Dwarfs in Nanoworld
Have you ever heard of the Ig Nobel Prize? Itfs a parody version of the Nobel Prize given to achievements that gcannot, or should not, be reproducedh and gfirst make people laugh, and then make them think.h Included in the list of past winners are the inventors of karaoke and Bow-Lingual, and unique researches like gwhy woodpeckers donft get headachesh and gthe scientific validity of the five-second rule about whether it's safe to eat food that's been dropped on the floor.h
In 2003, there was a paper published which looked like it was going to be a good candidate for the Ig Nobel Prize. It was gSynthesis of Anthropomorphic Molecules: TheNanoPutiansh by Professor James Tour, a chemistry professor at Rice Universityfs Institute for Nanoscale Science and Technology. The word gNanoPutianh is a portmanteau of gnanoh, which means a billionth and the gLilliputianh from the novel Gulliverfs Travels.
The Tour group designed and synthesized a number of human-shaped organic molecules in this paper. Shown in Figure 1 is a molecule named NanoKid, which was chosen by the group as a basic skeleton. The 3-D model looks like the figure on the right and the structural formula used by chemists is shown on the left. The structural formula might look more human, since the oxygen atoms look kind of like the eyes.
Fig 1 NanoKid
The functional group used for the head part of NanoKid is called acetal. This group is easily exchangeable to make NanoPutians of various occupations (Figure 2). Letfs not be too picky about the bond angles of NanoMonarch and NanoTexan.
Fig 2 various NanoPutians
Unfortunately, NanoBalletDancer seems to be the only one having a different posture (Figure 3). Personally, I would be interested in making NanoPitcher or NanoGermanSuplex!
Fig 3 NanoBalletDancer
The Tour Group also synthesized NanoPutians standing on gold surface with thiol functional groups on their feet, a NanoPutian couple dancing (Figure 4), and even a polymer of NanoPutians (Figure 5).
Fig 4 NanoPutian Couple
Fog 5 NanoPutian polymer
NanoPutians arenft actually the first example of human-shaped molecule. For example, the molecule shown in Figure 6 has appeared as a joke in a journal published on April Foolfs Day. The molecule shown in Figure 7 has been introduced once as Buddha molecule. Nevertheless, NanoPutians were probably the first case where human-shaped molecules were synthesized systematically(?) to be published as a full paper.
Fig 6 human-shaped molecule Fig 7 molecular Buddha
The Role of NanoPutians
Besides being human-shaped, the NanoPutian molecules have neither notable properties nor potential usefulness for future. The synthesis is also too straightforward to make any significant methodological contribution to chemical science.
Then how did this research get funded and get to be published on Journal of Organic Chemistry? It turns out that the synthesis was a part of the chemistry education program at Rice University aimed at introducing nanotechnology to young students. In fact, it has also been on the cover page of Journal of Chemical Education too. Itfs funny though, to imagine the faces of the journal editors when they first read the paper.
But come to think of it, molecules like dodecahedrane and kekulene might not be so different in terms of not having much to appeal other than their structural beauty. Even gtotal synthesis of biologically active natural productsh, the most respected subfield of organic chemistry, has been criticized on its meaning recently. In a way, the NanoPutian research seems to me as a voice saying gsynthetic targets should be selected more freelyh and almost as an antithesis against the state of organic chemistry today.
Anyway, this paper was introduced by general media and was also one of the topics that received most feedbacks on my homepage. There were those who dismissed it as a meaningless play by chemists, but in terms of directing public interest toward organic chemistry wasnft it a hundred times more effective than ordinary researches? I think it was an excellent work for the education of young chemists as well.
Professor Tourfs playful sense of molecular design can be seen in his research of NanoCars too, which I will introduce in a separate column. This is a wonderful work which can impress both serious scientists and general public.