Spectrophotometric study of the cobalt(II) bromide--aluminum bromide vapor complex

Journal Article · Sun May 01 04:00:00 EDT 1977 · Inorg. Chem.; (United States)

DOI:https://doi.org/10.1021/ic50171a007· OSTI ID:7209046

Papatheodorou, G N; Kucera, G H

The reaction of solid cobalt(II) bromide with gaseous aluminum bromide to form deep green gaseous complex(es) has been investigated spectrophotometrically in the range 550 to 900/sup 0/K and at pressures up to 2 atm. Thermodynamic considerations suggest the reaction CoBr/sub 2/(s) + Al/sub 2/Br/sub 6/(g) reversible CoAl/sub 2/Br/sub 8/(g) (..delta..H = 9.9 kcal/mole; ..delta..S = 9.4 eu.). The electronic absorption spectra are discussed in terms of the possible coordination of Co(II) in the gaseous molecule(s). Spectroscopic and thermodynamic considerations suggest that the predominant absorbing species in the gas phase is Co(AlBr/sub 4/)/sub 2/ molecules having the Co(II) in a close-to-octahedral coordination. The volatility enhancement ratios of cobalt(II) halide in the presence of various ''acidic'' A/sub 2/X/sub 6/ gases are calculated and compared. At temperatures below 750/sup 0/K, aluminum bromide is a better gas-complexing agent than aluminum chloride for the respective cobalt halides.

• Research Organization: Argonne National Lab., IL
• OSTI ID: 7209046
• Journal Information: Inorg. Chem.; (United States), Journal Name: Inorg. Chem.; (United States) Vol. 16:5; ISSN INOCA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
ALUMINIUM BROMIDES
ALUMINIUM COMPOUNDS
BROMIDES
BROMINE COMPOUNDS
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
COBALT BROMIDES
COBALT COMPOUNDS
HALIDES
HALOGEN COMPOUNDS
HIGH TEMPERATURE
KINETICS
REACTION KINETICS
SPECTROPHOTOMETRY
THERMODYNAMICS
TRANSITION ELEMENT COMPOUNDS