[en] The complex PPN⁺ CpV(CO)₃H^- (Cp=eta⁵-C₅H₅ and PPN = (Ph₃P)₂) was prepared in 70% yield and its physical properties and chemical reactions investigated. PPN⁺ CpV(CO)₃H^- reacts with a wide range of organic halides. The organometallic products of these reactions are the vanadium halides PPN⁺[CpV(C)₃X]^- and in some cases the binuclear bridging hydride PPN⁺ [CpV(CO)₃]₂H^-. The borohydride salt PPN⁺[CpV(CO)₃BH₄]^- has also been prepared. The reaction between CpV(CO)₃H^- and organic halides was investigated and compared with halide reductions carried out using tri-n-butyltin hydride. Results demonstrate that in almost all cases, the reduction reaction proceeds via free radical intermediates which are generated in a chain process, and are trapped by hydrogen transfer from CpV(CO)₃H^-. Sodium amalgam reduction of CpRh(CO)₂ or a mixture of CpRh(CO)₂ and CpCo(CO)₂ affords two new anions, PPN⁺ [Cp₂Rh₃(CO)₄]^- and PPN⁺[Cp₂RhCo(CO)₂]^-. CpMo(CO)₃H reacts with CpMo(CO)₃R (R=CH₃,C₂H₅, CH₂C₆H₅) at 25 to 50⁰C to produce aldehyde RCHO and the dimers [CpMo(CO)₃]₂ and [CpMo(CO)₂]₂. In general, CpV(CO)₃H^- appears to transfer a hydrogen atom to the metal radical anion formed in an electron transfer process, whereas CpMo(CO)₃H transfers hydride in a 2-electron process to a vacant coordination site. The chemical consequences are that CpV(CO)₃H^- generally reacts with metal alkyls to give alkanes via intermediate alkyl hydride species whereas CpMo(CO)₃H reacts with metal alkyls to produce aldehyde, via an intermediate acyl hydride species