A FORMAÇÃO DE LIGAÇÕES DE HIDROGÊNIO π‧‧‧H, F‧‧‧H E C‧‧‧H NOS COMPLEXOS C₂H₂‧‧‧(HF), C₂H₂‧‧‧2(HF) E C₂H₂‧‧‧3(HF)

THE FORMATION OF THE π‧‧‧H, F‧‧‧H AND C‧‧‧H HYDROGEN BONDS ON THE C₂H₂‧‧‧(HF), C₂H₂‧‧‧2(HF) AND C₂H₂‧‧‧3(HF) COMPLEXES

In this work, a theoretical study on the basis of structural, vibrational, electronic and topological parameters of the C₂H₂‧‧‧(HF), C₂H₂‧‧‧2(HF) and C₂H₂‧‧‧3(HF) complexes concerning the formation of π‧‧‧H, F‧‧‧H and C‧‧‧H hydrogen bonds is presented. The main difference among these complexes is not properly the interaction strength, but the hydrogen bond type whose benchmark is ruled justly by the structure. Meanwhile, the occurrence of π‧‧‧H hydrogen bonds was unveiled in both C₂H₂‧‧‧(HF) dimer and C₂H₂‧‧‧3(HF) tetramer, although in latter, this interaction is stronger than C‧‧‧H of the C₂H₂‧‧‧2(HF) trimer. However, the F‧‧‧H hydrogen bonds within the subunits of hydrofluoric acid are the strongest ones, reaching a partial covalent limit, and thereby contribute decisively to the stabilization of the tetramer structure. In line with this, the largest red-shifts were observed on the hydrofluoric acid trimer of the C₂H₂‧‧‧3(HF) complex.

Keywords:
hydrogen bonds; infrared; QTAIM; NBO