Augusto Sirigu (1939–2007)

Augusto Sirigu (1939–2007)

Professor Augusto Sirigu died in Naples on June 14th, 2007. He was born in San Gavino Monreale, a small town in Sardinia (Italy), on February 23th, 1939. Having graduated in Chemistry in 1963 at Università di Cagliari with the highest ranking, he started his research activity with Professor Paolo Corradini at the Chemistry Institute of the University of Naples where he made his academic career: assistant professor from 1966, professor from 1971, full Professor of General and Inorganic Chemistry from 1980 until his retirement in November 2006. The first part of the research activity of Professor Sirigu was on X‐ray crystallography. He studied the crystal and molecular structures of model compounds of stereoregular polyolefins, of carbonyl metal clusters, of metallorganic and inorganic compounds, of aminoacids.

At the beginning of the 1970s he moved his research interests from ordinary crystallography to the quest of “strange structures”. In particular, in searching for solid materials having non crystalline order, he entered the field of liquid crystals with the aim of obtaining a polymeric liquid crystal. At that time, while the literature on low molar mass liquid crystalline compounds was already large, that on polymeric liquid crystals was not. The idea he followed was very simple, if we consider it now: to take a typical liquid crystal small molecular fragment, say a rod‐like nematic one, and from that build a polymer chain containing in an alternating sequence along the main chain those mesogenic units and flexible spacers. The paper he published in 1975 with Antonio Roviello as coauthor in the Journal of Polymer Science 1 dealt with the liquid crystalline properties of thermotropic polyesters containing the mesogenic group, dimethylbenzalazine, and aliphatic dicarboxylic acids as flexible spacers: it was the first example of a rationale synthesis of thermotropic liquid crystalline main chain polymers. That paper was the birth of a new area in the research both on liquid crystals and on polymers.

In the following years several research groups world‐wide started to study semiflexible liquid crystalline polymers and to publish experimental reports on them. This research field is still active. It has to be noted that in the same year of the publication by Roviello and Sirigu of the first example of a class of thermotropic segmented chain liquid crystalline polymers there appeared (independently) in the literature a short paper by P. G. de Gennes, Nobel prize winner for Physics in 1991 and also deceased in 2007, in which interesting elastic properties were expected for the anisotropic melts of that class of polymers 2. The research on liquid crystalline polymers by Professor Sirigu and his group was thorough. He studied homopolymers, copolymers, and model compounds. At the end of 1980s the group started to study metal containing liquid crystalline polymers and liquid crystalline networks. In the middle of 1990s the research interests of Professor Sirigu moved toward polymers for optoelectronic and photonic applications.

Professor Sirigu

All his colleagues and students will remember him with deep gratitude and sympathy.