Yep. There are lists of the molecules we've detected: https://en.wikipedia.org/wiki/List_of_interstellar_and_circumstellar_molecules, https://www.astrochymist.org/, https://arxiv.org/abs/2109.13848 (last is a regularly updated, curated, peer reviewed list maintained by Brett McGuire)

It is absolutely insane the amount of information that can be extracted from the "color" of incoming light. They're talking about trying to see the light from a distant star but not just any light. Specifically they are looking for light from that distant star when it passes through the atmosphere of a planet orbiting that star. The difference between that light and the light of the star can tell you about the chemical composition of the planet's atmosphere.

Look up Dr. György Tarczay or Astrochemistry in general!

There is a whole field of science about studying molecules in space and proving they exist by replicating astronomic conditions in a lab.

I got to tour Dr. Tarczay's lab and it was super impressice. Look up Tarczay VIZSLA for an article about his latest piece of equipment.