Irreversible metalation,

Fig. 6. Metal-crosslinking in antisense and antigene technology. The recognition of the target (sense) strand by the antisense strand is rapid and is followed by a slower irreversible metal crosslinking. 

Porphyrin Cofactors Their Advantages and Irreversible Metal Insertion. 215... 

In an irreversible metal hydride, hydrogen is generated through a chemical reaction, which is not easily reversible onboard a vehicle. Common reactant is water or an alcohol. For example, sodium borohydride can produce hydrogen as... 

This reaction is not easily reversible onboard a vehicle. Hence, the by-products must be removed from the vehicle and regenerated offboard. The irreversible metal hydrides can include a transition metal, for example, Mg2FeH6 (5.5 wt% hydrogen capacity), a nontransition metal such as Be(BH4)2 (20.8 wt% hydrogen capacity), or NaAlH4. Various promising metal hydrides are discussed in the following sections. 

In agreement with its catecholate nature, the complex does not display any predisposition to undergo reduction processes583 (even if an irreversible metal-centred [MnIV(3,5-di-Butcat)3]2 /[MnIII(3,5-di-Bu cat)3]- reduction has been reported5813). 

FIGURE 9.4 Irreversible metal peroxide forming reactions examined in Ref. 30. 

We have applied Eq. 29 to a series of Cp and Tp Group 6 metal carbonyl hydrides in acetonitrile, mostly on the basis of irreversible metal-hydride oxidation... 

In order to understand fluorescence quenching of anthyl units in Rh(I) and Ir(I) complexes of the type shown in Fig. 26, the redox chemistry of these complexes has been investigated (91). There are two main redox processes observed with cyclic voltammetry in THF a reversible antryl centered reduction and an irreversible metal centered oxidation in all cases. The observation of irreversible oxidation waves in THF indicates that the electrode generated cationic species are not stable at room temperature. Apparently, however, the use of the solvent l,l,l,3,3,3-hexafluoropropan-2-ol (HFP) somewhat stabilizes these species. Oxidation of the M(I) species with thalium(III) trifluoroacetate in... 

Fig. 16 Mechanochemical evolution of metallosupramolecular polymers generated by (a) combination of an Eu(III) salt and a telechelic poly(ethylene-co-butylene) with 2,6-bis(l- -methylbenzimidazolyl)pyridine ligands at the termini counterions are omitted for clarity, (b) Reversible dissociation upon ultrasonication (i) irreversible metal exchange with Fe(II) ions as a result of (ii) ultrasonication or (Hi) other mechanical forces, (c) Dipicolinic acid ligands bind strongly to Eu(III) and the supramolecular network cannot easily be disassembled under mechanical stress. Reproduced with permission from [88]. Copyright 2014 American Chemical Society...

The energy of bonds, formed at the reaction, RT since heptylbenzoate molecule formation is irreversible. Metal ions dissolved in methylbenzoate decrease value and therefore influence directly on p magnitnde. Consequently, E value can be considered as the value [30] Eq. (27) ... 

There are cases when the cobalt dioxygen complexes are only intermediates in the irreversible oxidation of the cobalt(II) complex en route to the cobalt(III) derivatives. The situation is largely dependent on the ligands, solvent and acidity. Protic solvents promote irreversible metal-centered oxidation, which may involve some complex pathways. It is usually the p-peroxodicobalt species which is regarded as the precursor of the cobalt(III) product. The reduction product from 0 may be either or H O. 

Example 13.3 Determine the current and impedance of a system displaying negative impedance (described below). It represents the irreversible metal dissolution and electrosorption of a species A on the surface, which block metal dissolution ... 

An example of a conventional cascade system with two catalysts comprising a high-valent metal triflate Lewis add and a supported Pd catalyst for the hydrogenolysis of ethers is illustrated in Fig. 8.24. Since primary C—O bonds are resistant to cleavage, in the presence of water, there is formation of the parent primary alcohol that further undergoes acid-catalyzed dehydration to alkene and rapid, irreversible metal-catalyzed hydrogenation to alkane. 

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