After UV irradiation

Fig. XVIII-7. Br(3p) XPS spectra of a 2.2-L dose of DBr on Pt(l 11) before (a) and (b) after UV irradiation. The 182.8-eV peak is due to DBr and the 181.5 peak, to atomic Br. On irradiation the latter peak increases relative to the former [38]. (Reprinted with permission from American Chemical Society, copyright 1992.)...

Fig. 16 Detection of cis/trans isomerization of piperine by the SRS technique after UV irradiation (A) originai chromatogram, (B) schematic representation.

Fig. 17 Detection of the photochemical cis/trans isomerization of butter yeliow after UV irradiation by using the SRS technique. (A) original chromatogram — treated with hydrochloric acid vapor for better recognition (yellow then turns red) — and (B) schematic representation.

Fig. 1. Electrophoretic mobility of Hind lll-restrict fragments of X DNA after UV irradiation (A) and DNA electrophoregram trace (B) 1 - control, 2 - after UV irradiation for 3 hours (3.64 J/m2 ), 3, 4 - the same in the presence of Q-AR in concentrations of ICHM and lO M, 5, 6 - the same in the presence of Q-AR at concentrations of lO M and lO M. The arrow shows...

Figure 9. ESR spectrum of 1,2,4-trichlorodihenzo-p-dioxin in TFMS acid after UV irradiation...

Three isomeric tetrachlorodibenzo-p-dioxins were studied. All were insoluble in TFMS acid. To dissolve these compounds and form cation radicals, UV irradiation was necessary. The 1,2,3,4-tetrachloro compound was particularly sensitive to UV irradiation, and as a solid, even turned pink when exposed to ordinary fluorescent light. When subjected to constant UV irradiation, radical ions were induced rapidly. The change in the cation radical concentration was monitored by the ESR signal as illustrated in Figure 10. To determine whether the tetrachloro isomer had been converted to lower chlorinated derivatives after UV irradiation, the dissolved dioxin was then poured into ice water and recovered. The GLC retention time of the recovered dioxin was unchanged in addition, no new GLC peaks were observed. Moreover, the ESR spectrum see Figure 11) for the recovered material was not altered between widely... 

Savoure, N. et al., Vitamin A status and metabobsm of cutaneous polyamines in the hairless mouse after UV irradiation action of P-carotene and astaxanthin, Int. J. Vitamin Nutr. Res., 65, 79, 1995. 

Figure 3. IR spectra of Lipid 1, (a) monomeric lipid, (b) After UV irradiation, (c) hydrolyzed lipid.

When a thin liquid film with a thickness of approximately 2 pm prepared by spin coating of a 15% benzene solution of polymer 1 was irradiated with a 500-W Xe-Hg lamp for 300 s in air, a transparent solid film was obtained. The UV spectrum of this solid film shows that an absorption at 235 nm due to phenyldisilanyl units vanishes after UV-irradiation (Figure 1). This clearly indicates that photolytic cleavage of silicon-silicon bonds leading to the cross-linking occurred. Similar photolysis of the thin liquid films under a nitrogen atmosphere again afforded transparent solid films whose UV spectra show no absorption at 235 nm due to phenyldisilanyl units. 

Irradiation of a solid film prepared from the polymer 11 in air afforded photodegradation products which are soluble in 2-ethoxy-ethanol. IR spectra of the products show strong absorption bands attributed to Si-OH and Si-O-Si stretching frequencies. In contrast to the products from 10, these products show absorption due to the Si-H bond. This result indicates that some of the silenes would be formed in this system. The intense absorption at 254 nm in the UV spectrum again disappeared after UV-irradiation. 

It explodes upon ignition, or after UV irradiation and then heating to 120°C. 

In investigations of healthy persons under normal conditions and after UV irradiation of the whole body we have found that ASC correlates significantly (p < 0.001) negatively with ACR [35], A plausible explanation was that some of the above antioxidants can replace ASC in case of its increased consumption during an oxidative stress. 

Figure 14 Time course of ACW of HSA (60 g/L) and cystine (2 mmol/L) during (filled circles) and 24 h after UV irradiation (open circles). (From Ref. 36.)...

The ESR spectrum of triplet anthronylidene lp was recorded after UV irradiation of 2p at 77 K.95-97 At 0.365 cm-1 the zero field parameter D in lp is larger than that in la, which indicates that the delocalization of the unpaired n -electron in lp is less efficient — despite the larger 7t-system — than in la. Obviously the phenoxyl resonance structure in la is more favorable than in lp. 

Grubbs group reported a series of cross-linkable triarylamine-containing poly(norbor-nenes) (51) and investigated them as the HTMs in a bilayer OLED (Scheme 3.19) [94]. However, cross-linking was found to decrease the device performance due to the low Ts of the polymers and the poor film quality after UV irradiation. 

Figure 1. EPR spectra of methyl radicals (a) after reaction of CHif with 0 on Mo/Si02, (b) after UV irradiation of oxidized Mo/Si02 in the presence of CHi. Reactions were carried out and spectra recorded with the sample at 77K.

Literature data on cytotoxic effects of photoexcited fullerene C60 are controversial. In the studies on transformed B-lymphocytes of Raji fine, phototoxic action of water-soluble carboxy-C60 was not revealed even upon its concentration of 5 x 10 5 M (Irie et al., 1996). In the study (Kamat et al., 2000) damaging effect of fullerenes C60 in dependence on intensity of irradiation toward CHO cells has been demonstrated. Using microsomal fraction of rat liver that was treated with C -cyclodextrin complex, it was shown that already in 5-30 min after UV-irradiation the accumulation of LPO products occurs that is suppressed by antioxidants like ascorbic acid and a-tocopherol. Similar effect of fullerenes C60 has been revealed in microsomal fraction of the cells of ascitic sarcoma 180 (Kamat et al., 2000). 

The ultraviolet (UV) rearrangement of polyarylesters and their related model compounds have been previously studied (20,21). The chemical changes which occur during the UV irradiation of styrylpyridine based ester and carbonate were investigated. The UV spectra of the p-VPPB and p,p -BVPDPC in 1,2-dichloroethane were monitored during the irradiation (Fig. 3 and 4). The maximum absorption for unirradiated p-VPPB was at 319 nm. After UV irradiation, the maximum peak shifted from 319 nm to 350 nm and the observed increased absorption in the... 

Legube, G., et al., Tip60 is targeted to proteasome-mediated degradation by Mdm2 and accumulates after UV irradiation. Embo J, 2002, 21(7), 1704-12. 

After UV irradiation, betaine 369 exhibits a novel photooxidative interconversion, as shown in Scheme 133. The originally deep red starting... 

The potential usefulness of 3//-l,2,4-diazaphospholes for the synthesis of other phosphorus heterocycles was demonstrated using 234 (Scheme 8.55) which, after UV irradiation at —40°C, gave a 5 1 mixture of 4,5-dihydro-3//-phospholes 235 and 236. The latter compound is the hrst example of the previously unknown 2H-phosphirene system (288). This reaction probably proceeds via a photochemical ring opening of 234 and formation of a phosphavinyl carbene. 

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