Nucleobases and C2 and C4 Imidazolium Acetate Interactions: FTIR-ATR, Raman and NMR Spectra and ab Initio Calculations Insights

Room Temperature Ionic Liquids (RTILs) are revolutionizing the world of solvents due to the unique combination of their many interesting properties. The number of synthesized RTILs continues to rise, and by judicious choice of the constituent cations and anions, RTILs tailor-made for specific applications can be designed. The tunable nature of the solubility of various compounds, including molecules of pharmaceutical and biological interest, in RTILs makes extraction them attractive for many separation and purification processes [1;2]. Exploring new applications requires fundamental understanding of the phase behavior. In the present work, we explore the use of RTILs to dissolve Nucleobases, Nucleosides and Nucleotides. Nucleobases are the parts of Nucleic Acids (DNA and RNA) that are involved in pairing. The system of a base covalently bound to the 1’ carbon of a ribose or deoxyribose is called a Nucleoside, and a nucleoside with one or more phosphate groups attached at the 5’ carbon is called a Nucleotide. Nucleotides comprise the structural units of RNA and DNA. The structural elements of the most common Nucleotides are depicted in the Figure 1. Uracil, a common and naturally occurring pyrimidine derivative [3], was selected as illustrative model for deeper solubility study of nucleobases. Found in RNA, it base pairs with adenine and is replaced by thymine in DNA translation. In this work, we focus on uracil, adenine and thymine solubility. The capability of RTILs as tunable solvents to dissolve nucleobases is perceived. The results obtained for the three ILs families outlined, Imidazolium-, Phosphonium- and Ammonium-based ILs, show that the ILs containing a carbonyl group in the anion present higher dissolution capabilities. This is due to the establishment of hydrogen bonds between uracil and IL. The combined use of FTIR, FT-RAMAN and NMR-spectroscopy, as well as computer simulation, will be attain to better understand the solubility mechanism of nucleobases, nucleosides and nucleotides. The results here obtained show the enormous potential of the use of RTILs to dissolve nucleobases, nucleosides and nucleotides and disclose a favorable trends in the application of RTILS in DNA extraction and purification.