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. 2026 Jul 14;17(29):8206–8211. doi: 10.1021/acs.jpclett.6c01429

Gas-Phase Infrared Spectroscopic Investigation of S–H···S Hydrogen Bonds in (H2S) n (n = 2–6) Clusters

Chengcheng Wei 1, Yoshiyuki Matsuda 1,*, Asuka Fujii 1
PMCID: PMC13403306  PMID: 42444489

Abstract

While O–H···O hydrogen (H) bonds have been vigorously investigated, gas-phase studies of S–H···S H bonds remain very limited, especially in cases where multiple H bonds form a network. In this study, we investigate S–H···S H bonds in hydrogen sulfide clusters, (H2S) n (n = 2–6), in the gas phase with size-selective infrared spectroscopy based on vacuum ultraviolet photoionization detection. For clusters with n ≥ 3, the H-bonded SH stretching frequency remains nearly constant irrespective of the cluster size, a trend that contrasts with previously reported observations from the Ar matrix isolation spectra. (H2S) n (n > 3) clusters prefer to form dense three-dimensional H-bond networks to enhance the contribution of dispersion forces. These behaviors of (H2S) n significantly differ from those of the OH H-bond networks in (H2O) n . This study reveals that S–H···S H-bond networks in (H2S) n are characterized by weak cooperativity and a substantial contribution from dispersion forces.

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Sulfur-containing hydrogen (H) bonds have garnered significant attention across various scientific fields. − While it has been revealed that their characteristics differ from those of conventional OH···O H bonds, many aspects remain elusive. − One such aspect is the cooperativity of sulfur-containing H bonds. In typical H bonds, strong cooperativity is observed; as H bonds form sequential networks, their mutual strengths are synergistically enhanced. − This stepwise emergence of cooperative effects, accompanying the development of the H-bond network, has been extensively studied in gas-phase water clusters, (H2O) n , via infrared (IR) spectroscopy, where it is observed as a significant red shift in the OH stretching frequency with an increasing cluster size. − In contrast, most studies on sulfur-containing H bonds in gas-phase clusters have been limited to 1:1 complexes, and there has been almost no investigation into networks where multiple H bonds are linked. −

Hydrogen sulfide (H2S) is the most fundamental model molecule for sulfur-containing H bonds. Thus, its clusters, (H2S) n , are expected to provide a foundational basis for discussing the cooperativities of these bonds. However, IR spectroscopy of gas-phase (H2S) n has only been reported up to the dimer (n = 2). While studies using microwave spectroscopy exist, they do not provide direct insight into the strengths of the H bonds. On the other hand, IR spectroscopic studies of (H2S) n in argon (Ar) matrices have been reported, showing a stepwise red shift in the SH stretching frequency for n = 2–4, similar to the behaviors of water clusters of corresponding sizes. However, it is well-known that the SH···S H bond is significantly weaker than those between water molecules and is dominated by dispersion forces. , Therefore, it must be noted that an environment surrounded by Ar atoms, which themselves exhibit dispersion forces, may not be truly inert toward this specific system.

In this study, we report the IR spectra of (H2S) n (n = 2–6) in the S–H stretch region in the gas phase, to elucidate the H-bond properties of S–H bonds and their cooperativities in intermolecular interactions. To interpret the observed spectral profiles, we employ the coupled-cluster method (CCSD) for geometry optimizations and vibrational calculations. Our findings indicate very weak cooperativity among the S–H···S H bonds in (H2S) n along with a substantial contribution from dispersion forces.

Figure shows the observed IR spectra of (H2S) n (n = 2–6) in the SH stretching vibrational region. Of these, only the IR spectrum of (H2S)2 has already been reported and was remeasured in this study. Its spectral profile is essentially the same as the previous report, but the band features have been observed with higher resolution. The spectra of (H2S) n (n = 3–6) exhibit essentially identical profiles, each characterized by a single band located at nearly the same position within the H-bonded SH stretching region. These bands are red-shifted by 5 cm–1 compared to the H-bonded SH stretching bands of the dimer. In the present spectroscopic study, there remains some unclearness in the size selection. Although the ion intensities are size-selectively monitored, the monitored mass channels might contain contributions from the dissociation of larger clusters during the photoionization process. In such cases, while a monitored channel may include fragments from larger species, it remains free from any contributions from smaller clusters. Unfortunately, since tuning the wavelength of the VUV light used for ionization was not practically possible in this study, it is difficult to experimentally and quantitatively estimate the extent to which fragments from larger clusters contribute to the spectrum of each size for n ≥ 3 (the energetics of fragmentation accompanying ionization are discussed in Figure S3 of the Supporting Information). However, if there were contributions from larger sizes and their spectra varied depending on the size, the spectra of larger clusters would overlap with those of smaller ones. This should cause observable changes in the spectra, such as shifts or broadening, as the size increases. In this study, the spectra remained essentially unchanged for sizes from n = 3 to 6. The only plausible interpretation for this is that the spectra of neutral clusters are indistinguishable from one another in this size range; even if spectra of different sizes overlap, they cannot be discernibly observed because the bands are located at almost exactly the same positions. Therefore, we emphasize that the remaining experimental ambiguity regarding cluster size selectivity does not pose a problem in interpreting the spectra within the n = 3–6 size range.

