Mercury spectrum

Derivatives of 5-alkyl-2-(l,3,4-oxadiazol-2-yl)thiophenes 168 were synthesized and their photochromic and fluorescent properties studied. A solution of the photochrome was subjected to irradiation over a wide range, including the lines of the mercury spectrum at 313, 365, 405, 436, 546, and 578 nm. It was discovered that the open form of compounds 168 showed strong fluorescence <2002CHE165>. 

For entire class) spectrum tubes (hydrogen, neon, and mercury) spectrum tube power supplies (3)... 

In his recent work on the fine structure of the mercury spectrum, Ruarke has met with only limited success in his attempt to construct a fine structure energy level diagram. The most extensive work on fine structure in mercury has been by Nagaoka, Sugiura and Mishima. Of their results Wood has found the structure assigned to the line 2537 A incorrect and the author has foimd that there appears to be some discrepancies in the structiue reported for the lines 3650 and 2967 A. The full report is being sent the Phil, Mag. for publication. The structures fotmd for these lines are as follows ... 

Step-and-repeat (S/R) cameras use refractive lenses with numerical apertures of 0.2 to 0.4. The best lenses expose a field of about 2 cm x 2 cm at a numerical aperture of 0.3. Higher numerical aperture is available for smaller field-size. The field-size and numerical aperture for many of the lenses used in microcircuit cameras are shown in Figure 3. Most lenses are designed to operate at a single wavelength that corresponds to a strong line in the mercury spectrum (365 nm, 405 nm, or 436 nm), but lenses have also been corrected for two wavelengths (405 nm and 436 nm) in order to reduce the effects of... 

Figure 6 shows the absorption curve for acetone superimposed upon the emission spectrum of a medium pressure mercury vapor lamp of the type commonly used in photochemical investigations. If the possibility of mercury photosensitization is neglected, it can be seen that the emission line in the mercury spectrum which will be most effective in photolysis is that at 3130 A., and, in fact, this line is frequently isolated by the... 

A similar lamp was developed for solid elements in order to give intense light at wave lengths not included in the mercury spectrum. The situation is more difficult because the lamp cracks when the metal freezes. It is necessary then to use a new lamp for every experiment, but they are not expensive and they can be made to run for several hours. The most serious difficulty lies in the fact that these more basic metals attack the quartz at the very high temperatures forming a silicate coating which may be opaque to the ultraviolet light. The chemical combination of the metal with the silica is sufficient in a few hours to cause a considerable increase in the internal diameter. 

This compound has been photolyzed in the gas phase with a Pyrex reaction vessel and a medium pressure mercury arc without the use of any filters. Under these conditions the effective radiation is that emitted between 290 and 334 ray in the mercury spectrum with the major contribution from the lines at 313 m,u. The volatile products produced were ethylene, acetylene, hydrogen, and nitrogen. To explain the relative yields of these compounds the following mechanism was suggested ... 

The traditional sodium D wavelength was (historically) chosen for practical reasons associated with the use of visual polarimeters rather than for any technical advantage. Current technology makes the photoelectric polarimeter the instrument of choice, permitting the use of several lines in the mercury spectrum, in addition to the classical choice of the sodium D wavelength. Chafetz (6) has provided a variety of examples of the higher... 

The mercury spectrum is even less regular. The electron configuration in Hg consists of two valence electrons outside of a closed-shell core. .. (5s) (5p) (4/) (5d) . The Hg spectrum features that are not anticipated in H or K arise from electron spin multiplicity (i.e., the formation of triplet as well as singlet excited states in atoms with even numbers of valence electrons) and from spin-orbit coupling, which assumes importance in heavy atoms like Hg (Z = 80). The mercury spectrum in Fig. 2.2 has been widely used as a spectral calibration standard. 

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