The History of Chemistry

In which we consider what, really, is a chemical bond. Lewis and Langmuir promoted the idea that bonding was sharing of electron pairs. Then we hear about Slater, Hellman, and Ruedenberg's discussion of how covalent bonding works. Kossel and Lewis also introduced ionic bonding. Finally Drude and Lorentz offered metallic bonding. But there are more chemical bonds: the hydrogen bond, the haloge...

In which we talk about the fastest spectroscopy yet, attosecond spectroscopy, which can resolve electrons moving around atoms. The topic begins with Christian Spielmann in 1997, working to get shorter and shorter laser pulses, and continues with Ferenc Krausz. We discuss what you might be able to inspect using these short light pulses, such as how the shape of atomic orbitals oscillates after ioni...

Instead of molecules that absorb light based on their molecular orbitals, this episode talks of nanostructures and their materials that refract light based on interference of light waves. We start with Robert Hooke who described this process in his book Micrographia . We continue through Isaac Newton and Lord Rayleigh. We discuss Eli Yablonovitch's photonic crystals. We mention various kinds...

This episode concerns the phenomenon in organic chemistry of classifying a set of similar reactions by a single umbrella name. Most named reactions honor a person, but not always. We discuss the early history of named reactions from the 1870s onward. We then talk about the slant of named reactions towards white men, and away from other people, and even whether that can be a problem for minority an...

Polyfluoroalkyl substances, or PFAS, seem to be ubiquitous now in the environment and the news. In this episode I delve into why chemists found these compounds so fascinating and useful. Then I discuss some history of how the world finally learned how dangerous these compounds can be if used and disposed of improperly. Finally I talk of some possible methods chemists are currently researching on h...

Mechanochemistry, using purely mechanical processes to run a reaction, is much less known in the chemical world, but has been around since the ancient Greek Theophrastus described a mechanochemical process. We describe the history of mechanochemistry from then through its rediscovery by Michael Faraday, and the first systematic attempts to understand it by Mathew Carey Lea. He got into a dispute w...

In which we learn of the history of graphite, its molecular structure, and electrical properties. Then we discuss the isolation of thinner and thinner layers of graphite through the mid-to-late 20th century. The first isolation of a single atomic layer of graphite, called graphene, was accomplished in 2004 by Andre Geim and Konstantin Novoselov, which set off a new flurry of chemical research, muc...

With this episode, we complete our history of the discovery of the elements (up through writing this episode). We talk of elements 110 through 118, completing that row of the Periodic Table, and the various experiments that the major heavy-ion research facilities in Russia, Germany, the USA, and Japan, were doing. We begin to hear of collaboration between several groups as the difficulties of obta...

In which we discuss the entry of People of Color into chemistry, mostly in the USA. We start with the first Black to get an Ph. D. in Chemistry in the USA, St. Elmo Brady, and work forward through the 1940s through the 1960s. We discuss various organizations to assist people of color in chemistry (and other sciences), such as NOBCChE, SACNAS, AISES, and the Society for Asian Scientists and Enginee...

In which we talk of a huge problem currently plaguing chemistry (and science in general), the "paper mill," in which researchers pay to get their name attached to others' publications, or they write fraudulent publications and pay to get them in print. We hear of a Chinese firm discovered to be such a broker, possible reasons why chemists would fake research, and specific examples o...

Here we discuss all sorts of kits chemists use to build models of different molecules. We start with the pre-molecule set built for John Dalton, and then we hear of August von Hofmann's set for lecture demonstrations. We talk of John Dewar's brass constructions, and then to Tinkertoy-like setups in the 20th century. Plastic first appears in molecular-model kits by the 1950s, and we conti...

Our history of LEDs continues with the entry of LEDs into commercial lighting. We talk of different ways to get white light out of LEDs, and materials for white-light LEDs. We briefly discuss color temperature because there are different kinds of white. Then we hear of the publication of an article in 2000 that consolidated thinking about home usage for LEDs, and why LEDs have advantages over othe...

This episode gives a basic review of geochemistry, starting with pioneers such as Christian Friedrich Schönbein, Frank Wigglesworth Clarke, and thence into the 20th century, especially Victor Goldschmidt. We hear about the development of geochemical societies around the world, then we talk about various subfields of geochemistry. The question of "what's inside the Earth" is still a...

