Molecules made to order

As already mentioned, with hundred atomic species available, a vast number of molecules can be formed. The chemist, explorer of nature, has discovered tens of millions to date. Over the years, the chemist has also become an inventor and has begun to create artificial molecules, behaving exactly as Leonardo da Vinci said: «[…] where nature finishes producing its species there man begins with natural things to make with the aid of this nature an infinite number of species […]» (Richter 1977).
The molecules synthesized by chemists in their laboratories are much more numerous than the natural ones discovered so far. Chemistry, therefore, is a “book” not only to “read” (exploration of molecules and natural processes), but also to “write” (development of molecules and artificial processes) and if the part not yet read is very large and complicated, the one to be written is practically infinite in extension and complexity.

Much of the creative activity of chemists has brought enormous benefits to humanity. Chemists have invented molecules capable of healing diseases and alleviating pain, as well as molecules that protect us from cold and heat; molecules to dye textiles and to make food more pleasant; molecules that protect the eyes from excessive light and protect the skin when exposed to the sun; molecules that repel insects and fragrant molecules; intelligent molecules, capable of processing electrical or light signals, and of revealing the presence of other molecules. Chemists have also created molecules that, judging by models enlarged one hundred million times, have peculiar shapes, sometimes aesthetically valuable (tree-shaped molecules, knot, chain, bridge and dome), demonstrating that creativity and beauty can be combined even in the world of the infinitely small. Unfortunately, as it often happens in human activity, chemists have also created molecules without worrying about their danger and the side effects they may have on organisms and the environment; even worse, sometimes they intentionally program and synthesize new molecules capable of destroying, burning, poisoning and killing.