The first practical route to substituted carbonyl anions of niobium and tantalum, involving the photolytically induced substitution of mono- and bidentate phosphines into the hexacarbonylmetallate(-I) anions of these metals, has been utilized in obtaining [(C2H5)4N][M(CO)5P(C6H5)3] and [(C2H5)4N][M(CO)4- (C6H5)2PCH2CH2P(C6H5)2] (M = Nb, Ta). This new pathway also represents the best available method for preparing phosphine, arsine, and stibene substituted carbonyl anions of vanadium; tetraethylammonium salts of [V(CO)5L]-, where L represents (C6H5)3M (M = P, As, Sb), or (n-C4H9)3P and [V(CO)4L′]-, where L′ is (C6H5)2PCH2CH2P(C6H5)2 or [(C6H5)2AsC5H4]2Fe have been obtained in high yields by this procedure.
Bibliographical noteFunding Information:
We wish to thank the National Science Foundation for (Grants GP 6672 and GP-11001).
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