The reaction of equimolar amts. of (h5-C5H5)(OC)2FeAs(SiMe3)2 (I) with RCOCl (R = Me3C, 2,4,6-Me3C6H2, 2,4,6-Me3CC6H2) yields the arsaalkenyl complexes Z-[h5-C5H5)(OC)2FeAs:C(OSiMe3)R (II). The diacylarsenido complexes (h5-C5H5)(OC)2FeAs[C(O)R]2 are generated by treatment of I with two equiv of pivaloyl chloride or mesitoyl chloride. The As:C double bond length of 1.821(2) .ANG. in II (R = CMe3) was detd. by single crystal x-ray anal.