Spin Crossover in a Vacuum-Deposited Submonolayer of a Molecular Iron(II) Complex

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• 作者：Matthias Bernien ; Dennis Wiedemann ; Christian F. Hermanns ; Alex Kr眉ger ; Daniela Rolf ; Wolfgang Kroener ; Paul M眉ller ; Andreas Grohmann ; Wolfgang Kuch
• 刊名：The Journal of Physical Chemistry Letters
• 出版年：2012
• 出版时间：December 6, 2012
• 年：2012
• 卷：3
• 期：23
• 页码：3431-3434
• 全文大小：243K
• 年卷期：v.3,no.23(December 6, 2012)
• ISSN：1948-7185

文摘

Spin-state switching of transition-metal complexes (spin crossover) is sensitive to a variety of tiny perturbations. It is often found to be suppressed for molecules directly adsorbed on solid surfaces. We present X-ray absorption spectroscopy measurements of a submonolayer of [Fe^II(NCS)₂L] (L: 1-{6-[1,1-di(pyridin-2-yl)ethyl]-pyridin-2-yl}-N,N-dimethylmethanamine) deposited on a highly oriented pyrolytic graphite substrate in ultrahigh vacuum. These molecules undergo a thermally induced, fully reversible, gradual spin crossover with a transition temperature of T_1/2 = 235(6) K and a transition width of 螖T₈₀ = 115(8) K. Our results show that by using a carbon-based substrate the spin-crossover behavior can be preserved even for molecules that are in direct contact with a solid surface.

Keywords:

spin crossover; iron(II); N4 ligands; magnetic molecules; surfaces; monolayer; X-ray absorption spectroscopy