STUDY OF POTASSIUM, RUBIDIUM HEXAFLUOROACETYLACETONATES AND BY-PRODUCTS OF THEIR SYNTHESIS AND CRYSTALLIZATION

• Published in: Journal of structural chemistry 2023, Vol.64 (1), p.82-96
• Main Authors: Kochelakov, D. V., Vikulova, E. S., Kuratieva, N. V., Sukhikh, A. S., Gromilov, S. A.
• Format: Article
• Language: English
• Subjects: Atomic; Atomic/Molecular Structure and Spectra; Cesium; Chemical analysis; Chemical synthesis; Chemistry; Chemistry and Materials Science; Chloroform; Crystallization; Crystals; Diketones; Infrared spectroscopy; Inorganic Chemistry; Molecular; Optical and Plasma Physics; Physical Chemistry; Potassium; Room temperature; Rubidium; Solid State Physics; Thermogravimetry; X ray powder diffraction
• ISSN: 0022-4766; 1573-8779
• DOI: 10.1134/S0022476623010055

Complexes M I (hfac), where M I  = K + , Rb + , (hexafluoroacetylacetonate ion) are synthesized and characterized (elemental analysis, IR spectroscopy, powder X-ray diffraction analysis). It is shown that in the synthesis of K(hfac) from an ethylacetate (EtOAc) solution of K 2 CO 3 and Hhfac taken in a stoichiometric ratio, at the intermediate stage, EtOAc molecules come into the K + coordination sphere, and {K 2 (hfac) 2 (EtOAc)} ∞ crystals are formed. At room temperature EtOAc is removed, and the K(hfac) target product is obtained. The twofold excess of Hhfac results in a mixture of products in which adduct crystals with water and hydrated β-diketone {K 2 (H 4 hfpt) 2 (hfac) 2 (H 2 O)} ∞ (H 4 hfpt = 1,1,1,5,5,5-hexafluoropentane-2,2,4,4,-tetraol) are present. Slow crystallization of Rb(hfac) in and L-shaped ampoule at 35-40 °C in chloroform leads to the formation of {Rb 3 (hfac) 2 (CF 3 COO)(ttpt)} ∞ (ttpt = 2,4,6-tris(trifluoromethyl)tetrahydropyrane-2,4,6-triol) crystals, and at crystallization in a drop of the 1.1 M NaCl solution, {Na 2 Rb(hfac) 3 } ∞ crystals are found. By thermogravimetry it is shown that rubidium hexafluoroacetylacetonate is thermally less stable than similar complexes of potassium and cesium.