Iron Bridge

An unusual variant is to have both carboxylates in the same molecule, as in the m-phenylene-dipropionate (mpdp, (215)), which can support an oxide bridge as shown schematically in (216). Complexes containing such iron-iron bridging include [Fe2(/i-0)(/i-/2-mpdp) HB(pz)3 2] and [Fe2(/i-0)(/2-mpdp)(bipy)2Cl2]. ... 

A 48-year-old painter is referred for evaluation of recent onset of severe abdominal pains, headaches, and myalgias. For the last week, he has been removing old paint from an iron bridge using grinding tools and a blow torch. His employer states that all the bridge workers are provided with the equivalent of "haz-mat" (hazardous materials) suits. What tests should be carried out Assuming positive test results, what therapy would be appropriate ... 

Note that in the structure in Fig. 15, there are six ligands two labile sulfur , iron-bridging ligands and four cysteinyl-sulfur ligands. 

Iron(III) weso-tetraphenylporphyrin chloride [Fe(TPP)Cl] will induce the autoxidation of cyclohexene at atmospheric pressure and room temperature via a free radical chain process.210 The iron-bridged dimer [Fe(TPP)]2 0 is apparently the catalytic species since it is formed rapidly from Fe(TPP)Cl after the 2-3 hr induction period. In a separate study, cyclohexene hydroperoxide was found to be catalytically decomposed by Fe(TPP)Cl to cyclohexanol, cyclohexanone, and cyclohexene oxide in yields comparable to those obtained in the direct autoxidation of cyclohexene. However, [Fe(TPP)] 20 is not formed in the hydroperoxide reaction. Furthermore, the catalytic decomposition of the hydroperoxide by Fe(TPP)Cl did not initiate the autoxidation of cyclohexene since the autoxidation still had a 2-3 hr induction period. Inhibitors such as 4-tert-butylcatechol quenched the autoxidation but had no effect on the decom-... 

Figure 5 Self-assembly synthesis of the iron-bridged double cubane [Mo2Fe7S8(SEt)i2] ...

Briggs, A. 1979, Iron Bridge to Crystal Palace Impact and Images of the Industrial Revolution, Thames Hudson, London. 

Aeration, water-holding capacity, and permeability are all improved by humus. The frequent addition of easily decomposable organic residues leads to the synthesis of complex organics (e.g., polysaccharides) that bind soil particles into aggregates. The intimate association of clay-sized particles (layer silicates) with humus via cation (e.g., calcium, magnesium, aluminum, iron) bridges also promotes aggie-... 

There are, however, other ways of crossing water than by boat, and many millions of tons of iron in its various forms have been used in the construction of tunnels and of bridges. The first cast iron bridge in the world appears to have been that over the Severn near Colebrooke Dale about 1785. To-day steel is more commonly used, although the year before last (1949) saw the opening of a bridge of aluminium-alloy (p. 164). 

Figure 5. A working model for [2Fe-2S] formation on the ISU scaffold that is consistent with published data. (A) Frataxin mediates initial delivery of iron ions to apo ISU through an iron-bridged complex, establishing a nucleation site for [2Fe 2S] cluster formation. (B) Subsequent sulfide delivery is mediated through the persulfide form of NifS/IscS that forms a complex with ISU. Reductive cleavage of NifS/IscS persulfide bonds by reduced NFU yields the two equivalents of inorganic S for cluster formation. The reduced [2Fe 2S] cluster initially formed on IscU may then be oxidized by F

In spite of the tendency to rust, iron either alone or as reinforcement in concrete has been the basis of civil engineering projects since the world s first iron bridge was constructed over River Severn at Coalbrookdale in England by Abraham Darby in 1780. Many wrought iron bridges performed well with modest but regular maintenance. 

Anonymous (1887). Ellis, Theodore G. Appletons cyclopaedia of American biography 2 334. Ellis, T.G. (1866). Description of the iron bridge over the Connecticut River, on the Hartford New Haven R.R. Brown Gross Hartford CT. 

The traditional view of lap joint failure is old and familiar and was, in essence, employed by Fairbairn(36) who considered the failure mode of riveted joints on iron bridges. However, the topic of bonded lap shear joints is probably best reviewed in detail by... 

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