Absorption maxima hydrocarbons

Ocimene is a pleasant-smelling hydrocarbon found in the leaves of certain herbs. It has the molecular formula C10Hi6 and a UV absorption maximum at 232 nm. On hydrogenation with a palladium catalyst, 2,6-dimethyloctane is obtained. Ozonolysis of /3-ocimene, followed by treatment with zinc and acetic acid, produces the following four fragments ... 

Riverside, Calif. The specific method developed by Cohen and Purcell (9) was used here titanium IV and 8-quinolinol react with H2O2 to form a colored complex with absorption maximum at 450 m/A. There was no interference in the method for urban atmospheric levels of NO, NO2, O3, PAN, SO2, and hydrocarbons. 

Cytochromes P-450, the CO complexes of which have a characteristic absorption maximum at 450 nm, use molecular oxygen to catalyze monooxygenation of versatile organic compounds such as hydrocarbons, sulfides, and amines with reducing agents (Eq. 1) [27-33],... 

The fluorescence of methyl 3-hydroxy-2-naphthoate has been investigated by Nabolkln and co-workers (37). They found two emisslOns ln hydrocarbon solvents with maxima near 23,800 and 15,400 cm The former should be due to a normal emission, analogous to A A (see Section III-A). The Stokes shifts amounts to 3200 cm l, relative to the long wavelength absorption maximum. A shift of 4000 cm is observed in methyl 3-methoxy-2-naphthoate. The red fluorescence (15,400 cm ) is rather weak. 

The fluorescence of salicylldene-o-toluldene (SAT) has been investigated by Becker and Richey (55). There is a 10,000 cm Stokes shift between the first absorption maximum and the fluorescence maximum in hydrocarbon solvents (Table 7). Addition of small amounts of propionic acid to the 3-methylpentane solution of SAT produced some cis-qulnold tautomer whose fluorescence maximum is at 20,100 cm, blue shifted by about 1000 cm, compared to that of SAT "phenol." The cis-quinold tautomer could further be produced by controlled heating of a solution of the... 

The structures of some prominent d,v-isomcrs of lycopene are shown in Figure 4.2. G. s-isomers have distinct physicochemical characteristics (and hence, bioactivity and bioavailability) compared to their all-trans counterparts. In general, the di-isomers are more soluble in oil and hydrocarbon solvents than their all-trans counterparts. They are less prone to crystallization because of their kinked structures. They also are less intense in color, which may influence the consumers perception of food quality. The appearance of a distinct absorption maximum in the UV region ( di-peak ) is useful for distinguishing between the different isomers. 

In the survey of 7t-electron semiempirical studies we have missed a paper of Karwowski, J. (Bull. Acad. Polon. Sci., Ser. Sci. Math. Astronom. Phys. 20, 413 (1972)) on the interpretation of the electronic spectra of benzene ion radicals. Recently Shida, T. and Iwata, S. (J. Am. Chem. Soc. 95, 3473 (1973)) recorded spectra of a large series of ion radicals of aromatic hydrocarbons and analyzed them in terms of 7T-electron SCF Cl calculations. They confirmed experimentally a long-wavelength transition in the mono-negative azulene ion predicted by the theory. Their absorption curve of the monopositive azulene ion is in better agreement with the calculation than the curve presented in Fig. 31 a strong absorption maximum at 15 AK in the latter is thus likely due to other species than the azulene radical cation. From recent ab initio studies we wish mention those on CH (Lie,... 

The carbanionic active centers based on 1,3-butadiene and isoprene with lithium as counterion generally possess good stability in hydrocarbon solvents at ambient temperatures. However, poly(dienyl)lithiums undergo complex decomposition reactions upon prolonged storage or heating at elevated temperatures. Poly(butadienyl)lithium in ethylbenzene exhibits an absorption maximum at 300 nm, which... 

Localized electrons in organic glasses exhibit an optical absorption spectrum similar to that of electrons in liquid hydrocarbons. In 3-methylhexane irradiated with Co-y-radiation or fast electrons, the absorption maximum occurs between 1600 and 2000 nm (Klassen et al., 1971). Trapped electrons can be mobilized by light of a suitable wavelength. The electrons are promoted out of the trap and they contribute to the conductivity imtil they become retrapped. The spectral dependence of the photocurrent due to trapped electrons in glassy methyl cyclohexane is shown in... 

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