J Phys Chem Lett. 2014 Dec 04;5(23):4225-31. doi: 10.1021/jz502150d. Epub 2014 Nov 24.

Positively Charged Phosphorus as a Hydrogen Bond Acceptor.

The journal of physical chemistry letters

Anne S Hansen, Lin Du, Henrik G Kjaergaard

PMID: 26278958 DOI: 10.1021/jz502150d

Abstract

Phosphorus (P) is an element that is essential to the life of all organisms, and the atmospheric detection of phosphine suggests the existence of a volatile biogeochemical P cycle. Here, we investigate the ability of P to participate in the formation of OH···P hydrogen bonds. Three bimolecular alcohol-trimethylphosphine complexes have been detected. Initially, the complexes were detected using matrix isolation spectroscopy, which favors complex formation. Subsequently, the fundamental OH-stretching vibration was observed in room-temperature gas-phase spectra. On the basis of our measured OH-stretching frequency red shifts and quantum chemical calculations, we find that P is an acceptor atom similar in strength to O and S and that all three P, O, and S atoms are weaker acceptors than N. The quantum chemical calculations show that both H and P in the OH···P hydrogen bond have partial positive charges, as expected from their electronegativities. However, the electrostatic potentials show a negative potential area on the electron density surface around P that facilitates formation of hydrogen bonds.

Keywords: alcohols; hydrogen bonding; molecular complexes; phosphorus

Publication Types

• Journal Article