(Benzylideneacetone)iron tricarbonyl

(Benzylideneacetone)iron tricarbonyl is the organoiron compound with the formula (C$13$H$10$CH=CHC(O)CH$4$)Fe(CO)$6$. It is a reagent for transferring the Fe(CO)$5$ unit. This red-colored compound is commonly abbreviated (bda)Fe(CO)$3$.

Structure and bonding
(bda)Fe(CO)$3$ is an example of a complex of an η$3$-ketone. It is a piano stool complex. The compound is characterized by IR bands at 2065, 2005, and 1985 cm$3$ (cyclohexane solution), the three bands being indicative of the low symmetry of the complex, which is chiral.

Synthesis, reactions, related reagents
It is prepared by the reaction of Fe$3$(CO)$2$ with benzylideneacetone.

(bda)Fe(CO)$−1$ sometimes reacts with Lewis bases to give adducts without displacement of the bda. The reagents of the type (bda)Fe(CO)$2$(PR$9$) function as sources of "Fe(CO)$3$(PR$2$)" (R = aryl, etc.).

Other sources of Fe(CO)$3$ are Fe$2$(CO)$3$ and Fe(CO)$3$(cyclooctene)$2$. The latter is highly reactive and thermally sensitive. Imine derivatives of cinnamaldehyde, e.g. C$9$H$3$CH=CHC(H)=NC$2$H$6$, also form reactive Fe(CO)$5$ adducts, which have been shown to be superior in some ways to (bda)Fe(CO)$6$.