1.

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(a–e) Observed IR spectra of the (H2S) n (n = 2–6) clusters recorded in the SH stretching region.

Figure S1 of the Supporting Information shows (a) the observed spectrum of (H2S)2 and (b) the simulated IR spectrum for its unique stable structure, which is characterized by a SH···S H bond. In the monomer of H2S in the gas phase, the symmetric (ν1) and antisymmetric (ν3) SH stretching bands are observed at 2614 and 2628 cm–1, respectively. − The H-bonded SH stretching band in (H2S)2 is red-shifted by 26 cm–1 relative to ν1 of the monomer. The simulated spectrum is in good agreement with the observed one.

Figure shows (a) the observed IR spectrum of (H2S)3 and (b and c) the simulated IR spectra of its two stable structures, Tr­(I) and Tr­(II), along with their relative energies (REs) and binding energies (BEs). Their schematic structures are also provided in the figure. Both simulated isomers possess the cyclic H-bonded structures that differ only in the orientation of their SH bonds. Similar types of isomers have also been reported in previous Ar matrix isolation IR spectroscopic studies. These two isomers likely coexist, as the calculated energy difference between them is negligibly small (<1 kJ mol–1). The observed band feature, characterized by a single strong band, is well-reproduced by the antisymmetric SH stretching mode, which has the highest intensity in the simulated spectra. Therefore, we conclude that these cyclic structures are observed in the spectrum.

2.

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(a) Observed IR spectrum of (H2S)3 and (b and c) simulated IR spectra of its two isomers. The simulated spectra are calculated at the CCSD/aug-cc-pVDZ level, and frequencies are scaled by 0.962. Relative energies (REs), corrected for zero-point vibrational energy (ZPE), and binding energies (BEs), corrected for both ZPE and basis set superposition error (BSSE), are in kJ mol–1.

Figure shows (a) the observed spectrum of (H2S)4 and (b–f) the simulated IR spectra for its stable isomers depicted in the figure with their REs and BEs. The simulated frequencies are summarized in Table S1 of the Supporting Information. Unlike the clusters up to n = 3, a wide variety of stable structures are identified for sizes larger than this. The most stable structure, Te­(I), along with Te­(II) and Te­(V) form dense three-dimensional (3D) type structures, while Te­(III) possesses a two-dimensional (2D) cyclic H-bonded structure, which are similar to that of the corresponding water cluster, (H2O)4. Te­(IV) forms a bicyclic structure. Similar types of isomers have also been reported in previous Ar matrix isolation IR spectroscopic studies and some theoretical works. − Notably, higher level CCSD­(T) calculations also identify that the RE of 3D structures is 3.68 kJ mol–1 lower than the 2D cyclic H-bonded structure. Consistent with this result, the counterpoise-corrected CCSD­(T)/CBS calculations show that the BE of 3D structures is 1.31 kJ mol–1 lower than 2D cyclic H-bonded structure. The predicted vibrational frequencies for the low-energy 3D structures, Te­(I) and Te­(II), are very close to those of the cyclic n = 3 clusters, showing only negligible shifts. In contrast, cyclic structures exhibit noticeable, albeit small, frequency shifts, reflecting the cooperative enhancement of H bonds. The experimental spectrum shows better agreement with the 3D structures, supporting the preferential formation of stable 3D networks. This result stands in contrast to (H2S)4 in Ar matrices and (H2O)4 in the gas phase, for both of which only the cyclic structures have been reported. The origin of this discrepancy will be discussed later.

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(a) Observed IR spectrum of (H2S)4 and (b–f) simulated IR spectra of five isomers. The simulated spectra were calculated at the CCSD/aug-cc-pVDZ level. Simulated frequencies are scaled by 0.962. REs, corrected for ZPE, and BEs, corrected for both ZPE and BSSE, are in kJ mol–1.

