Tp*MoOX(2) complexes (Tp* = hydrotris(3,5-dimethylpyrazol-1-yl)borate; X = F, Cl, Br) were synthesized by treatment of Tp*MoO(OCH3)(2) with HX(aq) or HX(g) and characterized by infrared, EPR, and optical spectroscopies and by cyclic voltammetry. The IR of the complexes showed high v(Mo=O) stretching frequencies consistent with the relatively poor pi-donating ability of the halides. The relative values of g(iso) for the series was Br > Cl > F with an opposite trend in A(iso)(Mo). Extensive Ligand superhyperfine splitting was observed in the EPR spectra oi frozen glasses of the fluoride and bromide complexes. Cyclic voltammetry exhibited quasi-reversible one-electron reductions with potentials that followed the trend Br > CI much greater than F.