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N-Isocyanoiminotriphenylphosphorane Synthesis Coordination Chemistry and Reactions at the Metal.

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Table I . 6("C) values [a] of the nickelocenes (1)-(6) at 298 K [b]: syntheses of
( 1 ) and f3)-f6): [Sbl. of 12): [9].
other C
- 1367
- 1368
- 1536
- 1518
- 1438t2
- 1510
- 1504
- 1532
- 1509
C-314 C-215
- 1547
- 1470
4 0 0 pprn
Fig. 1 . "C-NMR spectrum of (nBuC<H&Ni (5) in C,H, at 77°C. A) Overview.
B) C-l to C-5 amplified; L solvent. C,, and C,, expanded.
- 51.1;
- 18.6
[a] Measured rel. to solvent [(1)-(4): tetrahydrofuran; (5) and (6). benzene]. calculated rel. to analogous ferrocene [6]; accuracy [ppm] (if not otherwise quoted):
C-l to C-5: t 10; other C: + I: downfield shift negative. [b] After recalculation
from the measuring temperatures according to the Curie law. [c] Concentration
[mol-Yo]: (1)= 15.5: (2)= 15.9. (3). 14). (6)= 15-25: (5)=47.4. [d] Proposed
assignment (cf. Text).
one, in substituted nickelocenes the other orbital determines
broad signals occur close to each other at the same time. As
Figures 1B and 1C show, the spectrum of ( ~ B u C ~ H pro~ ) ~ N ~ the transfer of unpaired electrons to the ligand. Hence, the
assignment of C-3/4 and C-2/5 (cf. Table 1) should also be
vides information on C-H coupling[41and the symmetry of
opposite to that in cobaltocenes[xl.
the five-membered ring. The poorly developed shoulder for
We have checked the accuracy with which such I3C-NMR
C-1 is clearly recognizable in the spectrum of (tBuC,H,),Ni
spectra are obtainabte with perdeuterated nickelocene. Table
(6) (Fig. 2). This spectrum also provides the long sought151
1 shows the very small difference of 8 ppm between the signals of (1) and (2), which to our knowledge is, nevertheless,
the largest I3C-NMR isotope shift observed so far. This value
falls neatly in line with our findings on other metalloC-314 C-215
Received: November 30. 1979 [Z 480 I€]
German version: Angew. Chem. 92, 487 (1980)
CAS Registry numbers
( I ) , 1271-28-9 (2). 51510-35-1; (3). 1293-95-4; (4). 31886-51-8; (5). 60064-87-1;
(6). 32964-16-2
4 0 0 pprn
Fig. 2. "C-NMR spectra of(rBuC$H&Ni (6) in C,D, at 35, 77 and 97OC; C-1 to
C-5 amplified; V = impurity.
evidence for strong temperature dependence of the shifts and
The I3C-NMR data of the nickelocenes investigated are
collected in Table 1.
According to these data the nickelocenes (1)-(6) are radicals, which, with two unpaired electrons, shift in particular
the signals of the five-membered ring C-atoms to an extreme,
characteristic region. The number and position of the signals
afford proof of structure just as easily as in the case of diamagnet; , molecules.
Surprisingly, the C-1 signal in the compounds (RC5H4)2Ni
[(3)-(6)] is shifted further than the rest of the five-membered ring signals. In analogy to c o b a l t ~ c e n e sthe
[ ~ ~opposite
was to be expected. It can be concluded, therefore, that the
unpaired electrons in both metallocenes are in e f gorbitals['"I,
but slight perturbation of the degeneration (by substitution
with R) leads to e & and e lg[7b1,each of which give opposite
signal splittings. In substituted cobaltocenes apparently the
@ Verlag Chemie, GmbH. tiV40 Weinheim, IY80
111 C. F. Halch. J. W. Neely, R. W. Kreilrck. J. Magn. Res. 16. 408 (1974).
[2] Spectrometer. Bruker CXP 200; typical parameters: frequency 50.3 MHz.
spectral width 125 and 166 kHz. pulse width 8 and 6 p.s, 32 K accumulations,
data collection time 44 min, data points 8 K (after zero point filling).
[3] F. H. Kdhler. Z. Naturforsch. B 29, 708 (1974).
[4] The signals of C,. and C,, are also observable as tripiets after using appropriate filter functions.
[S] a) We could not reproduce the preliminary results quoted in [Sb]: b) F. H.
Kohler. J. Organomet. Chem. 110. 235 (1976).
[6] F H. Kohler. G. Marsubayashi, J. Organomet. Chem. 96. 391 (1975): F. H.
