Tetranitromethane reduction

The oxidative behaviour of glycolaldehyde towards hexacyanoferrate(III) in alkaline media has been investigated and a mechanism proposed, which involves an intermediate alkoxide ion. Reactions of tetranitromethane with the luminol and luminol-peroxide radical anions have been shown to contribute substantially to the tetranitromethane reduction in luminol oxidation with hexacyanoferrate(III) in aerated aqueous alkali solutions. The retarding effect of crown ethers on the oxidation of triethylamine by hexacyanoferrate(III) ion has been noted. The influence of ionic strength on the rate constant of oxidation of ascorbic acid by hexacyanofer-rate(III) in acidic media has been investigated. The oxidations of CH2=CHX (where X = CN, CONH2, and C02 ) by alkaline hexacyanoferrate(III) to diols have been studied. ... 

Reduction of cytochrome c Reduction of tetranitromethane Reduction of nitroblue tetrazoliumchloride Autoxidation of pyrogallol i 6)... 

Figure 19.22 Phenolic compounds may be derivatized to contain reactive diazonium groups by nitration with tetranitromethane followed by reduction with sodium dithionite and diazotization with sodium nitrite in dilute HCI.

However, to be a quantitative assay of superoxide detection, Reaction (1) had to be an exothermic reaction, i.e., the difference between the one-electron reduction potentials of reagents AE° = / °[02 /02] / °[A /A] must be <0. In this case the rate constants of Reaction (1) will be sufficiently high (10s—109 1 mol 1 s ). Among traditionally applied assays, three compounds satisfy this condition cytochrome c, lucigenin, and tetranitromethane (Table 32.1). 

Most peroxyl radicals are oxidants18, however the peroxyl radicals formed from the reaction of O2 with the radicals induced by HTOH reacting with 1,4-cyclohexadiene are reductants, as was proven by reduction in pulse radiolysis of tetranitromethane (TNM)... 

Note that this provides an alternative to tetranitromethane for nitration of propenylbenzenes, and an alternative to lithium aluminum hydride or Zn-Hg for reduction of nitropropenes. 

This is a fast easy method. If you have a battery powered stirring device it can be performed most anywhere. If you wish to do this formula on a smaller scale then use the following formula. As tetranitromethane is expensive, I suggest you practice on the small scale first. Nitropropenes or nitrostyrenes are not psychoactive, you need to find a reduction. 

As discussed above, the nitro groups of tetranitromethane and trinitromethyl compounds are susceptible to nucleophilic attack. Both potassium iodide and alkaline hydrogen peroxide affect the reductive denitration of trinitromethyl groups to em-nitronitronates 1,1,1-trinitroethane (33) is quantitatively reduced to potassium 1,1-dinitroethane (24) on treatment with alkaline hydrogen peroxide. Nucleophiles such as potassium fluoride in DMF can displace nitrite anion from tetranitromethane. Various nucleophiles, including azide, chloride, fluoride and ethoxide have been used to displace one of the nitro groups from fluorotrinitromethane. 

The three types of SOD showed a similar activity near pH 7.0 with a second-order rate constant of about 2x 10 M s , as determined by the reduction of Fe(III)-cytochrome c and of tetranitromethane. The activity of the (Fe)- and (Mn)-SOD decreased with increasing pH in contrast with that of (Cu,Zn)-SOD... 

The presence of an essential tyrosine residue near the active site was suggested on the basis of experiments with tetranitromethane.54 Treatment of apotryptophanase with this reagent caused almost complete loss of catalytic activity, a great reduction of affinity for PLP and modification of about one tyrosine residue. The modified enzyme was unable to form the quinonoid intermediate with L-tryptophan or L-alanine.55 PLP protected the apoenzyme from inactivation only in the presence of activating cations (K+, NH4+, Rb+). It was shown that inactivation by tetranitromethane was not caused by oxidation of SH-groups, but partial modification of methionine (0.8 residue) was detected and might also be responsible for inactivation. It is worthy of note that modification of tryptophanase with chloramine T indicated that some methionine residues may be important for maintaining the catalytically active conformation of the enzyme.56 ... 

Tetranitromethane is frequently used in inorganic systems, for example, as a scavenger of superoxide. Upon one-electron reduction the immediate products are C(N02)3" and N02 (248). An estimate of E° for this couple can be made by using published values of A(H° for C(N02)4 and HC(NOz)3 in the gas phase 82.0 and —0.2 kj/mol, respectively (241). The calculation also uses AfG° from this review for aqueous N02, entropies from the NBS tables, and pKa = 0.06 for HC(N02)3 (284). It is assumed that HC(NOz)3 and C(N02)4 have identical heats of hydration and identical partial molar entropies. The outcome is E° = 0.93 V for the C(N02)4/(C(N02)3", NOz) couple. Berdnikov et al. performed a similar calculation and obtained E° = 0.9 V (47). These workers used different sources of data and made more refined estimates of the entropies and hydration energies the agreement is gratifying. 

