This is one of the most exciting papers I have read in a few months.
First of all, I really like the synthesis of all these complexes even the starting materials like Tp*W(CO)3. A lot of work! And then there are these unexpected (to me) diphenylphosphino-acetylene complexes. I actually don't know how many of these as ligands have been isolated, but I don't think they are more than a handful. So, we know almost nothing about them as ligands. This whole complex can be tuned by different substituents on the phosphines or on the metal center! You can use it as a metalloligand and synthesize bimetallic complexes! Lots of opportunities here.. The groups spent a lot of time and effort to find out the H-atom source (SI28). They did labeling experiments, KIE, tried to keep everything super dry, tried some interesting set ups etc. but couldn't find out the source. The source is most likely the solvent as they mentioned. So much greatness for a 4-page Communication. Really great work.