The formation of metastable O-2(b(1) Sigma g(+)) in the energy-transfer reaction of NH/ND(a(1) Delta,v) with O-2 was investigated for different photolysis systems. Rate constants for the energy transfer from the vibrational levels v = 0, 1, 2 of NH/ND(a) were estimated by quantitatively comparing the phosphorescence intensities of the NH/ND(a(1) Delta-->X(3) Sigma(-)) and O-2(b(1) Sigma g(+)-->X(3) Sigma g(-),-) transitions. The values of the rate constants are in the range (4-20) x 10(-14) cm(3) s(-1). They increase significantly with the vibrational quanta of MI(a,v), while, for ND(a, v), an increase is barely noticeable. A comparison with previously determined rate constants for the quenching of the same vibrational states by O-2 reveals that the efficiencies of the energy-transfer processes are close to unity. Recent kinetic measurements of the quenching of O-2(b(1) Sigma g(+)) by HN3, DN3, HNCO, and DNCO are confirmed.