Hg lamp high pressure

Fig. 14 Radiation characteristics of a high pressure Hg lamp (Osram HBO 100 continuous line) and of a xenon lamp (PEK 75 broken line) [4]. The intensity /is represented logarithmically in relative units.

A solution of quinoline 1-oxide (0.29 g, 2 mmol) in cyclohexane (1 L) was dehydrated by azeotropic distillation in the reaction vessel. The solution was purged with dry N2 and irradiated with a Hanau high-pressure Hg lamp. The resulting solution was evaporated and the residue was extracted with a little cyclohexane. The insoluble part contained carbostyril (3). The cyclohexane extract was evaporated and the residue purified by short-path distillation at 50°C/0.1 Torr yield 0.174g (60%) moisture-sensitive oil. 

A solution of K.OH (l.l2g, 20mmol) in MeOH (lOmL) was added dropwise over 30 min to a solution of 10a (3.5 g, 10 mmol) in MeOH (350 mL) under irradiation with a 400-W high-pressure Hg lamp with a Pyrex filter. After further irradiation for 1 h, the solution was evaporated under reduced pressure below 30 C, Et20 was added and the solution was washed with sat. brine and then dried (MgS04). Evaporation was followed by chromatography of the residue (alumina, hexane/Et20) yield 1.05 g (70%) red crystals mp 81-8.3 C (i-Pr20). 

The imine 13 (1.0-2.0 g) in benzene or CH2C12 (200-300 mL) was irradiated under N2 in an immersion apparatus equipped with a 400-W high-pressure Hg lamp and a Pyrex filter and cooled internally with running water. When TLC showed that all the starting material had been consumed (1 -3 h) the solvent was removed under reduced pressure and the residue was chromatographed (silica gel. CH2C12). 

The pyridinium salt 3 (0.427 g, 1.81 mmol) in H20 (1 L) was irradiated for 40 min with a high-pressure Hg lamp. The resulting solution was treated with 2M HC1 to pH 1 and then extracted with CHd3 under Nj. The extract was dried (MgS04) and evaporated in vacuo and the residue was chromatographed (silica gel) yield 0.157g (63%) mp 35-39 C. 

A solution of a 3-azidopyridine (0.5-1.0 g) in a mixture of MeOH (75 mL) and dioxane (75 mL) containing NaOMe (2.5-3.0g, large excess) was irradiated under N2 with a 400-W high-pressure Hg lamp with a Pyrcx filter. When TLC indicated that no azidopyridine was left (1 —2 h), the solvents were removed in vacuo, ice-water (10-25 mL) was added to the residue and the mixture was extracted with hexane. The extract was washed with H20, dried and evaporated under reduced pressure and the residue was chromatographed (Sephadex, hexane) to give the products as colorless oils. 

Azido-2-methylquinoline (4, R - Me 0.500 g, 2.7 mmol) and NaOMc (4.0 g. large excess) in a mixture of MeOH (70 mL) and dioxane (70 mL) was irradiated for 30 min with a 400-W high pressure Hg lamp (Pyrex filter). The solvents were removed in vacuo and ice-water (20 mL) was added. The mixture was extracted with CH2C12 and the extract was washed with H20, dried and evaporated. The residue was chromatographed (silica gel, 1 % acetone/CH2Cl2) to give 5a yield 0.194 g (38%) pale-yellow prisms (acetone/hexanes) mp 78-79 C. 

A solution of the 4-azidopyrimidine 1 or 2-azidopyrazine 3 in MeOH/dioxane (1 1) containing a large excess of Ct2Nll or NaOMe was irradiated with a 400-W high-pressure Hg lamp (Pyrcx) for 20-30 min 10 give ihe product as a viscous oil. No further details were reported. 

The polymer = 8.19 dlg in hexafluoro-2-propanol, HFIP, solution) in Figs 1 and 2 is prepared on photoirradiation by a 500 W super-high-pressure Hg lamp for several hours and subjected to the measurements without purification. The nmr peaks in Fig. 1 (5 9.36, 8.66 and 8.63, pyrazyl 7.35 and 7.23, phenylene 5.00, 4.93, 4.83 and 4.42, cyclobutane 4.05 and 1.10, ester) correspond precisely to the polymer structure which is predicted from the crystal structure of the monomer. The outstanding sharpness of all the peaks in this spectrum indicates that the photoproduct has few defects in its chemical structure. The X-ray patterns of the monomer and polymer in Fig. 2 show that they are nearly comparable to each other in crystallinity. These results indicate a strictly crystal-lattice controlled process for the four-centre-type photopolymerization of the [l OEt] crystal. 

