Thiols as Hydrogen Bond Acceptors and Donors: Spectroscopy of 2-Phenylethanethiol Complexes

Abstract

Evidence and understanding of sulfur-centered hydrogen bonding, especially where the donor is a thiol, lags far behind that for conventional OH interactions. To help address this deficiency, conformer specific IR spectra of 2-phenylethanethiol (PET) and associated 1:1 solvent complexes have been measured in SH, OH, and CH stretch regions using resonant-two-photon-ionization (R2PI) and IR-UV ion dip spectroscopic techniques. The aromatic and aliphatic CH stretch regions show signature differences between anti and gauche conformers. Supported by ab initio calculations, a PET-water cluster with an OH···S arrangement and a PET-diethyl ether cluster expressing an SH···O interaction were identified. The SH stretch band of the SH···O complex is red-shifted and undergoes significant intensity enhancement compared to the bare molecule, which is characteristic of hydrogen bonding. These findings offer insight into the nature of the thiol functional group as a potential hydrogen bond donor and acceptor.

Investigation of GTP-dependent dimerization of G12X K-Ras variants using ultraviolet photodissociation mass spectrometry

“…This outcome implies engagement of fewer interactions between Raf RBD and the β-interface, since G12V K-Ras was more rigidly pre-organized prior to effector binding. Collectively these results suggest that mutations of K-Ras which introduce hydrogen-bonding groups (G12C, G12S) result in a stabilized β-interface, although it is also acknowledged that thiols form weaker hydrogen bonds than alcohols 75. In contrast, a bulkier, more hydrophobic substitution (G12V) relies preferentially on contacts along the α-interface for oncogenic activation of K-Ras.…”

Heterogeneous Fenton-like activity of novel metallosalophen magnetic nanocomposites: significant anchoring group effect

“…Moreover, the lone pair of S atom is prone to form hydrogen bonding with H 2 O 2 adjacent to catalytic site which facilitates bond cleavage of peroxide. 38 Thus, Fe(III)salophenCl anchored on thiolate-functionalized SMNP is an effective catalyst for removal of different structurally dyes pollutants, with further advantage of high catalyst durability.…”

Unbiased Detection of Cysteine Sulfenic Acid by 473 nm Photodissociation Mass Spectrometry: Toward Facile In Vivo Oxidative Status of Plasma Proteins

“…Moreover, the highest amount of cysteine oxiderivatized peptide was formed using DMSO as an organic solvent (black lines in Figure 3). This could be explained by the higher solubility of DabDn in DMSO or by the possible formation of H bonds with a thiol group in MeOH, 37 which could preserve the cysteine from oxidation. Furthermore, for both MeOH and DMSO solvents, the lowest percentage of organic phase tested (33%, squares) induces a greater formation of oxi-derivatized peptide.…”