Nitrate band

As shown in Figure 13.10, the storage oflOOO ppm NO2 in Heover Ba/AbO (20 100 w/w) is accompanied by the evolution of N O in the gas phase which is observed with no dead time. The uptake of N O 2 is fairly effective since large amounts of Narc stored at the end of the pulse, near 9 x 10 mol gcaC, and results in the formation of only nitrates [bands at 1320,1420 and 1560 cm in inset (b) in Figure 13.10]. 

For a linear oxo-bridge between two metal ions, a strong infrared band is expected around 850 cm i 38). The poljoner spectrum is blank in this region, except for the weak nitrate band at 830 cm-i. Instead the spectnun shows a strong band at 700 cm i, a stronger one at 450 cm i with a shoulder at 500 cm , and a weak band at 270 cm i. These features... 

The exact position of nitrate bands (at 1274 and 1276 cm 1 for EPDM and polyoctenamer respectively) is consistent with the selective formation of secondary hydroperoxides (a)15. 

C0/C02/He (2/11/87) at 660 K and evacuated to 10 Pa for 1 h at 660 K, This treatment has been shown to convert essentially all of the iron to the ferrous state. Spectrum 2a was taken following exposure of 1% Fe/Al203 to NO at beam temperature for 120 min. Gas phase NO bands and the background spectrum of the sample (which was collected before exposure to NO) were subtracted from each spectrum so that only spectral features caused by exposure to NO are displayed. Spectrum 2a was fit with infrared bands at 1805, 1743, and 1655 cm". The intensities of these bands were essentially constant after the first two minutes of exposure to gaseous NO. The peak at 1655 cm" can be assigned to a nitrate band on AI2O3 (36). 

Evidence to support this "counterion modified" model comes from the investigation of hydrated Ln(NC>3)Cl2 prepared in the usual way in water (LnCl3, AgN03). The lanthanide(III) chlorides themselves show little or no catalytic activity for nitrations. A possible rationale for this is obtained by noting that HC1 is a poor activator of nitric acid in nitration chemistry since it is not sufficiently acidic to protonate nitric acid. However, the IR spectra of the Ln(NC>3)Cl2 salts are essentially identical to those of Ln(N03)(0Tf)2 indicating that the chloride ions are outer sphere in these complexes. Additionally the nitrate bands show the same trend as demonstrated for the triflate series (e.g., for La(N03)Cl2 the characteristic nitrate stretch is observed at 1459 cm1 and for Yb(NC>3)Cl2 the band appears at 1497 cm-1)- This indicates that the lanthanide chlorides are capable of activating nitric acid (via metal-nitrate interactions) but critically, the counterion (i.e. chloride) is incapable of fulfilling its role (in whatever capacity that may be) and hence no nitration occurs. 

Alkaline hydrolysis of starch nitrate produced ammonia, cyanides, nitrites, and nitrates.1478 Starch nitrate could be denitrated by use of diluted solutions of ammonium sulfite followed by the addition of hydrogen peroxide to remove colloidal sulfur.1448 The strong nitrate band absorption in the infrared between 730 and 960 cm-1 complicates the identification of polysaccharides. The region suitable for identification of starch nitrates is between 900 and 1350 cm M479 Nitration of glyceryl starch into a trinitrate was also reported.1480 Starch nitrates readily react with an TV.TV-dimethylformamidc-SO complex to give trisulfates.1481... 

As was shown by Hadjiivanov [780], the adsorption of NO-1-O2 leads to the formation of NO+, which can be used as a probe for the location of OH groups [781 ]. Thus, co-adsorption of NO and O2 into mordenite produced two separate bands of NO+, a band at 2168 cm due to the interaction with OH groups in the main channels and a second one at 2215 cm, indicating the acid hydroxy groups in the side pockets. From the ratio of the intensities of these bands (2 1), the authors concluded that the population of the main channels with OH groups is twice as that in the side pockets (see, however, above and cf. [477]). When Na cations were present in the mordenite structure, nitrate was formed and indicated by intense nitrate bands. The situation was more complicated when not only B-... 

IR data (THF-dg) Nitrate bands 1549,1500,1300,1288,1255 cm i. Nitrosyl band 1860 cm . The nitrosyl compound could be independently generated by treating CuCl2 with NOCl in THF. This nitrosyl complex is rapidly converted to the mixture of nitrate species on exposure to oxygen. 

On the basis of intensity measurements and low temperature crystal spectra other assignments have been suggested for the nitrate band at ca. 300 nm (e.g. but the general consensus of opinion ... 

In the investigation of products and intermediates from the reactions between NO3 and the alkenes (propene isobutene trans- and cis butene 2-methyl-2-butene 2,3-dimethyl-2-butene and isoprene) it was found that all of them followed a similar pattern. The build-up of organic nitrate bands (845, 1280 and 1667 cm ) and peroxynitrate bands (790,1300,1725 cm" ) were observed in the IR-spectra as showed in Fig. 2. The subsequent decay of the peroxynitrate bands was accompanied by a build-up of spectral features attributed to stable products (see Fig. 2). These stable products were identified as aldehydes, alcohol nitrates, carbonyl nitrates and dinitrates [3,4]. 

Kg. 6b Raman spectra of amorphous carbon [soot+ (a) soot + sodium nitrate + nitrocalcite (b) soot (c)] identified on the stage 5 sample during summer. ( sodium nitrate band (1067 cm" ) + nitrocalcite band (1050 cm" )). 

The visual information can be related to very accurate spectroscopic information, as can be seen in Figure 7.9 when the dataset is plotted as an accumulation of spectra in the spectral domain only. The nitrate band appears in the nitric acid solution (A) and in the membrane (overlapped with a membrane matrix Raman line), whereas there are no nitrate ions in the other side of the membrane (B). The wide water band (stretching Vqh) can also give some structural properties of water, both inside and outside the membrane. 

Figure 7.9 Superimposed spectra during the depth scan of an ARA membrane (A) and (A ) intensity of the nitrate band in the nitric acid solution and within the membrane respectively, (B) nitrate absence in the hydrochloric solution, (C) water intensity, (D-F) membrane matrix intensities.

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