Deprotonation reactions of the non-rigid bis-(2,5-diamidopyrrole) induced by anions

Abstract

The molecular structures of 4-aminomethyl-phenylamino-bis-(3,4-dichloro-5-phenylcarbamoyl-1H-pyrrole-2-carboxamide), LH2, its deprotonated species and fluoride,chloride and hydroxide complexes were obtained by geometry optimizations using thedensity functional theory (DFT) calculations. Energetics, thermodynamic properties andequilibrium constants of deprotonation processes of the compound in the presence andabsence of fluoride, chloride and hydroxide ions were computed at the B3LYP/6-31G(d)level with zero point vibration energy (ZPVE) corrections. In gas phase, the fluoride andhydroxide ions are able to form complexes with the deprotonated species of the compoundsand finally the compounds became the free deprotonated form. However, the chloride ionsprefer to form the dichloride complexes without the deprotonation processes of thecompound. The B3LYP/6-31G(d)-optimized data of L2??? also shows a strong support for itsX-ray crystallographic structure.

Keywords: anion coordination; computational chemistry; 2,5-diamidopyrrole; DFT;deprotonation.