Computational Investigations on Stability and Equilibrium Composition of (Z)-indol-3-ylidenemethanol: An Enol-tautomer of 1H-indole-3-carbaldehyde via DFT Approach

Title:Computational Investigations on Stability and Equilibrium Composition of (Z)-indol-3-ylidenemethanol: An Enol-tautomer of 1H-indole-3-carbaldehyde via DFT Approach

Volume: 8 Issue: 3

Author(s): Ibrahim Asiata Omotayo, Oyebamiji Abel Kolawole and Semire Banjo*

Affiliation:

• Department of Pure and Applied Chemistry, Faculty of Pure and Applied Sciences, Ladoke Akintola University of Technology, Ogbomoso,Nigeria

Keywords: (Z)-Indol-3-ylidenemethanol, 1H-indole-3-carbaldehyde, DFT, dipole moment, hardness, molecular properties.

Abstract: Background: The stability and molecular properties of 1H-indole-3- carbaldehyde (A) and its tautomer, (Z)-indol-3-ylidenemethanol (B) are examined using B3LYP/6-311++G(d,p), M06/6-311++G(d,p), wB97xD/6-311++G(d,p) and MP2/6- 311++G(d,p) methods.

Method: The molecular reactivity indices calculated and discussed are the EHOMO, ELUMO, Δ(EHOMO-LUMO), dipole moment, softness (σ), chemical hardness (η), chemical potential (µ), ionization potential (IP), electron affinity (EA), nucleophilicity index (ω) and thermodynamics parameters.

Observations: The band gap reveals that compound A is hard, more thermodynamically stable and less labile than B. This is in agreement with the total energy, chemical hardness and chemical softness calculated for the compounds.

Result: The equilibrium constant calculation shows that the mixture of the tautomers in aqueous medium is 99.98 % and 0.12 % for compounds A and B respectively. This reveals that compound B is unstable in aqueous medium and is fast converted to compound A, this might explain the reason for compound B not to have been synthesized or reported in any literature.

Conclusion: Critical analysis of the charge population distributions shows that charge distribution responded more to the basis sets rather than the computational methods used for the calculations.

Cite this article as:

Omotayo Asiata Ibrahim , Kolawole Abel Oyebamiji and Banjo Semire *, Computational Investigations on Stability and Equilibrium Composition of (Z)-indol-3-ylidenemethanol: An Enol-tautomer of 1H-indole-3-carbaldehyde via DFT Approach, Current Physical Chemistry 2018; 8 (3) . https://dx.doi.org/10.2174/1877946809666181212113209