Disulfide Bond in Diethyl Disulfide: A Rotational Spectroscopic Study

Abstract

Diethyl disulfide was investigated by pulsed jet Fourier transform microwave spectroscopy. The spectroscopic study was complemented by ab initio calculations. The first two most stable conformers predicted at the MP2/6-311++G(d,p) level of theory were observed in the supersonic expansion. Two C and oneS isotopologues for the most stable conformer ( GGG) and two S isotopes for the second most stable form ( GGG') were also assigned in natural abundance, respectively, allowing a thorough investigation of the molecular structure and conformation. The relative population ratio of the two conformers in the supersonic expansion was estimated to be about 4:1.

The Characteristics of Disulfide‐Centered Hydrogen Bonds

“…Figure 1 presents the most stable isomer for each cluster, in which the DEDS adopts its lowest energy conformation (GGG). [21] The complete computational results for all three clusters are provided in Figures S1-S3 and Tables S1-S3.…”

The Characteristics of Disulfide‐Centered Hydrogen Bonds

“…The Boys–Bernardi's counterpoise method [20] was used to correct the basis set superposition error (BSSE). Figure 1 presents the most stable isomer for each cluster, in which the DEDS adopts its lowest energy conformation (GGG) [21] . The complete computational results for all three clusters are provided in Figures S1–S3 and Tables S1–S3.…”

“…A careful search of the rotational transitions belonging to other isomers of the three clusters was not successful. For DEDS⋅⋅⋅H 2 O and DEDS⋅⋅⋅HCONH 2 , their second most stable isomers ( II ) were predicted to be formed with the GGT conformer of DEDS, whose rotational spectrum has been not detected in the supersonic jet, [21] suggesting that the population of GGT in the jet should be low and thus resulting in a low population of the clusters involving this conformer. Other isomers of both DEDS⋅⋅⋅H 2 O and DEDS⋅⋅⋅HCONH 2 clusters have higher energies, which lead to low populations of these isomers in the jet.…”

“…The observed isomer for each cluster could be assigned to its global minimum ( Figure 1) as shown in Table 1 by making a comparison between the theoretical spectroscopic parameters (Tables S1-S3) and their experimental values (Table S13- , their second most stable isomers (II) were predicted to be formed with the GGT conformer of DEDS, whose rotational spectrum has been not detected in the supersonic jet, [21] suggesting that the population of GGT in the jet should be low and thus resulting in a low population of the clusters involving this conformer.…”

Rotational spectrum and intramolecular hydrogen bonding in 1,2-butanedithiol

“…Additionally, the combination of microwave spectroscopy and internally cooled supersonic jets offers the possibility to generate, stabilize and probe weaklybound aggregates and to analyze the interaction forces [5,6,7]. To date, rotationally resolved investigations of thiols and related sulfides have included mostly small alkyl derivatives like ethanethiol [8], ethanedithiol [9], propanethiol [10], propanedithiol [11], 3-butene-1-thiol [12], 3-butyne-1-thiol [13], cyclopropanemethanethiol [14], mercaptoacetonitrile [15], furfuryl mercaptane [7], diethyldisulfide [16], diallyldisulfide [17] and diphenyldisulfide [18]. For selenols, the 2-propene [19], 3-butene [20], 3-butyne [21], cyclopropylmethyl [22] and propargyl [23] derivatives have been studied.…”