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1. Examination of the structures, energetics, and vibrational frequencies of small sulfur‐containing prototypical dimers, (H ₂ S) ₂ and H ₂ O/H ₂ S

   https://doi.org/10.1002/jcc.25578  

   Dreux, Katelyn M.; Tschumper, Gregory S. (October 2018, Journal of Computational Chemistry)

   The optimized geometries, vibrational frequencies, and dissociation energies from MP2 and CCSD(T) computations with large correlation consistent basis sets are reported for (H₂S)₂and H₂O/H₂S. Anharmonic vibrational frequencies have also been computed with second‐order vibrational perturbation theory (VPT2). As such, the fundamental frequencies, overtones, and combination bands reported in this study should also provide a useful road map for future spectroscopic studies of the simple but important heterogeneous H₂O/H₂S dimer in which the hydrogen bond donor and acceptor can interchange, leading to two unique minima with very similar energies. Near the CCSD(T) complete basis set limit, the HOH⋯SH₂configuration (H₂O donor) lies only 0.2 kcal mol⁻¹below the HSH⋯OH₂structure (H₂S donor). When the zero‐point vibrational energy is included, however, the latter configuration becomes slightly lower in energy than the former by <0.1 kcal mol⁻¹. © 2018 Wiley Periodicals, Inc. 

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2. Fluorogenic hydrogen sulfide (H ₂ S) donors based on sulfenyl thiocarbonates enable H ₂ S tracking and quantification

   https://doi.org/10.1039/c8sc05200j  

   Zhao, Yu; Cerda, Matthew M.; Pluth, Michael D. (February 2019, Chemical Science)

   Hydrogen sulfide (H 2 S) is an important cellular signaling molecule that exhibits promising protective effects. Although a number of triggerable H 2 S donors have been developed, spatiotemporal feedback from H 2 S release in biological systems remains a key challenge in H 2 S donor development. Herein we report the synthesis, evaluation, and application of caged sulfenyl thiocarbonates as new fluorescent H 2 S donors. These molecules rely on thiol cleavage of sulfenyl thiocarbonates to release carbonyl sulfide (COS), which is quickly converted to H 2 S by carbonic anhydrase (CA). This approach is a new strategy in H 2 S release and does not release electrophilic byproducts common from COS-based H 2 S releasing motifs. Importantly, the release of COS/H 2 S is accompanied by the release of a fluorescent reporter, which enables the real-time tracking of H 2 S by fluorescence spectroscopy or microscopy. Dependent on the choice of fluorophore, either one or two equivalents of H 2 S can be released, thus allowing for the dynamic range of the fluorescent donors to be tuned. We demonstrate that the fluorescence response correlates directly with quantified H 2 S release and also demonstrate the live-cell compatibility of these donors. Furthermore, these fluorescent donors exhibit anti-inflammatory effects in RAW 264.7 cells, indicating their potential application as new H 2 S-releasing therapeutics. Taken together, sulfenyl thiocarbonates provide a new platform for H 2 S donation and readily enable fluorescent tracking of H 2 S delivery in complex environments. 

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3. Anchoring the hydrogen sulfide dimer potential energy surface to juxtapose (H ₂ S) ₂ with (H ₂ O) ₂

   https://doi.org/10.1063/5.0008929  

   Perkins, Morgan A.; Barlow, Kayleigh R.; Dreux, Katelyn M.; Tschumper, Gregory S. (June 2020, The Journal of Chemical Physics)
4. Dithioesters: simple, tunable, cysteine-selective H ₂ S donors

   https://doi.org/10.1039/c8sc04683b  

   Cerda, Matthew M.; Newton, Turner D.; Zhao, Yu; Collins, Brylee K.; Hendon, Christopher H.; Pluth, Michael D. (February 2019, Chemical Science)

   Dithioesters have a rich history in polymer chemistry for RAFT polymerizations and are readily accessible through different synthetic methods. Here we demonstrate that the dithioester functional group is a tunable motif that releases H 2 S upon reaction with cysteine and that structural and electronic modifications enable the rate of cysteine-mediated H 2 S release to be modified. In addition, we use (bis)phenyl dithioester to carry out kinetic and mechanistic investigations, which demonstrate that the initial attack by cysteine is the rate-limiting step of the reaction. These insights are further supported by complementary DFT calculations. We anticipate that the results from these investigations will allow for the further development of dithioesters as important chemical motifs for studying H 2 S chemical biology. 

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5. Heterolytic H–H and H–B Bond Cleavage Reactions of {(IPr)Ni(μ-S)} ₂

   https://doi.org/10.1021/acs.inorgchem.7b01420  

   Olechnowicz, Frank; Hillhouse, Gregory L.; Cundari, Thomas R.; Jordan, Richard F. (July 2017, Inorganic Chemistry)