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Synthesis of Azide Halides and Nitride Halides and some Related Structural Problems.

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distillable liquid (b.p. 63 “C/IO-3 mm Hg), which dimerizes
through the azide group; its infrared spectrum indicates a
strictly planar four-membered Al-N ring.
[Lec:ure at Erlangen (Germany), December 2nd, 19651
[VB 970/277 IE]
German version: Angew. Chern. 78, 339 (1966)
[LectuTe at Frciburg (Gemany), November 26th, 19651
[VB 9711278 IE]
German version: Angew. Chem. 78, 339 (1966)
[I] T. D . Stewart and B. J . Fontnna, J. Amer. chem. SOC.62, 328
( I 940).
[2] J. G. Erickson, J. org. Chemistry 20, 1569 (1955).
[3] P . L. Benneville, J. S. Strong, and V. T. Elkind, J. org.
Chemistry 21, 772 (1956); M . Seefclder, unpublished work.
[4] W . Jentzsch and M. Seefelder, Chem. Rer. 98, 1342 (1965).
Synthesis of h i d e Halides and Nitride Halides
and some Related Structural Problems
K. Dehnicke, Stuttgart (Germany)
Reaction of WBrs and BrN3 afford the highly explosive compound WBrgN3 (symmetry class C4,), soluble in CC14:
An analogous reaction occurs with UCls and CIN3, affording
an azide chloride, probably UC15N3, which loses N2 and CI2
in boiling CC14 and thus yields polymeric UNCI3.
ClN3 or BrN3 react with the metal carbonyls Fe(C0)5,
Mo(CO)~,and W(CO)6 with formation of well-defined carbony1 azide halides M(CO)zN3X (X = C1 or Br). Their infrared spectra and magnetic behavior indicate that a substantially planar four-membered ring occurs in these iron compounds,
the halide being ionic:
[ I ] With collaboration of G. Longe, J . Miller, D . Seybold, and
J. Strci’hle.
Synthesis of Graft and Block Copolymers
G. Greber, Freiburg (Germany)
Addition of dialkylaluminum hydrides to molecules with
C = C double bonds in side chains or at chain ends, and treatment of the products with transition-metal halides (e.g.
TiC14), afford macromolecular Ziegler catalysts that initiate
graft and block polymerization of ethylene and cc-alkenes.
Graft polymers with stereoregular poly-cc-alkene side chains
become accessible in this way.
Macromolecules containing R C = N M linkages are formed on
addition of organometallic compounds of lithium (LiR) or
magnesium (MgRHal) to the N = C triple bond in styieneacrylonitrile copolymers, and they initiate anionic graft polymerization ofacrylonitrile(AN), methyl methacrylate (MMA),
2-vinylpyridine (2-VP), and 4-vinylpyridine (4-VP).
Reaction with Na of macromolecules containing O=C, N =C,
or C = C linkages i n side chains gives macromolecular radical
anions (e.g. high-polymeric ketyls in the case of poly-pvinylbenzophenone) or dianions, formed by electron-transfer
from the metal to the multiple bond. Both the radical anions
and the dianions initiate anionic graft polymerization of AN,
MMA, 2-VP, 4-VP, butadiene, and styrene, and in this way
pure graft copolymers arc formed, free from “backbone
molecules” and from homopolymers of the grafted monomer.
Pure graft copolymers are formed also on use of macromolecular organometallic initiators, such as those formed by metalation of poly-4-chlorostyrene or 4-chlorostyrene-styrene copolymers with stoichiometric amounts of naphthalene sodium.
Since the anionic end groups of the growing side chains remain ‘‘living’’ during these processes, second and third monomers can be added to afford graft copolymers whose side
chains are block copolymers. If the growing chains are
terminated, e.g. by chlorosilanes containing functional
groups, then reactive end groups are introduced into the
side chlins.
These compounds show the paramagnetism of the unperturbed Fez’ ion (p = 5.29 B.M., 0 = 0 OK) and are the first
examples of paramagnetic iron-carbonyl compounds. The
Fe-C linkage appears to be a pure o-bond without backdonation. On thermal decomposition at 9OoC in a vacuum
the CO-free azide halides FcCIN3 and FeBrN3 (p = 4.80 B.M.,
0 = 12°K) are formed. The carbonyl azides and the simple
azide halides of FeII are not explosive; this is attributed to
locking of the lone electron pair on the cc-Natom.The carbonyl
azide halides of Mo and W, M(CO)zCIN3, are polymeric
(n = 6), both CI and N3 acting as bridges. Intense metal-metal
interaction results, as shown by the magnetic behavior:
M O ( C O ) ~ C I N ~ := 0.93 B.M., 0 = -20°K; W(C0)2CIN3:
xrn = -74.9 x 10-6 EMU/mole.
CIN3 reacts with organometallic compounds such as
Cd(CH3)z and [Al(C2H5)3]2 with partial replacement of alkyl
by azide:
Finally, graft and, in particular, block copolymers can be obtained when “finished” macromolecules containing very reactive silicon side or end groups (e.g. HSi-, CISi-, HOSi-,
CH2=CH--CH2-Si-)
are joined together by chemical
reactions. These methods open a route to block copolymers having stereoregular blocks. Macromolecules containing suitable functional groups attached to silicon atoms also
piovide a bridge to anionic processes. For instance, macromolecules containing p-vinylphenylsilicon end groups react
surprisingly readily with sodium to yield radical anions
which effect block copolymerization of vinyl monomers.
[Lecture at Krefeld (Germany), December 16th, 19651
[VB 9721279 IE]
German version: Angew. Chem. 78, 309 (1966)
Ammonolytic Processes in Liquid Ammonia
0. Schmitz-DuMont, Bonn (Germany)
Azidomethylcadmium forms colorless crystals that do not
melt and for which infrared spectra indicate an ionic structure: [CdCH3]0Nje. Azidodiethylaluminum is a colorless
322
The hexamminecobalt(II1) ion behaves as a cationic ammono
acid in liquid ammonia:
+
[cO(NH3)6]3L NH3 & [CO(NH~)~NH#’+ NH4-
(I)
Angew. Chem. internat. Edit. / Vul. 5(1966) / No. 3
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structure, synthesis, azido, problems, halide, related, nitride
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