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Formal Insertion of the HCO Fragment into a Trinuclear Cluster Metal-Carbyne Bond Synthesis Structure and Reactivity of Cluster-bound Ethynol.

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In the paramagnetic dinuclear sandwich complex 2,
which has a center of inversion, the V-atoms (V-V*
2.351( I ) A) are each surrounded by a five-membered ring
and six-membered ring. The bridging atoms C5 and C9 are
located at an average distance of 2.274(6) A from the central V atoms, a distance greater than all other V-C distances in the molecule. The same holds for the distances
between ?5/C9 and the neighboring C atoms. The C6-C7
(1.417(3)A) and C7-CS (1.411(2)A) bonds in the fivemembered ring are about 0.03 A shorter than the other
three C-C bonds, whereas a long-short-long sequence is
observed for the C-C bond lengths between the C1-C4
atoms in the six-membered ring. The planar moiety C1-<4
(V-C,er,,,,ndl 2.166(2) A, V-Ccentral2.236(2) and 2.239(2) A,
respectively) bound to vanadium like a diene forms an angle of 13.5" with the Cl-C4-C5-C9 plane.
Fig. 1. Crystal structure of diindenyldianadium 2 [XI. Selected bond lengths
[.&I and angles ["I (see text also): CI-C2 1.425(3), C 2 X 3 1.403(2), C3-C4
1.430(2), C5-C9 1.457(2); V-C6* 2.212(2), V-C7* 2.252(2), V-C8* 2.223(2).
140°C. Recrystallization of the sublimate from toluene/hexane fur^
nished dark green crystals; these were washed and dried at 20°C under
oil-pump vacuum (yield 10.34 g, 85%). Correct elemental analysis. MS:
m / z 281 (.We, 100%). I R [ c m - ' (KBr): G(CH)=3095 (w), 3074 (w), 3050
(m), 3008 (w); ?(CC)= 1446 (m), 1326 (s), I208 (m), I149 (m): ?(fivemembered ring)= 1031 (s): n(CH)=770 (vs), 730 (vs).
171 Experimental procedure for 2 : to a stirred solution of 1 (17.48 g,
62.2 mmol) in THF (300 mL) at 0°C was added 2.41 g (61.6 mmol) of
potassium pellets over a period of 3 h. After 10 hours' stirring at 2 0 ° C
the reaction mixture was evaporated to dryness and the residue taken up
in boiling toluene. The hot solution was filtered free of insolubles. On
cooling the filtrate to 20°C. dark purple crystals of 2 crystallized (4.74 g,
46%). Correct elemental analysis. MS: m / z 332 (Ma,
100°/o). IR [cm - ' I
(KBr): C(CH)=3038 (m), 3049 (w), 3039 (w); I;(CC)= 1457 (m), 1375
(m), 1294 (s), 1138 (m); ?(five-membered ring)= I030 (s): n(CH)=736
[8] Crystal structure analysis of 2 : space group P 2 , / n , No. 14. 2 = 2 ,
p,,,i,=1.71 g c m P , p(MoKn)=13.86 c m - ' , 0=7.7537(9), b=8.1145(7),
c = 10.8774(6) A, b= 109.541(6)", solution of structure by Patterson
methods. 1654 observed reflections with 1 > 2 a ( l ) ,R=0.025, R,=0.034
( w = t/&(F")). Further details of the crystal structure investigalion are
available on request from the Fachinformationszentrum Energie, Physik, Mathematik GmbH, D-75 14 Eggenstein-Leopoldshafen2 (FRG), on
quoting the depository number CSD-51932, the names of the authors,
and the full citation of the journal.
[9] T. J. Katz, N. Acton, J . Am. Chem. SOC.94 (1972) 3281; T. J. Katz, N.
Acton, J. McGinnis, ibid. 94 (1972) 6205.
[lo] An article on di- and polynuclear sandwich complexes, in which almost
exclusively hypothetical molecules are theoretically treated, appeared in
1985: J. K. Burdett, E. Cannadell, Organometallics 4 (1985) 805.
