Organometallics 1983, 2, 189-191
rangement. The ferrocene molecules have an Fe-ring center distance of 1.656 (4)A and an average F A ! distance of 2.018 (4)A. This material cannot be recrystallized nor can it be assembled from its congeners. These observations are consistent with the solid complex being a kinetically formed phase,12 likely a decomposition product of ferricenium-TCNE-. which has been shown to be in equilibrium with ferrocene-TCNE. If moisture (but not oxygen) is excluded from the reaction described above, the products include both TCEA- and pentacyanopropenide anions. This latter observation is in excellent agreement with the reactivity pattern observed, e.g., in acetonitrile solutions of the TCNE radical anion.13
Acknowledgment. This work was supported in part by the Office of Naval Research. We thank L. Acampora and G. D. Zoski for performing electrochemical measurements and D. J. Sandman, A. Reis, and L. S. Stuhl for helpful discussions. Registry No. [ (C5H,),Fe]l,5+[CSN,0]-,83587-82-0; ferrocenetetracyanoethylene, 12116-72-2.
Supplementary Material Available: Tables of atomic coordinates, thermal parameters, and observed and calculated structure factors (7 pages). Ordering information is given on any current masthead page.
189
tention on the chemistry of bi- and polynuclear carbonyl derivatives containing these m0ieties.l Several examples of attack by amines on coordinated CO in Ru&CO),~and O S ~ ( C O )have , ~ been described,2 and Kaesz3 has recently generated edge bridging p-O=C(X) groups from anionic nucleophiles (NMe2-, Me-, or OR-) via the proposed intermediacy of q’-C(=O)X species. Oxygen and carbon coordinated CO have also been implicated in the catalytic reduction of CO by binuclear ruthenium systems4although the proposed intermediates were not isolated. Intuitively one might expect both ql- and p-O=C(X) complexes to be involved in homogeneously catalyzed or stoichiometric reductive carbonylations of organic substrates in the presence of polynuclear compounds. We wish to report the synthesis of the novel, a-substituted p-acyl complexes Mz(CO)6[p-O=CCH=CPhNRR’](PPh2) (2, M = Fe, Ru, R = Ph, R’ = H; M = Ru, R = R’ = Et, n-Pr, R, R’ = 2-EtC5H9)via the facile carbonylation-amination of the unsaturated alkynyl ligand in M,(CO),(~-T~-C=CP~)(PPh2). Our results have relevance to strategies for the elaboration of carbocationic multisite bound unsaturated ligands and to the synthesis of oxygenates from C0.4 Furthermore trapping of p-O=CCH=C(Ph)NRR’ ligands in 2 suggests the possible use of binuclear carbonyls in reductive carbonylations of the Reppe-type, reactions that are at present mechanistically o b ~ c u r e . ~
(12)Sandman, D. J. Mol. Cryst. Liq. Cryst. 1979,50, 235. (13)Webster, 0. W.; Mahler, W.; Benson, R. E. J . A m . Chem. SOC. 1962,84, 3678.
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I Carbonylation and Amination of p-v2-Acetylides In M2(CO),( p-v2-C=CPh)( PPh,): Synthesis of p-O=CCHC( Ph)NR, Complexes and the X-ray Ph)NEt,](PPh,) Structure of Ru,(CO),[p-O=CCHC(
R
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Graham Nigei Mott, Ruthanne Granby, Shane A. MacLaughiin, Nicholas J. Taylor, and Arthur J. Carty’ Guelph- Waterloo Centre for Graduate Work in Chemistry Waterloo Campus, University of Waterloo Waterloo, Ontario, Canada N2L 3G1 Received August 18, 1982
Summary: The multisite bound acetylide in M,(CO)&v2-CsPh)PPh,) (M = Ru, Fe) reacts with CO in the presence of primary and secondary amines NHRR‘ to generate via carbonylation and amination the p-keto (2). compounds M,(CO),[p-O=CCHC(Ph)NRR’](PPh,) X-ray analyses of 2 (M = Ru, R = R’ = Et) and 2 (M = Fe, R = Ph, R‘ = H) revealed the presence of oxygen and carbon bonded acyl groups with regiospecific addition of the amine to the original P-alkynyl carbon atom. These p 0 , C complexes may be closely related to species implicated in the reduction of CO by H, to oxygenates in the presence of binuclear catalysts. The possible use of this reductive carbonylation strategy for the elaboration of other mukisite bound carbocationic ligands is suggested.