In the observed 3D structures, the S–H···S bond angles deviate significantly from 180° (linearity). While this is disadvantageous for optimizing H bonding, it facilitates shorter S···S distances (as shown in Figure S2 of the Supporting Information). These shorter distances are expected to significantly enhance dispersion interactions among sulfur atoms, as dispersion interactions are highly sensitive to atomic distances. This effect contributes significantly to the stability of the (H2S) n clusters in addition to S–H···S H bonds. Consistent with this interpretation, in previous theoretical calculations of tetramers and pentamers, they also reported that this type of interaction is a stabilizing interaction. Previous studies on 1:1 clusters have already highlighted the critical role of dispersion in sulfur-containing H bonds, attributable to the large polarizability of sulfur. , The weight of dispersion is significantly larger in Te­(I) than in Te­(III) (as shown in Table S2 of the Supporting Information). Therefore, for networks of this size, the system prioritizes enhancing dispersion contributions over H-bonding cooperativity. This structural transition is further attributed to the relatively low polarity of the S–H bond, which stems from the small electronegativity difference between sulfur and hydrogen. The resulting weak inductive cooperativity fails to provide sufficient non-additive stabilization in the H2S clusters. Consequently, dispersion forces emerge as the dominant factor, dictating the energetic landscape and steering the system toward the observed 3D networks.

Figure shows (a) the observed IR spectrum and (b–e) the simulated IR spectra of the most stable four isomers of (H2S)5 at the CCSD/aug-cc-pVDZ level. The scaled simulated frequencies are summarized in Table S1 of the Supporting Information. Similar types of these isomers have also been reported in previous theoretical works. − The simulated spectra show almost no peak frequency shifts from those of the trimer and tetramer; instead, only a slight broadening of the bands toward the lower wavenumber side is predicted. These simulated spectra are in good agreement with the experimental spectrum, indicating that these isomers are indeed observed. Similar to the observations in the tetramers, the S–H···S bond angles in these 3D structures deviate significantly from linearity. This deviation facilitates shorter S···S distances, thereby enhancing dispersion interactions. Consequently, the same mechanism proposed for the tetramer can be applied to the pentamer to interpret the observed structural trend.

4.

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(a) Observed IR spectrum of (H2S)5 and (b–e) simulated IR spectra of four isomers. The simulated spectra were calculated at the CCSD/aug-cc-pVDZ level. Simulated frequencies are scaled by 0.962. REs, corrected for ZPE, and BEs, corrected for both ZPE and BSSE, are in kJ mol–1.

Figure shows (a) the observed IR spectrum and (b–e) the simulated IR spectra of the most stable four isomers of (H2S)6. The scaled simulated frequencies are summarized in Table S1 of the Supporting Information. The lowest three, He­(I), He­(II), and He­(III), have the dense 3D type structures. He­(IV) involves a partial 2D H-bond network with a single molecule out of the ring. Similar types of isomers were reported in previous theoretical works. , The structural and spectral trends of the hexamer are also consistent with those observed for the tetramer and pentamer. The simulated spectra of these low-energy isomers are in good agreement with the observed spectrum, showing negligible frequency shifts from the smaller clusters along with minor line broadening.

5.

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(a) Observed IR spectrum of (H2S)6 and (b–e) simulated IR spectra of four isomers. The simulated spectra were calculated at the CCSD/aug-cc-pVDZ level. Simulated frequencies are scaled by 0.962. REs, corrected for ZPE, and BEs, corrected for both ZPE and BSSE, are in kJ mol–1.

In summary of the above results, in the observed IR spectra of the clusters at n = 3–6, only a single band is observed at nearly the same frequency across the sizes. These results demonstrate very weak cooperativity in the H-bond networks of (H2S) n . Low-energy isomer searches and IR spectral simulations at n = 3–6 at the CCSD/aug-cc-pVDZ level reveal that the most stable isomer shifts from the cyclic structure to a dense 3D configuration at n = 4. The calculated H-bonded SH stretching bands in these lowest energy isomers are located in nearly the same frequency region, resulting in an essentially negligible shift as the cluster size increases. These experimental and simulated results were in excellent agreement. Therefore, we conclude that (H2S) n (n = 4–6) clusters form dense 3D structures in which dispersion forces are enhanced at the expense of H-bond cooperativity. We also note that this conclusion is consistent with the latest, highest level computational studies. ,

