J. Am. Chem. SOC.1990, 112, 1825-1833
1825
Synthesis and Spectroscopic Characterization of Diruthenium a,?r-Vinyl Complexes Ru2{p-O=C(NMe2),p-a,?r-C(Ar) =C(Ar)H)(CO)5PPh3(Ar = Phenyl or p-Tolyl) and Ru2(p-O=C(NMe2),p-a,r-C(Ph)=CH2J( CO)5PPh3. Crystal and Molecular Structures of Ru2(p-0=C( NMe2),p-a,r-C(p-tolyl) =C(p-tolyl)HJ(CO)5PPh3 and Ru2(p-O=C(NMe2),p-a,r-C(Ph)= CH2J(CO)5PPh3 Ziling Xue, Werner J. Sieber, Carolyn B. Knobler, and Herbert D. Kaesz* Contribution from the Department of Chemistry & Biochemistry, University of California, Los Angeles, California 90024- 1569. Received June 20, 1989 Abstract: The 13C-enrichedcomplex
Ru~(~-O=C(NM~,),~-U,~-*C(P~)=*C(P~)H)(CO)~ (3) is obtained by reaction of Ru$p-H,p-O=C(NMe2))(CO)lo (la) with I3C-enricheddiphenylacetylene,Ph*C=*CPh. This has assisted in the assignment of NMR spectra in the parent complexes Ru2(p-O=C(NMq),pu,r-C(Ar)=C(Ar)H)(C0)6 (2a, Ar = phenyl; Zb, Ar = ptolyl). (4) and Ru2(p-O==C(NMe2),p-u,r-CThe substituted complexes RU~(~-O=C(NM~~),~-U,~-*C(P~)=*C(P~)H](CO)~PP~, (Ar)=C(Ar)H)(CO),PPh, (Sa, Ar = phenyl; Sb, Ar = p-tolyl) have been obtained by reaction of triphenylphosphine with 3, Za,or Zb, respectively. "C NMR spectrum of 4 shows the gem isomer to predominate in solution, although the vic isomer is the only one observed in the crystal. Reaction of phenylacetylene with complex la gives an unstable dinuclear product that (6a).I3C NMR spectra can be isolated only as a PPh,-substituted complex, RU~(~-O=C(NM~~),~-U,~-C(P~)=CH~}(CO)~PP~~ of the new complexes have been obtained, and an assignment of resonances has been proposed. In contrast to Sb, the vic isomer is the predominating species in solution while the gem isomer is found exclusively in the solid state. Complex 5b crystallizes in the monoclinic space group P2,/c, with cell dimensions a = 10.003 (3) A, b = 17.942 (7) A, c = 21.842 (7) A, and @ = 94.523 (9)'. A total of 5229 unique reflections with I > 3 4 I ) were used in the refinement of 469 variables; final discrepancy indices were R = 0.056 and R, = 0.066. Complex 6a crystallizes in the triclinic space group Pi, with cell dimensions a = 11.2603 (9) A, b = 11.4473 (9) A, c = 13.8467 (IO) A, (Y = 110.587 (2)O, p = 90.634 (2)O, and y = 103.388 (2)O. A total of 4884 unique reflections with I > 3u(I) were used in the refinement of 235 variables; final discrepancy indices were R = 0.052 and R, = 0.077. Both complexes contain a doubly bridged metal-metal bond, Ru-Ru (A): Sb, 2.746 ( I ) ; 6a, 2.720 ( I ) . I n Sb, the bridging groups are vicinally bonded, Le., { 1,2-p-(NMe2)C=O)(2,1-p-u,r-C(p-tol)=C(p-tol)H}, while in 6a they are geminally bonded, l,2-p-(NMq)C~H1,2-p-u,r-C(Ph)=CH2).In both complexes, the PPh, is attached to the ruthenium to which the oxygen of the p-carboxamido group is coordinated. In companion papers,lg2 we showed that dimethylacetylene reacts with RU$~-H,~-O=C(NM~~)}(CO)~~ (la) at room temperature to give as the principal product a trinuclear complex containing a s3-allyl group; some dinuclear complexes resulting from fragmentation of the starting cluster complex were obtained as minor byproducts. With diphenyl or di-p-tolyl acetylene, by contrast,&Sbprincipally dinuclear fragmentation products Ru2(pO=C(NM~,),~-U,T-C(A~)==C(A~)H~(CO)~ (Za, Ar = phenyl; Zb,Ar = p-tolyl) are obtained. "C N M R spectra indicated the presence of two isomers in solution in unequal amounts, with one of the vinyl group carbon resonances appearing among the resonances of the carbonyl groups. Other examples of di- or trinuclear metal complexes containing the p-u,r-vinyl group have been reported,' which will be discussed in relation to this work in the sections that follow.
