LesserKnown Atmospheric Compounds While the discussion of atmospheric compounds has focused on such important molecules as N0,and SO,, and their reactions with OH and VOC's, there are other species that should not be overlooked. Lesser-known atmospheric compounds include JOz, LOr, BOX,DOr, and FOX.
JOx These species possess an unusual number of translational, rotational, and vibrational modes, even a t room temperature, along with exceptionally low excitation energies for orbital electrons. Reactivity seems ta he strongly influenced by steric considerations and the overall s h a m of the electron densitv. For examde, some JO, have electron densitv distributed in an almost perfect sphere, theso-called basketball, and seem very;eactive with aromatic rings or any ring-shaped moiety including crown ethers. JOx with Gshaped electron density resembling hockey sticks exert a pressure on container walls hieher than calculated values due to freauent collisions. JO, with faathall-shaoed electron ~~~~density srrm rn r d l d e r a p d y , sometmes dnasaoci3t~ng.sometimes being repelled mutually, or 31 t.mcs atcumulatrng ~n small heaps. JO, seem to remain common nround rnllrpr mmpusrs, unlike the free rxdirnls SD3, which dmppenrell about the a-me rimr ns the I.'S.m~teorrhgicalphmomcnon k n w n as the \\'eather Underwmnd. ~~~
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LO, These compounds are a n area source emission. They seem to be in greatest concentration in some parts of large metropolitan areas. Delicatessens have been suggested as the origin of the emissions.
BOX Visible in the atmosphere when in high concentration, these often have a brownish color. BOXcompounds usually are cubic or prismatic in shape. They became caught in the Upward Particle Stream (UPS), are transported to lower altitudes in the troposphere, and are dispersed within several days to various destinations. At times BO, compounds became entrained in the jet stream, and are found a t distant destinations, usually by the next morning. This phenomenon is known as the Federal Express.
These dark brown to black molecules apparently form when lignin comes in contact with large bodies of water, both fresh and marine. DO, are found in the Los Angeles area in places such as Marina Del Rey and Newport Beach. Unlike some other pollutants, DOz are found in the highest income neighborhoods and are considered a status symbol.
The FOXmolecules have different size absorption cross sections and reflect different wavelengths of light. FOXmalecules are entirely natural in origin. Some, which reflect longer wavelengths (red FOX)or a mixture (grey FOJ appear to have declined in concentration over the past 40 years. At least one, the small kit FOX,has become so rare by some estimates that it has been designated an endangered species. .I.Karlik
Volume 72 Number 12 December 1995
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