Potassium and Rubidium Benzoyltrifluoroacetonates: A Crystal Chemical Study and Thermal Properties

• Published in: Journal of structural chemistry 2020-03, Vol.61 (3), p.439-448
• Main Authors: Kochelakov, D. V., Vikulova, E. S., Kuratieva, N. V.
• Format: Article
• Language: English
• Subjects: Atomic; Atomic/Molecular Structure and Spectra; Chemical analysis; Chemistry; Chemistry and Materials Science; Coordination polymers; Crystal structure; Crystallography; Crystals; Fluorine; Infrared analysis; Infrared spectroscopy; Inorganic Chemistry; Melting points; Molecular; Optical and Plasma Physics; Oxygen atoms; Physical Chemistry; Potassium; Rubidium; Solid State Physics; Thermodynamic properties; Thermogravimetry; Water chemistry
• ISSN: 0022-4766; 1573-8779
• DOI: 10.1134/S0022476620030105

Complexes of potassium and rubidium with benzoyltrifluoroacetone (C 6 H 5 COCH 2 COCF 3 = Hbtfac) of the composition M (btfac)(H 2 O) x , where M = K, Rb, x ∈ [0.5 … 1] are synthesized for the first time. The compounds are characterized by the elemental analysis and IR spectroscopy. By X-ray crystallography the crystal structures of M (btfac)(H 2 O) are determined: for the potassium complex a = 10.4955(4) Å, b = 13.9715(6) Å, c = 7.5197(3) Å, α = β = γ = 90°, space group Pcc2, Z = 4, R = 0.0242 [ I > 2σ( I )]; for the rubidium complex a = 10.6363(8) Å, b = 27.9354(18) Å, c = 7.7205(5) Å, α = 90°, β = 93.759(2)°, γ = 90°, space group P2 1 / c, Z = 4, R = 0.0287. The compounds represent layered coordination polymers where the metal cation coordinates eight oxygen atoms of four β-diketonate anions or four fluorine atoms of four β-diketonate ligands and four oxygen atoms of water molecules. The structures of M (btfac)(H 2 O) complexes with M = K, Rb, Cs are compared and the common structural motifs are revealed. From the thermogravimetry data the melting points and temperature ranges of the stability of anhydrous complexes are found.