The possible involvement of p-bound ligands of the general type 1 (e.g., X = OH, OR) in the nucleophilic activation of carbon monoxide has focused increasing at0276-733318312302-0189$01.50/0
The phosphido-bridged binuclear acetylide Fez(C0)6(p-q2-C=CPh)(PPh2)6in benzene reacts cleanly with aniline in the presence of carbon monoxide. Infrared monitoring of the reaction mixture showed essentially quantitative replacement of the v(C0) bands of the precursor with those of a single product’ of composition Fe2(C0),-
(1) See, for example: (a) Lin, Y. C.; Knobler, C. B.; Kaesz, H. D. J . Am. Chem. SOC.1981, 103,1216. (b) Butts, S. B.; Strauss, S. H.; Holt, E. M.; Stimson, R. E.; Alcock, N. W.; Shiver, D. F. Ibid. 1980,102,5093. (c) Marsella, J. A.; Folting, K.; Huffman, J. C.; Cadton, K. G. Zbid. 1981, 103, 5596. (d) Maata, E. A.; Marks, T. J. Ibid. 1981, 103,3576. (e) Wolczanski, P. T.; Bercaw, J. E. Acc. Chem. Res. 1980, 13,121. (2)(a) Azam, K. A.; Choo Yin, C.; Deeming, A. J. J. Chem. SOC., Dalton Trans.1978, 1201. (b) Szostak, R.;Strouse, C. E.; Kaesz, H. D. J. Organomet. Chem. 1980,191,243.(c) Adams, R.D.; Golembeski, N.; Selegue, J. P. Inorg. Chem. 1981, 20, 1242. (3)Mayr, A.; Lin, Y. C.; Boag, N. M.; Kaesz, H. D. Inorg. Chem. 1982, 21, 1704. (4)Daroda, R. J.; Blackborow, J. R.; Wilkinson, G. J. Chem. SOC., Chem. Commun. 1980, 1101. (5)See, for example: Collman, J. P.; Hegedus, L. S. “Principles and Applications of Organotransition Metal Chemistry”; University Science Books: Mill Valley, CA, 1980;Chapter 8. (6) Smith, W. F.; Yule, J.; Taylor, N. J.; Paik, H. N.; Carty, A. J. Inorg. Chem. 1977, 16,1593.
0 1983 American Chemical Society
190 Organometallics, Vol. 2, No. 1, 1983
Communications
Figure 1. A perspective view of the molecular structure of R u z ( C O ) , ~ - - o = C C H C ( P h ) ~ ~ Pdrawn h 3 80 &s to emphasize the new ligand. (C2Ph)(PhzP)(PhNHz)(2, M = Fe, R = Ph, R' = H). Minute amounts of this complex had previously been isolated from the reaction of aniline with the parent acetylide where the major product is the zwitterionic p-alkylidene complex Fe,(CO), [CHC(Ph)NHPh](PPhz). The solution IR spectrum of 2 (M = Fe, R = Ph, R' = H) exhibited a u ( c = O ) hand at 1555 cm-' typical of a p-O= C(X) ligand,' and the 31Pchemical shift is characteristic of a phosphido group across a metal-metal bond simultaneously bridged by a two atom ligands In the NMR spectrum a resonance at 6 253.6 can be attributed to the acyl carbon atom. Analogous produrta were obtained from Ru,(CO).(u-n2-C~Ph)(PPh.) with PhNH,. Et-NH. In=~ ~~, Prj,NH,"and 2-ethylpiperidine.lo Structural details, particularly the stereochemistry of the hydrocarbon chain in 2, were revealed by single-crystal X-ray analyses of a ruthenium (2, M = Ru, R = R' = Et) and an iron (2, M = Fe, R = Ph, R' = H) derivative." Since the two ~~
1 .