I l l ] R. J. Bouma, J. H. Teuben, W. R. Beukema, R. L. Bansemer, J. C. Huffmann, K. G . Caulton, Inorg. Chem. 23 (1984) 2715; F. A. Cotton, S. A.
Duraj, W. J. Roth, h i d . 23 (1984) 41 13, and references cited therein.
Formal Insertion of the H C O @Fragment into a
Trinuclear Cluster Metal-Carbyne Bond :
Synthesis, Structure and Reactivity of
Cluster-bound Ethynol**
By K . Peter C. Vollhardt* and Matthias Wolfgruber
Aside from 2, there are only two other dinuclear complexes with two bridging ligands which are bicyclic annulated hydrocarbon systems. These compounds, which are
formed in low yields (4% and 4-10%, respectively) upon
reaction of NiCI, or CoCI, with dilithium pentalenide,
have, on the basis of elemental analyses and 'H-NMR and
mass spectra, been characterized as [(C8H6),Ni2] and
[(c8H6),Co,].[" 'I Katz et al. have proposed a dinuclear
sandwich structure for these two complexes, but such a
structure has not, as yet, been confirmed by a crystal structure analysis.
Received: May 15, 1986;
revised: July 2, 1986 [ Z 1780 IE]
German version: Angew. Chem. 98 (1986) 905
[I] K. Jonas, Angew. Chem. 97 (1985) 292; Angew. Chem. Int. Ed. Engl. 24
(1985) 295, and references cited therein.
[2] R. Benn, K. Cibura, P. Hofmann, K. Jonas, A. Rufinska, Organometallirs 4 (1985) 2214.
[3] K. Cibura, Dissertalion, Universitat Bochum 1985.
[4] K. Jonas, W. Riisseler, C. Kriiger, E. Raabe, Angew. Chem. 98 (1986)
902; Angew. Chem. In l. Ed. Engl. 25 (1986) 925.
I S ] K. Jonas, W. Riisseler, unpublished.
161 Experimental procedure for 1: 20.31 g of the pale green product
(43. I mmol V, found 10.82% V), which was obtained by reaction of VCIJ
with zinc in T H F [ I I], was added with stirring at 0°C t o a solution of
Lilnd (prepared from indene and nBuLi in hexane) in T H F (300mL).
After 15 hours' heating under reflux, the reaction mixture was evaporated to dryness and the residue sublimed under high vacuum at 120Angew. Chem. In1 Ed. Engl. 25 (1986) No. 10
A recent report of the observation of ethynoi (hydroxyacetylene) in the gas phase,"] prompts us to disclose the isolation of this usually unstable molecule as a ligand to a
trinuclear cobalt cluster. Its formation proceeds by the
novel formal insertion of the hydroxymethylidyne cation
HO-C:@ into a cobalt-methylidyne bond, the isoelectronic
carbon version of the related reaction of NO@.[*'
Addition of HBF,.OEt, to a slurry of the cluster lf3Iin
CH2C12 caused an immediate color change from red to
bright green and complete dissolution. Addition of pentane precipitated the e d g e - p r ~ t o n a t e dcluster
2 (94%),[51
characterized by a single I3C-NMR signal (CD2CI2) at
6 = 87.61 (methylidyne C-signal not observed), and three
'H-NMR signals (CD,CI,, -90°C) at 6= -27.49 (s, 1 H),
4.99 (s, 15 H), and 16.79 (s, 2 H). The single Cp resonance
indicates either accidental isochronism o r a fluxional process around the trinuclear core.141
['I Prof. Dr. K.
P. C. Vollhardt, Dr. M. Wolfgruber
Department of Chemistry, University of California
and the Materials and Molecular Research Division
Lawrence Berkeley Laboratory
Berkeley, CA 94720 (USA)
[**I This work was supported by the National Science Foundation (CHE
8504987). K . P. C. V. is a Miller Research Professor in Residence (19851986). M. W. was the recipient ofa Deutscher Akademischer Austauschdienst Postdoctoral Fellowship (1984- 1985). The X-ray structural analysis was carried out by Dr. F. J . Hollander. staff crystallographer.
