Clean Synthesis as Environmentally Friendly Chemistry

Abstract

I grew up in the North of England not far from major centres of chemical manufacture on Merseyside. On sites adjacent to these factories it was common to see brightly coloured sediments: greens, presumably copper, yellows, perhaps chromates, and reds, probably from iron(III) salts were all visible. These deposits together with characteristic smells have contributed to giving the chemical industry its low public esteem and today, more sophisticated objections couched in molecular scientific terms are common. Much of what causes concern comes from an era of the chemical industry now passed. Chemistry, although a mature science, is far from being exhausted in providing solutions to environmental problems and moreover to developing new reactions and processes with today’s environmental concerns in mind from the beginning of research. This is not just a matter for the attention of the industrialist; it is quintessentially what academic research is about: the development of ideas and the creation of opportunities. Therefore I shall not be concerned with whether a particular product or material in a given application is itself environmentally friendly or acceptable nor shall I consider so-called ‘end of the pipe’ solutions to current pollution problems. Others in this book deal strongly with these aspects. The discussion in this paper derives from a report prepared for two of the then Research Councils in the UK by myself and colleagues from the University of Strathclyde defining themes for research in clean synthesis as part of a Clean Technology Initiative (Suckling et. al., 1992). I have prepared the text in such a way as to make as much of the discussion as possible accessible to non-expert chemists. Clean up can be clearly contrasted with clean synthesis. The essence of clean synthesis is that the reactions are designed so that clean up is simply not necessary.