skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Guest-, Light- and Thermally-Modulated Spin Crossover in [Fe II 2] Supramolecular Helicates

Abstract

Here, a new bis(pyrazolylpyridine) ligand (H 2L) has been prepared to form functional [Fe 2(H 2L) 3] 4+ metallohelicates. Changes to the synthesis yield six derivatives, X@[Fe 2(H 2L) 3]X(PF 6) 2∙xCH 3OH (1, x=5.7 and X=Cl; 2, x=4 and X=Br), X@[Fe 2(H 2L) 3]X(PF 6) 2∙yCH 3OH∙H 2O (1 a, y=3 and X=Cl; 2 a, y=1 and X=Br) and X@[Fe 2(H 2L) 3](I 3) 2∙3 Et 2O (1 b, X=Cl; 2 b, X=Br). Their structure and functional properties are described in detail by single-crystal X-ray diffraction experiments at several temperatures. Helicates 1 a and 2 a are obtained from 1 and 2, respectively, by a single-crystal-to-single-crystal mechanism. The three possible magnetic states, [LS–LS], [LS–HS], and [HS–HS] can be accessed over large temperature ranges as a result of the structural nonequivalence of the Fe II centers. The nature of the guest (Cl - vs. Br -) shifts the spin crossover (SCO) temperature by roughly 40 K. Also, metastable [LS–HS] or [HS–HS] states are generated through irradiation. All helicates (X@[Fe 2(H 2L) 3]) 3+persist in solution.

Authors:
 [1];  [1];  [2];  [3];  [1]
  1. Univ. of Barcelona (Spain). Dept of Inorganic Chemistry
  2. Univ. of Zaragoza (Spain). Inst. of Materials Science of Aragon (ICMA) and Spanish National Research Council (CSIC)
  3. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Advanced Light Source (ALS)
Publication Date:
Research Org.:
Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22); Government of Catalonia; European Research Council (ERC); Ministry of Science, Innovation and Universities (MICINN) (Spain); European Union (EU). AVEMPACE II Erasmus Mundus Action 2
OSTI Identifier:
1459362
Grant/Contract Number:  
AC02-05CH11231; 258060; CTQ2012‐32247; MAT2014‐53961‐R
Resource Type:
Journal Article: Accepted Manuscript
Journal Name:
Chemistry - A European Journal
Additional Journal Information:
Journal Volume: 22; Journal Issue: 25; Related Information: © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim; Journal ID: ISSN 0947-6539
Publisher:
ChemPubSoc Europe
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; coordination chemistry; crystallography; iron (II) helicates; spin crossover; supramolecular chemistry

Citation Formats

Darawsheh, Mohanad, Barrios, Leoni A., Roubeau, Olivier, Teat, Simon J., and Aromi, Guillem. Guest-, Light- and Thermally-Modulated Spin Crossover in [FeII2] Supramolecular Helicates. United States: N. p., 2016. Web. doi:10.1002/chem.201601080.
Darawsheh, Mohanad, Barrios, Leoni A., Roubeau, Olivier, Teat, Simon J., & Aromi, Guillem. Guest-, Light- and Thermally-Modulated Spin Crossover in [FeII2] Supramolecular Helicates. United States. doi:10.1002/chem.201601080.
Darawsheh, Mohanad, Barrios, Leoni A., Roubeau, Olivier, Teat, Simon J., and Aromi, Guillem. Tue . "Guest-, Light- and Thermally-Modulated Spin Crossover in [FeII2] Supramolecular Helicates". United States. doi:10.1002/chem.201601080. https://www.osti.gov/servlets/purl/1459362.
@article{osti_1459362,
title = {Guest-, Light- and Thermally-Modulated Spin Crossover in [FeII2] Supramolecular Helicates},
author = {Darawsheh, Mohanad and Barrios, Leoni A. and Roubeau, Olivier and Teat, Simon J. and Aromi, Guillem},
abstractNote = {Here, a new bis(pyrazolylpyridine) ligand (H2L) has been prepared to form functional [Fe2(H2L)3]4+ metallohelicates. Changes to the synthesis yield six derivatives, X@[Fe2(H2L)3]X(PF6)2∙xCH3OH (1, x=5.7 and X=Cl; 2, x=4 and X=Br), X@[Fe2(H2L)3]X(PF6)2∙yCH3OH∙H2O (1 a, y=3 and X=Cl; 2 a, y=1 and X=Br) and X@[Fe2(H2L)3](I3)2∙3 Et2O (1 b, X=Cl; 2 b, X=Br). Their structure and functional properties are described in detail by single-crystal X-ray diffraction experiments at several temperatures. Helicates 1 a and 2 a are obtained from 1 and 2, respectively, by a single-crystal-to-single-crystal mechanism. The three possible magnetic states, [LS–LS], [LS–HS], and [HS–HS] can be accessed over large temperature ranges as a result of the structural nonequivalence of the FeII centers. The nature of the guest (Cl- vs. Br-) shifts the spin crossover (SCO) temperature by roughly 40 K. Also, metastable [LS–HS] or [HS–HS] states are generated through irradiation. All helicates (X@[Fe2(H2L)3])3+persist in solution.},
doi = {10.1002/chem.201601080},
journal = {Chemistry - A European Journal},
number = 25,
volume = 22,
place = {United States},
year = {Tue May 10 00:00:00 EDT 2016},
month = {Tue May 10 00:00:00 EDT 2016}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record

Citation Metrics:
Cited by: 14 works
Citation information provided by
Web of Science

Save / Share:

Works referenced in this record:

Revised effective ionic radii and systematic studies of interatomic distances in halides and chalcogenides
journal, September 1976


SHELXT – Integrated space-group and crystal-structure determination
journal, January 2015

  • Sheldrick, George M.
  • Acta Crystallographica Section A Foundations and Advances, Vol. 71, Issue 1, p. 3-8
  • DOI: 10.1107/S2053273314026370

Crystal structure refinement with SHELXL
journal, January 2015

  • Sheldrick, George M.
  • Acta Crystallographica Section C Structural Chemistry, Vol. 71, Issue 1, p. 3-8
  • DOI: 10.1107/S2053229614024218

SWISS-MODEL and the Swiss-Pdb Viewer: An environment for comparative protein modeling
journal, January 1997