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.
- Award ID(s):
- 2100870
- PAR ID:
- 10317315
- Date Published:
- Journal Name:
- Journal of the American Chemical Society
- Volume:
- 143
- Issue:
- 33
- ISSN:
- 0002-7863
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
More Like this
-
-
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.more » « less
-
Abstract Hydrogen sulfide (H2S) is an important reactive sulfur species that is involved in many biological functions, and H2S imbalances have been indicated as a potential biomarker for various diseases. Different H2S donors have been developed to deliver H2S directly to biological systems, but few reports include donors with optical responses that allow for tracking of H2S release. Moreover, donor systems that use the same chemistry to deliver H2S across a palette of fluorescent responses remain lacking. Here we report five thiol‐activated fluorescence turn‐on COS/H2S donors that utilize blue, yellow, orange, red, and near infrared‐emitting dyes functionalized with an H2S‐releasing sulfenyl thiocarbonate scaffold. Upon treatment with thiols, each donor provides a fluorescence turn‐on response (3–310‐fold) and high H2S release efficiencies (>60 %). Using combined electrode and fluorescence experiments, we directly correlate the measured H2S release with the fluorescence response. All donors are biocompatible and release H2S in live cell environments. In addition, we demonstrate that the NIR donor allows for imaging H2S release in live rats via subcutaneous injection of the donor loaded into an alginate gel, which to the best of our knowledge is the first in vivo tracking of H2S release from a fluorogenic donor in non‐transparent organisms.
-
Abstract Hydrogen sulfide (H2S) is an important reactive sulfur species that is involved in many biological functions, and H2S imbalances have been indicated as a potential biomarker for various diseases. Different H2S donors have been developed to deliver H2S directly to biological systems, but few reports include donors with optical responses that allow for tracking of H2S release. Moreover, donor systems that use the same chemistry to deliver H2S across a palette of fluorescent responses remain lacking. Here we report five thiol‐activated fluorescence turn‐on COS/H2S donors that utilize blue, yellow, orange, red, and near infrared‐emitting dyes functionalized with an H2S‐releasing sulfenyl thiocarbonate scaffold. Upon treatment with thiols, each donor provides a fluorescence turn‐on response (3–310‐fold) and high H2S release efficiencies (>60 %). Using combined electrode and fluorescence experiments, we directly correlate the measured H2S release with the fluorescence response. All donors are biocompatible and release H2S in live cell environments. In addition, we demonstrate that the NIR donor allows for imaging H2S release in live rats via subcutaneous injection of the donor loaded into an alginate gel, which to the best of our knowledge is the first in vivo tracking of H2S release from a fluorogenic donor in non‐transparent organisms.