The crystal of 2 OPr recrystallized from EtOH/H20 solution, and the mixed crystal of the same ethyl and propyl cinnamate derivatives (2 OEt and 2 OPr), on photoirradiation for 2h at room temperature with a 500 W super-high-pressure Hg lamp, afforded the highly strained tricyclic [2.2] paracyclophane (2 OEt-2 OPr-cyclo) crystal quantitatively (Maekawa et ai, 1991b). A crystal structure analysis was carried out of a single crystal of the complex of 2 OEt-2 OPr-cyclo with HFIP (recrystallization solvent) in a 1 2 molar ratio. Fig. 13 shows the molecular structure of 2 OEt-2 OPr-cyclo viewed along the phenylene planes. The short non-bonded distances and deformation of the benzene rings, as seen in Fig. 13, are common to those of [2.2] paracyclophanes, as previously reported (Hope et ai, 1972a,b). 

Fig. 6. UV-Vis absorption spectral change of trans-25 (0.126 mM) in acetonitrile under a nitrogen atmosphere upon photoirradiation with three bright lines (Amaj[ = 365, 436, and 546, nm) of a super-high-pressure Hg lamp. The spectra are depicted at 10 min intervals of photoirradiation. The irradiation with each bright line was continued for 30 min in ascending order of wavelength. (Reprinted with permission from Ref. 153.)...

Irradiation of (+ )-crystals of 96 with a 400 W high-pressure Hg-lamp, with occasional grinding with an agate mortar and pestle for 40 h at room temperature gave ( + )-97 of 93 % ee in 74 % yield. Irradiation of (—)-crystals of 96 under the same conditions gave (—)-97 of 93 % ec in 75% yield48. Purification to 100% ee can easily be achieved by recrystallization from benzene. Although the photochemical conversion of 96 into 97 on irradiation in the solid state has been reported, enantioselectivity of the reaction has not been discussed 441. 

Halmann and Aurian-Blajeni115 also examined C02 reduction by irradiation either with sunlight or a high-pressure Hg lamp of aqueous suspensions of various oxide semiconductors (i.e., Ti02, Fe203, W03, ZnO, and nontronite, an ion-containing clay mineral). 

Later, an improved system for C02 photofixation was reported by the same authors.164 The new system consisted of 6.5 x 1(T5 M tris(2,2 -bipyridine)ruthenium(II), Ru(bpy)3, as the photosensitive electron donor, methyl viologen (MV2+, 20 mM) as the electron acceptor, and triethanolamine (TEOA, 0.6 M) as a sacrificial electron donor in a C02-saturated aqueous solution (Fig. 18). Under irradiation with a 300-W high-pressure Hg lamp with a CuS04 chemical filter (A > 320 nm), formic acid, which was detected by isotachophoresis, was produced in quantum yields of ca. 0.01%. Recently, however, Kase et al.165 have repeated this experiment using a 13C02 tracer and have claimed that the formic acid obtained was produced not by C02 reduction but rather by oxidative cleavage of TEOA. 

Note Catalyst, 1 g (Ti02 0.3 g) water, 350 mL Na2C03, optimum quantity. An inner irradiation-type quartz cell, high-pressure Hg lamp (400 W) from Arakawa, H. and Sayama, K., Photocatalysis, Science and Technology, Kodansha/Springer, Berlin, 2002. 

Figure 1. Surface photografting apparatus (a) 100W high-pressure Hg lamp (b) interference filter (c) borosilicate glass plate (d) reacting solution (e) polymer film (f) glass vessel (g) clamp screw (17)...

Light source. Is a 200-W medium-pressure Hg lamp 2X irradiation through a glass plate (A>300 nm). II a 100-W high-pressure Hg lamp mono chromatic irradiation at 366 nm, 20 W hr/m. ... 

Table 1. Relative Sensitivity Using Ultra-High Pressure Hg Lamp as a Light Source...

Measured in outer irradiation cell from a 500 W high-pressure Hg lamp HjO 100 ml + MeOH 50 ml, catalyst 0.5 g, 420 nm cutoff filter was used 1 wt.% of Pt was loaded using HjPtCl by photoplatinization... 

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