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Hexameric KN2Co [P(CH3)3]3ЧA Novel Potassium-Dinitrogen Cluster.

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The arrangement and mutual linkage of the rings is of
such a kind that each K atom is surrounded by eight 0
atoms roughly occupying the corners of a cube around K
[interatomic distances: 2.79, 2.82, 2.87 (2 x ), 2.90 (2 x ), 2.95,
3.05 A].
If the usual interpretation of the structure of ZnO and
the oxozincates.mentioned above is adopted, i. e. assuming
a covalent Zn-0 bond (sp3hybrid orbitals), it remains inexplicable why Rb2Zn02 should not be isotypic with K 2 Z n 0 2 ,
both containing ZnOLI2tetrahedral chains analogous to SiS2.
It is even more difficult to understand that a trigonal planar
configuration should occur in K 2 Z n 6 0 7whose composition
shows it to be so close to ZnO. However, a plausible interpretation can be formulated if the predominant role is assigned
not to the hybridization of the orbitals but to the influence
of the counterions (Rb' in place of K') and account is taken
of the composition of the Zn/O part of the zincate.
+ olefin
olefin = propene, cyclopentene
[ ( M ~ , P ) , C O N , ] , M ~ ( T H F+) ~2 K
2 (2) t M g
stable up to 140°C under 1 bar N2 but immediately ignite
on exposure to air. The structure of compound (2) was determined by X-ray crystallography. The monoclinic unit cell
(space group C ~ / C ) [contains
four [KN2C~(PMe3)3]6molecules. Their fundamental structural unit can be described in
simple terms as a double cube made up of six K atoms
and six N2 groups (Fig. 1).
Received. May 16, 1977 [Z 736 IE]
German version: Angew. Chem. 89, 498 (1977)
CAS Registry numbers:
R b 2 Z n 0 2 ,63018-05-3; K2Zn607, 62990-75-4
[I] Part of the Thesis by K.-R. Wambach, Universitat Giessen.
[2] H . G. c. Scknering, Naturwissenschaften 48, 665 (1961).
[3] H . G. i . Sdmering, R . Hoppe, J . Zrmann, Z . Anorg. Allg. Chem. 305,
241 (1960).
[4] E. Vielhaber, R. Hoppe, 2.Anorg. Allg. Chem. 338, 209 (1965).
[S] H . G . 1 . Schnrring, R. H o p p r . Z. Anorg. Allg. Chem. 312, 87 (1961).
161 E. Vielhaber, R . H o p p e , 2.Anorg. Allg. Chem. 360, 7 (1968).
[7] P. Kastiier, R . H o p p e , Z. Anorg. Allg. Chem. 409, 69 (1974).
[S] P . Ku.>tmr, R. Hoppe, Naturwissenschaften 61, 79 (1974); G. Erachtel,
R. H o p p r . ibid. 63, 339 (1976). H . Rieck, R. Hoppe, Naturwissenschaften
61. 126 (1974); H . Rieck, R. Hoppe, Z. Anorg. Allg. Chem. 400. 31 I (1973).
Fig. I.Crystal structure of ( 2 ) [for bond lengths see text].
Hexameric KN2C~[P(CH3)3]3-A Novel PotassiumDinitrogen Cluster[**]
By Reinhurd Hummer, Hans-Friedrich K lein, Peter Friedrich,
and Gottfried Huttner"]
In the few previously reported bimetal-dinitrogen complexes, in which the N2-unit is bonded side-on or end-on
to a transition metal and an electropositive main group element, ether- or alkoxide-donor ligands are essential components of the molecular structures[']. We have now synthesized a potassium salt of the dinitrogentris(trimethy1phosphane)cobalt anionI21, which crystallizes free of ether from
ethereal solutions.
Surprisingly, the dark brown solutions of the olefintris(trimethy1phosphane)cobaltates ( I )I3] in tetrahydrofuran or
diethyl ether react spontaneously under 1 bar N2 in accordance
with Eq. (a), whereupon the color changes to bright orange
and the dinitrogencobaltate (2) is formed in almost quantitative yield.
(2) is also obtained from the magnesium complex (3)""l
according to Eq. (b). On slow cooling of (2) in pentane/
diethyl ether (4: 1 ) orange-red crystals are formed which are
[*] Dr. R. Hammer, Doz. Dr. H.-F. Kleiii
Dip1.-Chem. P. Friedrich,
Prof. Dr. G. Huttner ["I
Anorganisch-chemisches lnstitut der Technischen Universitat
Arcisstrasse 21, D-8000 Miinchen 2 (Germany)
Author to whom correspondence should be addressed.
[ +'1 Lehrstiihl fur Synthetische Anorganische Cheniie, Fachbereich Chemie
der Universitiit, D-7750 Konstanz (Germany)
This work was supported by the Deutsche Forschungsgemeinschaft
and the Fonds der Chemischen Industrie.
