiments on single molecular spins [18, 19]. As in the optical single-molecule experiments the essential ingredients are a narrow-band laser, an efficient collection of the emitted fluorescence and a small excitation volume of the sample. To achieve a small sample volume the incoming laser light is either focussed... 

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