Influence of the dipolar interactions on the relative stability in spin crossover systems.

Abstract

Molecules exhibiting a spin-crossover transition have been proposed for a number of applications such as molecular switches, spintronic tunable interfaces, and single molecule gates. Both the rational design of new spin-crossover systems and the improvement of the properties of the already existing ones require a theoretical understanding of the relative energy of the high (HS) and low spin state (LS) molecules in the solid-state. This has proved to be very challenging so far. Here, we shed some light on the importance of considering the symmetry and the geometry of the crystallographic cell to correctly evaluate the influence of the dipolar interactions on the relative energies of the molecular complex in both different spin states. Moreover, in the case of Fe(SCN)2 (phen)2 dipolar interactions are found to play an important role for the stabilization of the LS complex. © 2016 Wiley Periodicals, Inc.