Angew. Chem. Int. Ed. Engl. 16 ( 1 9 7 7 ) N o . 7
The N2 dumbbells [d(NN): 116 to 118pml are orientated
pairwise along the three axes of the inversion-symmetric skeleton. In the extension of these axes the N2 units bear terminal
Co(PMe3)3 groups, which shield the cluster externally
[d(CoN): 170 to 171 pm]. Each dinitrogen unit is involved
in bonding, both along the N-N axis as well as perpendicular
to it: along the axis each unit is bonded to a cobalt atom
outside the cluster, and to a potassium atom inside the cluster
[d(KN): 276 to 293pml. Perpendicular to the N-N axis,
two and three K-N2 interactions, respectively, are observed:
The N2 groups bound to the corners of the double cube
are thus each in contact with two K atoms; the two N2
groups at the center of the edges (hatched groups in Fig.
l), on the other hand, have three nearest K neighbors in
the plane perpendicular to the N-N axis.
It would appear that the observed structure of the complex
cluster has no parallel in the structural chemistry of molecules;
however, there are striking similarities when compared with
solid-state structures (ThC2,...)[']. Accordingly the usual electron counting rules of molecular chemistry cannot be applied
in a simple manner. Since there are more bonds than electron
pairs in the cluster, the bonding might be best described
with models having multicenter electron-deficient bonds.
A solution of chlorotris(trimethylphosphane)cobalt[61
(485 mg, 1.50mmol) in tetrahydrofuran (50ml) saturated with
propene is stirred together with 500mg clean pieces of potassium for 24 h at 20°C under argon. The volatile components
are removed in uacuo, and the ocher-colored residue taken
up in 20ml ether. The filtered red-brown solution is stirred
under 1 bar Nz,whereupon its color changes within a few
minutes to orange-red. After 2 h the reaction mixture is filtered
and slowly cooled to -78°C. The solution is decanted off
and the orange-red crystals dried at 2OoC/0.l torr. Yield of
(2): 450mg (85 %).-IR: v(NN): 1795 vs (br) and 1758 m
(br) cm-' (Nujol mull); v(NN): 1868 vs (br) and 1843 m
(br) cm-' (THF). Conductivity of (2) (0.25 M in THF, 2 0 T ,
1 bar Nz): ~ < 1 0 R
- -~' cm-'.
The site-exchange of the tellurium is fast on the NMR
but can be perceptibly slowed down by lowering
the temperature. Compound ( 3 ) forms pale yellow crystals
(softening 77-83 "C, melting range 83-90°C) which dissolve
very well in ether and methylene chloride, readily in benzene
Received: May 20, 1977 [Z 745 I€]
German version: Angew. Chem. 89,499 (1977)
CAS Registry numbers:
K[(Me3P)3Co(propene)], 63181-07-7; K[(Me~P),Co(cyclopentene)], 6318108-8; (2), 63181-09-9; ( 3 ) , 63181-11-3: (Me3P)3CoCI,53432-06-7
a) R . Hammer, H.-F. Klrin, U . Schubert.
A. Frank, C . Hurrner, Angew.
Chem. 88, 648 (1976); Angew. Chem. Int. Ed. Engl. 15, 612 (1976);
b) K . Jonas, hid. 85, 1050 (1973) and 12, 997 (1973); C. Kriiger, Y-H.
Guy, ;bid 85, 1051 (1973) and I Z , 998 (1973). K . Jqnas, D . J . Bruurr.
C . Kruger, P . J . Roberts, Y-H. Tyay, J. Am. Chem. Soc. 98, 74 (1976);
c) M. Mercer, R. H . Crabtree, R . L. Richards. J. Chem. Soc. Chem.
Commun. 1973, 808.
Dinitrogencobaltates NaN2Co(PR3), were first described by M . Aresta,
C . F. Nobile, M . Ross;, A ., Chem. Commun. 1971, 781.
R . Hummer, H:F. Klein, unpublished.
u=2767.3, b=1627.4, c=2802.5pm, p = l 15.94"; d,,,,=1.25g/cm3. Data
collection with a Syntex-P2, diffractometer: solution of structure (2639
independent reflections. R , = 0.085) with Syntex-XTL.
A. F. PVells: Strucrural Inorganic Chemistry. 3rd Ed. Clarendon Press,
Oxford 1962, pp. 761 R
H.-F. Klein, H . H. Kursch, Inorg. Chem. 14, 473 (1975).
or toluene, and modestly in pentane. Elemental analysis, mass
spectrum [16eV: m/e=362 (50% M+), 178 (IOO)], molecular
weight determination (378, cryoscopic in benzene), and a crystal structure analysis['] confirm the composition and structure
of the molecule, which is monomeric both in solution and
in the solid state.
Tellurium (0.67g, 5.25 mmol) is added to an ice-cooled (cu.
