The research reported in this thesis concerns some reactions
of the simplest organic entity - methylene.
Reactivity of this species, indicative of its radical
character was the reason why, though its presence in many chemical
reactions was postulated in the last decade of the 19th century, the
confirmation of its existence came much later, in the thirties of the
present one, when the new techniques of investigation of unstable compounds
such as the Paneth -mirror technique, were developed.
From then till the 1950's the methylene reactions were the
domain of organic chemists, who studied them mainly for their preparative
Invention of new analytical methods, such as mass spectrometry
and gas chromatography, has enabled us to investigate these reactions
quantitatively, with the prospect of elucidating the structure of methylene.
The results of this work on reactions of methylene with 1,3
butadiene, butene -1, pentene -1 and tetrafluoroethylene are included in the
first part of this thesis which attempts to be a survey of the methylene
reactions, and can thus be regarded as the joint introduction and
As the biradical nature of methylene, which would correspond to
its triplet state, is still a matter of controversy and as, in many reactions
methylene shows both radical and non -radical behaviour, no special division
will be made between its monoradical reactions and those peculiar to
biradicals, all reactions being classified into: -
b) Abstraction and Displacement,
and e) Addition reactions.
The conclusions about the structure of methylene supported by studies
of its reactions will be discussed in the paragraph "Structure of
Unimolecular reactions of the cyclopropane derivatives, formed
by the addition of methylene to a double bond of defins are the subject
of the last paragraph in this survey.