Effect of counterion on the reactivity, stability, aromaticity and charge distribution in mono- and polyphosphacyclopentadienide ions - A Theoretical Investigation

Publication date: Available online 3 July 2018Source: Computational and Theoretical ChemistryAuthor(s): Angelina Mary, Raakhi GuptaAbstractThe effect of counterion (Li+, Na+ and K+) on π-charge distribution vis-a-vis aromaticity, chemical reactivity and stability of cyclopentadienide ion and its mono- and polyphospha-analogues has been investigated using the second-order Møller-Plesset (MP2) level of theory. The reactivity descriptors namely, chemical potential, electrophilicity index and chemical hardness based on LUMO, HOMO energy values are calculated at MP2/6-31++G(d,p) level. The aromaticity, thermochemistry, hydrogen-bending phenomena, Hirshfeld Population Analysis, Charge Model 5 (CM5) charges and electrostatic potential mapping are also computed at the same level of theory. All the results indicate greater stability of the Li+-π complexes in comparison to the Na+-π and K+-π complexes. The distortion of the π-electrons cloud is mainly governed by the polarization effect of the cation. Furthermore, the Nucleus-Independent Chemical Shift (NICS(1)zz) values indicate that the extent of aromaticity remains almost unaffected by complexation and the nature of the counterion.Graphical abstract

Source: Computational and Theoretical Chemistry - July 6, 2018 Category: Chemistry Source Type: research