6°C) stirred solution of (2)"' (1.2 g, 5.12 mmol) in benzene
(1 6ml).After 3 hat room temperature, excess tellurium is filtered
off (G4 frit), the solvent is drawn off and the product (3)
dried under oil-pump vacuum; yield quantitative.
Received: May 24, 1977 [Z 747 IE]
German version: Angew. Chem. 89,500 (1977)
CAS Registry numbers:
(21,63104-58-5: (J), 63104.59-6
cis-2-Telluro-l,3,2h5,4h3-diazadiphosphetidineA Fluxional Redox System
By Otto J . Scherer and Giinter Schnubl[*]
Judicious choice of X and Y and ofthe other ligands attached
to the two P atoms in the phosphorus-chalcogen compounds
( I ) [e.g. X=O, S; Y=O, S, (CH2)", NR] known in such
great variety should permit preparation of a fluxional redox
system in which X undergoes reversible intramolecular shift.
Conditions for the study ofsuch a process are ideally fulfilled
by cis-1,3,2h3,4h3-diazadiphosphetidine(2)['], whose 1 : 1
reaction with
yields cis-l,3-dimethyl-2,4-di-tertbutyl-2-telluro-l,3,2h5,4h3-diazadiphosphetidine
(3 ).
[l] 0. J . Scherer, G . Schnubl, Angew. Chem. 88, 845 (1976); Angew. Chem.
Int. Ed. Engl. 13, 772 (1976).
[2] (is-[RP(Te)NCH3I2 can also be synthesized.
[3] Examples: a) K . J . Iryolic. The Organic Chemistry of Tellurium. Gordon
and Breach, New York 1974. p. 256; h) 0. J . Scherer, G . Sehnabl, Chem.
Ber. 109, 2996 (1976): c) W-W Du Monr, H.-J. Kroth, J. Organomet.
Chem. 113, C 3 5 (1976); d ) D. H . Brown, R. J . Cross, D. Millmgron,
hid. 125, 219 (1977); the rollowing fast equilibria R , P T e + R j P s
RjPTe+R,P and R3PTe+R3P+Te were first mentioned in [3c] and
[3d] (tellurium shift probably bimolecular).
Compound ( 3 ) can be stored at room temperature for several weeks,
r.g. in benzene solution, and for several months in crystalline form
(sealed flask, daylight).
'H-NMR spectrum (cu. 15 "/, in CH2C12,TMS int., 35°C): 6CH3C= 1.12
(d), , J P H = 16.9 Hz: 6CH3N=2.56 (t), 3 J p ~ =13.7Hz. -50°C: GCH3C
(>L3P)=l.13(d), ,JpH=13.7 Hz: 6CH3C (hSP)=1.12 (d), 3 J p H = 1 9 . 9 Hz;
GCH3N=2.49 (dd), 3./j.3pH= 10.7, ' J J A ~ P H = I ~ . ~ H
spectrum(cu. 15 : b i n CH2C12, 85 "/, H3PO4 ext., -60°C): 6(A3P)=200.4
(d), 6(h5P)=119.5 (d), 'Jpp= 1 8 . 0 H ~ .
The concentration dependence of the coalescence temperature (T,:
-3O0Cfora35%solutionand :
- I0"Cfor a3.5% so1ution)measurable
at higher dilutions show that both an intramolecular and an intermolecular exchange can occur. Formation of a mixture of (2) and ci.s
[RP(Te)NCH3]2 conceivable in the latter case can be detected neither
in the ' H - nor in the 3 ' P low-temperature NMR spectrum.
Dr. S. Pohl, Bielefeld, personal communication.
Synthesis of a Secondary Aminophosphane['l
Unlike the few known phosphorus-tellurium compounds
of similar kindI'1, compound ( 3 ) is exceptionally stable141.
Temperature dependent H- and 31P-NMR studies[51 show
(3) to have dynamic behavior.
By Edgar Nircke and Gerhard Ringel[*]
Aminoiminophosphanes, phosphorus-nitrogen compounds
containing a strongly polar 3p,(Pk2pn(N) bond (1 ), undergo
addition with proton donors to give aminophosphanes ( 2 a )
and the tautomeric iminophosphoranes (2 b)lz1.
[*] Prof. Dr. 0.
J. Scherer, Dr. G. Schnabl
Fachbereich Chemie der UniversitPt
Pfaffenbergstrasse 95, D-6750 Kaiserslautern (Germany)
[*] Priv.-Doz. Dr E. Niecke, Dipl.-Chem. G . Ringel
Anorganisch-chemisches lnstitut der Universitat
Tammdnnstrasse 4. D-3400 Gottingen (Germany)
Angew. Chrm.
/or. E d . Engl. 16 ( 1 9 7 7 ) N o . 7
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kn2co, clusters, potassium, 3чa, hexameric, dinitrogen, ch3, novem
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