・Naming Organic Molecules (1) : Names Derived from Shapes

Chemists work on experiments around the clock, trying to synthesize or discover unknown compounds. When a new compound is finally obtained, it needs a name, of course. The official naming follows the international standard set by an organization called International Union of Pure and Applied Chemistry (IUPAC), which assigns a name to the compound based strictly on its structural formula. While this naming standard gives you a precise description of the molecular structure, the names tend to be extremely long for complex molecules. For example, the official IUPAC name for table sugar (sucrose) is (2R, 3R, 4S, 5R, 6R)-2-[(2S, 3S, 4R, 5R)-3,4-dihydroxy-2,5-bis(hydroxymethyl)oxolan-2-yl]oxy-6-(hydroxymethyl)oxane-3,4,5-triol (Figure 1). This is obviously too inconvenient, so many molecules have simpler nicknames. In this section, let’s go through some of the man-made molecules that are named after their unique appearances.

Fig 1 sugar (sucrose)

The cube-shaped molecule shown in Figure 2 was synthesized by Professor Philip Eaton and his coworkers at University of Chicago in 1964, and it was named cubane. Cubane displayed some interesting properties owing to its highly strained structure, and became a quite popular molecule back then. The molecule shown in Figure 3 looks like cubane with a handle attached, and is called basketane. The name, not surprisingly, came from its shape that appears an opened basket.

Fig 2 cubane (left) Fig 3 basketane (right)

The molecules shown in Figure 4 and Figure 5 are named lampane and propellane, respectively. Clearly, they got the names after their unique shapes. These are molecules made in labs, but molecules possessing the core propellane skeleton have been found in nature as well.

Fig 4 lampane (left) Fig 5 propellane (right)
hydrogen atoms omitted for clarity

Sometimes molecules are compared to animals. The molecule shown in Figure 1.6 is called penguinone because of its resemblance to penguin, and the one in Figure 1.7 is called felicene, because the molecule looks like a feline face. Also shown in Figure 1.8 is pterodactyladiene, a molecule named after its resemblance to an ancient flying reptile pterodactyl.

Fig 6 (left) penguinone Fig 7 (right) felicene

Fig 8 pterodactyladiene

An example of flower-shaped molecules shown in Figure.9 is named sumanene, after suman, a sanskrit word for flower. Having been known as the partial structure of fullerenes, sumanene had its name even before it was synthesized. The first chemical synthesis of the molecule was ingeniously completed in 2003 by Professors Shunichi Hirao and Hidehiro Sakurai of Osaka University in Japan.

Fig 9 sumanene

The molecule shown in Figure.10 looks like sunflower, and the fact that it contains sulfur atoms led to its name sulflower. This is one of the rare organic molecules that contains no hydrogen atom, but consists of only carbon and sulfur atoms.

Fig 10 sulflower (yellow : sulfur atom)

There is a whole variety of interesting chemical names, including such examples as apollane and rocketene (Figure.11,.12, respectively). You might disagree, but both molecules were given their names because they look like a rocket.

Fig 11 apollane (left) Fig 12 rockettene (right)

Naming Organic Molecules part 2

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