The behaviors observed in this study differ from those reported in a recent IR spectroscopic study of (H2S) n (n = 2–4) in an Ar matrix. In the matrix study, the observed H-bonded SH stretching bands at 2581.5, 2568.4, and 2547.6 cm–1 were assigned to the dimer, trimer, and tetramer, respectively. This indicates that the H-bonded SH stretching bands exhibit gradual red shifts down to ∼2550 cm–1 as the cluster size increases. Such stepwise spectral shifts provide clear evidence of cooperative effects within their H-bond networks. In this Ar matrix study, it was concluded that the tetramer prefers the cyclic Te­(III) structure based on MP2-CP/aug-cc-pV­(Q+d)­Z and ωB97X-D/aug-cc-pV­(D+d)­Z levels. In contrast, the present study at the CCSD/aug-cc-pVDZ level identifies Te­(I) as the most stable structure. The difference in the treatments of dispersion forces likely affects the evaluation of relative energies. For clusters of n ≥ 3 in the present gas-phase study, all the H-bonded SH stretching bands are observed near 2583 cm–1 with no significant size-dependent shifts. Consequently, the observed spectral profiles and thus the identified isomer structures differ between the gas phase and Ar matrix. Due to the inherent weakness of S–H···S H bonding, the solvation effect of the surrounding Ar matrix becomes significant. In the Ar matrix environment, the (H2S) n clusters are surrounded by Ar atoms and therefore experience additional Ar···S interactions that are absent in the gas phase. The magnitude of this Ar···S dispersion interaction is considered to be approximately proportional to the surface area of the (H2S) n cluster accessible to Ar atoms. Compared to the squeezed 3D structures, the planar 2D structures possess a larger surface area, allowing them to interact with a greater number of Ar atoms. Consequently, the relative stability is reversed in the Ar matrix compared to the gas phase, which explains why the 2D structures were observed as the most stable conformers in the Ar matrix. Although quantum chemical calculations would be required to rigorously analyze these qualitative inferences, simulating the matrix environment is practically highly challenging. Fully surrounding a cluster as small as the tetramer requires approximately 10–20 Ar atoms, and the structure of the first solvation layer could also be influenced by the second layer. Therefore, we refrain from engaging in quantitative discussions in this manuscript.

On the other hand, gas-phase clusters governed solely by their intrinsic intermolecular interactions, (H2S) n , are free to undergo structural relaxation. Consequently, compact 3D structures, in which S–H···S bond angles deviate significantly from 180°, become increasingly favorable because their compact geometries enhance intermolecular dispersion interactions. Compared to the compact 3D networks, the planar cyclic configurations provide more accessible space around the sulfur atoms for Ar atoms. The resulting enhancement of dispersion interactions with the matrix likely shifts the structural preference toward cyclic forms. This accounts for the discrepancy between the structures identified in the Ar matrix isolation studies and the present gas-phase observations. Furthermore, the results in the Ar matrix imply that S–H···S H bonds, while inherently weak, possess the potential to exhibit cooperative effects. This supports our conclusion that, in the gas phase, such cooperativity is sacrificed in favor of enhancing dispersion interactions among sulfur atoms.

Since sulfur and oxygen both belong to group 16, H2S is often considered an analogue of H2O. However, the well-established IR spectra of (H2O) n stands in sharp contrast to the present results of (H2S) n . In water clusters, H-bonded O–H stretching bands exhibit large, stepwise red shifts as the cluster size increases. (H2O) n (n = 3–5) clusters prefer 2D cyclic structures, while (H2O)6 exhibits a delicate competition between 3D cages and 2D cyclic structures. − These H-bonded OH stretching bands gradually shift to lower frequency (down to ∼3000 cm–1) as n increases. In contrast, the H-bonded SH stretching bands for (H2S) n (n ≥ 3) observed in this study appear at nearly the same position. (H2S) n (n ≥ 4) clusters prefer dense 3D structures stabilized by dispersion forces in addition to H bonds. Such compact and dense 3D configurations have no counterpart in water clusters within this size regime. The discrepancy between (H2S) n and (H2O) n arises from the different balance between the H bonding and dispersion (although a strict separation of the two is physically meaningless). This finding highlights the significant contribution of dispersions in sulfur-containing systems, even within S–H···S H-bond networks.

