The reactions of Tp(iPr)Mo(VI)O(2)Cl with salicylanilides and NEt3 produce cis-Tp(iPr)Mo(VI)O(2)(2-OC6H4CONHR) (Tp(iPr) = hydrotris(3-isopropylpyrazol-1-yl)borate, R = Ph, 4-C6H4Cl, 4-C6H4OMe). The N-methyl complex, Tp(iPr)MoO(2)-{2-OC6H4CON(Me)Ph}, is similarly prepared. Reduction of the amido complexes by cobaltocene produces green, EPR-active compounds, [CoCp2][Tp(iPr)Mo(V)O(2)(2-OC6H4CONHR)], that exhibit strong, low energy, v(MoO2) IR bands at similar to 895 and 790 cm(-1) (cf. similar to 935 and 900 cm(-1) for the Mo(VI) analogues). The X-ray structures of all seven complexes have been determined. In each case, the Mo center exhibits a distorted octahedral coordination geometry defined by mutually cis oxo and phenolate ligands and a tridentate fac-Tp(iPr) ligand. The Mo(V) anions exhibit greater Mo=O distances (ay. 1.738 angstrom vs 1.695 angstrom) and O=Mo=O angles (ay. 112.4 degrees vs 102.9 degrees) than their Mo(VI) counterparts, indicative of the presence of a three-center (MoO2), pi* semioccupied molecular orbital in these ell complexes. The amido Mo(VI) and Mo(V) complexes exhibit an intramolecular hydrogen-bond between the NH and O-phenolate atoms. Protonation of [CoCp2][Tp(iPr)Mo(V)O(2)(2-OC6H4CONHR)] by lutidinium tetrafluoroborate is quantitative and produces EPA-active, cis-(hydroxo)oxo-Mo(V) complexes, Tp(iPr)Mo(V)O(OH)(2-OC6H4CONHR), related to the low pH Mo(V) forms of sulfite oxidase.