The heterobimetallic triple-decker complex [(Cp*Fe)(Cp ''' Co)(mu,eta(5) : eta(4)-P-5)] (1) was functionalized by main group nucleophiles and subsequently electrophilically quenched or oxidized. Reacting 1 with group 14 nucleophiles revealed different organo-substituted P5R middle-decks depending on the steric and electronic effects of the used alkali metal organyls (2: R= tBu; 3: R= Me). Further, with group 15 nucleophiles, the first structural characterized monosubstituted complexes with phosphanides could be obtained as P-5 ligands containing exocyclic {PR2} units (4: R = Cy, H; 5: R = Ph). These monoanionic complexes 2-5 were isolated and subsequent electrophilic quenching revealed novel types of neutral functionalized polyphosphorus complexes. These complexes bear formal chains of P5R ' R '' (6: R ' = tBu, R ' = Me) in a 1,3-disubstitution pattern or P6R ' R '' R ''' units (7: R ' = Cy, R '' = H, R ''' = Me; 8: R ' = Me, R '' = Ph, R ''' = Me) in a 1,1,3-substitution as middle-decks stabilized by one {Cp ''' Co} and one {Cp*Fe} fragment. One-electron oxidation of 2, 3 or 5 by AgBF4 gave access to paramagnetic triple-decker complexes bearing P5R middle-decks in various coordination fashions (R = tBu (10), R = PPh2 (12)). Interestingly, for R = Me (11), a dimerization is observed revealing a diamagnetic tetranuclear cluster containing a unique dihydrofulvalene-type P10R2 ligand. All complexes were characterized by crystallographic and spectroscopic methods (EPR, multinuclear NMR and mass spectrometry) and their electronic structures were elucidated by DFT calculations.