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
13 С和19的一系列的F NMR光谱对位-取代的heptafluorotoluenes和hexafluorobenzyl阳离子进行了分析。的量子
化学计算δ 13C和δ 19F以及
化学移位(CS)19 F- 19 F和13 C- 19进行˚F自旋-自旋耦合常数(SSCCs)。通过GIAO / PBE /
L22方法预测了19 F和13 C CSs。结合阴离子(作为离子对)进行阳离子计算时,理论CSs值的准确性提高了。S
OPPA(CC
SD)方法的计算具有足够的准确性,可用于预测19 F- 19 F,13 C- 19 F SSCC和Ramsey捐助。从七
氟甲苯到相应的苄基碳正离子传递过程中,还检查了对自旋-自旋相互作用的各种贡献的变化及其对对位取代基的依赖性。