Synthetic Precursors for TCNQF₄^2– Compounds: Synthesis, Characterization, and Electrochemical Studies of (Pr₄N)₂TCNQF₄ and Li₂TCNQF₄

Careful control of the reaction stoichiometry and conditions enables the synthesis of both LiTCNQF₄ and Li₂TCNQF₄ to be achieved. Reaction of LiI with TCNQF₄, in a 4:1 molar ratio, in boiling acetonitrile yields Li₂TCNQF₄. However, deviation from this ratio or the reaction temperature gives either LiTCNQF₄ or a mixture of Li₂TCNQF₄ and LiTCNQF₄. This is the first report of the large-scale chemical synthesis of Li₂TCNQF₄. Attempts to prepare a single crystal of Li₂TCNQF₄ have been unsuccessful, although air-stable (Pr₄N)₂TCNQF₄ was obtained by mixing Pr₄NBr with Li₂TCNQF₄ in aqueous solution. Pr₄NTCNQF₄ was also obtained by reaction of LiTCNQF₄ with Pr₄NBr in water. Li₂TCNQF₄, (Pr₄N)₂TCNQF₄, and Pr₄NTCNQF₄ have been characterized by UV–vis, FT-IR, Raman, and NMR spectroscopy, high resolution electrospray ionization mass spectrometry, and electrochemistry. The structures of single crystals of (Pr₄N)₂TCNQF₄ and Pr₄NTCNQF₄ have been determined by X-ray crystallography. These TCNQF₄^2– salts will provide useful precursors for the synthesis of derivatives of the dianions

Synthetic Precursors for TCNQF₄^2– Compounds: Synthesis, Characterization, and Electrochemical Studies of (Pr₄N)₂TCNQF₄ and Li₂TCNQF₄

Careful control of the reaction stoichiometry and conditions enables the synthesis of both LiTCNQF₄ and Li₂TCNQF₄ to be achieved. Reaction of LiI with TCNQF₄, in a 4:1 molar ratio, in boiling acetonitrile yields Li₂TCNQF₄. However, deviation from this ratio or the reaction temperature gives either LiTCNQF₄ or a mixture of Li₂TCNQF₄ and LiTCNQF₄. This is the first report of the large-scale chemical synthesis of Li₂TCNQF₄. Attempts to prepare a single crystal of Li₂TCNQF₄ have been unsuccessful, although air-stable (Pr₄N)₂TCNQF₄ was obtained by mixing Pr₄NBr with Li₂TCNQF₄ in aqueous solution. Pr₄NTCNQF₄ was also obtained by reaction of LiTCNQF₄ with Pr₄NBr in water. Li₂TCNQF₄, (Pr₄N)₂TCNQF₄, and Pr₄NTCNQF₄ have been characterized by UV–vis, FT-IR, Raman, and NMR spectroscopy, high resolution electrospray ionization mass spectrometry, and electrochemistry. The structures of single crystals of (Pr₄N)₂TCNQF₄ and Pr₄NTCNQF₄ have been determined by X-ray crystallography. These TCNQF₄^2– salts will provide useful precursors for the synthesis of derivatives of the dianions

Synthetic Precursors for TCNQF₄^2– Compounds: Synthesis, Characterization, and Electrochemical Studies of (Pr₄N)₂TCNQF₄ and Li₂TCNQF₄

Careful control of the reaction stoichiometry and conditions enables the synthesis of both LiTCNQF₄ and Li₂TCNQF₄ to be achieved. Reaction of LiI with TCNQF₄, in a 4:1 molar ratio, in boiling acetonitrile yields Li₂TCNQF₄. However, deviation from this ratio or the reaction temperature gives either LiTCNQF₄ or a mixture of Li₂TCNQF₄ and LiTCNQF₄. This is the first report of the large-scale chemical synthesis of Li₂TCNQF₄. Attempts to prepare a single crystal of Li₂TCNQF₄ have been unsuccessful, although air-stable (Pr₄N)₂TCNQF₄ was obtained by mixing Pr₄NBr with Li₂TCNQF₄ in aqueous solution. Pr₄NTCNQF₄ was also obtained by reaction of LiTCNQF₄ with Pr₄NBr in water. Li₂TCNQF₄, (Pr₄N)₂TCNQF₄, and Pr₄NTCNQF₄ have been characterized by UV–vis, FT-IR, Raman, and NMR spectroscopy, high resolution electrospray ionization mass spectrometry, and electrochemistry. The structures of single crystals of (Pr₄N)₂TCNQF₄ and Pr₄NTCNQF₄ have been determined by X-ray crystallography. These TCNQF₄^2– salts will provide useful precursors for the synthesis of derivatives of the dianions

