Estudio computacional de las energías de interacción de dímeros <span style="font-style:italic">cis-trans</span> y <span style="font-style:italic">trans-trans</span> del ácido fórmico

Abstract

In this work, potential energy surface (PES) of cis-trans and trans-trans formic acid dimers has been sampled using a modified version of annealing simulated method, and the geometries, interaction energies and delocalization energies were calculated at MP2/6-311++G(3df,2p) level of theory. In our findings, the interaction energy had deviations of up to 38.0% if basis set superposition error (BSSE) and zero-point energy (ZPE) are not taken in account. Also, for the hydrogen bond formation, we calculated delocalization energy of proton donor - proton acceptor interaction, being -64.4 kcal mol$^{-1}$ the minimum value for delocalization energy of the most stable dimer. Generally, delocalization energies diminished with increasing of hydrogen bond length, and particularly, a reasonable correlation coefficient was found for $\ln [E(2)]$ as a exponential function of the hydrogen bond length. In addition, we have found a good correlation between interaction energies and delocalization energies: high values of $E(2)_{\textrm{tot}}$ correspond to the most exergonic interaction energies. This finding allowed approximate the interaction energy as function of total delocalization energy of hydrogen bonds in formic acid dimers.