0 VCH Verlagsgesellschaft mbH. 0-6940 Wernheim, I986
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Remarkably, 1 is completely inert to C O at room temperature, whereas 2 is smoothly carbonylated (23 "C,
55 bar, CH2C12, 97%) to a new compound formulated as
the ethynol complex 3.I'' The composition of 3 is confirmed by elemental analysis. The 'H-NMR spectrum
([DJacetone) exhibits signals at 6=22.18 (C-H of the intact methylydyne group), 11.16 (OH, assigned by deuterium exchange), 10.38 (C-H of the new ligand), and 5.10 (s,
15H, Cp). Not unexpectedly,lZ1the alkyne ligand is fluxional, leading to only a single peak for the C p protons. The
I3C-NMR spectrum (CD,NO2) shows signals at 6= 197.52
and 124.25 (ethynol C-atoms) and 87.69 (Cp); a methylidyne C-signal could not be observed. The IR spectrum
(KBr) shows a broad peak at i;=3380 c m - ' and additional
strong absorptions at V=1419, 1266, 1070, 985, and 840
cm - I . The mass spectrum contains characteristic fragments at m/z 426 (Me-H, 68%) and 398 (Me-HCO,
66%). Final structural confirmation of 3 was obtained by
an X-ray structural analysis (Fig. l).@I
The alkynol ligand in 3 adopts a parallel"1 arrangement,
and is bent and stretched as expected.['' Its mechanism of
formation by HOCO coupling may be related to other acidmediated methylidyne-CO couplings of interest as a fundamental step in hydrocarbon build-up by C O hydrogenation.191 We have observed that this protonation-carbonylation sequence occurs also with other biscarbyne clusters of
the type 1.
On attempted chromatography (silica gel), 3 oxidized to
the acid 4 in low yield,"01 synthesized independently from
the cluster 6 (obtained by alkyne cleavageL3I)by hydrolysis
(1. HBF,.OEt,, 2. H 2 0 ; 94%). When 3 was treated with
C O at 70°C (CH2C12, 16 bar, 5 h, 73%) an unprecedented
rearrangement to 5 occurred, involving apparent C O deinsertion and coupling of two methylidyne ligands! The IR
spectrum of 5 (KBr) exhibits a strong peak at 5=1845
c m - ' , indicative of a bridging C O ; the mass spectrum is
identical to that of 3, and the 'H-NMR spectrum ([D6]ace930
0 VCH Verlagsgesellschafi mhH. 0-6940 Weinheim. 1986
Fig. 1. ORTEP drawing o f the crystal structure 01the cation in 3 . tilipsoids
are scaled to represent the 50% probability surface. Hydrogen atoms are not
refined and are represented by arbitrary spheres. H(0) and H2 are given in
their positions as found on an electron density map. All other hydrogens are
in idealized positions. Selected band lengths [A] and angles ["I: C2-C3
1.368(4), C2-H2 1.11, 0 - H ( 0 ) 1.02, Col-C2 1.881(3), Co2-C3 1.886(3), co3c'2 1.993(3), C03-C3 2.036(3), Col-Co2 2.501(1), Col-Co3 2.392(1), C02-Co3
2.435(1), COI-CI 1.834(3), C02-CI 1.830(3), C03-CI 1.874(3), Col-Cpl 1.695,
C02-Cp2 1.701, C03-Cp3 1.677, Col-C2-C3 l08.1(2), Col-C2-H2 131.2, C3C2-H2 119.0, Co3-C3-C2 106.9(2), C02-C3-0 128.1, C2-C3-0 123.6(3), C30 - H ( 0 ) 107.8.
tone) reveals the absence of the methylidyne signal and the
presence of a peak at 6=9.18 (s, 2 H, ethyne H) in addition
to two peaks at 6=5.49 (s, 10H, 2Cp) and 5.41 (s, 5 H, Cp).
