Reinitzer

Friedrich Reinitzer was an Austrian botanist and chemist best known for his role in the discovery of liquid crystals. In 1888, while studying cholesteryl benzoate, he observed an unusual two-stage melting behavior: the substance did not melt directly into a uniform liquid; instead it first formed an anisotropic liquid phase and then, at a higher temperature, became isotropic liquid. This phenomenon, now called the Reinitzer phenomenon, provided the first evidence of mesophases between solid and liquid states.

Reinitzer communicated his results to Otto Lehmann, a physicist who specialized in the study of condensed matter. Lehmann's subsequent experiments and theoretical work helped to interpret the liquid-crystalline phase and led to the coining of the term liquid crystal and the establishment of a new field of study. The Reinitzer phenomenon is regarded as the foundational observation upon which modern liquid-crystal science was built.

Today, the study of liquid crystals traces back to Reinitzer's report and Lehmann's interpretation, influencing the development of display technologies and a broad range of materials science applications. Reinitzer's contribution remains a milestone in the understanding of phase behavior in organic compounds.