Peroxide stretching frequencies

The amide carbonyl vibrational frequencies of A-acyloxy-Af-alkoxyamides are similar to that observed for the twisted l-aza-2-adamantanone (98, 1731 cm ) . It is apparent from the extensive data available for both A-chlorohydroxamic esters (Table 2, Section in.B.2) and Af-acyloxy-A-alkoxyamides that when an amide nitrogen lone pair loses conjugation with the carbonyl (either through twisting/pyramidalization or, in the case of anomeric amides, pyramidalization alone), the configuration is analogous to an ester rather than a ketone. As with esters, acid halides and anhydrides or diacyl peroxides , the carbonyl stretch frequency is higher than that of ketones and aldehydes... 

Benzoyl peroxide has clear IR and Raman stretching frequencies at vO—O 846 and 847 cm , respectively, whereas for lauroyl peroxide the IR band at 886 cm is very weak and only the Raman band at 876 cm can be useful for structural assignments . ... 

Type III. EPR-silent binuclear copper site that binds dioxygen as peroxide and exhibits unusual physicochemical characteristics (1) diamagnetism, (2) two characteristic absorption bands at 350 and 580 nm, and (3) a low O—O vibration stretching frequency (-750 cm-1). 

Various porphyrin compounds such as NFevOEP are known.62 The i Fe=N) stretching frequency of 853 cm-1 is lower than that of the Cr and Mn analogues the nitrido Fev complex is stable only at very low temperature ( 30 K). It is widely accepted that one of the intermediate species in the catalytic cycle of cytochrome P-450 (see later) contains pentavalent iron. The reduction of an R3CFev moiety is an accepted part of the mechanism of dismutation of hydrogen peroxide to water and oxygen catalyzed by catalase. 

Inorg. Chem., 9, 11, 2485 (1970). It should be noted that the stretching frequency of the peroxide bond, y(O-O) 798 cm , is low and is compatible with the ready dissociation of S2O6F1 FS(0)26-0S(0>2-F - 2PSO3 This may be associated with the high electron-... 

Except for the a-peroxylactones, which have characteristic carbonyl stretching frequencies at 1850-1875 cm (for specific values, see Table 2), infrared spectra are of no great help for the identification of 1,2-dioxetanes. The weak and controversial 0-0 stretching frequency of peroxides is not sufficiently characteristic for structural confirmation. ... 

Scatter diagram showing the distribution of O — O stretching frequencies and separations in ionic superoxides and peroxides (A) and in coordination compounds. An open circle denotes O2 coordinated to one metal a filled circle denotes O2 bridging two metals. The O — O stretching frequencies of oxyhemoglobin, oxyhemocyanin, and oxyhemerythrin are marked by dashed lines. 

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