TRANSITION-METAL-SUBSTITUTED ARSAALKENES, IV - METALLOARSAALKENE [(ETA(5)-C5ME5)(CO)(2)FEAS=C(NME2)(2)] AS A LIGAND IN CARBONYLCHROMIUM, CARBONYL-IRON, AND CARBONYL-NICKEL COMPLEXES

Reaction of equimolar amounts of the metalloarsaalkene [(eta(5)-C5Me5) (CO)(2)FeAs=C(NMe2)(2)] (1) with the carbonyl complexes [Ni(CO)(4)], [ Fe-2(CO)(9)], and [{(Z)-cyclooctene}Cr(CO)(5)], respectively, affords the adducts [(eta(5)-C5Me5)(CO)(2)FeAs-{M(CO)(n)}=C(NMe2)(2)] with [M( CO)(n)] = [Ni(CO)(3)] (2); [Fe(CO)(4)] (3), and [Cr(CO)(5)] (4). These feature eta(1) coordination of the arsaalkene ligand via the arsenic atom. The molecular structures of the complexes 3 and 4 have been dete rmined by X-ray diffraction analyses.