The hydride signal could not be detected. The I3C-NMR
spectrum (CD3N02)shows absorptions at 6= 161.02 (CO),
149.14 (ethyne), 91.48 and 87.52 (Cp). The elemental analysis and additional IR bands at 1000-1 150
confirm the formulation of 5 as a BF? salt. A related rhodium
complex has been reported."21 The transformation of 3
into 5 is analogous to the equally unprecedented baseinduced NO-cleavage with CH/CH coupling of the related
N O insertion products of 1.I2]
Received: May 5, 1986;
revised: July 1 I, 1986 [Z 1759 IE]
German version: Angew. Chem. 98 (1986) 919
CAS Registry numbers:
1, 74127-99-4:2, 104131-40-0;3, 104131-42-2;4, 104131-43-3:5, 104131-45-5;
6, 104131-46-6; Co, 7440-48-4.
[I]a) B. van Baar, T. Weiske, J. K. Terlouw, H. Schwarz, Angew. Chem. 98
(1986) 275; Angew. Chem. In/. Ed. Engl. 25 (1986) 282; b) Complexed
ethynol has been invoked as a n intermediate: E. Boyar, A. J. Deeming,
S . E. Kabir, 3. Chem. Soc. Chem. Commun. 1986. 577.
[2] A. Goldhaber, K. P. C. Vollhardt, E. C. Walhorsky, M. Wolfgruber, J
Am. Chem. Soc. 108 (1986) 516.
131 J. R. Fritch, K. P. C. Vollhardt, Angew. Chem. 92 (1980) 570; Angew.
Chem. Int. Ed. Engl. I9 (1980) 559.
141 D. E. Van Horn, K. P. C. Vollhardt, J. Chem. Soc. Chem. Commun. 1982,
[5] All new compounds isolated were fully characterized.
161 Monoclinic, P2,/n, a=9.7371(6), h = 12.0361(9), c = 15.7240(17)A,
j3=91.246(7)", V=1842.4(5)A3, Z=4, p,.,,,,=1.85 g cm-', pCrlid=27.1
cm I , MoKn radiation (graphite monochromator): scan range
3 " 5 2 6 5 4 5 " ; reflections collected 2703; 2108 unique with F , , > 3 u ( F 2 ) ,
R=0.0329, R,, =0.0532. Further details of the crystal structure investigation are available o n request from the Fachinformationszentrum Energie, Physik, Mathematik GmbH, D-75 14 Eggenstein-Leopoldshafen2
(FRG), on quoting the depository number CSD-51991, the names of the
authors, and the full citation of the journal.
0570-0833/86/1010-0930 $ 02.50/0
Angew. Chem. Inr. Ed. Engl. 25 11986) No. 10
171 A. I>. C'lauss, J. R. Shapley, C. N. Wilker. R. Hoffmann, Orgnnomerollics
3 (1984) 619.
181 See M. R. Churchill, J. C. Fettinger, J. B. Keister, R. F. See, J. W. Ziller,
0rgonomerallic.r 4 (1985) 21 12, and references cited therein. For a review
see t.Sappa. A. Tiripicchio, P. Braunstein, Coord. Chem. Rev. 65 (1985)
[9] For \elected recent work, see D. C. Brower, K. R. Birdwhistell, J. L.
Templeton, Organometal1ic.s 5 (1986) 94; J. Hriljac, D. F. Shriver, ibid. 4
(1985) 2225: M. J. Sailor, D. F. Shriver, ibid. 4 (1985) 1476; K. R. Birdwhistell, T. L. Tonker, J. L. Templeton, J. A m . Chem. Soc. 107 (1985)
4474. S J. Holmes, R. R. Schrock, M. R. Churchlll, H. J . Wasserman,
Organnrnerallrcs 3 (1984) 476; F. R. Kreissl, W. J. Sieber, M. Wolfgruber,
J . Rirde, Angew. Chem. 96 (1984) 618; Angew. Chem. Int. Ed. Engl. 23
(1984) 640; F R. Kreissl, W. Sieber, M. Wolfgruber, ibid. 95 (1983) 503
and 22 (1983) 493; Angew. Chem. Suppl. 1983, 631; M. R. Churchill, H.
