Coupling Interactions between Sulfurous Acid and the Hydroperoxyl Radical

Abstract

Radical-molecule complexes associated with the hydroperoxyl radical (HOO) play an important role in atmospheric chemistry. Herein, the nature of the coupling interactions between sulfurous acid (H(2)SO(3)) and the HOO radical is systematically investigated at the B3LYP/6-311++G(3df,3pd) level of theory in combination with the atoms in molecules (AIM) theory, the natural bond orbital (NBO) method, and energy decomposition analyses (EDA). Eight stable stationary points possessing double H-bonding features were located on the H(2)SO(3)...HOO potential energy surface. The largest binding energies of -12.27 and -11.72 kcal mol(-1) are observed for the two most stable complexes, where both of them possess strong double intermolecular H-bonds of partially covalence. Moreover, the characteristics of the IR spectra for the two most stable complexes are discussed to provide some help for their possible experimental identification.

Theoretical studies on the coupling interactions in H2SO4⋯HOO˙⋯(H2O)n (n = 0–2) clusters: toward understanding the role of water molecules in the uptake of HOO˙ radical by sulfuric acid aerosols

“…Similar to our previous studies, 61 there are significant resonant couplings between the stretching vibrational modes of the O6-H7 bond of H 2 SO 4 fragment and O8-H9 bond of The relative energies between R1 and R2 are presented in Table 2. Obviously, R1 is lower in energy by about 5.60 kcal mol À1 than R2.…”

“…28 Obviously, both clusters are characterized by the double intermolecular H-bonds with the distances varying from 1.665 to 1.759 A ˚for O10Á Á ÁH7-O6 and 1.704 to 1.901 A ˚for O2(O4)Á Á ÁH9-O8 contacts, where the HOO radical acts as an H-bond donor and acceptor simultaneously. Here, it should be noted that the interaction mode of R1 is similar to the most stable cluster formed between H 2 SO 3 and HOO in our previous study, 61 where the corresponding H-bond distances of 1.689 and 1.640 A ˚have been observed, respectively. As displayed in Fig.…”

“…Here, it should be noted that a similar large binding energy of À12.27 kcal mol À1 has also been observed previously for the most stable cluster formed between H 2 SO 3 and HOO at the same level of theory. 61 Therefore, the optimum coupling mode between H 2 SO 4 and HOO in R1 cluster should be confirmed. To get a better understanding of the coupling interactions between H 2 SO 4 and HOO , further energy decomposition analyses have been performed using ADF program.…”

Methane activation on Fe4 cluster: A density functional theory study

“…AIM theory and NBO analysis which have been used to successfully determine intermolecular interactions of different systems were carried out on the basis of the optimized structures of Fe 4 -CH 4 system in order to better clarify the nature of the intermolecular interactions [18,[20][21][22][23][24][25][26][27]. In the AIM analyses, the existence of a bond is indicated by the presence of a so-called bond critical point (BCP).…”

Theoretical Insights into the Electron Capture Behavior of H2SO4···N2O Complex: A DFT and Molecular Dynamics Study

“…To investigate the electron redistribution details for H 2 SO 4 and N 2 O upon complexation, the electron density difference maps of them have been constructed based on the optimized complexes A and B. As shown in Figure 5 , electron redistribution mainly occurs along the intermolecular H-bond axis in the complexes, which is consistent with the features of the H-bonding complexes [ 39 , 40 , 41 ]. In more details, in complex A, the loss of the electron is mainly concentrated on the positions of the proton involved in the intermolecular H-bond in H 2 SO 4 and the other two atoms of N 2 O not participating in the H-bonds.…”