Atomization Enthalpies of the Molecules Cu3, Ag3, and Au3

Abstract

AbstractThe gaseous species in equilibrium with Cu(l), Ag(l), and Au(l) were investigated by vaporization studies according to the method of high temperature mass spectrometry with a Knudsen cell. From the observed ion intensity ratios of dimer to monomer and of trimer to monomer the dissociation enthalpies of Cu2, Ag2, and Au2 were redetermined. The following atomization and sublimation enthalpies for the trimer in kJ mol−1 could be additionally determined by assuming a linear structure for these molecules: D00(Cu3) = 294 ± 13, D00(Ag3) = 253 ± 13, D00(Au3) = 367 ± 13, δsubH00(Cu3) = 714 ± 13, δsubH00(Ag3) = 598 ± 12, and δsubH00(Au3) = 737 ± 13. At the mean temperature of the measurements of 1849 K (Cu), 1500 K (Ag), and 1883 K (Au) the vapour pressures of the trimers are by a factor of 2.4 · 107 (Cu3), 2.9 · 107 (Ag3), and 1.7 · 107 (Au3) smaller than those of the corresponding monomers.