J. Wasserman, Inorg Chem. 22 (1983) 41.
[lo] 4 : red powder; m / z 442 ( M a , 39%), 189 (100); 'H-NMR (CDCl3):
6 = 18.92 ( s , I H), 10.00 (br. s , 1 H), 4.55 ( s , 15H); IR (KBr): G=33002500 (br.). 1636, 1264, 808 c m - ' .
[ I I ] K. Richter, E. 0. Fischer, C. G. Kreiter, J. Organomet. Chem. 122 (1976)
1121 R. S. Ihckson, C. Mok, G. Pain, J. Organomer. Chem. 166 (1979) 385.
Fig. 1. Crystal structure 0 1 2a [41 Selected bond lengths [pm] and angles ["I:
Ir-NI 205.7(5), Ir-S2 239.1(3), lr-S4 233.5(3), Ir-P 237.5(3), NI-SI 152.8(6).
N2-S2 169.2(6), N3-S3 157.5(7), N4-S4 160.8(6), SILN2 I58.1(6), S2-N3
164.6(7), S3-N4 156.0(6), Ir-CI 241.4(3), Ir-C 190.2(6),C - 0 1 Il.9(8); NI-lr-S2
86.7(2), S2-Ir-S4 95.0(1), S2-Ir-CI 79.6(1), NI-lr-C 176.8(3), S4-lr-C 94.3(2),
NI-lr-P 90.1(2), S4-Ir-P 89.9( I), C-Ir-P 89.8(2), NI-lr-S4 82.4(2), Nl-lr-Cl
88.9(2), S4-Ir-CI 170.0( I), S2-lr-C 93.7(2), CI-lr-C 94.4( I), N2-S2-N3
S4N4 as Tridentate Ligand in
IIrX( CO)(PPh3)(S4N4)IComplexes**
By Frank Edelrnann. Herbert W . Roesky.*
Claudia Spang, Mathias Noltemeyer, and
George M . Sheldrick
In all the adducts of S4N4 and transition metal halides
described in the literature so far, S4N4is coordinated to the
metal atom via an electron lone pair on a nitrogen atom."]
The Vaska complex [IrX(CO)(PPh,),] 1 reacts with S4N4
with elimination of triphenylphosphane to give
[IrX(CO)(PPh,)(S,N,)] 2 . The chloro complex 2a has already been mentioned in the literature,'21but so far has not
been satisfactorily characterized.
+ S,N,
+ PPh,
sulfur-nitrogen bond (S4-Nl) of S,N4 while S2 is coordinated to the iridium atom, thus resulting in formation of a
bicyclo[4.3.0]-skeleton. Of the two sulfur atoms coordinating the Ir atom, one (S4) has a C.N. (coordination number)
of 2, the other (S2) a C.N. of 3. The S-atom with the lower
C.N. should have the higher electron density and, consequently, the shorter Ir-S distance; this is indeed found to
be the case: Ir-S4 233.5(3), Ir-S2 239.1(3) ppm. However,
it should also be noted that the CI-atom is trans to S4 while
the PPh3 ligand is trans to S2, and that these influence the
bond lengths differently. In [(Me,P),OsS,] with similar
phosphane ligands, however, the S-atom with C.N. 3 has a
shorter 0s-S bond than the two S-atoms with C.N. 2.15]
a, X = C I ; b, X = B r ; c, X = I
The intense red complexes 2a-c are stable towards air
and hydrolysis. Their purity was checked by thin-layer
chromatography (silica gel, benzene; 2 : R,=0.8).L3'The IR
spectra of 2a-c show a distinct shift of the V ( C 0 ) band of
more than 100 c m - ' to higher frequency compared to that
of the starting compounds ( l a 1951, 2a 2065, l b 1955, 2b
2069, lc 1975, 2c 2075 c m - ' ) . The increased bond order
can be attributed to oxidative addition of S4N4 to the Ir
atom. I t leads to reduction of the electron density at the
iridium, and consequently to a weakening of the d,-p,
back-bonding to the carbonyl group. In the EI-mass spectra, lines for the molecule ions with relative intensities between three and eighteen percent were observed for all
three complexes, thus underscoring the kinetic stability of
Single crystals for an X-ray structure analysis'41were obtained by the diffusion method from benzenelhexane. The
crystals contain two molecules of benzene per molecule of
2a. The distinguishing feature of the structure of 2a (Fig.
