TY - JOUR T1 - Deprotonation of 1,2-dialkylpyridinium ions: a DFT study of reactivity and site selectivity JF - Journal of Physical Chemistry A Y1 - 2007 A1 - Gupta, Neelima A1 - Garg, Reena A1 - Shah, Kirti Kr. A1 - Tanwar, Akhilesh A1 - Pal, Sourav AB -

A site-selectivity model, based on the Fukui function as a local reactivity descriptor, has been applied to 1.2-disubstituted pyridinium ions incorporating two competing sites of similar reactivity, i.e., 1-methylene and 2-methylene, which may undergo deprotonation depending on the nature of substituent present on these moieties. Applicability of the local HSAB rule, in context with the Li-Evans' generalized HSAB principle suggesting the hard-hard interactions to be controlled by minimum Fukui function, has been illustrated. Global and local reactivity descriptors have been computed by carrying out DFT calculations at B3LYP/6-31++G** level using Mulliken and NPA methods for charge analysis. A comparison with the calculated deprotonation energies involving two sites indicates that the observed site selectivity in differently substituted pyridinium ions is better explained by the Li-Evans rule of minimum Fukui function for hard-hard interactions.

PB - AMER CHEMICAL SOC CY - 1155 16TH ST, NW, WASHINGTON, DC 20036 USA VL - 111 IS - 36 U3 - Foreign U4 - 2.883 ER -