Emanuele Paternò di Sessa was an Italian chemist, discoverer of the Paternò–Büchi reaction.

He was born as the Marquess

Marquess

A marquess or marquis is a nobleman of hereditary rank in various European peerages and in those of some of their former colonies. The term is also used to translate equivalent oriental styles, as in imperial China, Japan, and Vietnam...

 di Sessa and studied at the University of Palermo

University of Palermo

The University of Palermo is a university located in Palermo, Italy, and founded in 1806. It is organized in 12 Faculties.-History:The University of Palermo was officially founded in 1806, although its earliest roots date back to 1498 when medicine and law were taught there...

 with Stanislao Cannizzaro

Stanislao Cannizzaro

Stanislao Cannizzaro, FRS was an Italian chemist. He is remembered today largely for the Cannizzaro reaction and for his influential role in the atomic-weight deliberations of the Karlsruhe Congress in 1860.-Biography:...

. In 1871 he became lecturer at the University of Torino, but returned to Palermo in the following year as Cannizzaro's successor. In 1892 he became a professor at the University of Rome. He did photochemistry

Photochemistry

Photochemistry, a sub-discipline of chemistry, is the study of chemical reactions that proceed with the absorption of light by atoms or molecules.. Everyday examples include photosynthesis, the degradation of plastics and the formation of vitamin D with sunlight.-Principles:Light is a type of...

 research, and discovered the Paternò–Büchi reaction in 1909. This was improved by George Hermann Büchi in 1954.

He was politically active. He was the mayor of Palermo (1890–1892) and a member of the regional parliament (1898–1914). He was also a member of the senate and vice president of the senate.