Why ‘chemical’ has become a dirty word
Obviously, when dealing with more than 50 million known compounds, each requiring a unique name, complex terminology has to enter the picture. Chemists are thankful for the systematic nomenclature that has been worked out, but to the public, complex chemical names are frightening and tend to conjure up images of doom.
Some marketers try to capitalize on this fear by advertising “chemical-free” products. So we have “chemical-free” cosmetics, cleaning agents and, believe it or not, books about “chemical-free kids.”
The message is that chemical-free means safer, healthier, greener. Given that it is a nonsensical term, what are these products all about? Mostly, “chemical-free” refers to being free of synthetic chemicals. This insinuates that synthetic chemicals are more problematic than natural ones, an inference that is not valid.
Formal chemical nomenclature is demonstrably incomplete. It cannot name several classes of stereocenters, including planar stereocenters. Trivial example: “R” and “S” are enantiomeric stereocenters in Cahn-Ingold-Prelong (CIP) notation [e.g., -C(H)(CH3)(Cl)]. Label the sense of chirality of the following carbon atoms,
R2C=CR2
S2C=CS2
The carbons and the entire molecules possess no mirror planes, points of inversion, or higher improper axes. Rotation axes are irrelevant to chirality. Label the sense of chirality of the center five atoms of [6.6]chiralane,
http://www.mazepath.com/uncleal/schwartz.png
framework stereogram
http://www.mazepath.com/uncleal/schwart3.png
Proof of chirality
It cannot be done, even in principle. Pookie pookie on formal chemical nomenclature.