Kohier. Z. Naturforsch. B 31, L151 (1976).
[7] a) M. Nussbaum. J. Voirlunder. Z. Naturforsch. A 20, 1417 (1965). b) Simplified. On going from (C,H,),M to (RC5H4),M with staggered conformation,
D5,, changes to Clh
[S] F. H. Kohler, J Organomet Chem. 160, 299 (1978).
191 F. H. Kohler. W. Prossdorf: J. Am. Chem. Sac. /OO,5970 (1978).
Coordination Chemistry, and Reactions at the
Metal" 'I
By Bernd Weinberger and Wolf Peter Fehlhammerl'l
Dedicated to Professor Helmut Behrens on the occasion
of his 65th birthday
Isodiazomethane (CNNH2) cannot be obtained as a pure
substance owing to its ready decomposition"'; it can however
[*] Prof. Dr. W. P. Fehlhammer, DipLChem. B. Weinberger
Institut fur Anorganische Chemie der Universitat Erlangen-Niirnberg
Egerlandstrasse 1. D-8520 Erlangen (Germany)
Metal complexes of functional isocyanides. Part 4. This work was supported
by the Deutsche Forschungsgemeinschaft and the Fonds der Chemischen Industrie.-Part 3: 121.
0570-0833/80/0606~4RO $ 02.50/0
Angew. Chem. Inr. Ed. Engl. 19 (1980) No. 6
be stabilized by coordination to a metal. Unfortunately,
the precursor for the synthesis of
Cr(CO),CNNH2121is not easily acce~sible~~l.
In search of a suitable "form of storage" of isodiazomethane we have now been able to prepare N-isocyanoiminotriphenylphosphane
according to
+ 2PPh, + 2CC14 + 2NEtx +
+ 2HCCI, + 2[NEt3H]C1+ OPPh,
The surprising stability (dec. pt. 159-160°C) of this functional N-isocyanide is apparently due to the masking of the
primary amine function.
Apart from synthetic route and IR spectrum [(KBr): 2067
w (u(CN)), 1117 s, 1009 sh (u(P=N)) cm-'1 it is particularly
its strong tendency to form complexes, which proves (1) to be
an isocyanide. Thus, the stablef5]complexes (2a-c) and (3)
are formed smoothly from tetrahydrofuran or bromo derivatives and (I), respectively. No more problems arise in the
syntheses of (4) and (5) by, respectively, addition of (I) to
(2a-c), M = Cr. Ma, W
PdIz and cleavage of the bridge in [PtCl(PPh3)2]2[BF4]2.
Complex formation is accompanied by an increase Au(CN)
in the u(CN) frequency, which in the case of N-isocyanides
reaches values up to 130 cm-' (Pt" complexes)[']. In view of
the high Au(CN) values found here, and the low-lying CO
bands of the pentacarbonylmetal moiety [(2a): KBr: 2055 s
[A,], 1924 vs [El cm-'1 (I) is primarily a donor ligand, i.e.
bonding in metal complexes of (1) is perhaps best described
by the resonance formula
As expected, the iminophosphorane bond in (2) can be
cleaved hydrolytically under conditions leaving the rest of
the molecule untouched. The isodiazomethane complexes
(6)121formed in >70% yield according to
(2) + H2O _ _ M(CO)SC_N--NH2
+ OPPh,
are stable enough to be sublimed after chromatographic separation from phosphane oxide.
(2) reacts with aldehydes and ketones in a Wittig-type
reaction to give complexes (7) with N-isocyanoiminoalkane
(2) + R R ' C - - 0
+ OPPh,
_ j
All solvents and reagents must be anhydrous and, where
necessary, saturated with NZ.
(1): A suspension of PPh3 (157.4 g, 0.6 mol) in CHzClz
(600 ml) is treated with 50.6 g (0.5 mol) of NEt, and 15.3 g
(0.25 mol) of formylhydrazine and heated to 50-60 "C.CCl,
(77.0 g, 0.5 mol) is added dropwise to the mixture, which is
kept at 50-60°C for 4-5 h. After removal of the volatile
components at room temperature, the residue is dried in a
high vacuum, pulverized, stirred in 200 ml ethanol/water
(1 : 1.5), filtered, and recrystallized from hot ethanol; yield
31.7 g (42%) ( 1 ) as orange-brown crystals.
