Effect of microhydration on the atmospherically important metastable carbonyl sulfide anion: Structure, energetic, and infrared study

Abstract

Structure, energetics, and vibrational frequency of the microhydrated carbonyl sulfide anion [OCS−(H2O)n (n = 1–6)] have been explored by the systematic ab initio study to have a comprehensive understanding about the hydration‐induced stabilization phenomenon of OCS−. Water binds with the OCS− in single hydrogen‐bonded (SHB) or double hydrogen‐bonded (DHB) fashion with OH ⋯S and OH ⋯O contacts. Maximum five water molecules can stay in a cyclic water network of these hydrated clusters forming interwater hydrogen bonding (IHB) with each other and out of this, maximum of two water molecules can bind directly to the OCS− in (DHB) arrangement. The stabilization energy values of OCS−(H2O)n depict that ion–water interaction is significant up to four water molecules and beyond that OCS− is stabilized by IHB between the water molecules. The CO stretching frequency of OCS− gets red shifted, whereas CS stretching frequency gets blue shifted on hydration. Charge analysis of hydrated clusters of OCS− indicates that negative charge moves toward oxygen from sulfur on hydration. © 2015 Wiley Periodicals, Inc.

Combined Molecular Dynamics, Atoms in Molecules, and IR Studies of the Bulk Monofluoroethanol and Bulk Ethanol To Understand the Role of Organic Fluorine in the Hydrogen Bond Network

“…A (3, −1) bond critical point (BCP) with a positive Laplacian (∇ 2 ) indicates the presence of noncovalent interaction, whereas, the presence of a (3, + 1) ring critical point (RCP) shows that the corresponding structure is cyclic in nature. The values of topological parameters shown in Table S2 are in the range of acceptable values for the noncovalent interaction. − It can be clearly seen that the linear structures of alcohols have the (3, −1) BCP between the O–H···O intermolecular hydrogen bond whereas (3, +1) RCP is present along with (3, −1) BCP for the closed structure assert their cyclic nature. The hydrogen-bonded complexes of MFE shows the presence of (3, −1) BCP for the intermolecular O–H···O and O–H···F interactions confirming the presence of these hydrogen bonds in the linear MFE complexes.…”

Charge-Shifted Weak Noncovalent Interactions in the Atmospherically Important OCS Microhydrates

“…The complexation energy (ΔE Comp ) of the mono to pentahydrated OCS complexes was calculated using the eq 1, where the zero-point vibrational energy (ZPVE) and basis-set superposition error (BSSE) corrected total energy of OCS and water were subtracted from the ZPVE, and BSSE corrected total energy of the complex. 17,18 Therefore, ΔE Comp measures the total energy released due to the complexation of neutral OCS with water accounting for both solute−solvent and solvent−solvent interaction. Further, the ZPVE and BSSE corrected incremental association energy (ΔE IA ) was calculated according to eq 2, where the energy of the most stable complex and energy of the water monomer was subtracted from the next higher-order complexes.…”

“…The present study thus unravels significant differences between the microhydrated clusters of metastable anionic OCS, which we have reported previously, 17,18 and the neutral OCS in terms of their structural organization and the type of interactions between the OCS and water molecules. The anionic OCS microhydrates are stabilized by typical…”

“…Although the presence of S OCS ···O W , O OCS ···O W , and C OCS ···O W interactions were previously reported between the neutral OCS and water molecules in the microhydrated clusters, the origin, type of such interactions, and their impact on the hydration behavior remain grossly overlooked. However, in sharp contrast, we previously observed that water molecule binds with the anionic OCS moiety only through H-bonding interactions in their microhydrated clusters. , …”

Effect of hydration on the organo-noble gas molecule HKrCCH: role of krypton in the stabilization of hydrated HKrCCH complexes

“…Hence, vibrational spectroscopy has been one of the most sensitive tools for the experimentalist to understand the nature of interaction between the interactive species. [36][37][38] The vibrational frequencies of hydrated HKrCCH complexes along with monomers have been calculated at the MP2/aug-cc-pVDZ level of calculation and the values are given in Table 4, Tables S3 and S4 (ESI †). The C-HÁ Á ÁO hydrogen bonded complex of the mono-hydrated HKrCCH shows a red shift for the C-H, Kr-H and CRC stretching frequencies whereas the Kr-HÁ Á ÁO hydrogen bonded complex of mono-hydrated HKrCCH shows a blue shift for the Kr-H stretching frequency and red shift for the C-H and CRC stretching frequencies.…”