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

Title: Cerium Tetrakis(tropolonate) and Cerium Tetrakis(acetylacetonate) Are Not Diamagnetic but Temperature-Independent Paramagnets

Abstract

Here, a new synthesis of cerium tetrakis(tropolonate), Ce(trop) 4, where trop is deprotonated 2-hydroxy-2,4,6-cycloheptatrienone) or Ce(O 2C 7H 5) 4, is developed that results in dark-purple crystals whose X-ray crystal structure shows that the geometry of the eight-coordinate compound closely resembles a D2d dodecahedron, based on shape parameters. The magnetic susceptibility as a function of the temperature (4-300 K) shows that it is a temperature-independent paramagnet, χ = 1.2(3) × 10 -4 emu/mol, and the L III-edge X-ray absorption near-edge structure spectrum shows that the molecule is multiconfigurational, comprised of a f 1:f 0 configuration mixture in a 50:50 ratio. Ce(acac) 4 and Ce(tmtaa) 2 (where acac is acetylacetonate and tmtaaH 2 is tetramethyldibenzotetraaza[14]annulene) have similar physical properties, as does the solid-state compound CeO 2. The concept is advanced that trop -, acac -, tmtaa 2-, cot 2-, and O 2- are redox-active ligands that function as electron donors, rendering the classification of these compounds according to their oxidation numbers misleading because their magnetic susceptibilities, χ, are positive and their effective magnetic moments, μeff, lie in the range of 0.1-0.7 μ B at 300 K.

Authors:
 [1]; ORCiD logo [2];  [3]; ORCiD logo [4];  [5]
  1. Univ. of California, Berkeley, CA (United States)
  2. Univ. of California, Berkeley, CA (United States); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Univ. Paris Saclay, Palaiseau (France)
  3. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
  4. Univ. de Toulouse, Toulouse (France)
  5. Univ. of California, Berkeley, CA (United States); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
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)
OSTI Identifier:
1458512
Grant/Contract Number:  
[AC02-05CH11231]
Resource Type:
Accepted Manuscript
Journal Name:
Inorganic Chemistry
Additional Journal Information:
[ Journal Volume: 57; Journal Issue: 12; Related Information: © 2018 American Chemical Society.]; Journal ID: ISSN 0020-1669
Publisher:
American Chemical Society (ACS)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY

Citation Formats

Halbach, Robert L., Nocton, Gregory, Booth, Corwin H., Maron, Laurent, and Andersen, Richard A. Cerium Tetrakis(tropolonate) and Cerium Tetrakis(acetylacetonate) Are Not Diamagnetic but Temperature-Independent Paramagnets. United States: N. p., 2018. Web. doi:10.1021/acs.inorgchem.8b00928.
Halbach, Robert L., Nocton, Gregory, Booth, Corwin H., Maron, Laurent, & Andersen, Richard A. Cerium Tetrakis(tropolonate) and Cerium Tetrakis(acetylacetonate) Are Not Diamagnetic but Temperature-Independent Paramagnets. United States. doi:10.1021/acs.inorgchem.8b00928.
Halbach, Robert L., Nocton, Gregory, Booth, Corwin H., Maron, Laurent, and Andersen, Richard A. Mon . "Cerium Tetrakis(tropolonate) and Cerium Tetrakis(acetylacetonate) Are Not Diamagnetic but Temperature-Independent Paramagnets". United States. doi:10.1021/acs.inorgchem.8b00928. https://www.osti.gov/servlets/purl/1458512.
@article{osti_1458512,
title = {Cerium Tetrakis(tropolonate) and Cerium Tetrakis(acetylacetonate) Are Not Diamagnetic but Temperature-Independent Paramagnets},
author = {Halbach, Robert L. and Nocton, Gregory and Booth, Corwin H. and Maron, Laurent and Andersen, Richard A.},
abstractNote = {Here, a new synthesis of cerium tetrakis(tropolonate), Ce(trop)4, where trop is deprotonated 2-hydroxy-2,4,6-cycloheptatrienone) or Ce(O2C7H5)4, is developed that results in dark-purple crystals whose X-ray crystal structure shows that the geometry of the eight-coordinate compound closely resembles a D2d dodecahedron, based on shape parameters. The magnetic susceptibility as a function of the temperature (4-300 K) shows that it is a temperature-independent paramagnet, χ = 1.2(3) × 10-4 emu/mol, and the LIII-edge X-ray absorption near-edge structure spectrum shows that the molecule is multiconfigurational, comprised of a f1:f0 configuration mixture in a 50:50 ratio. Ce(acac)4 and Ce(tmtaa)2 (where acac is acetylacetonate and tmtaaH2 is tetramethyldibenzotetraaza[14]annulene) have similar physical properties, as does the solid-state compound CeO2. The concept is advanced that trop-, acac-, tmtaa2-, cot2-, and O2- are redox-active ligands that function as electron donors, rendering the classification of these compounds according to their oxidation numbers misleading because their magnetic susceptibilities, χ, are positive and their effective magnetic moments, μeff, lie in the range of 0.1-0.7 μB at 300 K.},
doi = {10.1021/acs.inorgchem.8b00928},
journal = {Inorganic Chemistry},
number = [12],
volume = [57],
place = {United States},
year = {2018},
month = {6}
}

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

Citation Metrics:
Cited by: 6 works
Citation information provided by
Web of Science

Save / Share:

Works referencing / citing this record:

Isolation of a TMTAA-Based Radical in Uranium bis-TMTAA Complexes
journal, November 2018

  • Hohloch, Stephan; Garner, Mary E.; Booth, Corwin H.
  • Angewandte Chemie International Edition, Vol. 57, Issue 49
  • DOI: 10.1002/anie.201810971