Optical and magnetic properties of organoactinide complexes an application of relativistic density functional theory
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Fecha
2012
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Profesor/a Guía
Facultad/escuela
Idioma
es
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Universidad Andrés Bello
Nombre de Curso
Licencia CC
Licencia CC
Resumen
The discovery of slow magnetic relaxation in certain transition metal-oxo clusters revealed a
new family of magnetic materia Is known as single-molecule magnets. Such molecules possess
a high-spin ground state (with total spin S) for which spin-orbit coupling results in a zero-field
splitting of the (2S + 1 )-fold degeneracy in a manner that creates a thermal relaxation barrier
and gives rise to magnetic bistability at low temperature. Two major goals of research in this
area are generating new molecules with larger relaxation barriers and understanding the
quantum tunneling processes that can sho1tcut the ban-ier. The greater radial extension of the
5/ valence orbitals of actinides can potentially provide increased overlap with bridging ligand
orbitals, thereby enhancing the concerted magnetic behavior between bridged metal centers
within a single cluster unit. Researchers have confronted the intricacies of the magnetic
exchange in a number of interesting ways, often with the goal of identifying and, to the extent
possible, quantifying ferro- or antife1TOmagnetic exchange coupling. Understanding these
exchange interactions not only is essential to the development of models for the basic
electronic stmcture of the Velements but also may represent the key to producing the first
actinide-based SMMs. In this work we present the theoretical investigation about the
magnetic and optical properties for a group of organoactinide complexes. Our calculations
reveal that the electron mobility (delocalization) and relativistic effect pa1ticularly spin-orbit
coupling have a principal role for a good description of these properties in this kind of
molecule. Also we propose sorne molecular models with desirable structural parameters when
the optical and magnetic properties detennined should open the door to the design of new
materials with potential technological applications.
Notas
Tesis (Doctor en Físicoquímica Molecular)
Palabras clave
Propiedades Ópticas, Propiedades Magnéticas, Actinidos