übergangsmetall‐substituierte Acylphosphane und Phosphaalkene, XV. Zur Umsetzung des Phosphaallylkomplexes (η 5 ‐C 5 Me 5 )(CO)Fe‐{η 3 ‐P[CH(SiMe 3 ) 2 ](CHCO)} mit Chalcogenen und Fe 2 (CO) 9

Transition‐Metal‐Substituted Acylphosphanes and Phosphaalkenes, XV. – Reaction of the Phosphaallyl Complex (η 5 ‐C 5 Me 5 )(CO)Fe{η 3 ‐P[CH(SiMe 3 3 ) 2 ](CHCO}} with Chalcogenes as well as with Fe 2 (CO) 9 The (η 3 ‐phoshaalyl)iron complex (η 5 ‐C 5 Me 5 )(CO)Fe{η 3 ‐P(CH(SiMe 3 ) 2 ](CHCO)} ( 1 ) is oxidized by sulfur and selenium to afford the methylenethioxo‐ and methyleneselenoxophosphorane complexes 4 and 5 with an anti ‐configuration of the CH(SiMe 3 ) 2 substituent relative to iron. The chalcogene atoms are attached to the phosphorus atom of the ligand and do not participate in the bonding to the metal Equivalent amounts of 1 and Fe 2 (CO) 9 lead to the phosphaalkenyl complex 6 with an Fe – C σ bond. On the other hand, a large excess of Fe 2 (CO) 9 converts 1 as well as 6 into the cluster compound 7 featuring the bridging 1‐oxa‐4‐phosphabutadiene ligand (η 5 ‐C 2 Me 5 )(CO) 2 Fe—C(O)—CHP—CH(SiMe 3 ) 2 . Constitution and configuration of all compounds have been elucidated by spectroscopic methods (IR, 1 H, 13 C, 31 P NMR, and MS). In addition complexes 5 and 7 have been characterized by single crystal X‐ray diffraction analyses.