Observation of the Water-HNSO2 Complex

Junfei Xue; Xin Shao; Jia Li; Jun Li; Tarek Trabelsi; Joseph S Francisco; Xiaoqing Zeng

doi:10.1021/jacs.3c13127

Observation of the Water-HNSO₂ Complex

J Am Chem Soc. 2024 Feb 28;146(8):5455-5460. doi: 10.1021/jacs.3c13127. Epub 2024 Feb 15.

Authors

Junfei Xue¹, Xin Shao¹, Jia Li², Jun Li², Tarek Trabelsi³, Joseph S Francisco³, Xiaoqing Zeng¹

Affiliations

¹ Department of Chemistry, Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Fudan University, Shanghai 200433, China.
² School of Chemistry and Chemical Engineering and Chongqing Key Laboratory of Theoretical and Computational Chemistry, Chongqing University, Chongqing 401331, China.
³ Department of Earth and Environment Science and Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6243, United States.

PMID: 38359146
DOI: 10.1021/jacs.3c13127

Abstract

Sulfamic acid (NH₂SO₃H, SFA) is supposed to play an important role in aerosol new particle formation (NPF) in the atmosphere, and its formation mainly arises from the SO₃-NH₃ reaction system in which weakly bonded donor-acceptor complexes such as SO₃···NH₃ and isomeric HNSO₂···H₂O have been proposed as the key intermediates. In this study, we reveal the first spectroscopic observation of HNSO₂···H₂O in two forms in a solid Ar matrix at 10 K. The major form consists of two intermolecular H bonds by forming a six-membered ring structure with a calculated dissociation energy of 7.6 kcal mol^-1 at the CCSD(T)-F12a/aug-cc-pVTZ level of theory. The less stable form resembles SO₃···H₂O in containing a pure chalcogen bond (S···O) with a dissociation energy of 7.2 kcal mol^-1. The characterization of HNSO₂···H₂O with matrix-isolation IR spectroscopy is supported by D- and ¹⁸O-isotope labeling and quantum chemical calculations.