Design of Exceptional Strong Organosuperbases Based on Iminophosphorane and Azaphosphiridine Derivatives: Harnessing Ring Strain and Aromaticity to Engineer Neutral Superbases

摘要

A new class of non-ionic organosuperbases was designed using iminophosphorane and azaphosphiridine frameworks,and their gas phase proton affinity(PA)and gas phase basicity(GB)were assessed by using density functional theory computations.The utilized strategy for tailoring the organosuperbases is based on stimulating of ring opening upon protonation bearing substituents which have the ability of positive charge delocalization.After protonation,most of the superbases formed positive aromatic rings(C3H3 ~+ and C7H7 ~+).This strategy led to the design of organobases with exceptional basicity in the range of 1013–1317 kJmol~(-1).Five designed organosuperbases show the PA values>1254 kJmoll~(-1),above the range of a hyperbase.To better comprehend the basicity of the compounds,the aromaticity indices(NICS and HOMA data)associated with the organosuperbases and their corresponding conjugate acids have been calculated and compared with each other.