2025 - Sustainable Industrial Processing Summit
SIPS2025 Volume 13. Intl. Symp on Solid State Chemistry, Physical Chemistry, Corrosion and Coating

Editors:F. Kongoli, I. Chung, H. Kageyama, M.G. Kanatzidis, F. Marquis, A. Navrotsky, A. Tressaud, J. Atwood, G. Duca, R. Kuroda, A. Legocki, J. Lipkowski, M. Zaworotko, R. Singh, R. Gupta, M. Halama, D. Macdonald, F. Wang
Publisher:Flogen Star OUTREACH
Publication Year:2025
Pages:262 pages
ISBN:978-1-998384-62-4 (CD)
ISSN:2291-1227 (Metals and Materials Processing in a Clean Environment Series)
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    SYNTHESIS AND RAMAN SPECTRA OF PALLADIUM TETRACHLORIDE COMPLEXES WITH ALKALI- AND ALKALINE-EARTH CHLORIDES

    Alexander Salyulev1; Emma Vovkotrub2;
    1INSTITUTE OF HIGH TEMPERATURE ELECTROCHEMISTRY, URAL BRANCH OF RUSSIAN ACADEMY OF SCIENCE, Ekaterinburg, Russian Federation; 2INSTITUTE OF HIGH TEMPERATURE ELECTROCHEMISTRY, URAL BRANCH OF RUSSIAN ACADEMY OF SCIENCE, Ekaterinburg, Russian Federation;
    Type of Paper: Regular
    Id Paper: 12
    Topic: 52

    Abstract:

    In technological and analytical practice, in preparative chemistry, halogenide complexes of platinum group metals play an important role. Available information concerning Pd(IV) chloride complexes is limited due to the instability of PdCl4 [1-3], which exists in an individual state only as dichloride. Chlorination of metallic palladium in molten alkali metal chlorides at high temperatures (630-980 °C) and at elevated chlorine pressures (8-10 atm) allows, according to our data, obtaining palladium in rapidly cooled and solidified salt melts based on CsCl mainly in the tetravalent state in the form of Cs2PdCl6. However, in RbCl- and KCl-based solidified melts there are complex compounds both of Pd(II) and of Pd(IV), and in solidified melts containing NaCl and LiCl only divalent palladium is present in the form of M2PdCl4 compounds.

    The ratio of valence forms (II, IV) of palladium chlorides in salt melts and in solidified fusions at different stages and process regimes can be conveniently and quickly monitored by changing the ratio of intensities of the bands of the groupings [PdCl6]2- (Oh): n1(A1g) ~ 315, n2(Eg) 290, n5(F2g) ~ 170 cm-1 and [PdCl4]2- (D4h): n1(A1g) ~ 300, n2(B1g) ~ 270, n4(B2g) ~ 200 cm-1 of the chloride complexes of M2[PdCl6] and M2[PdCl4] in the Raman spectra, recorded using a Renishaw U1000 spectrometer [4]. 

    The use of low-temperature chlorination of Pd(II) compounds in solidified fusions with alkali and alkaline earth metal chlorides (exposed in liquid chlorine for several days at room temperature and for 10-12 hours at 100 °C) made it possible to obtain known hexachloropalladates(IV): M2[PdCl6] with M=Cs, Rb, K and new low-stability compounds Na2[PdCl6], Li2[PdCl6] and Ba[PdCl6]. The experimental vibration frequencies are within the ranges of 309-323 - n1(A1g), 283-295 - n2(Eg) and 169-176 cm-1- n5(F2g), with a tendency to increase in a series from Cs2[PdCl6] to Li2[PdCl6] and to Ba[PdCl6].

    Pd(IV) chloride complexes with chlorides of other alkaline earth metals did not form under the conditions of this study.

    Keywords:

    Chlorides; Palladium(IV); Complex Compounds; Synthesis

    Cite this article as:

    Salyulev A and Vovkotrub E. (2024). SYNTHESIS AND RAMAN SPECTRA OF PALLADIUM TETRACHLORIDE COMPLEXES WITH ALKALI- AND ALKALINE-EARTH CHLORIDES . In F. Kongoli, I. Chung, H. Kageyama, M.G. Kanatzidis, F. Marquis, A. Navrotsky, A. Tressaud, J. Atwood, G. Duca, R. Kuroda, A. Legocki, J. Lipkowski, M. Zaworotko, R. Singh, R. Gupta, M. Halama, D. Macdonald, F. Wang (Eds.), Sustainable Industrial Processing Summit Volume 13 Intl. Symp on Solid State Chemistry, Physical Chemistry, Corrosion and Coating (pp. 215-216). Montreal, Canada: FLOGEN Star Outreach