ORGANO-NITROGEN COHPOUNDS OF COBALT
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The reactions of cobalt halides with lithium dialkylamides have
been investigated. The reaction with lithium diethylamide proved to
be very unusual. This reaction was fully studied and the main
products were shown to be lithium chloride, cobalt metal and
bis(4-ethylimino-2-butene-2-ethylamino)Cob~lt(II). The latter product
which was a volatile brown liquid was identified by its physical and . .
chemical properties and the physical properties of derivatives prepared
from the ligand after removal of the cobalt.
Bis-(4-ethylimino-2-butene-2-ethylamino)cobalt(II) is a
nitrogen analogue of the metal acetylacetonates and shows many
similar properties. The ligand 4-ethylimino-2-ethylamino-2-butene •
was shown, by the magnetic moment and electronic spectra of the
tetrahedral cobalt compound, to produce a very high ligand field.
A reaction mechanism has been proposed to explain the products
'of the reaction of cobalt chloride with lithium diethylamide.
The reactions of other lithium dialkylamides with cobalt halides
haye shown that dialkylamino compounds of cobalt(II) exist but are
generally unstable thermally and very oxygen sensitive. The only
stable (thermally) dialkylamino cobalt(II) compound prepared was
bis-hexamethyldisilylamino cobalt(II). In solution this compound
was shown· to be a linear two coordinate compound of cobalt(II). This
unusual stereochemistry for cobalt(II) presents many theoretical
problems before the magnetic and spectral properties ,are fully
understood. It was found that the other dialkylamino cobalt(II) compounds
produced were u!lstable.thermally decomposing above room temperature.
The most stable compounds were formed when the dialkyl- group
produced large steric hindrance.Two new alkolides were prepared from the dialkyamino cobalt(II)
compounds. The magnetic and spectral properties of these compounds
indicate that they are polymeric. possibly three coordinate compounds
of cobalt.
Authors
Fisher, Keith JohnCollections
- Theses [4222]