Spontaneous Redox Synthesis of the Charge Transfer Material TTF₄[SVMo₁₁O₄₀]

The charge-transfer material TTF-SV^IVMo₁₁O₄₀ (TTF = tetrathiafulvalene) was prepared by a spontaneous redox reaction between TTF and the vanadium-substituted polyoxometalate (n-Bu₄N)₃[SV^VMo₁₁O₄₀] in both solution and solid state phases. Single crystal X-ray diffraction gave the stoichiometry TTF₄[SVMo₁₁O₄₀]·2H₂O·2CH₂Cl₂, with the single V atom positionally disordered with eight Mo atoms over the whole α-Keggin polyanion [SVMo₁₁O₄₀]^4‑. Raman spectra support the 1+ charge assigned to the oxidized TTF deduced from bond lengths, and elemental and voltammetric analysis also are consistent with this formulation. Scanning electron microscopy images showed a rod-type morphology for the new charge-transfer material. The conductivity of the solid at room temperature is in the semiconducting range. The TTF and (n-Bu₄N)₃[SV^VMo₁₁O₄₀] solids also undergo a rapid interfacial reaction, as is the case with TTF and TCNQ (TCNQ = tetracyanoquinodimethane) solids. EPR spectra at temperatures down to 2.6 K confirm the presence of two paramagnetic species, V­(IV) and the oxidized TTF radical. Spectral evidence shows that the TTF-SV^IVMo₁₁O₄₀ materials prepared from either solution or solid state reactions are equivalent. The newly isolated TTF-SV^IVMo₁₁O₄₀ material represents a new class of TTF-polyoxometalate compound having dual electrical and magnetic functionality derived from both the cationic and anionic components

Spontaneous Redox Synthesis of the Charge Transfer Material TTF₄[SVMo₁₁O₄₀]

The charge-transfer material TTF-SV^IVMo₁₁O₄₀ (TTF = tetrathiafulvalene) was prepared by a spontaneous redox reaction between TTF and the vanadium-substituted polyoxometalate (n-Bu₄N)₃[SV^VMo₁₁O₄₀] in both solution and solid state phases. Single crystal X-ray diffraction gave the stoichiometry TTF₄[SVMo₁₁O₄₀]·2H₂O·2CH₂Cl₂, with the single V atom positionally disordered with eight Mo atoms over the whole α-Keggin polyanion [SVMo₁₁O₄₀]^4‑. Raman spectra support the 1+ charge assigned to the oxidized TTF deduced from bond lengths, and elemental and voltammetric analysis also are consistent with this formulation. Scanning electron microscopy images showed a rod-type morphology for the new charge-transfer material. The conductivity of the solid at room temperature is in the semiconducting range. The TTF and (n-Bu₄N)₃[SV^VMo₁₁O₄₀] solids also undergo a rapid interfacial reaction, as is the case with TTF and TCNQ (TCNQ = tetracyanoquinodimethane) solids. EPR spectra at temperatures down to 2.6 K confirm the presence of two paramagnetic species, V­(IV) and the oxidized TTF radical. Spectral evidence shows that the TTF-SV^IVMo₁₁O₄₀ materials prepared from either solution or solid state reactions are equivalent. The newly isolated TTF-SV^IVMo₁₁O₄₀ material represents a new class of TTF-polyoxometalate compound having dual electrical and magnetic functionality derived from both the cationic and anionic components