Komplexierung von 1,3‐Dihydro‐1,3‐diborapentafulven‐Derivaten mit Fe(CO) 3 ‐Fragmenten: Synthesen, Kristall‐ und Elektronenstruktur von μ‐(η 4 :η 5 ‐1,3‐Dihydro‐1,3‐diborapentafulven)‐bis (tricarbonyleisen)‐Komplexen

Complexation of 1,3‐Dihydro‐1,3‐diborapentafulvene Derivatives with Fe(CO) 3 Fragments: Syntheses, Crystal and Electronic Structure of μ‐(η 4 : η 5 ‐1,3‐Dihydro‐1,3‐diborapentafulvene)‐bis(tricarbonyliron) Complexes Reactions of the 1,3‐diborapentafulvene derivatives 1a – c with (CO) 3 Fe(C 8 H 14 ) 2 lead to the violet dinuclear complexes 3a – c , which possess a slipped triple‐decker structure. The X‐ray structure analyses of 3b , c reveal that one Fe(CO) 3 group is pentahapto‐coordinated to the 1,3‐diborole frame of C 2 B 2 C=C, whereas the other interacts with the Y‐shaped B 2 C=C unit. The latter resembles the interaction of Fe(CO) 3 with trimethylenemethane. An MO calculation indicates that the formation of 3 occurs by distortion of 1 · Fe(CO) 3 ; the slippage of Fe(CO) 3 from η 5 to η 4 bonding is followed by η 5 coordination of the second Fe(CO) 3 group.