Bridging allyl ligands upon allene insertion into electron-deficient triosmium-hydride clusters [Os3(CO)9(μ3-NSC7H3R)(μ-H)] (R = H, Me)

Allene reacts with the benzothiazolide clusters [Os3(CO)9(μ3-NSC7H3R)(μ-H)] (R = H, Me) to afford the bridging allyl complexes [Os3(CO)7(μ-CO)2(μ-NSC7H3R)(μ-η1:η2:η1-CH2CHCH2)] resulting from insertion of allene into the metal–hydride. Both have been crystallographically characterized and differ with respect to the relative arrangement of allyl and benzothiazolide at the triosmium centre.