Solvolysis of aromatic benzoyl chlorides: how is the π-electron stabilization of the aromatic acyl chlorides and acylium cations related to the π-electron delocalization?

Homodesmotic stabilization energies of XPhCOCl and XPhCO+ estimated at the B3LYP/6–311G** level of theory for eight para‐substituted derivatives (X = H, Cl, F, OH, OCH3, NH2, NO2 and CH3) are good descriptors for changes of the π‐electron delocalization parameters of the ring, measured by NICS and HOMA, and also for geometry parameters of COCl and CO+ groups. Good correlations are also found for atomic charges in these groups. Electron‐donating substituents elongate the C—Cl bond dramatically and increase the negative charge at the Cl atom in the XPhCOCl molecule. Copyright © 2004 John Wiley & Sons, Ltd.