The standard (p degrees = 0.1 MPa) molar enthalpies of formation Delta(f)H(m) degrees for crystalline 5-, 6-, 8-nitroquinoline and 8-nitroquinaldine were derived from the standard molar enthalpies of combustion in oxygen at T = 298.15 K Delta(c)H(m) degrees, measured by static bomb combustion calorimetry; the Knudsen mass-loss effusion technique was used to measure the vapour pressures of the crystals as functions of temperature, and the standard molar enthalpies of sublimation, at T = 298.15 K, Delta(cr)(g)H(m) degrees were derived by the Clausius-Clapeyron equation. Direct measurements of the standard molar enthalpies of sublimation, using microcalorimetry, for 5-, 6-, 8-nitroquinoline, and 8-nitroquinaldine confirmed the values from the Knudsen technique. [GRAPHICS]