American Chemical Society
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Ion Pair pKs of Some Amines: Extension of the Computed Lithium pK Scale

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journal contribution
posted on 2012-01-20, 00:00 authored by Andrew 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.