Anion‐Anion Complexes Established between Aspartate Dimers

MIRANDA, MATIAS O.; DUARTE, DARÍO J. R.; ALKORTA, IBON

Chemphyschem

WILEY-V C H VERLAG GMBH

Año: 2020 vol. 21 p. 1052 - 1059

1439-4235

Stable dimers aspartate-aspartate have been studied in aqueousand gas phase through theoretical simulations. The polarizablecontinuum model (PCM) has been applied to simulate the effectof the hydration on monomers and complexes. The quantumtheory of atoms in molecules (QTAIM) and the interactingquantum atoms (IQA) scheme has been used to inquire into if,in the aqueous phase, individual hydrogen bonds haveattractive electrostatic components. In all cases a spontaneousformation of the complexes in the aqueous phase are observed,while in the gas phase a considerable energy barrier must beovercome (between 100.8 to 263.2 kJmol􀀀 1). The intermoleculardistance at which this barrier is indicates when the hydrogenbondinteractions begin to take importance between thedimers and the corresponding molecular recognition amongthem. The IQA analysis shows that in aqueous phase, thehydrogen bonds N􀀀 H···O are mainly electrostatic in nature witha certain covalent character which increases linearly with thedecrease of internuclear distances H···O. The H···H interactionsobserved are stabilizing and they are mainly quantum in nature.