The 1H and 19F spectra of 2H,3H-decafluoropentane demonstrate the complexity highly fluorinated short-chain hydrocarbon compounds. The presence of two protons along the carbon backbone disrupts molecular symmetry resulting in additional multiplicity in the 19F NMR spectrum. In the absence of 1H-19F coupling, the 1H spectrum would contain a simple doublet of doublet signal as the 2H proton couples to the 3H proton. In addition, both protons experience strong 1H-19F geminal coupling to fluorine, and two different vicinal couplings to adjacent fluorine atoms, yielding a complex splitting pattern. In the 19F spectrum primary and secondary alkyl fluorides experience vastly different shielding along the carbon backbone, spanning a range from -220 ppm to -75 ppm. This benefits the analysis since individual fluorine groups can be analyzed separately for various contributions from 1H-19F and 19F-19F coupling.
These spectra reveal complex fluorine and proton spectra, demonstrating the wealth of structural information attainable from a benchtop NMR. Fluorine-19 NMR is a very useful tool, providing a complimentary technique to 1H NMR for structure determination and dynamics. With the Thermo Scientific picoSpin 8019F NMR spectrometer, fluorine samples can be tested as neat liquids or diluted in deuterated or protonated solvents, allowing for straightforward sample preparation and analysis.
Vertrel™ XF was developed as an effective replacement of ozone depleting CFC and HCFC compounds, but has wide-ranging application in various industries. Formulations of 2H,3H-decafluoropentane are used for electronics and landing gear cleaning and as a heat transfer fluid in the aerospace industry, for PCB cleaning in the electronics industry, as a cleaner and drying agent in optics, jewelry and watch making. HFC specialty fluids are also used as dry cleaning fluids for clothes, as carrier fluids for lubricants, as degreasers, and as dielectric fluids in high-voltage applications.
Chemical name: 2H, 3H-decafluoropentane
Experimental conditions: 16 scans
Concentration: Neat (19F); 50% CDCl3 (1H)
Field: 77 MHz (19F), 82 MHz (1H)
Nuclear testing: 19F, 1H
Applications: QA, Pharma, Synthesis, Reaction Monitoring
About NMR Tech Talk
Featuring the latest news, events, and educational approaches in benchtop NMR, Tech Talk is your forum for bringing this interesting and valuable technique into the classroom or as part of your analytical laboratory. Discover what's new from peers and from our experts at Thermo Fisher Scientific.
Access a targeted collection of application notes, case studies, videos, webinars and white papers covering a range of applications for Fourier transform infrared (FTIR) spectroscopy, near infrared spectroscopy, Raman spectroscopy, nuclear magnetic resonance, ultraviolet-visible (UV-Vis) spectrophotometry, X-ray fluorescence, and more.