A new series of complexes containing two electron donating groups, {M(CO)(3)}(+) ions, M = Re or Mn, on one polytungstate electron acceptor group have been prepared and characterized. These complexes containing two electron donating groups, {M(CO)(3)}(+) ions, M = Re or Mn, on one polytungstate electron acceptor group have been prepared and characterized. These two-component polyoxometalate (POM) compounds have been made by reaction of solvated {M(CO)(3)}(+) ions (M = Re or Mn) with [X2W22O74(OH)(2)](12-) (X = Sb or Bi) POM multidentate ligands in aqueous solution. These syntheses reveal that the fac-{WO(OH)(2)}(2+) groups in the terminal positions of these two POM ligands are easily replaced by the topologically equivalent units fac-{M(CO)(3)}(+). Four compounds, [X2W20O70{M(CO)(3)}(2)](12-) (1a: X = Sb, M = Re; 1b: X = Bi, M = Re; 2a: X = Sb, M = Mn; 2b: X = Bi, M = Mn) have been isolated and characterized of X-ray crystallography, spectroscopic, and computational methods. The charge transfer dynamics, investigated by femtosecond transient absorption (TA) spectroscopy of 1a and 1b combined with the density functional theory (DFT) calculations indicate that both complexes exhibit metal-to-polyoxometalate charge-transfer (MPCT) from the Re centers to the POM ligands, while MPCT from the Mn centers to the POM ligands in 2a and 2b leads to decomposition of starting compounds. The studies suggest a general synthetic route to a potentially very large class of POM-based hybrid compounds.