|
Showing 1 - 4 of
4 matches in All Departments
The present volume, Thorium C5, deals with the compounds of thorium
and sulfur, selenium, tellurium, and boron, as well as with oxoacid
compounds of the three chalcogen elements. Thorium borates have
already been treated in Thorium C2. In contrast to the
corresponding compounds of uranium the thorium sulfides, etc. , do
not show any nuclear or other technological application; they are
only of academic interest, despite some very interest ing
electronic properties, especially of the 1 : 1 compounds. The
thorium-sulfur and the thorium boron systems in particular were
studied in detail, so that we have a clear picture of them, whereas
there are still a lot of open questions in the systems Th-Se and
Th-Te - not very different from other metal chalcogenide systems.
Thorium sulfates are of some technological importance because they
are formed in solution during recovery of thorium from monazite by
sulfuric acid leaching. The very detailed and critical treatment of
the chemical and physical properties of the compounds discussed
also enables us to find gaps still remaining in our knowledge and
thus to initiate new research in this field. I want to thank the
two authors, Dr. Horst Wedemeyer (Karlsruhe) and Dr. David Brown
(Harwell), for their excellent contributions, the
"Literaturabteilung" of the Karlsruhe Nuclear Research Center for
its help in providing reports and other documents difficult to
procure, as well as the staff of the Gmelin-Institute, especially
to Dr. K. -C.
The 3rd supplement continues the updating of the original 20
volumes on boron compounds published between 1974 and 1979. The
first supplement consisting of 3 volumes covered all the literature
uniformly up to the end of 1977, whereas the two volumes of the 2nd
supplement have extended the literature coverage of boron compounds
to 1980 and the four volumes of the 3rd supplement to 1984. The
present volume continues the description of boron compounds with
halogens, presenting those with chlorine, bromine and iodine. The
compounds with chalcogens are completed here along with those of
boron with S, Se, Te and Po. The final chapter on carboranes
contains the carboranes themselves, together with
metallacarboranes, and in the last section a description of
carborane-containing polymers, mostly derived from the three
isomeric dicarbadodecarboranes. Volume 4 of the 3rd supplement
brings this supplement series to an end. It will be supplemented by
a separately appearing index volume, which contains all the boron
compounds dealt with in volumes 1 - 4 of this supplement series.
The present volume of the Gmelin thorium series describes the solid
thorium-carbon compounds with the exception of the carbides and
coordination compounds of the type 4 ThAn* X B, where B is a
neutral ligand. The complex equilibria of the Th + ion with
C-containing complexing agents are treated in the ThD1 volume. A
first look into this volume demonstrates that a very large number
of ThlV complexes has 4 been prepared. This may be explained by the
fact that the Th + ion is the largest tetravalent ion of the
periodic table. Therefore, the preparation of complexes with, e. g.
, multidentate ligands can give a well-established picture of the
coordination number as a function of charge and ionic radius.
However, there are very few modern and updated comprehensive
treatments of such data. Many compounds described in this volume
are characterized by no other means than analytical composition and
IR spectra (whereby IR spectra of organic ThlV salts mostly give
information only on the ligand). Besides thorium carbonate and
carbonato complexes, which are relevant for the environmental
behaviour of this radioactive element and some organic complexes
like oxalates, which are used in the field of analytical and
separation chemistry nearly all other compounds described here are
practically only of scientific interest. On the other hand in order
to have scientifically reliable data, a very large part of these
compounds needs further investigation and characterization.
Alloys of Uranium with Alkali Metals, Alkaline Earths, and Elements
of Main Groups III and IV. The description of uranium and its
compounds, for which the Gmelin Institute has started a series of
volumes supplementing the main volume of 1936, follows in its
arrangement closely the order chosen for the transuranium volumes.
Part A treats "The Element," Part B "The Metal and its Alloys,"
Part C "The Compounds," Part D "The Chemistry in Solution," and
finally Part E "The Coordination Compounds." Part E, "The
Coordination Compounds" comprises two volumes which already have
been finished and are available - completely written in English.
Series A comprises 7 volumes which are all available. Series C will
comprise 14 volumes of which only volume 6 is missing. Series D
consists of 4 volumes dealing with the chemistry in solution, which
already have been finished and are available. The present volume
describes the alloys and the intermetallic compounds with the
metals of main groups I to IV - those systems with semimetals such
as boron and germanium are to be found in corresponding volumes in
Uranium C series. In the volume B 2 main emphasis is given to the
binary systems. The most frequently investigated systems are
uranium-beryllium and uranium-aluminium because of their special
scientific (U-Be) and technological (U-Al) importance.
|
|