Rationalization of the mechanism of bistability in dithiazolyl-based molecular magnets
|PhD ceremony:||Mr T. (Tommaso) Francese|
|When:||March 25, 2019|
|Supervisors:||prof. dr. H.B. (Ria) Braam, J.J. Novoa|
|Co-supervisors:||dr. R.W.A. (Remco) Havenith, J. Ribas|
|Where:||Academy building RUG|
|Faculty:||Science and Engineering|
Theoretical predictions of magnetic properties of bistable purely organic molecule-based magnets have experienced an incredible development during the last years. Nevertheless, some of these compounds present peculiarities that cannot yet be explained with the state-of-the-art theoretical models. Our attention is devoted to dithiazolyl-based compounds, namely TTTA, PDTA, TDPDTA, and 4NCBDTA, because they are among the best candidates for potential technological applications, like storage devices, sensors, and quantum computers. The four selected DTA compounds present a common trend in the solid state: the planar DTA radicals pile up forming stacks.
Our first goal is to evaluate by means of the so-called First Principles Bottom Up working strategy which pairs of radicals are magnetically non-negligible in order to identify the magnetic topology of the molecule-based crystals. Next, our objective is to assess whether structural (geometrical), as well as the electronic (DTA-ring, substituent interactions) factors, affect the magnitude of the overall radical···radical JAB magnetic coupling. Finally, we aim at providing a magneto-structural map as a function of the substituents of the DTA-moiety to highlight which is the static ferromagnetic fingerprint region.
At this point, we would like to stress that this magneto-structural map could be used as a practical tool to help experimentalists to design more stable and efficient purely organic radicals with ferromagnetic properties in the solid state. The static analysis is also complemented by the study of the corresponding dynamical properties.