The synthesis and the spectroscopic, thermal, and structural properties of the M2[(fumarate)Ni(CN)4]·2(1,4-Dioxane) clathrate (M = Co, Ni, Cd and Hg)

Abstract

In this study, the clathrates of fumarate–tetracyanonickel–dioxane, given by the formula M2[(fumarate)Ni(CN)4]·2(1,4-Dioxane) (M = Co, Ni, Cd and Hg), have been obtained for the first time through chemical methods. These clathrates have been characterized by elemental, thermal, FT-IR, and FT-Raman spectroscopies. The parameters of structures of clathrates have been determined by X-ray powder diffraction. The thermal behaviors of these clathrates have been also investigated by thermo-gravimetric analysis (TGA), differential thermal analysis (DTA), and derivative thermal gravimetric analysis (DTG) in the range of 20–900 °C. X-ray powder diffraction data have been recorded at ambient temperature in the 2θ range 5–50°. The FT-IR and FT-Raman spectra of clathrates have been recorded in the region of 4000–400 cm−1 and 4000–100 cm−1, respectively.The results of the spectral and thermal analyses of the newly synthesized clathrates of fumarate–tetracyanonickel–dioxane suggest that these clathrates are new examples of the Hofmann–type dioxane clathrates. In our study, the Hofmann-type dioxane clathrates, which are formed by bounding electrons of oxygen–donor atoms of fumarate ion ligand molecule to transition metal atoms, consist of the corrugated |M–Ni(CN)4|∞ polymeric layers, which are held in parallel through the chain of (–M–fumarate–M–).