Iron dibromides

CuSe COPPER SELENIDE 632 FeBr2 IRON DIBROMIDE 680... 

Cu2Se[B] DICOPPER SELENIDE 632 FeBr2[g] IRON DIBROMIDE (GAS) 681... 

As with the ketimine variant of the pincer, we initiated this chemistry by the reduction of the iron dibromide complex ( " PDAl)FeBr2 ( PDAl = 2,6(2,6- Pr2-CgH3N=CH)2C5H3N) [40],... 

Of the anhydrous dihalides of iron the iodide is easily prepared from the elements but the others are best obtained by passing HX over heated iron. The white (or pale-green) difluoride has the rutile structure the pale-yellow dichloride the CdCl2 structure (based on cep anions, p. 1212) and the yellow-green dibromide and grey diiodide the Cdl2 structure (based on hep anions, p. 1212), in all of which the metal occupies octahedral sites. All these iron dihalides dissolve in water and form crystalline hydrates which may alternatively be obtained by dissolving metallic iron in the aqueous acid. 

The reduction ofsec-, and /-butyl bromide, of tnins-1,2-dibromocyclohexane and other vicinal dibromides by low oxidation state iron porphyrins has been used as a mechanistic probe for investigating specific details of electron transfer I .v. 5n2 mechanisms, redox catalysis v.v chemical catalysis and inner sphere v.v outer sphere electron transfer processes7 The reaction of reduced iron porphyrins with alkyl-containing supporting electrolytes used in electrochemistry has also been observed, in which the electrolyte (tetraalkyl ammonium ions) can act as the source of the R group in electrogenerated Fe(Por)R. ... 

Catalysis by various low-valent metalloporphyrins of the type already depicted in Section 3.7.2 (see reference lb for a precise list) is represented in Figures 4.3 and 4.4 for several cyclic and acyclic 1,2-dibromides. A striking example of the contrast between redox and chemical catalyses is shown in Figure 4.3a, with fluorenone anion radical on the one hand and iron(I) octaethylporphyrin on the other. Starting with the oxidized, inactive form of the catalyst, in each case—the active form is produced at a reversible wave. Addition of the same amount of 1,2-dibromocyclohexane triggers a catalytic increase in the current that is considerably less in the first... 

Rajagopal and Burris (1999) studied the degradation reaction of ethylene dibromide in water with zero-valent iron. Ethylene dibromide degraded rapidly following pseudo-first order kinetics. The observed end products were ethylene and bromide ions and were probably formed via a P-elimination pathway. Bromoethane and vinyl bromide were not observed as possible intermediate products. 

Halogenation of dibenzofuran produces the 2-halo compounds. Bromina-tion can be achieved in good yield with bromine in acetic acid " or with N-bromosuccinimide in boiling carbon tetrachloride. The 2,8-dibromo compound has been made, using dioxane dibromide. Chlorination of dibenzofuran in acetic acid in the presence of iron powder can be controlled to yield the 2-chloro or the 2,8-dichloro compounds. 2-Chlorodi-benzofuran is best prepared by reaction of dibenzofuran with phosphorus pentachloride. 2-Iododibenzofuran (45%) results from treatment of dibenzofuran with iodine in boiling chloroform in the presence of nitric acid. 2,8-Diododibenzofuran is best prepared by reaction of dibenzofuran with iodine and iodic acid in aqueous acetic acid. ... 

The ARS Technologies, Inc., Ferox process is an in situ remediation technology for the treatment of chlorinated hydrocarbons, leachable heavy metals, and other contaminants. The process involves the subsurface injection and dispersion of reactive zero-valence iron powder into the saturated or unsaturated zones of a contaminated area. ARS Technologies claims that Ferox is applicable for treating the following chemicals trichloroethene (TCE), 1,1,1-trichloroethane (TCA), carbon tetrachloride, 1,1,2,2-tetrachloroethane, lindane, aromatic azo compounds, 1,2,3-trichloropropane, tetrachloroethene (PCE), nitro aromatic compounds, 1,2-dichloroethene (DCE), vinyl chloride, 4-chlorophenol, hexachloroethane, tribromomethane, ethylene dibromide (EDB), polychlorinated biphenyls (PCBs), Freon-113, unexploded ordinances (UXO), and soluble metals (copper, nickel, lead, cadmium, arsenic, and chromium). 

The stopper carrying the iron wire is removed, 2 g. of aniline is added, and then 528 g. (2 moles) of finely powdered, dry styrene dibromide is added gradually with vigorous stirring. The addition requires about 1 hour (Note 4). Stirring is continued for 2 hours (Note 5) after the addition is completed, after which 600 ml. of concentrated ammonium hydroxide is added, followed by 1 1. of distilled water, and the mixture is allowed to stand until the frost on the outside of the flask is entirely melted. 

Heated to dull redness in bromine vapour, iron yields a yellow crystalline dibromide, FeBr2, or the dark red ferric salt, FeBr3, according to circumstances, excess of bromine vapour being essential to produce the latter compound. 

Figure 3,159 Reactivity ofth e iron (II) pincer carbene dibromide complex.

The reaction of a vicinal dibromide with triethylamine and DMF with micro-wave irradiation leads to vinyl bromide. Alkenes are formed from vicinal bromides by heating with iron in methanol " or samarium in the presence of TMSCl and a trace of water. a,(3-Dibromo amides are converted to conjugated amides upon photolysis in methanol. ... 

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