Search for Interstellar monohydric Thiols

TL;DR

This paper investigates the formation and spectroscopic properties of interstellar monohydric thiols, especially 1-propanethiol, using quantum chemical calculations to aid future astronomical detection efforts.

Contribution

It introduces quantum chemical modeling of 1-propanethiol and provides spectroscopic parameters to facilitate its detection in interstellar space.

Findings

Tg conformer of 1-propanethiol identified as a promising candidate for detection.

Spectroscopic parameters of 1-propanethiol calculated for astronomical observations.

Study highlights potential presence of higher-order thiols in interstellar regions.

Abstract

It has been pointed out by various astronomers that very interesting relationship exists between interstellar alcohols and the corresponding thiols (sulfur analogue of alcohols) as far as the spectroscopic properties and chemical abundances are concerned. Monohydric alcohols such as methanol and ethanol are widely observed and 1-propanol is recently claimed to have been seen in Orion KL. Among the monohydric thiols, methanethiol (chemical analogue of methanol), has been firmly detected in Orion KL and Sgr B2(N2) and ethanethiol (chemical analogue of ethanol) has been claimed to be observed in Sgr B2(N2) though the confirmation of this detection is yet to come. It is very likely that higher order thiols could be observed in these regions. In this paper, we study the formation of monohydric alcohols and their thiol analogues. Based on our quantum chemical calculation and chemical modeling, we find that `Tg' conformer of 1-propanethiol is a good candidate of astronomical interest. We present various spectroscopically relevant parameters of this molecule to assist its future detection in the Interstellar medium (ISM).