title: Estimating pKa values for pentaoxyphosphoranes.
abstract: pKa values are estimated independently, by two entirely different methods, for the ionizations of the apical and equatorial OH groups of two representative hydroxyphosphoranes. A bond length-pKa correlation based on crystal structures of cyclohexanol derivatives gives values of 13.5 +/- 1.5 and 8.62 +/- 1.87, respectively, for the apical and equatorial OH groups of tetracyclohexyloxyhydroxyphosphorane, and an ab initio molecular dynamics calculation gives values of 14.2 and 9.8 for the corresponding first ionizations of pentahydroxyphosphorane.
authors.affiliation: University Chemical Laboratory, Cambridge Uiversity, Cambridge CB2 1EW, United Kingdom.
authors.forename: J E
authors.initials: JE
authors.lastname: Davies
authors.forename: N L
authors.initials: NL
authors.lastname: Doltsinis
authors.forename: A J
authors.initials: AJ
authors.lastname: Kirby
authors.forename: C D
authors.initials: CD
authors.lastname: Roussev
authors.forename: M
authors.initials: M
authors.lastname: Sprik
mesh_terms: D018360:Crystallography, X-Ray; D007700:Kinetics; D008958:Models, Molecular; D008968:Molecular Conformation; D010753:Phosphoranes / Q000737:chemistry*; D012313:RNA / Q000737:chemistry
chemical_list: D010753:Phosphoranes; D012313:RNA