Accession Number : AD0651562

Title :   RARE EARTHS. IV. DISSOCIATION ENERGIES OF THE GASEOUS MONOXIDES OF THE RARE EARTHS.

Descriptive Note : Technical rept.,

Corporate Author : PENNSYLVANIA UNIV PHILADELPHIA DEPT OF CHEMISTRY

Personal Author(s) : Ames,L. L. ; Welsh,P. N. ; White,David

Report Date : MAY 1967

Pagination or Media Count : 67

Abstract : The dissociation energy of the gaseous rare earch monoxides together with the closely related compounds ScO and YO were determined from Knudsen effusion and mass spectrometric isomolecular oxygen-exchange reaction studies. It is shown that there is a double periodicity in the variations of the dissociation energies with atomic number and that these variations closely match those of the heats of sublimation of the rare earth metals. Assuming a common bound state for the monoxides, M++O--, it is shown that the variations in the dissociation energies in the lanthanide series correspond to the magnitude of the 4f(n) to 4f(n-1)5d transitions of the divalent ions. (Author)9

Descriptors :   (*RARE EARTH ELEMENTS, DISSOCIATION), (*RARE EARTH COMPOUNDS, MONOXIDES), GASES, THERMOCHEMISTRY, MASS SPECTROSCOPY, EXCHANGE REACTIONS, CHEMICAL BONDS, ELECTRON TRANSITIONS, VAPORS, HEAT OF FORMATION, ATOMIC ORBITALS, SPECIFIC HEAT, FREE ENERGY, SCANDIUM COMPOUNDS, YTTRIUM COMPOUNDS

Subject Categories : Atomic and Molecular Physics and Spectroscopy

Distribution Statement : APPROVED FOR PUBLIC RELEASE