posted on 2012-01-20, 00:00authored byAndrew Streitwieser, Antonio Facchetti, Linfeng Xie, Xingyue Zhang, Eric C. Wu
The pK of p-(methylamino)biphenyl, 1, on our Li scale, pK(Li) = 22.09, compared
to the cesium scale, pK(Cs) = 28.60. For hexamethyldisilazane,
HMDS, pK(Li) = 23.05, pK(Cs) = 29.26.
These results are those for the monomers in THF; corrections were
made for dimers present in some cases. The pK(Li)
of these two amines fit well the previously found correlation with
Hartree–Fock calculations at 6-31+g(d) using RLi coordinated
with three dimethyl ethers as a computational model for RLi in THF.
The results are also compared with earlier pK(Li)s
reported from equilibria with lithium amides in which aggregation
was not considered.