(2c): A solution of W(CO), (1.76 g, 5 mmol) in tetrahydrofuran (100 ml) is irradiated until -110 ml of CO have
evolved. The solution is then cooled to - 30 "C, mixed with
1.39 g (4.6 mmol) of (I), stirred for 2 h at -30 "C, and for 1 h
at 0 "C. After removal of the solvent (0 "C, high vacuum) and
sublimation of W(CO)6, the residue is extracted with 6 x 50
ml boiling petroleum ether (40-60 "C), the extract filtered
rapidly through filter-cellulose, concentrated to ca. 1/3 of its
volume and transferred to a refrigerator. Pale yellow (2c)
crystallizes out; yield 2.91 g (93%).
(7), M = W, R = R'= CH,: Dry HCI gas is passed into a solution of (2c) (0.63 g, l mmol) in acetone (30 ml) for ca. 1/2
min. The solution is stirred for 2 h, the solvent removed, and
the mixture chromatographed on silica gel with CH2C12/nhexane (4:l). After evaporation of the solvent 0.20 g of a
pale yellow solid (50%, m.p. 86.5 "C) are left behind.
Received: January 2. 1980 [ Z 484 IE]
German version: Angew. Chem. Y2, 478 (1980)
[ I ] E. Muller, P. Kadner, R. Beutler, W Rundel, H. Suhr, B. Zeeh, Justus Liebigs
Ann. Chem. 713, 87 (1968).
121 W. P. Fehlhammer, P. BuraEas, K. Bartel, Angew. Chem. BY, 752 (1977); Angew. Chem. Int. Ed. Engl. 16, 707 (1977)
(31 N Wiherg. G Huhler. Z Naturforcch R 31. 1317 (1976)
[4] Similar results have been obtained with Br2PPhl/NEt, [L. Horner. H . Oediger, Justus Liebigs Ann. Chem. 627, 142 (1959); H. J. Besrmann. J. Lienert, L.
Moll, ibid. 718.24 (1968)j in the place of the Appel three-component reagent
[R. Appel, Angew. Chem. 87, 863 (1975); Angew. Chem. In! Ed. Engl. 14.
801 (1975)J.
151 In contrast. PhrPN-NCO and Ph-PN-NCS which, according to the "6electron chalcogen atom/ 16-electron metal fragment" analogy should be
comparable with metal complexes of / I ) . were formulated only as lahile intermediates: R. Appel. G.Siegemund. Z. Anorg. Allg. Chem. 363, 183 (1968).
161 W. P. Fehlhammer. Habililationsschrift. Universitat Munchen 1976.
171 I. Hagedorn, U. Eholzer, Angew. Chern. 74. 499 (1962); Angew. Chem. In!.
Ed. Engl. 1.75 (1962).
[S] Cr(CO)sNCNPPh, had been synthesized previously (by photolysis of
Cr(CO)* in the presence of NCNPPL,) and studied IR spectroscopically: H.
Bock, H. fom Dieck, Z. Anorg. Allg. Chem. 345, 9 (1966).
BsSl6-An "Inorganic Porphine"[**l
By Bernt Krebs and Hans- Ulrich Hurter"]
e.g. R=R'=CH3; R=ChHS,R ' = H
In this way, a class of compounds becomes readily accessible in metal complexes, of which only one representativeCNN= -C(CH3)C,H4-p-OCH3-has so far been characterized
in free forml'l.
There is definitely more synthetic potential in pentacarbonylmetal(6A) complexes of (I) as shown by the acid-catalyzed isomerization to the complex cyanamide (8), which is
complete in 2-3 d at room temperature1*lI.
This reaction proceeds particularly smoothly and quantitatively in the presence of palladium(I1) compounds in a CO atmosphere.
Angew Chem. 1111. Ed. Engl. 19 (1980) No. 6
The preparation and characterization of boron sulfides is
difficult. The only compound to have been unequivocally
identified in the solid state is B2S3, which has a polymeric
structure made up of B3S3 six-membered rings and B2S2
four-membered rings[']. The existence of BI2S,B4S, BS, and
B2S5121 as defined phases has not yet been confirmed. The
Prof. Dr. B. Krebs. Dip1.-Chem. H.-U. Hurter
Anorganisch-chemisches lnslitut der Universitat
Gievenbecker Weg 9, D-4400 Miinster (Germany)
["I This work was supported by the Minister fur Wissenschaft und Forschung
des Landes Nordrhein-Westfalen and the Fonds der Chemischen Industrie.
0 Verlag Chemie, GmbH. 6940 Weinherm, 1980
$ 02.50/0
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chemistry, synthesis, isocyanoiminotriphenylphosphorane, reaction, metali, coordination
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