Electronic transitions of jet-cooled SiC2, Si2Cn (n=1-3), Si3Cn (n=1,2), and SiC6H4 between 250 and 710 nm

TL;DR

This study measured electronic transitions of various silicon-carbon molecules between 250 and 710 nm using mass-resolved two-photon ionization, providing spectral data relevant for astronomical detection and supported by quantum chemical calculations.

Contribution

It provides new spectral data for silicon-carbon molecules, including key transitions, aiding astronomical searches and supporting analyses with theoretical calculations.

Findings

SiC2 has a prominent transition at 516.4 nm

SiC6H4 exhibits a notable band at 445.3 nm

Spectral properties support potential astronomical detection

Abstract

Electronic transitions of the title molecules were measured between 250 and 710 nm using a mass-resolved 1+1' resonant two-photon ionization technique at a resolution of 0.1 nm. Calculations at the B3LYP/aug-cc-pVQZ level of theory support the analyses. Because of their spectral properties, SiC$_2$, linear Si$_2$C$_2$, Si$_3$C, and SiC$_6$H$_4$ are interesting target species for astronomical searches in the visible spectral region. Of special relevance is the Si--C$_2$--Si chain, which features a prominent band at 516.4 nm of a strong transition ($f=0.25$). This band and one from SiC$_6$H$_4$ at 445.3 nm were also investigated at higher resolution (0.002 nm).