Umwandlungen zwischen Ru 3 ‐fixierten Azoalkan‐ und Dialkylhydrazin‐Baueinheiten

Interconversions Between Ru 3 ‐Bound Azoalkane and Dialkylhydrazine‐Derived Building Units Reactions involving hydrogen transfer have been investigated starting from the azoalkane‐bridged clusters Ru 3 (CO) 9 ‐(RCH 2 NNCH 2 R) ( 1a , R = H; 1b , R = Me). In boiling toluene they are isomerized to the hydrazonide‐bridged clusters HRu 3 (CO) 9 (RCH 2 N—NCHR) ( 2a , R = H; 2b , R = Me). Pd/C‐catalyzed hydrogenation converts both compound types into the hydrazide‐bridged clusters HRu 3 (CO) 9 (RCH 2 N—NHCH 2 R) ( 3a , R = H; 3b , R = Me). Hydride attachment to 1 and 2 and deprotonation of 3 yield a common anionic intermediate 4 which is converted into 3 upon protonation. While deuteration experiments and NMR spectra indicate that the anionic intermediate equilibrates between the N—H and Ru—H isomers, aurations of deprotonated clusters with Ph 3 PAuCl yield the Ru—Au‐connected clusters Ph 3 PAuRu 3 (CO) 9 (EtN—NCHMe) ( 5 ) and Ph 3 PAuRu 3 (CO) 9 (MeN—NHMe) ( 6 ). The reversible cluster expansion of 2b with Fe(CO) 3 fragments which results in the formation of FeRu 3 (CO) 12 (μ 4 ‐η 2 ‐N 2 Et 2 ) ( 7 ) involves a reversible reconversion of the hydrazonide ligand to the azoalkane ligand.