In summary, IR spectroscopy and quantum chemical calculations of (H2S) n (n = 3–6) were employed to characterize the structural motifs and the SH···S H bonds in these clusters. Unlike (H2O) n clusters, for which the H-bonded O–H stretching bands exhibit large, stepwise red shifts with an increasing cluster size. Both the experiments and simulations of (H2S) n consistently show no significant frequency shifts in the H-bonded SH stretching bands with an increasing size (n ≥ 3). These results indicate a preference of compact and dense 3D structures in (H2S) n (n > 3), where dispersion forces are enhanced at the expense of H-bond cooperativity. In contrast, (H2O) n (n = 3–5) clusters prefer 2D cyclic structures, and only (H2O)6 exhibits a delicate competition between 3D cages and 2D cyclic structures. Thus, this study demonstrates the unique properties of intermolecular interactions in (H2S) n in comparison to those of (H2O) n in the gas phase.

Supplementary Material

jz6c01429_si_001.pdf (1.2MB, pdf)

Acknowledgments

This study was supported by a Grant-in-Aid for Scientific Research (Projects 21H04671, 25K03402, and 26K01454) from JSPS. The authors thank Prof. T. Maeyama for his helpful discussion. C.W. appreciates the scholarship supported by the Strategic Student Acceptance Program of Tohoku University. The computation was performed using the Research Center for Computational Science, Okazaki, Japan (25-IMS-C091).

The data supporting this article are included in the Supporting Information.

The Supporting Information is available free of charge at https://pubs.acs.org/doi/10.1021/acs.jpclett.6c01429.

  • Methods (experimental and theoretical), simulated IR spectra of (H2S)2 (Figure S1), optimized structures of the most stable isomer of (H2S) n (n = 2–6) along with that of the water tetramer (Figure S2), simulated frequencies of these isomers (Table S1), energy decomposition of the overall binding energy of main structures for (H2S) n (n = 2–6) (Table S2), and configurations and coordinates of the stable structures of (H2S) n (n = 2–6) (PDF)

The authors declare no competing financial interest.

