New acetylene line list near 3.8-μm - Part III - 12C13CH2 and 12C2HD

•Fourier transform spectroscopy with high absorption path length.•Line intensities for bands of 12C13CH2 and 12C2HD.•12C13CH2 and 12C2HD line lists near 3.8 μm for the databases. The intensities of minor acetylene isotopologues 12C13CH2 and 12C2HD have been studied from Fourier transform spectra of acetylene in natural abundance using high optical path length. This study completes the work performed in the two first paper of the series (JQSRT 2023;295:108,413 and JQSRT 2023;311:108,771) where 71 bands of 12C2H2 were studied in the ΔP = 4 spectral region (∼2400–2900 cm−1). In this work, 692 measured line intensities allowed to derive vibrational transition dipole moment squared (and sometimes Herman-Wallis coefficients) for 11 bands of 12C13CH2 and 6 bands of 12C2HD. Using line positions and broadening parameters from literature, a line list has been generated for atmospheric and astrophysical applications. [Display omitted]