chiralitystä

Chirality is a property of an object or molecule that cannot be superimposed on its mirror image. Think of your hands: your left hand is a mirror image of your right hand, but you cannot perfectly align them no matter how you twist or turn them. Objects that possess this "handedness" are called chiral.

In chemistry, chirality is a fundamental concept, particularly when discussing molecules. A molecule is chiral if it contains at least one chiral center, which is typically a carbon atom bonded to four different atoms or groups of atoms. The two mirror-image forms of a chiral molecule are called enantiomers.

Enantiomers have identical physical properties like melting point and boiling point, but they can behave differently in certain environments. For instance, they can rotate plane-polarized light in opposite directions, a phenomenon known as optical activity. One enantiomer might rotate light clockwise (dextrorotatory), while the other rotates it counterclockwise (levorotatory).

The biological world is replete with chiral molecules, and often only one enantiomer is biologically active. This is because enzymes and receptors in living organisms are themselves chiral and can interact differently with each enantiomer. For example, the drug thalidomide had tragic consequences because one enantiomer was a sedative, while the other caused severe birth defects. Understanding and controlling chirality is therefore crucial in pharmaceuticals, materials science, and many other fields.