Anhydrous Lithium Acetate Polymorphs and Its Hydrates: Three-Dimensional Coordination Polymers

• Published in: Crystal growth & design Vol. 11; no. 4; pp. 1021 - 1032
• Main Authors: Martínez Casado, F. J, Ramos Riesco, M, Redondo, M. I, Choquesillo-Lazarte, D, López-Andrés, S, Cheda, J. A. Rodríguez
• Format: Journal Article
• Language: English
• Published: Washington,DC American Chemical Society 06-04-2011
• Subjects: Condensed matter: structure, mechanical and thermal properties; Crystalline state (including molecular motions in solids); Crystallographic aspects of phase transformations; pressure effects; Exact sciences and technology; Physics; Structure of solids and liquids; crystallography; Structure of specific crystalline solids; Differential scanning calorimetry; Infrared spectroscopy; Fourier transform spectroscopy; Molecular structure; Polychelate; Thermogravimetry; Lithium; XRD; One dimensional structure; Acetates; Monocrystals; Anhydrous compound; Hydrates; Polymorphism; Crystal structure
• ISSN: 1528-7483; 1528-7505
• DOI: 10.1021/cg1010133

Lithium acetate is a very common salt with many and varied uses. Nevertheless, only two compounds were known apparently, the anhydrous salt and lithium acetate dihydrate, but only the latter was really characterized. In this paper, two polymorphs of anhydrous lithium acetate and three novel hydrates (with lithium acetate/H2O ratios 4:1, 7:3, and 1:1) are reported for the first time, besides the well-known lithium acetate dihydrate. The five new compounds are three-dimensional (3D) coordination polymers, different from the one-dimensional (1D) structure of lithium acetate dihydrate. The structures and the relative stability of the two anhydrous lithium acetate polymorphs are also compared. The compounds were studied by single crystal X-ray diffraction (SCXRD), powder X-ray diffraction (PXRD), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and infrared spectroscopy (FTIR).