Formation mechanism of thiadiamondoids: evidence from thermochemical sulfate reduction simulation experiments with model compounds

•Ketones, alcohols, thiols and thiadiamondoids were generated from diamondoids by TSR.•Thiadiamondoids can be generated from C0 alkylated diamondoids species by TSR.•Diamondoidyl ketones may be reaction intermediates for thiadiamondoids.•Formation of thiadiamondoids is dominated by the free sulfur radical mechanism.