Long-chain mercury carboxylates relevant to saponification in oil and tempera paintings: XRPD and ssNMR complementary study of their crystal structures
The result's identifiers
Result code in IS VaVaI
<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61388980%3A_____%2F22%3A00554813" target="_blank" >RIV/61388980:_____/22:00554813 - isvavai.cz</a>
Alternative codes found
RIV/68378271:_____/22:00554813 RIV/61389013:_____/22:00554813 RIV/00216208:11310/22:10445501
Result on the web
<a href="https://doi.org/10.1039/D1DT04160F" target="_blank" >https://doi.org/10.1039/D1DT04160F</a>
DOI - Digital Object Identifier
<a href="http://dx.doi.org/10.1039/d1dt04160f" target="_blank" >10.1039/d1dt04160f</a>
Alternative languages
Result language
angličtina
Original language name
Long-chain mercury carboxylates relevant to saponification in oil and tempera paintings: XRPD and ssNMR complementary study of their crystal structures
Original language description
Saponification, resulting from pigment-binder interactions, is one of the most endangering phenomena affecting the appearance and stability of painted works of art. The crystallization of metal carboxylates (soaps) in paint layers is recently assumed as the most critical point for the development of undesirable changes induced by saponification, however, the factors triggering it are not fully understood. The red pigment cinnabar (HgS) has been suspected of contributing to saponification, however, the paucity of reliable reference structural data limited the experimental research of its effect at the molecular level. Within this study we synthesized mercury(ii) carboxylates of the formula Hg(C16)(x)(C18)(2-x) (x = 0.0, 0.2, 0.5, 0.8, 1.0, 1.2, 1.5, 1.8, 2.0) where C16 and C18 are hexadecanoate (palmitate) and octadecanoate (stearate), respectively, and characterize them by combination of X-ray powder diffraction (XRPD) and C-13 and Hg-199 solid state NMR (ssNMR). For a more detailed interpretation of their structural and thermal behavior, Fourier transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC) were used. The crystal structure of the studied mercury carboxylates was described on the basis of complementary ssNMR and XRPD measurements, Rietveld refinement and DFT calculations. All the subjected compounds crystallize in a monoclinic lattice of the C2/c symmetry. Mercury atoms are arranged in a slightly distorted square antiprismatic geometry and are monodentatically bonded to carboxylate anions. The structural disorder at the aliphatic end of the stearic acid chains was detected in the mixed carboxylates. Within the paper, the structural (dis)similarity with the corresponding lead carboxylates is discussed. The synthesized and characterized mercury carboxylates were applied to describe neo-formed mercury soaps in a model experiment simulating an egg-based paint system.
Czech name
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Czech description
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Classification
Type
J<sub>imp</sub> - Article in a specialist periodical, which is included in the Web of Science database
CEP classification
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OECD FORD branch
10402 - Inorganic and nuclear chemistry
Result continuities
Project
Result was created during the realization of more than one project. More information in the Projects tab.
Continuities
I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace
Others
Publication year
2022
Confidentiality
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů
Data specific for result type
Name of the periodical
Dalton Transactions
ISSN
1477-9226
e-ISSN
1477-9234
Volume of the periodical
51
Issue of the periodical within the volume
10
Country of publishing house
GB - UNITED KINGDOM
Number of pages
14
Pages from-to
4019-4032
UT code for WoS article
000756793200001
EID of the result in the Scopus database
2-s2.0-85125965108