Benjamin Wiley

Oil and water stay separate, which limited chemical reactions for a century. A chemical dissolved in one layer could not reach a chemical dissolved in the other, so factories used expensive solvents they had to keep strictly free of water. Around 1960 Mieczyslaw Makosza, a young chemist in Warsaw, found a way to make chemicals in the separate layers react. Stirring the layers with about one percent benzyltriethylammonium chloride, a plain white salt, lets the salt carry the chemicals between layers. That same year a small Polish firm ran the reaction in a factory kettle instead of a lab flask, using lye water without added solvent. Chemists call the method phase-transfer catalysis, and pharmaceutical and agrochemical plants now use it routinely. Annual sales of catalysts for the method exceed a billion dollars. Sixty years later the salt remains a cheap standard catalyst. The US imports about 220,000 pounds of it a year, and no US plant makes it.

In 1967 Karl Clauss, a chemist at Hoechst in Frankfurt, unexpectedly tasted something intensely sweet when he licked a fingertip to pick up a piece of paper. He had been reacting two violently reactive compounds, neither meant for food. He spent years studying the related ring-shaped molecules that caused the taste and developed acesulfame potassium, a sweetener 200 times as sweet as sugar. Acesulfame potassium tolerates the heat of an oven or a warm warehouse, while aspartame breaks down in both. So Coke Zero and Diet Pepsi use the two sweeteners together, and sugar-free baked goods rely on acesulfame potassium. The world's supply comes from a handful of plants, chiefly in Germany, where chemists invented it, and China, which now makes most of the volume. The US has no plant that makes acesulfame potassium.

A chemical used to make dyes for the fabric in your clothes sells for $120 per gram, 1.3 times the price of gold. This chemical is a dye intermediate, a starting molecule manufacturers react into color-making compounds for textiles. When a small input like this costs more than gold, it can set the price and availability of the colors that end up in fabric. AK Scientific in the US sells 1 gram for $120. A2B Chem in the US sells 1 gram for $130. This is one of 838 molecules selling today for more than gold per gram. Here's the list:

The white light in an old garage fluorescent tube comes from a powder that researchers invented in wartime London. In 1942 A.H. McKeag's team at the General Electric Company's laboratories in Wembley heated calcium phosphate with calcium chloride and fluoride and made a phosphor, a powder that glowed white without blending it with other powders. They added antimony and manganese to the new calcium halophosphate, which nearly doubled a lamp's light output. It also replaced earlier coatings containing beryllium; dust from those coatings had been destroying lamp-plant workers' lungs. US factories abandoned beryllium phosphors by 1949, and manufacturers coated the world's fluorescent tubes with calcium halophosphate for the next half century. Fluorescent tubes still hum in American warehouses and schools, as well as on shop ceilings. Manufacturers still coat cheap standard tubes with McKeag's phosphor. The US imports about 150,000 pounds of it a year, and no US plant makes it.

A chemical used to make donated blood safer before transfusion sells for $1,012 per gram, 11 times the price of gold. Amotosalen hydrochloride is mixed into donated blood before transfusion. Light activates it, then it stops microbes from multiplying. That lowers the chance that a transfusion carries an infection into a patient. Combi-Blocks in the US lists 1 gram for $1,012. A2B Chem LLC in the US lists 100 milligrams for $3,435. This is one of 838 molecules selling today for more than gold per gram. Here's the list:

In 2006 Geza Schoen, a German perfumer, bottled a single aroma chemical and sold it as a finished perfume. Molecule 01 has one ingredient, Iso E Super, a molecule with a woody amber smell that chemists John Hall and James Sanders invented in 1973 at the American fragrance firm International Flavors & Fragrances. They designed it as a cheap, durable substitute for cedarwood, and for its first decades it mostly scented laundry detergent and soap. Then perfumers noticed that it strengthened the scents they combined with it. By 1988 Iso E Super made up about a quarter of Dior's Fahrenheit. Schoen first proposed the single-ingredient perfume to Diesel, but the brand declined, so he launched it himself. Molecule 01 became one of the best known niche fragrances in the world, even though roughly one in five people cannot smell it at all. The patent has long since expired, and manufacturers now sell the molecule under more than thirty names. The US imports about 90,000 pounds of it a year for household soaps and cleaning products, and no US plant makes it.

A solvent used in air fresheners, cleaners, candles, and paints sells for $133 per gram, 1.4 times the price of gold. Butyl dipropasol is a solvent: it helps dissolve fragrance oils, cleaning ingredients, and coating additives so they spread evenly instead of separating. That makes it useful when a product has to smell consistent, clean consistently, or lay down a smooth film. A2B Chem LLC in the US sells 1 gram for $133. AA BLOCKS in the US sells 1 gram for $141. This is one of 920 molecules selling today for more than gold per gram. Here's the list:

In 1932 Albert Szent-Gyorgyi, a Hungarian chemist, proved that hexuronic acid was vitamin C, the compound whose absence causes scurvy. He had first extracted it from adrenal glands but needed far more than glands could give, so he turned to paprika, the crop his town of Szeged was famous for. His lab processed two thousand kilos of paprika to extract about half a kilo of pure white crystals. He won the Nobel Prize in 1937. Manufacturers now produce the compound, L-ascorbic acid, as a powder for supplements, IV bags, prenatal vitamins, and breakfast cereal. The US made it for decades at a plant in Belvidere, New Jersey, but the production line shut down in 2005 under pressure from cheaper Chinese product. The US now imports about 190 million dollars of it a year, 73% of that from China, and has no domestic production.

An ear-drop ingredient used for ear infections sells for $1,022 per gram, 11 times the price of gold. Thonzonium bromide is a surfactant. It helps ear-drop liquid spread across waxy, inflamed tissue so antibiotic ingredients can reach the infection instead of beading up at the surface. A2B Chem LLC in the US sells thonzonium bromide for $511 for 500 milligrams. Molnova in China sells it for $597 for 500 milligrams. This is one of 838 molecules selling today for more than gold per gram. Here's the list:

A fugitive named the chemical now used to make California's desert vines bud each winter. Stanislao Cannizzaro fought as an artillery officer in Sicily's failed 1848 revolution, then escaped to Paris. There in 1851 he and the French chemist Francois Cloez bubbled cyanogen chloride gas through a flask of ammonia and named the white crystals that formed cyanamide. Grape growers in the deserts of California and Arizona now spray cyanamide across miles of bare winter vines to make up for the cold the buds never received. In Japan doctors have prescribed the same molecule for decades to help heavy drinkers quit. Patients take it daily as a one percent solution, which blocks the liver enzyme that clears alcohol's first toxic byproduct, so even one drink causes flushing and nausea. For more than a century after its discovery, cyanamide was too unstable to sell. A German firm worked out how to stabilize it in 1965 and today calls itself the last Western producer. The US imports over 400,000 pounds of it a year and reports no production of its own.