TITLE:
Protonation Sites in Benzimidazolyl-Chalcones Molecules: An ab Initio and DFT Investigation
AUTHORS:
Mamadou Guy-Richard Kone, Sopi Thomas Affi, Nahossé Ziao, Kafoumba Bamba, Edja Florentin Assanvo
KEYWORDS:
Benzimidazolyl-Chalcone, Quantum Chemistry, Protonation, Proton Affinity, Gas Phase Basicity
JOURNAL NAME:
Computational Chemistry,
Vol.4 No.3,
June
2,
2016
ABSTRACT: In this work, we have focused our investigations on the protonation sites predilection in the benzimidazolyl-
chalcones (BZC) derivatives. Particularly, we are interested in the study of geometrical
and energetical parameters. BZC are well known for their particularly nematicidal activity. Ten
(10) BZC derivatives coded BZC-1 to BZC-10, with various larvicidal concentrations, have been selected
for this work. They all are different one from another by the phenyl ring which is substituted
by electron modulators such as alkyl, hydroxyl, alkoxy, aminoalkyl, halogen and nitro or replaced
by the furan. Quantum chemical methods, namely HF/6-311 + G(d,p) and MPW1PW91/6-
311 + G(d,p) theory levels have been used to determine the geometrical and energetical parameters
by the protonation on each heteroatom of the BZC derivative. An accuracy results with relatively
less time consuming has been obtained using Hartree-Fock (HF) and Density Functional
Theory methods (DFT/MPW1PW91). The calculations results allow identifying the sp2 nitrogen as
the preferential site of protonation in BZC derivative compounds.