Chemical
SYLVANIA
GENERAL TELEPHONE & ELECTRONICS
With chlorine it's loaded.
The organic glow.
Talk about crazy valence systems. Molybdenum will combine with 2, 3, 4, 5 and 6 chlorine atoms (MoCh to MoCU). The most important member of this halide family is molybdenum pentachloride, which we sell. We sell it in crystalline form, carefully packed in glass bottles in a dry, inert atmosphere. Because it's oxidationprone and hygroscopic. (It's also volatile when heated a little.) As soon as you leave it around in air, it becomes an oxychloride of some kind. Which is OK if you want oxychlorides. Or if you're trying to derive hydrogen chloride from moist air. What's nice about our stuff is that it's uncommonly pure, and you can get uncontaminated molybdenum out of it since it contains no other metals. You can do this with dry hydrogen. In a two-body collision with H2 at 900°C, the M0CI5 vapor yields a very fine powder of the metal. You can make it a three-body collision by providing a substrate, whereupon the substrate will be coated with molybdenum. The purpose may be protective or catalytic. M0CI5 is also chemically active in solution. Again, the point is to avoid oxidation. This leaves a wide range of organic solvents that will happily enfold our product: chlorinated hydrocarbons such as CCU, and anhydrous solvents such as ethers, alcohols, ketones, esters, etc. In some cases, there's a reaction when it dissolves. You can use M0CI5 to chlorinate aromatic rings. It's possible to chlorinate phthalic anhydride partially or completely. M0CI5 has been suggested as a Lewis acid catalyst in organic reactions. Some people are mixing M0CI5 with plastics, lending them fire retardance and possibly cross-linking the polymer. We're the only people who sell it. There's a fact-laden data sheet that goes into details. But the ultimate fact dispenser is us. Write.
Note carefully what happens when some panicky molecule drops back to the ground state. If it's been hit by a UV photon and throws out a wavelength that makes sense to the eye, it's fluorescing. If it also has a conjugated structure decorated by aromatic rings, it's an organic phosphor. Possibly ours. We hope it is. Not that we have anything against inorganic phosphors. In fact, we manufacture more of them than any other kind. But organics deserve their innings. Take the simple fact that organics dissolve and inorganics don't. That puts each in a different ball park. With organics, it's the molecule itself that fluoresces. With inorganics, it's the basic crystal structure, so you've got to have fair-sized particles to start with. Sometimes these don't work out so well. For instance, you can dissolve an organic phosphor in a volatile organic solvent to make a fluorescent ink for a felt marking pen. Inorganic particles would just clog up the felt. A dissolved phosphor deposits smoothly and dries out in the form of microcrystals. Organic phosphors are soft; inorganics are abrasive. Used in paint, organics won't wear out the rollers or other parts of the paint-making machine. Organics are generally brighter than inorganics under "black" light. Many have intense colors of their own in ordinary light, so you can use them as regular pigments with a built-in bonus of fluorescent color. The list of possible uses is long. (Think of how many dark places there are.) Use organics to give ordinary daytime materials a special nighttime look. Create dramatic effects in theaters. Apply them in crime detection, map making, effluent tracing. (Finely powdered organics are so light, they blow around like cornstarch—so you can even use them to trace air currents.) We're hoping this glowing tribute will get you to think organically and encourage you to get in touch with us if you come up with a bright idea. Touche.
Pentalollipop MoCb's deliciously simple structure. Three CFs form an equilateral triangle at the equator. Two hover over the Mo atom at the north and south poles. This is the gas phase (it's a dimer in crystal form).
Sometimes you can make points just by quoting the dictionary. As suppliers of molybdenum compounds to catalyst manufacturers, two sentences from the Encyclopedia of Chemical Technology touched our chemical-peddling hearts: "Molybdenum compounds may function as principal catalysts and also as activators and promoters of other catalysts. Particularly in the reactions involving petroleum and natural gas, the frequent interchangeability of sulfur and oxygen in molybdenum compounds is a highly useful property, since traces of sulfur may poison other catalysts but not those of molybdenum."
We're always glad to talk to you about tungsten, molybdenum and phosphor chemistry. Sylvania Metals & Chemicals, Chemical and Metallurgical Division, Towanda, Pa., 18848. 16 C&EN
