Studies on the Magnetic Ground State of a Spin Möbius Strip

Graham N Newton; Norihisa Hoshino; Takuto Matsumoto; Takuya Shiga; Motohiro Nakano; Hiroyuki Nojiri; Wolfgang Wernsdorfer; Yuji Furukawa; Hiroki Oshio

doi:10.1002/chem.201602439

Studies on the Magnetic Ground State of a Spin Möbius Strip

Chemistry. 2016 Sep 26;22(40):14205-12. doi: 10.1002/chem.201602439. Epub 2016 Aug 22.

Authors

Graham N Newton^{1

2}, Norihisa Hoshino¹, Takuto Matsumoto¹, Takuya Shiga¹, Motohiro Nakano³, Hiroyuki Nojiri⁴, Wolfgang Wernsdorfer⁵, Yuji Furukawa⁶, Hiroki Oshio⁷

Affiliations

¹ Graduate School of Pure and Applied Sciences, University of Tsukuba, Tennodai 1-1-1, Tsukuba, 305-8571, Japan.
² School of Chemistry, University of Nottingham, Nottingham, NG7 2RD, UK.
³ Research Center for Structural Thermodynamics, Graduate School of Science, Osaka University, Machikaneyama 1-1, Toyonaka, Osaka, 560-0043, Japan.
⁴ Institute of Materials Research, Tohoku University, Katahira 2-1-1, Aoba-ku, Sendai, 980-8577, Japan.
⁵ CNRS, Institut NEEL, Univ. Grenoble Alpes, 38000, Grenoble, France.
⁶ Ames Laboratory and, Department of Physics and Astronomy, Iowa State University, Ames, IA, 50011, USA.
⁷ Graduate School of Pure and Applied Sciences, University of Tsukuba, Tennodai 1-1-1, Tsukuba, 305-8571, Japan. oshio@chem.tsukuba.ac.jp.

PMID: 27546317
DOI: 10.1002/chem.201602439

Abstract

Here we report the synthesis, structure and detailed characterisation of three n-membered oxovanadium rings, Nan [(V=O)n Nan (H2 O)n (α, β, or γ-CD)2 ]⋅m H2 O (n=6, 7, or 8), prepared by the reactions of (V=O)SO4 ⋅x H2 O with α, β, or γ-cyclodextrins (CDs) and NaOH in water. Their alternating heterometallic vanadium/sodium cyclic core structures were sandwiched between two CD moieties such that O-Na-O groups separated the neighbouring vanadyl ions. Antiferromagnetic interactions between the S=1/2 vanadyl ions led to S=0 ground states for the even-membered rings, but to two quasi-degenerate S=1/2 states for the spin-frustrated heptanuclear cluster.

Keywords: cluster compounds; cyclodextrins; macrocyclic ligands; magnetic properties; vanadium.