Hanovia mercury lamp

The photochemical and thermal transformations of 5-methyldihydro-thiazolo[3,2-a]pyridinium-8-olate (515) have been investigated. Irradiation using a Hanovia mercury lamp and Pyrex filter gives the isomeric pyridone 516 (4%). When a Rayonet reactor was used, a product which appears to be the valence tautomer 517 (6%) was isolated. Further irradiation of 517 gave... 

A Hanovia mercury lamp having strong emission bands in the lower ultraviolet region (below 3000 A.). 

For the investigation into the Influence of u.v. radiation on the dielectric properties of polycarbonate, pressed sheets of the material were irradiated at room temperature in air by a standard Hanovia mercury lamp. The lamp provided a spectrum of wavelengths within the range 254 to 546 nm and sample intensities of 2.47 mW cm and 0.91 mW cm respectively at the principal wavelengths of 365 nm and 254 nm. A voltage-stabilized power supply assisted consistency of spectral output. 

Nopinone is a major product of the reaction of the biogenic compound pinene with ozone and OH radicals. The photodecomposition of nopinone in methanol and tert-butyl alcohol solutions has been studied by Shaffer et al. (1972). The solutions were outgassed with argon before and during photolyses, and Corex filtered light from a 450 W medium pressure Hanovia mercury lamp k > 255 nm) was used in... 

The apparatus is dried in an oven at 140° overnight and cooled under nitrogen or argon prior to the irradiation. A Vycor filter sleeve and a 450-watt medium-pressure mercury lamp are placed in the immersion well. The Vycor filter, the quartz immersion well (catlog No. 19434), the 450-watt mercury lamp (catalog No. 679A36), and the requisite transformer are all available from Hanovia Lamp Division, Canrad-Hanovia Inc., 100 Chestnut Street, Newark, New Jersey 07105. 

The energy distribution for the commonly used 450-W Hanovia medium-pressure mercury lamp is given in Table 2.5. 

W Hanovia medium pressure mercury lamp. s Benzene solvent. 

FIGURE 3.9 The most common type of power supplies for mercury lamps with large arc lengths combine a step-up transformer and a ballast capacitor placed in the secondary circuit of the transformer. (Courtesy Hanovia.)... 

Solid-state photolysis was performed using a 450-W hanovia medium-pressure mercury lamp fitted with a Pyrex filter (X >290 nm). The crystalline la was irradiated for 22.5 h at -20 °C to give a mixture of exo-isomer 3a and endo-isomer 4a in 63 and 12% yield, respectively. 

Experimental. All photodimerizations were carried out in a stainless steel fixed volume cell (1.75 cm ID with a 1.0 cm path length) with sapphire windows under the irradiation of a Hanovia medium pressure mercury lamp filtered through water and Pyrex for a 13.5 hour exposure. The cell and lamp assembly have been described previously (31). For selected runs a custom built 0.9 mL variable-volume pump was connected to the cell and the pressure was varied to determine the exact location of the phase boundary, based on light scattering measured in a Cary 2290 UV-Vis spectrophotometer (Varian Inst.). The spectrophotometer was also used to measure the concentrations of the monomeric cyclohexenone before and after reaction. 

Photolysis photolysis rate k = 2.03 x 10-4 s-1 at 313 nm using a Hanovia 450-W mercury lamp in hexane solution (Dulin et al. 1986)... 

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