Synthesis and characterization of tetraacetonitrilolithiumhexafluorophosphate crystal

• Published in: Journal of molecular structure Vol. 1094; pp. 9 - 12
• Main Authors: Li, Xuecong, Li, Xuanli, Zhang, Zhiye, Yang, Lin, Zhong, Benhe, Wang, Xinlong
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15.08.2015
• Subjects: Characterization; Lithium compound; Structure analysis; Synthesis; X-ray powder diffraction; Characterization; Lithium compound; Synthesis; Structure analysis; X-ray powder diffraction
• ISSN: 0022-2860; 1872-8014
• DOI: 10.1016/j.molstruc.2015.03.055

•Green synthesis of Li(CH3CN)4PF6 crystal.•X-ray powder diffraction and different spectroscopic characterizations were applied.•Solid-state NMR spectra and GAUSSIAN 09 program were used in determining structure. Tetraacetonitrilolithiumhexafluorophosphate (Li(CH3CN)4PF6) crystal is an important intermediate in the preparation of high purity lithium hexafluorophosphate electrolyte via a simple transformation method. In this study, the crystal parameters were determined by X-ray powder diffraction analysis, which showed that it belongs to the triclinic system with space group P1. FTIR spectral studies identified the characteristic absorption bands of CN and PF6− in the synthesized complex. Chemical analysis, gas chromatography, and ICP-AES results showed that the elementary ratio of Li:P:F: CH3CN in the complex is approximately: 1:1:6:4. Furthermore, the geometric optimization structure of Li(CH3CN)4PF6 was obtained using GAUSSIAN 09 program on a B3LYP/6-31+G(d, p) level. In this structure, two acetonitrile ligands bind strongly with the Li+ ion, whereas the other two are weakly-coordinated with lithium. The results of solid-state 13C-, 31P-, and 19F-NMR spectra confirmed that this configuration is reasonable.