Effects of temperature and pressure on deuterium migration

Structure of perdeuterated urea – phosphoric acid at 100K and 350K (

Structure of perdeuterated urea – phosphoric acid at 100K and 350K (ambient pressure), and at 0.1 and 3.2GPa (ambient temperature) showing migration of deuterium atom.
View full-size image

Effects of temperature and pressure on deuterium migration in urea – phosphoric acid

Urea and phosphoric acid form an adduct (UPA) in which a strong hydrogen bond is formed involving the hydrogen atom of the acid and the carbonyl oxygen of the urea. Previous studies have shown that at low temperatures this proton is localised on the urea molecule, but as temperature increases the proton migrates to a position midway between the two O atoms. We aimed to explore the effect on this migration phenomenon of replacing hydrogen for deuterium, especially as computational studies had suggested that coupling of vibrational modes may be important. Experiments performed on SXD and HIPR for perdeuterated-UPA showed migration of deuterium towards urea with either decreasing temperature or increasing pressure.

CK Spanswick , CA Morrison, CR Pulham (University of Edinburgh), DS Middlemiss, A Parkin, CC Wilson (University of Glasgow), MJ Gutmann, WG Marshall (ISIS)

Research date: December 2006

Further Information

Dr CR Pulham, [CRPulham@ed.ac.uk] CA Morrison et al., J. Am. Chem. Soc. 127 (2005) 4042

Bookmark and Share
Skip to the top of the page