The Knudsen cell mass spectrometric method has been employed to measure the partial pressures of Sn-n (n=1-7) under equilibrium conditions above liquid tin or a tin-gold alloy, contained in a graphite Knudsen cell. From the all-gas analyzed equilibria the following atomization enthalpies Delta(a)H(0)(:)(Sn-n), and enthalpies of formation, Delta(f)H(298.15)degrees(:)(Sn-n), in kJ mol(-1), have been obtained: Sn-4, 750.2 +/- 14 and 450.6 +/- 14; Sn-5, 990.2 +/- 22 and 512.3 +/- 22; Sn-6, 1349.7 +/-28 and 452.8 +/- 28; Sn-7, 1644.2 +/- 37 and 460.0 +/- 37. The atomization energies are compared with available theoretical values.