Spectrophotometric and Raman spectroscopic studies of the palladium(II) bromide--aluminum(III) bromide vapor complex

Journal Article · Fri Dec 01 04:00:00 EST 1978 · Inorg. Chem.; (United States)

DOI:https://doi.org/10.1021/ic50190a022· OSTI ID:6343771

Capote, M A; Papatheodorou, G N

The reaction of solid palladium(II) bromide with gaseous aluminum(III) bromide to form a ceramic-rod vapor complex has been investigated by spectrophotometry and by Raman spectroscopy at temperatures ranging from 550 to 900 K and total pressures up to approx. 2 atm. The electronic absorption spectra of the complexes show an intense d ..-->.. d band at approx. 1.96 ..mu..m/sup -1/ and a charge-transfer band at approx. 3.55 ..mu..m/sup -1/. The spectrophotometric data led to the conclusion that one predominant complex exists in the vapor formed by the reaction PdBr/sub 2/(s) + Al/sub 2/Br/sub 6/(g) in equilibrium PdAl/sub 2/Br/sub 8/(g) with ..delta..H = 8.27 kcal/mol and ..delta..S = 8.04 cu. Raman spectra of the equilibrium vapor mixtures PdAl/sub 2/Br/sub 8/--Al/sub 2/Br/sub 6/--AlBr/sub 3/ and Al/sub 2/Br/sub 6/--AlBr/sub 3/ were obtained at different temperatures. The main features of the Raman spectra of the PdAl/sub 2/Br/sub 8/ gaseous molecule are three polarized bands at 180, 114, and approx. 50 cm/sup -1/. The excitation profiles of these bands exhibit minima in the vicinity of the maximum Pd(II)d ..-->.. d absorption. The electronic absorption and Raman spectra of the complex were interpreted in terms of a D/sub 2h/ symmetry for the vapor complex PdAl/sub 2/Br/sub 8/, where Pd(II) is in a square-planar coordination. 5 figures, 5 tables.

• Research Organization: Argonne National Lab., IL
• OSTI ID: 6343771
• Journal Information: Inorg. Chem.; (United States), Journal Name: Inorg. Chem.; (United States) Vol. 17:12; ISSN INOCA
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360201 -- Ceramics
Cermets
& Refractories-- Preparation & Fabrication
360202* -- Ceramics
Cermets
& Refractories-- Structure & Phase Studies
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400104 -- Spectral Procedures-- (-1987)
ABSORPTION SPECTRA
ALUMINIUM BROMIDES
ALUMINIUM COMPLEXES
ALUMINIUM COMPOUNDS
BROMIDES
BROMINE COMPOUNDS
CERAMICS
CHEMICAL REACTION YIELD
CHEMICAL REACTIONS
COMPLEXES
FLUIDS
GASES
HALIDES
HALOGEN COMPOUNDS
HIGH TEMPERATURE
MEDIUM PRESSURE
PALLADIUM BROMIDES
PALLADIUM COMPLEXES
PALLADIUM COMPOUNDS
PRESSURE DEPENDENCE
RAMAN SPECTRA
SPECTRA
STEREOCHEMISTRY
SYMMETRY
TEMPERATURE DEPENDENCE
THERMODYNAMICS
TRANSITION ELEMENT COMPLEXES
TRANSITION ELEMENT COMPOUNDS
VAPORS
YIELDS