Carl Gräbe
Carl Gräbe (February 24, 1841 – January 19, 1927) was a German chemist from Frankfurt am Main.
Gräbe studied at a vocational high school in Frankfurt and Karlsruhe Polytechnic and in Heidelberg. Later he worked for the chemical company Meister Lucius und Brüning (today Hoechst AG). He supervised the production of Fuchsine and researched violet colorants made of Iodine. The work with Iodine gave Gräbe an eye infection, so he returned to academia.
Under the supervision of Robert Wilhelm Bunsen, Carl Gräbe received his PhD from the University of Heidelberg in 1862. In 1868 he wrote his habilitation, and became a professor in Leipzig. Gräbe was Professor of Chemistry at the University of Königsberg from 1870 until 1877, and at the University of Geneva from 1878 until 1906.
Together with Carl Theodore Liebermann, he synthesized the orange-red dye alizarin in 1868; alizarin had been isolated and identified from madder root some forty years earlier in 1826 by the French chemist Pierre Robiquet, simultaneously with purpurin, a violet dye.
He also introduced the "ortho", "meta" and "para" nomenclature on benzene rings.
He died in Frankfurt.