Alcohol bandwidth

Lin and DeMore (637) have irradiated mixtures of 03 and isobutane with monochromatic light of wavelengths from 2750 to 3340 A at —40 C. The bandwidth was 16 A. The relative quantum yields of OCD) production were obtained from the yield of isobutyl alcohol, a product of the reaction 0( D) + isobutane. The results are shown in Fig. VI -13. The quantum yields are constant below 3000 A and show a sharp cutoffat 3080 A, the thermochemical threshold wavelength for the production of O( D) + 02( A). 

Further studies have shown that there is evidence for the double proton transfer reaction arising from a two-proton concerted process <93JAioi58>. In addition to this excited-state double proton transfer, an excited state complex ((l)-alcohol exciplex) exists in alcohol solvents <83JPC3202>. This exciplex formation is responsible for the unusually long wavelength shift and the bandwidth of the fluorescence spectra of compound (1) in alcoholic and aqueous solvents. In aqueous solution at neutral pH, only one fluorescence is observed which corresponds to the fluorescence maximum displayed by the tautomeric species <92JA8343,93JPC11823). 

A system containing 20% of a tertiary alcohol in petroleum ether separated all the investigated pigments except -carotene and lycopene. A typical separation is shown in Fig. 12, where an extract from parsley was used as the carotenoid source, and the efficient spread of the polar pigments is evident. The separations are even better on plastic-backed silica gel (0.2 mm, Merck), where extremely narrow bandwidth can be produced. Combined with circular TLC, the system provides valuable information about samples with complicated pigment patterns in the polar area. 

Scheme 2 presents the most apphed cleavage strategies for esters of type A (carboxyhc and sulfur esters) with an aUcyl or an aryl substrate directly bound to the ester linkage. The bandwidth of products obtainable from carboxylic esters includes esters 14, acids 13, primary and tertiary alcohols... 

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