Reduction of [Mo(NO)L*Cl2] [L* = HB(3,5-Me2C3HN2)3] with n-butyl lithium in the presence of SnBun3Cl afforded the paramagnetic (17-electron) [Mo(NO)L*Cl(3,5-Me2C3HN2H)] (1). Related compounds, [Mo(NO)L*XQ] (Q = pyrazole, 3,5-dimethylpyrazole, 4-bromopyrazole and 4-bromo-3,5-dimethylpyrazole; X = Cl or I), were prepared by the reduction of [Mo(NO)L*X2] by Q (X = I) or by n-butyl lithium in the presence of Q (X = Cl). IR and EPR spectroscopic characterization of these species is reported and the X-ray structure of [Mo(NO)L*Cl(3,5-Me2C3HN2H)] . 1/2CH2Cl2, in which the molybdenum atom has octahedral coordination with disordered Cl and NO ligands, is described.