Investigation of a Tetrathiafulvalene-Based Fe2+ Thermal Spin Crossover Assembled on Gold Surface

Niccolò Giaconi,Fabrice Pointillart,Andrea Caneschi,Andrea Luigi Sorrentino,Matteo Mannini,Haiet Douib,Danilo Longo,Edwige Otero,Giuseppe Cucinotta,Lorenzo Poggini,Roberta Sessoli,Giulia Serrano

doi:10.3390/magnetochemistry8020014

Abstract

A thick film and a monolayer of tetrathiafulvalene-based Fe2+ spin-crossover complex have been deposited by solution on a Au (111) substrate, attempting both self-assembling monolayer protocol and a simpler drop-casting procedure. The thermally induced spin transition has been investigated using X-ray photoelectron spectroscopy (XPS) and X-ray absorption spectroscopy (XAS). Temperature-dependent investigations demonstrated the retention of the switching behavior between the two spin states in thick molecular films obtained by drop-casting, while in the monolayer sample, the loss of the spin-crossover properties appears as a possible consequence of the strong interaction between the sulfur atoms of the ligand and the gold substrate.

Highlights

Spin-crossover (SCO) compounds [1] are complexes of metal ions capable of switching between two spin states after the application of several kinds of external stimuli, such as temperature, pressure, magnetic or electric field, and light irradiation [2,3,4,5,6]
The reversible switching between the two spin states is accompanied by relevant changes in the chemical, physical, optical, and magnetic properties of molecules, and it makes these complexes very attractive for a wide range of applications [7,8]
=monolayer dihydrobis(1-pyrazolyl)-borate) where L= TTF-fused dipyrido-[3,2In this work, we studied the mononuclear

Summary

Introduction

Spin-crossover (SCO) compounds [1] are complexes of metal ions capable of switching between two spin states after the application of several kinds of external stimuli, such as temperature, pressure, magnetic or electric field, and light irradiation [2,3,4,5,6]. The reversible switching between the two spin states is accompanied by relevant changes in the chemical, physical, optical, and magnetic properties of molecules, and it makes these complexes very attractive for a wide range of applications [7,8]. Being that SCO complexes very interesting as building blocks for the development of molecular-based spintronics devices [10,11], the nanostructuration of these molecules on the surface represents a fundamental step. It has been observed that strong modifications or losses in the spin switching properties can occur once

Methods

Discussion

Conclusion