References

  1. Santos J. C., Enrique-Romero J., Lamberts T., Linnartz H., Chuang K.-J.. Formation of S-Bearing Complex Organic Molecules in Interstellar Clouds via Ice Reactions with C2H2, HS, and Atomic H. ACS Earth Space Chem. 2024;8(8):1646–1660. doi: 10.1021/acsearthspacechem.4c00150. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Hartle M. D., Pluth M. D.. A practical guide to working with H2S at the interface of chemistry and biology. Chem. Soc. Rev. 2016;45(22):6108–6117. doi: 10.1039/C6CS00212A. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Metya S., Goettl S. J., Medvedkov I. A., Alves M. O., Galvão B. R. L., Kaiser R. I.. Gas-Phase Synthesis of Germanium Monosulfide (GeS, X1Σ+) via the Elementary Reaction of Atomic Germanium (Ge, 3P) with Hydrogen Sulfide (H2S, X1A1) J. Phys. Chem. Lett. 2025;16(19):4780–4787. doi: 10.1021/acs.jpclett.5c00574. [DOI] [PubMed] [Google Scholar]
  4. Juanes M., Lesarri A., Pinacho R., Charro E., Rubio J. E., Enríquez L., Jaraíz M.. Sulfur Hydrogen Bonding in Isolated Monohydrates: Furfuryl Mercaptan versus Furfuryl Alcohol. Chem. - Eur. J. 2018;24(25):6564–6571. doi: 10.1002/chem.201705727. [DOI] [PubMed] [Google Scholar]
  5. Ghosh S., Chopra P., Wategaonkar S.. C–H···S interaction exhibits all the characteristics of conventional hydrogen bonds. Phys. Chem. Chem. Phys. 2020;22(31):17482–17493. doi: 10.1039/D0CP01508C. [DOI] [PubMed] [Google Scholar]
  6. Biswal H. S., Wategaonkar S.. Sulfur, Not Too Far Behind O, N, and C: SH···π Hydrogen Bond. J. Phys. Chem. A. 2009;113(46):12774–12782. doi: 10.1021/jp907747w. [DOI] [PubMed] [Google Scholar]
  7. Kananenka A. A., Skinner J. L.. Unusually strong hydrogen bond cooperativity in particular (H2O)20 clusters. Phys. Chem. Chem. Phys. 2020;22(32):18124–18131. doi: 10.1039/D0CP02343D. [DOI] [PubMed] [Google Scholar]
  8. Kar T., Scheiner S.. Comparison of Cooperativity in CH···O and OH···O Hydrogen Bonds. J. Phys. Chem. A. 2004;108(42):9161–9168. doi: 10.1021/jp048546l. [DOI] [Google Scholar]
  9. King B. F., Weinhold F.. Structure and spectroscopy of (HCN)n clusters: Cooperative and electronic delocalization effects in C–H···N hydrogen bonding. J. Chem. Phys. 1995;103(1):333–347. doi: 10.1063/1.469645. [DOI] [Google Scholar]
  10. Zhang B., Yu Y., Zhang Y.-Y., Jiang S., Li Q., Hu H.-S., Li G., Zhao Z., Wang C., Xie H., Zhang W., Dai D., Wu G., Zhang D. H., Jiang L., Li J., Yang X.. Infrared spectroscopy of neutral water clusters at finite temperature: Evidence for a noncyclic pentamer. P. Natl. Acad. Sci. USA. 2020;117(27):15423–15428. doi: 10.1073/pnas.2000601117. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. Burnham C. J., Xantheas S. S., Miller M. A., Applegate B. E., Miller R. E.. The formation of cyclic water complexes by sequential ring insertion: Experiment and theory. J. Chem. Phys. 2002;117(3):1109–1122. doi: 10.1063/1.1483259. [DOI] [Google Scholar]
  12. Keutsch F. N., Saykally R. J.. Water clusters: Untangling the mysteries of the liquid, one molecule at a time. P. Natl. Acad. Sci. USA. 2001;98(19):10533–10540. doi: 10.1073/pnas.191266498. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. Buck U., Ettischer I., Melzer M., Buch V., Sadlej J.. Structure and spectra of three-dimensional (H2O)n clusters, n = 8, 9, 10. Phys. Rev. Lett. 1998;80(12):2578–2581. doi: 10.1103/PhysRevLett.80.2578. [DOI] [Google Scholar]
  14. Nauta K., Miller R. E.. Formation of Cyclic Water Hexamer in Liquid Helium: The Smallest Piece of Ice. Science. 2000;287(5451):293–295. doi: 10.1126/science.287.5451.293. [DOI] [PubMed] [Google Scholar]
  15. Huisken F., Kaloudis M., Kulcke A.. Infrared spectroscopy of small size-selected water clusters. J. Chem. Phys. 1996;104(1):17–25. doi: 10.1063/1.470871. [DOI] [Google Scholar]
  16. Pribble R. N., Zwier T. S.. Size-Specific Infrared Spectra of Benzene-(H2O)n Clusters (n = 1 through 7): Evidence for Noncyclic (H2O)n Structures. Science. 1994;265(5168):75–79. doi: 10.1126/science.265.5168.75. [DOI] [PubMed] [Google Scholar]
