Radicals, Reactions, Realism - Philosophy of Chemistry - page 179

synthetic radical compound, as main-stream modernist history of chemistry has it.
Methodologically, this study consists of three main parts:

(a) Brief introduction of the historical episode (which took its start around 1900);
(b) Discussion of the chemical radical concept according to Gomberg and other
contemporary chemists such as Timmermans, Walden, Ostwald, and Wald;
(c) Analysis of existence claims and the role of experimentation with respect to
radicals in the framework of some modern philosophy of science as suggested
by Harr´, van Fraassen, and Heidelberger, respectively.

12.2 Historical Introduction

The chemical world was moving into the twentieth century quite happily with the
quadrivalency of the carbon atom and was inclined to look upon free radicals as speculative
inventions. It was in this environment that Moses Gomberg ' s paper ›Triphenylmethyl, ein
Fall von Dreiwerthigen [sic] Kohlenstoff‹ made its appearance.

In an article published in 1967 , the eminent American historian of chemistry
Aaron Ihde (1909-2000) used these words to describe the transition from what may
be called the prehistory of the chemical concept “radical” to its early history. 2
Whereas assumptions and suggestions of nineteenth-century chemists turned out to
be mere speculations, Gomberg (1866-1947) entered a field of endeavour which
had better prospects empirically. Trained as an organic chemist (doctorate 1894
from the University of Michigan), he was brave enough to try to prepare tetraphe-
nylmethane - the fully phenylated methane - in Victor Meyer s laboratory in

Heidelberg (a compound Meyer himself never succeeded in synthesizing) during
a research leave from his home institution. 3 Gomberg applied the cleavage of
triphenylmethaneazobenzene which in fact resulted in the desired product and
nitrogen as a by-product. 4 Encouraged by this success he proceeded on the path
of the synthesis of arylalkanes - which he would never leave during his professional
career (Ihde counts 35 papers on triphenylmethyl alone). Back in Michigan from
his research journey to Europe, he made attempts to prepare - “for comparative

'

2

Ihde 1967 , 5. Reference is made to Gomberg 1900a , the English version of which is Gomberg
1900b . Gay 1976 offers an investigation of what is called the prehistory of the radical concept here.
She critically accounts for the methodological approaches of Popper and Lakatos referring to the
historical example mentioned here.
It has been suggested - to add another note referring to the history of radical theory from an
extremely modernistic point of view - to consider and accept Michael Faraday as the discoverer of
free radicals, see Acheson 1996 .
3 Cf. the biographical entries in Schoepfle and Bachmann 1948 ; Bailar 1970 ;R¨chardt 2000 .
4 The experimental setup is described in Gomberg 1897 .