---
_id: '62819'
abstract:
- lang: eng
text: Novel oxalate-bridged heterotrinuclear complexes [A][Mn2Cr(bpy)2(H2O)2Cl2(C2O4)3]
(A = (CH3)2(C2H5)NH+ (1) and (CH3)(C2H5)2NH+ (2); bpy = 2,2′-bipyridine) were
synthesized using an aqueous solution of [A]3[Cr(C2O4)3] as a building block in
reaction with Mn2+ ions and with the addition of the N-donor ligand bipyridine.
The isostructural heterometallic complex salts were characterized by single-crystal
and powder X-ray diffraction, infrared and impedance spectroscopy, thermal analysis
and magnetization measurements. The trinuclear anion [{Mn(bpy)(H2O)Cl(μ-C2O4)}2Cr(C2O4)]−
consists of two [Mn(bpy)(H2O)Cl]+ units bridged by the [Cr(C2O4)3]3− anion, which
acts as a bidentate ligand towards each of the manganese atoms. The anions are
hydrogen bonded to each other via coordinated chloride anions, water molecules
and oxygen oxalate atoms, resulting in two-dimensional (2D) hydrogen bonding layers.
Compounds exhibit water-assisted proton conductivity behaviour, which was investigated
at different temperatures and relative humidities (RH). At 25 °C, an increase
in RH from 60% to 93% resulted in an obvious proton conducting switch from 9.1
× 10−11 to 5.6 × 10−5 S cm−1 for 1 and from 7.4 × 10−10 to 1.8 × 10−6 S cm−1 for
2, corresponding to high on/off ratios of about 106 for 1 and 104 for 2. In situ
powder X-ray diffraction (PXRD) analysis showed that unit cell parameters of compounds
1 and 2 slightly increase when exposed to humid conditions. This confirmed that
incorporation of water molecules into structures with pores and voids causes the
proton conductivity switching phenomenon. Magnetic susceptibility measurements
indicate a ferromagnetic interaction between Cr3+ and Mn2+ ions bridged by the
bis(bidentate) oxalate group. The prepared compounds 1 and 2 were explored as
single-source precursors for the formation of spinel oxide by their thermal treatment.
With increasing temperature, the spinel composition changed according to the formula
Mn1+xCr2–xO4 (0 ≤ x ≤ 1), where x = 0.7 at 500 °C and x = 1 at 900 °C when tet[MnII]oct[MnIIICrIII]O4
is formed. The (micro)structure, morphology, and optical properties of spinel
Mn2CrO4 were characterized by PXRD, scanning electron microscopy and UV-Vis diffuse
reflectance spectroscopy. The photocatalytic activity of this oxide in degradation
of the methylene blue dye under Vis irradiation without and with the support of
hydrogen peroxide was further investigated.
author:
- first_name: Ana
full_name: Lozančić, Ana
last_name: Lozančić
- first_name: Sanja
full_name: Burazer, Sanja
last_name: Burazer
- first_name: Tobias
full_name: Wagner, Tobias
last_name: Wagner
- first_name: Krešimir
full_name: Molčanov, Krešimir
last_name: Molčanov
- first_name: Damir
full_name: Pajić, Damir
last_name: Pajić
- first_name: Lidija
full_name: Androš Dubraja, Lidija
last_name: Androš Dubraja
- first_name: Michael
full_name: Tiemann, Michael
id: '23547'
last_name: Tiemann
orcid: 0000-0003-1711-2722
- first_name: Marijana
full_name: Jurić, Marijana
last_name: Jurić
citation:
ama: 'Lozančić A, Burazer S, Wagner T, et al. Water-assisted proton conductivity
and a magnetic study of heterotrinuclear oxalate-bridged compounds: molecular
precursors for the Mn2CrO4 spinel. Journal of Materials Chemistry C. 2025;13(41):21179-21195.
doi:10.1039/d5tc02569a'
apa: 'Lozančić, A., Burazer, S., Wagner, T., Molčanov, K., Pajić, D., Androš Dubraja,
L., Tiemann, M., & Jurić, M. (2025). Water-assisted proton conductivity and
a magnetic study of heterotrinuclear oxalate-bridged compounds: molecular precursors
for the Mn2CrO4 spinel. Journal of Materials Chemistry C, 13(41),
21179–21195. https://doi.org/10.1039/d5tc02569a'
bibtex: '@article{Lozančić_Burazer_Wagner_Molčanov_Pajić_Androš Dubraja_Tiemann_Jurić_2025,
title={Water-assisted proton conductivity and a magnetic study of heterotrinuclear
oxalate-bridged compounds: molecular precursors for the Mn2CrO4 spinel}, volume={13},
DOI={10.1039/d5tc02569a}, number={41},
journal={Journal of Materials Chemistry C}, publisher={Royal Society of Chemistry
(RSC)}, author={Lozančić, Ana and Burazer, Sanja and Wagner, Tobias and Molčanov,
Krešimir and Pajić, Damir and Androš Dubraja, Lidija and Tiemann, Michael and
Jurić, Marijana}, year={2025}, pages={21179–21195} }'
chicago: 'Lozančić, Ana, Sanja Burazer, Tobias Wagner, Krešimir Molčanov, Damir
Pajić, Lidija Androš Dubraja, Michael Tiemann, and Marijana Jurić. “Water-Assisted
Proton Conductivity and a Magnetic Study of Heterotrinuclear Oxalate-Bridged Compounds:
Molecular Precursors for the Mn2CrO4 Spinel.” Journal of Materials Chemistry
C 13, no. 41 (2025): 21179–95. https://doi.org/10.1039/d5tc02569a.'
ieee: 'A. Lozančić et al., “Water-assisted proton conductivity and a magnetic
study of heterotrinuclear oxalate-bridged compounds: molecular precursors for
the Mn2CrO4 spinel,” Journal of Materials Chemistry C, vol. 13, no. 41,
pp. 21179–21195, 2025, doi: 10.1039/d5tc02569a.'
mla: 'Lozančić, Ana, et al. “Water-Assisted Proton Conductivity and a Magnetic Study
of Heterotrinuclear Oxalate-Bridged Compounds: Molecular Precursors for the Mn2CrO4
Spinel.” Journal of Materials Chemistry C, vol. 13, no. 41, Royal Society
of Chemistry (RSC), 2025, pp. 21179–95, doi:10.1039/d5tc02569a.'
short: A. Lozančić, S. Burazer, T. Wagner, K. Molčanov, D. Pajić, L. Androš Dubraja,
M. Tiemann, M. Jurić, Journal of Materials Chemistry C 13 (2025) 21179–21195.
date_created: 2025-12-03T17:12:16Z
date_updated: 2025-12-03T17:13:22Z
department:
- _id: '35'
- _id: '2'
- _id: '307'
doi: 10.1039/d5tc02569a
intvolume: ' 13'
issue: '41'
language:
- iso: eng
main_file_link:
- open_access: '1'
oa: '1'
page: 21179-21195
publication: Journal of Materials Chemistry C
publication_identifier:
issn:
- 2050-7526
- 2050-7534
publication_status: published
publisher: Royal Society of Chemistry (RSC)
quality_controlled: '1'
status: public
title: 'Water-assisted proton conductivity and a magnetic study of heterotrinuclear
oxalate-bridged compounds: molecular precursors for the Mn2CrO4 spinel'
type: journal_article
user_id: '23547'
volume: 13
year: '2025'
...