~
~
(7) F e , ( C O ) , ( r , z - ~ P h ) ( P P h ~ )(1.0 g) was dissolved in degasaed benzene and heated t o 60 OC with a slow stream of CO gas a t 1 atm paasing through the solution. Aniline (1mL) was added via a serum cap by syringe and the mixture stirred magnetically with periodic IR monitoring of the reaction mixture. Complete conversion took 10 day. The reaction mixture waa concentrated, diluted with heptane, and chromatographed on Florisil. Heptane/benzene (1:l) eluted the product which was obtained fromthe mother liquor as red crmtds on mling a t -10 'C overnight: yield 70%;mp 137 'C; (C,H,,) u.(CO) 2061 (4,2018 (w), 1995 (d, 1978 (m), 1968 (m), 1958 (m) 1.555 (m) an-'; 31PNMR (ppm wrt 85% HQOJ f179.0. (8) Satisfactory elemental analyses have been obtained on all new compounds described herein. tY, fa) Cany. A J.; Mott, 0. N.;Taylor. Y. J.; Yule, J. E.J . Am. Chem. Soc. 1978. IW..1051. (1,) Cany, A. J. Ad". Chem. Srr. 19R2. No.1%. 163. (4Mutr. C.. N.:. C a .y A. J.. submitted for nubliration. (IO) 2 (M = Ru, R = R' Et): IR (C8HlJ u.(CO) 2066 (e), 2033 (8). 2ooo (a), 1986 (m), 1974 (m), 1960 (m), 1518 (m) em-'; N M R VIP) (C&) +150.7; I3C NMR (proton mupled; CD&) 6 243.6 (d, acyl CO), 203.3 (m), 200.8 (81, 199.7(s), 193.2 (8, CO), 155.7 (e, CPh), 140.8-125.7 (m,ring C). 112.5 (d, CH),45.0 (t),43.6 (0, (CHJ. 12.2 (91, 14.4 (9, CHJ. 2 (M = Ru, R = Ph, R' = H): IR (C,H,,) 4CO) 2070 (a), 2038 (s), 2007 (a), 1990 (m), 1979 (m), 1970 (m), 1559 (m) em-';NMR 6(s'P) (C,DJ f149.5. 2 (M = Ru, R = R' = n-Pd E l (C,H,,) v(C0) 2066 (e.), 2033 (s), Zoo0 (8). 1986 (m), 1975 (m), 1960 (m), 1516 (m) emP; NMR Na'P) ( C a 6 ) f150.2. 2 (M = Ru, R, R' = 2-ethyl-C5H,): IR (CJ3,J u(C0) 2066 (3 ,2033 (SI, 2wO (d,1985 (m), 1974 (m), 1959 (m), 1506 (m) em-'; NMR 6(31P)(C&6D,)
-
-
+150.5.
.
~
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Figure 2. A hall and stick plot of the structure of FeZ(CO)& O=CCHC(Ph)NHPh)(PPh,). structures are closely related and the ruthenium data set is the more precise, discussion here will center on the ruthenium complex. An ORTEP n plot is shown in Figure 1. The binuclear framework consists of two tricarbonylrutheninm moieties joined by a strong Ru-Ru bond (Ru(l)-Ru(2) = 2.7540(5) A) and a symmetrical bridging phosphido group. As expected from the 31PNMR shift the Ru(U-P-Ru(2) angle (71.6 (0)")is acute. The other bridging group is a 3-(diethylamin0)-3-phenyl-Zpropen-I-a1 ligand formed via formal insertion of CO into the meta-acetylide bond and cis addition of the secondary amine across the alkyne. The keto group is coordinated to Ru(1) via carhon and to Ru(2) via oxygen in p-C=C(X) fashion with a C(7)-0(7) bond length (1.275 (6) A) typical of $-bonded earbonyls;l2 the trapezoidal Ruz(CO) fourmembered ring is planar. A least-squares plane through the atoms N, C(9), C(14),C(8), CU), and 0(7)13 reveals that the entire hydrocarbon skeleton deviates little from planarity. Although the C(8)-C(9) bond (1.394 (6) A) is formally the olefinic link of the generated enamine, it is clear from the bond lengthsI4 that there is some delocal-
(11) Yellow prisms of Rul(CO).[p-O~CHC(Ph)NE~](PPh ) are triclinic of space group PI with a = 9.580 (2) A, b = 10.616 (3) e= 16.991 (5) A, a = 87.85 (2)". 0 = 95.83 (2)', y = 110.57 (2)-, 2 = 2, pm& = 1.55 pd = 1.563 g ac8,V = 1609.4 (8) A3, and ~ ( M Ka) o = 10.14 em-'. The structure was solved by using standard heavystom methods and refined by full-matrix leaat-squares techniques. With 3415 observed intensities (I 2 3 4 ) measured on a Synter P21 diffractometer with graphite-mond"sted Mo Ka radiation, anisotropic refinement of all non-hydrogen atoms gave R and R. valuee of 0.027 and 0.030. res~ec-
A,
..
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4. pnd = 1.46 g rm ¶, L, = 1.48 g cm I , V = 3084 (31 A', and LNO Koi = 10.66 cm I. In view of the similarities lietween the iron and nrhenium compounds B date get of 2497 chewed 1.Cl52measured to 45'1 reflections was collected and panially refined iaotrupirally to I< = 0.131
provide banr ~tructursldetails only. Penment distance (AI are Fe( I ) k 2 1 = 2.60. WI)-P = 2.22. ~ 4 2 1P = 2.2a. O,:I c i ? ) = 1.28. C~:l
