Vapor pressures of osmium, rhodium, and ruthenium carbonyls

Citation
D. Chandra et al., Vapor pressures of osmium, rhodium, and ruthenium carbonyls, J PH EQUIL, 20(6), 1999, pp. 565-572
Citations number
16
Categorie Soggetti
Apllied Physucs/Condensed Matter/Materiales Science
Journal title
JOURNAL OF PHASE EQUILIBRIA
ISSN journal
10549714 → ACNP
Volume
20
Issue
6
Year of publication
1999
Pages
565 - 572
Database
ISI
SICI code
1054-9714(199912)20:6<565:VPOORA>2.0.ZU;2-6
Abstract
Vapor pressures of solid Os-3(CO)(12),Rh-6(CO)(16), and Ru-3(CO)(12) were d etermined by the gravimetric torsion effusion method. The vapor pressures o f Os-3(CO)(12) ranged from 10(-6) to 10(-3) kPa at 349 to 396 K. There was virtually no decomposition of the Os-3(CO)(12), and the measured molecular weight was nearly the same as that of the actual value of 906.7 g/mol, The vaporization studies of Rhs(CO)(16) showed that it decomposed to Rh metal b etween 325 and 365 K. The measured molecular weight of the effusing gas fro m the solid Rh-6(CO)(16) was 27.75 g/mol, close to that of carbon monoxide compared to the values expected in absence of decomposition of 1065.56 g/mo l, The Ru-3(CO)(12) vaporization was complex as there was partial decomposi tion (approximately 52%) of the carbonyl to metallic Ru, as suggested by th e difference in the molecular weight of the vaporizing species of 107.58 g/ mol compared to the actual value of 639.33 g/mol, The total vapor pressures of these three carbonyls, the average molecular weights of the effusing ga ses, equilibrium constants for the vaporization reactions, their enthalpies , entropies, and Gibbs energies have beers determined.