  17. Gruenloh C. J., Carney J. R., Arrington C. A., Zwier T. S., Fredericks S. Y., Jordan K. D.. Infrared Spectrum of a Molecular Ice Cube: The S4 and D2d Water Octamers in Benzene-(Water)8 . Science. 1997;276(5319):1678–1681. doi: 10.1126/science.276.5319.1678. [DOI] [Google Scholar]
  18. Torres-Hernández F., Pinillos P., Li W., Saragi R. T., Camiruaga A., Juanes M., Usabiaga I., Lesarri A., Fernández J. A.. Competition between O–H and S–H Intermolecular Interactions in Conformationally Complex Systems: The 2-Phenylethanethiol and 2-Phenylethanol Dimers. J. Phys. Chem. Lett. 2024;15(21):5674–5680. doi: 10.1021/acs.jpclett.4c00903. [DOI] [PMC free article] [PubMed] [Google Scholar]
  19. Tang J., Wen W., Lesarri A., Feng G.. Sulfur-centered non-covalent interactions: emerging themes and challenges from rotational spectroscopy. Phys. Chem. Chem. Phys. 2026;28:9088–9102. doi: 10.1039/D6CP00259E. [DOI] [PubMed] [Google Scholar]
  20. Silva W. G. D. P., van Wijngaarden J.. Sulfur as a hydrogen bond donor in the gas phase: Rotational spectroscopic and computational study of 3-mercaptopropionic acid. J. Mol. Spectrosc. 2019;362:1–7. doi: 10.1016/j.jms.2019.05.009. [DOI] [Google Scholar]
  21. Biswal H. S., Gloaguen E., Loquais Y., Tardivel B., Mons M.. Strength of NH···S Hydrogen Bonds in Methionine Residues Revealed by Gas-Phase IR/UV Spectroscopy. J. Phys. Chem. Lett. 2012;3(6):755–759. doi: 10.1021/jz300207k. [DOI] [PubMed] [Google Scholar]
  22. Mundlapati V. R., Ghosh S., Bhattacherjee A., Tiwari P., Biswal H. S.. Critical Assessment of the Strength of Hydrogen Bonds between the Sulfur Atom of Methionine/Cysteine and Backbone Amides in Proteins. J. Phys. Chem. Lett. 2015;6(8):1385–1389. doi: 10.1021/acs.jpclett.5b00491. [DOI] [PubMed] [Google Scholar]
  23. Jäger S., Khatri J., Meyer P., Henkel S., Schwaab G., Nandi A., Pandey P., Barlow K. R., Perkins M. A., Tschumper G. S., Bowman J. M., van der Avoird A., Havenith M.. On the nature of hydrogen bonding in the H2S dimer. Nat. Commun. 2024;15(1):9540. doi: 10.1038/s41467-024-53444-6. [DOI] [PMC free article] [PubMed] [Google Scholar]
  24. Bhattacherjee A., Matsuda Y., Fujii A., Wategaonkar S.. The Intermolecular S-H···Y (Y = S,O) Hydrogen Bond in the H2S Dimer and the H2S-MeOH Complex. ChemPhysChem. 2013;14(5):905–914. doi: 10.1002/cphc.201201012. [DOI] [PubMed] [Google Scholar]
  25. Das A., Mandal P. K., Lovas F. J., Medcraft C., Walker N. R., Arunan E.. The H2S Dimer is Hydrogen-Bonded: Direct Confirmation from Microwave Spectroscopy. Angew. Chem., Int. Ed. 2018;57(46):15199–15203. doi: 10.1002/anie.201808162. [DOI] [PubMed] [Google Scholar]
  26. Monu, Oram B. K., Bandyopadhyay B.. Revisiting the IR Spectra of H2S in an Argon Matrix: Identification of (H2S)n (n ≤ 4) Clusters via the Spectral Assignment of νS‑H Transitions. J. Phys. Chem. A. 2024;128(32):6703–6713. doi: 10.1021/acs.jpca.4c04025. [DOI] [PubMed] [Google Scholar]
  27. Brown L. R., Crisp J. A., Crisp D., Naumenko O. V., Smirnov M. A., Sinitsa L. N., Perrin A.. The Absorption Spectrum of H2S Between 2150 and 4260 cm–1: Analysis of the Positions and Intensities in the First (2ν2, ν1, and ν3) and Second (3ν2, ν1+ ν2, and ν2+ ν3) Triad Regions. J. Mol. Spectrosc. 1998;188(2):148–174. doi: 10.1006/jmsp.1997.7501. [DOI] [PubMed] [Google Scholar]
  28. Gillis J. R., Edwards T. H.. Analysis of 2ν2, ν1, and ν3 of H2S. J. Mol. Spectrosc. 1981;85(1):55–73. doi: 10.1016/0022-2852(81)90309-X. [DOI] [Google Scholar]
  29. Lechuga-Fossat L., Flaud J.-M., Camy-Peyret C., Johns J. W. C.. The spectrum of natural hydrogen sulfide between 2150 and 2950 cm–1 . Can. J. Phys. 1984;62(12):1889–1923. doi: 10.1139/p84-233. [DOI] [Google Scholar]
  30. Sarkar S., Monu, Bandyopadhyay B.. Cooperative nature of the sulfur centered hydrogen bond: investigation of (H2S)n (n = 2–4) clusters using an affordable yet accurate level of theory. Phys. Chem. Chem. Phys. 2019;21(45):25439–25448. doi: 10.1039/C9CP05326C. [DOI] [PubMed] [Google Scholar]
  31. Hoffman M. P., Xantheas S. S.. Cooperativity of the Chalcogen Bond Juxtaposed to the Hydrogen Bond in the (H2X)n, X = O, S, Se, Te, n = 3, 4 Clusters. J. Am. Chem. Soc. 2026;148(10):10585–10598. doi: 10.1021/jacs.5c19414. [DOI] [PubMed] [Google Scholar]
