Mass spectrometric determination of dissociation energies of molecules Bi2, Bi3, Bi4 and BiPb

Abstract

The vaporization of pure bismuth and of a 1 : 1 Bi + Pb alloy were studied. Above pure bismuth the species Bi, Bi₂, Bi₃ and Bi₄ were observed in the approximate ratios 0.6 : 1.0 : 0.002 : 0.02. The atomization energies per bonding atom were calculated from partial pressure measurements to be 47.0, 43.0 and 47.0 kcal/mole for Bi₂, Bi₃ and Bi₄ respectively. The molecule BiPb was identified and its dissociation energy determined to be D^°₀(BiPb)= 33.0 kcal/mole.