Mehrfachbindungen zwischen Hauptgruppenelementen und Übergangsmetallen, XXV. Aufbau und Reaktivität von Se 1 ‐ und Se 2 ‐Brücken in Organochrom‐Komplexen

Multiple Bonds Between Main Group Elements and Transition Metals, XXV. Synthesis and Reactivity of Se 1 ‐ and Se 2 ‐Bridges in Organochromium Compounds Reaction of the ionic complex K[(η 5 ‐C 5 Me 5 )Cr(CO) 3 ] ( 1 ) with selenium( I ) with selenium( I ) chloride, Se 2 Cl 2 , yields the diselenium compounds 2 of composition (η 5 ‐C 5 Me 5 )Cr(CO) 5 Se 2 which is converted to the Se 1 derivative (μ‐Se)[η 5 ‐C 5 Me 5 )Cr 2 (CO) 2 ] 2 ( 3 ) with triphenylphosphane. 3 exhibits a linear, multiple bonded CrSeCr core structure. Reaction of 2 with diazomethane gives the novel mononuclear, paramagnetic selenoformaldehyde complex (η 5 ‐C 5 Me 5 )‐Cr(CO) 2 (SeCH 2 ) ( 4 ).