Even though the potential for using microwaves to do chemistry was there since 1946, it wasn't until the late 1970s that the first use of microwaves in the chemistry laboratory appeared. This episode covers the development of microwave chemistry from moisture analyzers to significant study of reactions, and then finally laboratory-standard microwave ovens appeared. We mention the controversy...

We talk about perovskite minerals and compounds, their discovery, and general crystal structure. Then we learn about how researchers gradually learned about their interesting electrical and optical properties. We hear of Tsutomu Miyasaka’s paper about building a solar cell using these perovskite minerals, and the sudden interest in making commercial, practical solar cells from perovskites. We delv...

Click Chemistry came about as several researchers came to similar conclusions in parallel, but from different angles: Barry Sharpless, Morten Meldahl, and Carolyn Bertozzi. We hear about their research goals in the 1990s and early 2000s: to snap together smaller molecules in a reliable way, perhaps with pharmaceutical or biological experiments and results in mind. We learn of Sharpless's goal...

We reach the point in our chemical history when microplastics were first recognized as a pervasive environmental pollutant. Visible plastic bits were first found by Edward Carpenter and K.L. Smith in the ocean back in 1972, and such detritus was confirmed all over the world's oceans over the next decades, resulting in the name "Eastern Garbage Patch" by 1997. Yet only in 2004 did Ri...

This episode deals with glues and adhesives, from prehistoric times to the present. We talk of prehistoric glue from tree saps, petroleum tar, animal glues, casein glues, albumin glues, and starch glues, all known in ancient times. Medieval knowledge added fish glue, and by the Renaissance we start industrial-scale adhesive factories. The 19th century brought rubber cement, mucilage, and library p...

The Periodic Table we've all seen in chemistry books and classes is not always the way it was, nor the way it must always be. In this episode we explore all kinds of periodic representations of the properties of elements, from Mendeleev's first published table in 1869, through wide and narrow tables, and spirals. There are even three-dimensional "tables," from helices to submar...

We introduce the first chemical construction set in chemistry (besides natural proteins, starches, sugars, etc.), the metal-organic framework. A DuPont employee, E.A. Tomic, invented this type of molecule in the 1960s, but it took until Omar Yaghi's research in 1990s until chemists realized the value of metal-organic frameworks. We discuss the experiments and results leading up to Yaghi'...

In this episode we talk about astrochemistry, which began in the 20th century. The first detection of molecules outside our solar system began with Theodore Dunham, which was finally recognized as a molecule in 1940. We talk of Gerhard Herzberg, Polydore Swings, and Dirk ter Haar, then meet Lyman Spitzer. Radio astronomy then became important in the 1960s and 1970s, allowing astrochemists to ident...

Here we talk of the first real molecular machines of the 1990s, and the chemistry advances required to invent them. We define what such a machine is, and reach back into organic chemistry of the 1940s and 1950s for "conformational analysis." We recall the Bell Labs chemists Harry Frisch and Edel Wasserman, and their foundation of chemical topology. Gottfried Schill, Arthur Lüttringhaus,...

On a topic that's a little different, here is an episode about chemistry sets. We explore their origins in Germany as portable laboratories in the late 1600s. Johann Fredrich August Göttling's portable laboratory might be considered the first true chemistry set as an amusement rather than solely a carry-along lab. Our story continues in Britain through the 19th century, and then in the U...

Here we discuss the discovery of quantum dots, those small particles hovering between molecule-size and macroscopic-size. We begin with physicist and refugee from Nazis Herbert Fröhlich, whose predictions led the way in the 1930s. Among the researchers we encounter are Aleksei Yekimov, Louis Brus, and Moungi Bawendi. Quantum dots were real, but could they be made reliably of specific sizes? The an...

We return to the history of light-emitting diodes, LEDs, but now talk about the development of organic versions, OLEDs, from the secret work of Roger Partridge to the now classic publication by Ching Tang and Steven Vanslyke at Eastman Kodak. Through the 1990s, more and more colors were added, so by the mid-1990s, the first commercial OLED product was marketed by electronics firm Pioneer. We also...