The pyrimidine C5 OH adducts have reducing properties (note the electron-donation by the a-nitrogen), while the C6 OH adducts are oxidizing (note the spin density at the heteroatom). This property has been used to determine the yields in pulse radiolysis experiments using oxidants (e.g. tetranitromethane) and reductants (e.g. N,iV,2, N -tetramethyl-phenylenedimine) as probes.The adenyl A (E = 1.56 V) and guanyl G (E = 1.29 V) radicals are both oxidizing. 

The mechanism of toxicity for tetranitromethane is not known. Methemoglobinemia formation reported following oral administration may be a result of reduction of tetranitromethane in the gut. Nasal lesions observed in lifetime inhalation studies of rats and mice were attributed to the significant irritating properties of the material. 

The hydrolysis products of Tl(II) exhibit different redox properties Tl(OH) and TP act as good oxidants in their reaction with me-thoxylated benzenes 342, 343) and disulfides 344), while Tl(OH)2 can react as a reductant (towards tetranitromethane) 86). This is in agreement with polarographic measurements showing that TP" is reduced over the entire potential range up to +400 mV, Tl(OH) is reduced at potentials less than +275 mV, and Tl(OH)2 shows a reduction current only at potentials below +200 mV, while at more positive potentials a much more pronounced oxidation current is observed than that for Tl(OH)+ 345). 

Or From Tetrabutyl-Ammonium Superoxide. Tetrabutyl-ammonium superoxide was found convenient for the superoxide dismutase assay since it dissolved readily without decomposition in N,N-dimethyl form-amide (70). Infusions of this solution into a cuvette containing aqueous oxidized cytochrome c reduced the available cytochrome c. In the presence of different erythrocuprein concentrations the reduction rate was progressively diminished. According to McCord and Fridovich (70) an enzyme unit was defined as 50% inhibition of the rate of reduction of cytochrome c. Alternatively tetranitromethane was found appropriate for monitoring Or (70, 136—148) where the stable nitroform anion C(N02)3 is being formed (Equ. (a)) ... 

Figure 4.21 Tyrosine reactive probes. Nitration of tyrosine by reaction with tetranitromethane, followed by reduction with sodium dithionite, to yield an o-aminotyrosine.

The reduction of other mercuric halides or pseudohalides HgXj (X = Br, T, CN , or SCN, respectively) by hydrated electrons or alcohol radicals yields as well transient HgX monomers. . They dimerize except HgCN which disproportionate. It was found that the HgjXj absorption spectra are at shorter wavelengths that those of HgX (Table 6). The monomer are strong electron donor towards O2, tetranitromethane and p-benzoquinone. On the contrary, in diluted solutions of HgClj, added with more concentrated salts such as Cd, ... 

Two distinct primary transients have been observed by optical spectroscopy in its pulse radiolysis [54]. One of these is not affected by O2 and has been attributed to an A-centered radical cation, A/ N-EDTA , directly bridged to the second EDTA nitrogen. Using strong reductants as probes, e.%. N,N,N N -tetramethylphenylenediamine, G(A/ A/ -EDTA) = 1.6 x 10 mol J has been obtained. Besides generating iV iV-EDTA, the OH radicals produce C-centered radicals by H-abstraction. These have reducing properties and are rapidly oxidized by tetranitromethane, giving rise to nitroform anion, G(NF ) = 4.2 x 10 mol J . The C-centered radicals react rapidly k = 7.6 x 10 dm mol s ) with O2, and subsequent fast 02 elimination. The Schiff bases thus formed hydrolyze to the final products. 

Only limited studies of oxidations in the highly acidic media useful in aromatic nitrations of deactivated systems have been reported. Bennett et al, found that in the nitration of 2,4-dinltrotoluene the major products of oxidation were CO, COj, and nitrous acid. (7) While the degree of oxidation was low In these laboratory experiments at low conversions, In largescale operations such as the manufacture of TNT, oxidation has been found to lead to significant reduction in yields, to problems of product purification, and to the production of relatively large quantities of noxious, volatile materials, including NO and tetranitromethane. (8)... 

In a study of the effects of added ethanol on the photolysis of alkoxy- and dialkoxyarenes in the presence of tetranitromethane, enhancements of adduct formation and trinitromethyl substitution have been found.Amongst the effects of added ethanol that have been identified are (i) stabilization of alkoxytrinitromethylarenes, thus reducing their tendency to decompose, (ii) a reduction in the nucleophilicity of the trinitromethanide anion, and (Hi) changes in the regioselectivity of trinitromethanide anion attack. 

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