Substituted Variants of the Cluster Type Fe 3 (CO) 9 (μ 3 ‐η 2 ‐RCN)

Various aromatic nitriles were used for the preparation of the nitrile‐capped clusters Fe 3 (CO) 9 (μ 3 ‐η 2 ‐RCN) ( 2 ) by reaction with Fe 3 (CO) 12 under hydrogen. Electron‐rich nitriles decrease, electron‐poor nitriles increase the thermal stability of clusters 2 . With CN‐substituted pyridines only traces of clusters 2 could be obtained. CO replacement in Fe 3 (CO) 9 (PhCN) ( 2a ) by isonitriles also causes a lowering of the stability. Conversely, more stable products were obtained by substitution reaction with trimethyl phosphite. One PPh 3 and two dppm derivatives were also obtained. The structure of Fe 3 (CO) 8 ‐ P(OMe) 3 (μ 3 ‐η 2 ‐PhCN) (5a) was determined.