53575-25-0Relevant articles and documents
A study of NMR parameters of para-substituted polyfluorinated benzyl cations and their precursors
Fadeev, Dmitriy S.,Chuikov, Igor P.,Mamatyuk, Victor I.
, p. 53 - 60 (2016/01/12)
13C and 19F NMR spectra of a series of para-substituted heptafluorotoluenes and hexafluorobenzyl cations were analyzed. The quantum-chemical calculations of δ13C and δ19F chemical shifts (CSs) as well as 19F-19F and 13C-19F spin-spin coupling constants (SSCCs) were performed. 19F and 13C CSs were predicted by the GIAO/PBE/L22 method. The accuracy of theoretical CSs values increased in the computation for cations in conjunction with anions as ionic pairs. The computation by the SOPPA(CCSD) method had enough accuracy for the prediction of 19F-19F, 13C-19F SSCCs and Ramsey contributions. Changes in various contributions to the spin-spin interaction along with their dependence on substituents at the para-position were also examined on passing from heptafluorotoluenes to the corresponding benzyl carbocations.