Influence of Substrate Electronic Properties on the Integrity and Functionality of an Adsorbed Fe(II) Spin-Crossover Compound [component]

The bistability of spin-crossover complexes on surfaces is of great interest for potential applications. Using x-ray absorption spectroscopy, we investigated the properties of [Fe(pypyr(CF 3 ) 2 ) 2 (phen)] (pypyr = 2-(2'-pyridyl)pyrrolide, phen = 1,10-phenanthroline), a vacuum-evaporable Fe(II) complex, in direct contact to a set of substrates. The electronic properties of these substrates range from metallic to semiconducting. While dissociation is observed on metal surfaces, efficient
more » ... nduced switching is realized on semimetallic and semiconducting surfaces. This indicates that the density of states of the substrate at the Fermi level plays a role for the integrity and functionality of the adsorbed compound. In an intermediate case, namely [Fe(pypyr(CF 3 ) 2 ) 2 (phen)] on graphene/Ni(111), functional and dissociated species are found to coexist. This result indicates that some previous studies may deserve to be reconsidered because the possibility of coexisting intact and fragmented spin-crossover complexes was neglected.
doi:10.1021/acs.jpcc.9b02845.s001 fatcat:r2wl26obhnh2fhlyjhh3wvdmsm