  32. Ibargüen C., Guerra D., Hadad C. Z., Restrepo A.. Very weak interactions: structures, energies and bonding in the tetramers and pentamers of hydrogen sulfide. RSC Adv. 2014;4(102):58217–58225. doi: 10.1039/C4RA09430A. [DOI] [Google Scholar]
  33. Monu, Oram B. K., Bandyopadhyay B.. A unified cost-effective method for the construction of reliable potential energy surfaces for H2S and H2O clusters. Phys. Chem. Chem. Phys. 2021;23(33):18044–18057. doi: 10.1039/D1CP01544C. [DOI] [PubMed] [Google Scholar]
  34. Pinacho P., Pérez C., Stahn M., Saragi R. T., Hansen A., Grimme S., Lesarri A., Schnell M.. Hydrogen Bond Interaction Networks in the Mixed Pentamers of Hydrogen Sulfide and Water. J. Am. Chem. Soc. 2025;147(22):18576–18582. doi: 10.1021/jacs.4c18276. [DOI] [PMC free article] [PubMed] [Google Scholar]
  35. Hoffman M. P., Xantheas S. S.. H2 × 100: A Gold-Standard CCSD­(T)/CBS Benchmark Dataset of Binding Energies, Structures, and Harmonic Frequencies for (H2X) n , X = S, Se, Te, n = 2–4, and Assessment of Lower-Scaling Density Functional Theory Methods. J. Chem. Theory Comput. 2026;22:5539. doi: 10.1021/acs.jctc.6c00405. [DOI] [PubMed] [Google Scholar]
  36. Biswas P., Kothari A.. Gas phase acidity of H2S clusters: A computational study. Comput. Theor. Chem. 2025;1254:115520. doi: 10.1016/j.comptc.2025.115520. [DOI] [Google Scholar]
  37. Patkar D.. Uncovering the Individual Hydrogen Bond Strengths and Cooperativity in Pure (H2S) n and Mixed (H2O) m (H2S) n (m + n = 2 to 8) Clusters. ChemRxiv. 2025 doi: 10.26434/chemrxiv-2025-gwdd6. [DOI] [Google Scholar]
  38. Pérez C., Muckle M. T., Zaleski D. P., Seifert N. A., Temelso B., Shields G. C., Kisiel Z., Pate B. H.. Structures of Cage, Prism, and Book Isomers of Water Hexamer from Broadband Rotational Spectroscopy. Science. 2012;336(6083):897–901. doi: 10.1126/science.1220574. [DOI] [PubMed] [Google Scholar]
  39. Liu K., Brown M. G., Carter C., Saykally R. J., Gregory J. K., Clary D. C.. Characterization of a cage form of the water hexamer. Nature. 1996;381(6582):501–503. doi: 10.1038/381501a0. [DOI] [Google Scholar]
  40. Richardson J. O., Pérez C., Lobsiger S., Reid A. A., Temelso B., Shields G. C., Kisiel Z., Wales D. J., Pate B. H., Althorpe S. C.. Concerted hydrogen-bond breaking by quantum tunneling in the water hexamer prism. Science. 2016;351(6279):1310–1313. doi: 10.1126/science.aae0012. [DOI] [PubMed] [Google Scholar]
  41. Lee H. M., Suh S. B., Lee J. Y., Tarakeshwar P., Kim K. S.. Structures, energies, vibrational spectra, and electronic properties of water monomer to decamer. J. Chem. Phys. 2000;112(22):9759–9772. doi: 10.1063/1.481613. [DOI] [Google Scholar]
  42. Samala N. R., Agmon N.. Temperature and Nuclear Quantum Effects on the Stretching Modes of the Water Hexamer. J. Phys. Chem. A. 2020;124(40):8201–8208. doi: 10.1021/acs.jpca.0c05557. [DOI] [PMC free article] [PubMed] [Google Scholar]
  43. Wang Y., Bowman J. M.. IR Spectra of the Water Hexamer: Theory, with Inclusion of the Monomer Bend Overtone, and Experiment Are in Agreement. J. Phys. Chem. Lett. 2013;4(7):1104–1108. doi: 10.1021/jz400414a. [DOI] [PubMed] [Google Scholar]
  44. Tokić N., Eraković M., Cvitaš M. T.. Tunneling splittings in the energetically low-lying structural isomers of the water hexamer: the prism, the cage and the book. Phys. Chem. Chem. Phys. 2025;27(14):6938–6957. doi: 10.1039/D5CP00155B. [DOI] [PubMed] [Google Scholar]
  45. Duan S., Zhang I. Y., Xie Z., Xu X.. Identification of Water Hexamer on Cu(111) Surfaces. J. Am. Chem. Soc. 2020;142(15):6902–6906. doi: 10.1021/jacs.0c01549. [DOI] [PubMed] [Google Scholar]
  46. Santra B., Michaelides A., Fuchs M., Tkatchenko A., Filippi C., Scheffler M.. On the accuracy of density-functional theory exchange-correlation functionals for H bonds in small water clusters. II. The water hexamer and van der Waals interactions. J. Chem. Phys. 2008;129(19):194111. doi: 10.1063/1.3012573. [DOI] [PubMed] [Google Scholar]

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