Korakot NavakhunVithaya RuangpornvisutiRamkhamhaeng UniversityMahidol University2018-07-122018-07-122008-09-15Journal of Molecular Structure: THEOCHEM. Vol.864, No.1-3 (2008), 26-30016612802-s2.0-49449116020https://repository.li.mahidol.ac.th/handle/20.500.14594/18859The molecular structures of 3,4-dichloro-2,5-diamidopyrrole LH, its deprotonated species L-, self-assembly dimeric species and its complexes with fluoride, chloride and hydroxide ions were obtained using the B3LYP/6-31G(d) calculations. The optimized structures at the B3LYP/6-31G(d) and ONIOM(B3LYP/6-31G(d):PM3) levels of the self-assembly dimer co-existing with TBA (tetrabutylammonium) as [L2.2TBA] were obtained and their geometrical data show good agreement with the X-ray crystallographic structure. In the presence of hydroxide (as TBA.OH), deprotonation of LH and dimerization of L-are the most favorable reaction as compared to systems in the presence of fluoride and chloride ions. The hydroxide ion is able to draw a pyrrole proton from the LH and afford one water molecule via proton-transfer process. © 2008 Elsevier B.V. All rights reserved.Mahidol UniversityBiochemistry, Genetics and Molecular BiologyChemistryPhysics and AstronomyArticleSCOPUS10.1016/j.theochem.2008.05.032