1) is that the [IrCI(CO)PPh,] fragment is inserted into a
[*] Prof. Dr. H. W. Roesky, Dr. F. Edelrnann, DipLChem. C. Spang,
Dr M . Noltemeyer, Prof. G . M. Sheldrick
lnstitut fur Anorganische Chemie der Universitat
Tammannstrasse 4, D-3400 Gottingen (FRG)
['*I This work was supported by the Deutsche Forschungsgemeinschaft and
the Fonds der Chemischen Industrie.
Anyew Chern Inr Ed Engl 25 (1986) No 1 0
Received: June 2, 1986;
supplemented: July 4, 1986 [Z 1798 IE]
German version: Angew. Ckem. 98 (1986) 908
hn, B. Dederer,
[ I ] A. Gieren, C.
W. Roesky, N min, Z. Anorg. Allg.
Chem. 447 (1978) 179; U. Thewalt, B. Miiller, Z . Narurforsch. 8 3 7 (1982)
828; U . Thewalt, 2. Anorg. ANg. Chem. 462 (1980) 221; U. Thewalt, Angew. Chem. 88 (1976) 807; Angew. Chem. Inr. Ed. Engl. I5 (1976) 765; R.
Christophersen, P. Klingelhofer, U. Muller, K. Dehnicke, D Rehder, Z .
Naturforsch. 8 4 0 (1985) 1631.
[2] B. J. McCormick, B. Anderson, J . Inorg. Nucl. Chem. 32 (1970) 3414.
[3] Experimental procedure: 2a: A solution of SdN4(0.12 g, 0.65 mmol) and
l a (0.5 g, 0.65 mmol) in benzene (50 mL) was stirred for 4 h at 50°C. The
solution turned from yellow to red-brown. It was filtered warm, and the
filtrate treated with 10 mL of n-hexane and cooled within 0.5 h to 4°C.
Unchanged S,N, that separated out was removed by filtration and the
S,N,-free filtrate re-cooled to 4°C. After a few hours, 2a precipitated in
the form of red crystals. Yield 0.2 g (40%), m.p. 186°C. 2b and Zc can be
prepared analogously. 2b: yield 0.18 g (39%), decomposition at 190°C.
2c: yield 0.6 g (29%). decomposition at 192°C.
141 2a .2CoH6 crystallizes triclinically, a = 1041.5(2), b= 1249.3(2), c =
1299.1(2)pm, a=88.60(2), 8=78.88(2), y=86.12(2)", t = 2 , pL.,,&=
1 . 7 2 3 ~106gcm-', ~ ( M o K " )4.42 m m - ' . Refined to R(F)=0.030 for
2544 absorption-corrected data with F > 3 o ( F ) with a riding model for
the H atoms and the residual atoms anisotropic. Further details of the
crystal structure investigation are available on request from the Fachinformationszentrum Energie, Physik, Mathematik GmbH, D-75 14 Eggenstein-Leopoldshafen 2 (FRG), o n quoting the depository number CSD5 1977, the names of the authors, and the full citation of the journal.
[51 J. Gotzig, A. L. Rheingold, H. Werner, Angew. Chem. 96 (1984) 813; Angew. Chem. Inr. Ed. Engl. 23 (1984) 814.
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forma, bond, bound, ethynol, insertion, reactivity, fragmenty, structure, synthesis, clusters, hco, metali, trinuclear, carbyne
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