Halogenated Alkyltetrazoles for the Rational Design of FeII Spin-Crossover Materials: Fine-Tuning of the Ligand Size

Danny Müller; Christian Knoll; Marco Seifried; Jan M Welch; Gerald Giester; Michael Reissner; Peter Weinberger

doi:10.1002/chem.201704656

Halogenated Alkyltetrazoles for the Rational Design of Fe^II Spin-Crossover Materials: Fine-Tuning of the Ligand Size

Chemistry. 2018 Apr 6;24(20):5271-5280. doi: 10.1002/chem.201704656. Epub 2018 Jan 9.

Authors

Danny Müller¹, Christian Knoll¹, Marco Seifried¹, Jan M Welch², Gerald Giester³, Michael Reissner⁴, Peter Weinberger¹

Affiliations

¹ Institute of Applied Synthetic Chemistry, TU Wien, Getreidemarkt 9/163-AC, 1060, Vienna, Austria.
² Atominstitut, TU Wien, Stadionallee 2, 1020, Vienna, Austria.
³ Department of Mineralogy and Crystallography, University of Vienna, Althanstraße 14 (UZA 2), 1090, Vienna, Austria.
⁴ Institute of Solid State Physics, TU Wien, Wiedner Hauptstraße 8-10/050, 1040, Vienna, Austria.

PMID: 29205547
DOI: 10.1002/chem.201704656

Abstract

1-(3-Halopropyl)-1H-tetrazoles and their corresponding Fe^II spin-crossover complexes have been investigated in a combined experimental and theoretical study. Halogen substitution was found to positively influence the spin transition, shifting the transition temperature about 70 K towards room temperature. Halogens located at the ω position were found to be too far away from the coordinating tetrazole moiety to have an electronic impact on the spin transition. The subtle variation of the steric demand of the ligand in a highly comparable series was found to have a comparatively large impact on the spin-transition behavior, which highlights the sensitivity of the effect to subtle structural changes.

Keywords: N ligands; iron; ligand design; nitrogen heterocycles; spin crossover.