Scheme I.
Synthesis of %-Enriched Compounds (*C = I)C-Enriched)
C-
NsCN
D
E
NWHz
FG
(C6HS)*CH(OH)*C(O)C6HS(D)
0%cm,
.*
C~HS*CO*COC~H~ (E)
C~HS*C(NNHZ)*C(NNH~)C~HS (F)
Ha0
(319
cat.
-
(C6Hs)*CSC(C6Hs)( G )
+ Ru,(p-H,p-O=C(NMe,)l(CO),~(la)
(4Y0
(5) (6)"
RU~(~-O=C(NM~~),~-~,~-*C(P~)=*C(H)P~)(CO (3) (7) 3 + PPh,
~-
~~~~
( I ) Boag, N. M.; Sieber, W. J.; Kampc, C. E.; Knobler, C. B.; Kaesz, H. D. J . Organomet. Chem. 1988, 355, 385. (2) (a) Companion paper, parallel submission to J . Organomet. Chem. 1990. (b) See also: Krone-Schmidt, W. Ph.D.Dissertation, Department of Chemistry & Biochemistry, University of California, Los Angeles, 1985. (c) Kaesz, H.D.; Xue, 2.;Chen. Y.-J.; Knobler, C. B.; Krone-Schmidt, W.; Sieber, W. J.; Boag, N. M. Pure Appl. Chem. 1988, 60, 1245. (3) (a) Shaplcy, J. R.; Richter, S. I.; Tachikawa, M.; Keister, J. B. J . Organomer. Chem. 1975, 94, C43. (b) Clauss, A. D.; Tachikawa, M.; Shapley, J. R.; Pierpont, C. G. Inorg. Chem. 1981, 20, 1528. (c) Brown, S. C.; Evans, J. J . Chem. Sm.. Dalton Trans. 1982, 1049. (d) Liu, J.-C.; Boyar, E.; Deeming, A. J.; Donovan-Mtunzi, S. J . Chem. Soc., Chem. Commun. 1984, 1182. (e) Lee, K.-W.; Brown, T. L. Organomerallics 1985, 4, 1030. (0 Seyferth, D.; Archer, C. M. Organometallics 1986, 5, 2572. (g) Davies, D. L.; Parrott, M. J.; Sherwood, P.; Stone, F. G. A. J . Chem. Soc., Dalton Trans. 1987, 1201. (h) Bassner, S. L.; Morrison, E. D.; Geoffroy, G.L. Organometallics 1987, 6, 2207. (i) Suzuki, H.; Omori, H.; Moro-Oka, Y. Organometallics1988, 7 , 2579. (j)Churchill, M. R.; Ziller, J. W.; Shapley, J. R.; Yeh, W.-Y. J . Organomet. Chem. 1988, 353, 103.
0002-7863/90/1512-1825%02.50/0
Ru~(~-O=C(NM~~),~-~,~-*C(P~)=*C(H)P~)(CO)~P (4) (8) Here we describe the synthesis and N M R spectra of triphenylphosphine-substituted complexes Ruz(p-O=C(NMe2),pU , ~ - C ( A ~ ) = C ( A ~ ) H ~ ( C O )(Sa, ~ P PAr ~ , = phenyl; 5b, Ar = p-tolyl) and I3C-enriched complexes Ru2(p-O=C(NMe2),p-u,r*C(Ph)=*C(Ph)H](CO), (3) and Ru2(p-O=C(NMe2),p-a,a*C(Ph)=*C(Ph)H](CO),PPh, (4). Presented here also is the study of the reaction product of la with phenylacetylene, isolated as the triphenylphosphine-substituted complex Ru,(p-O=C(NMe2),p-u,r-C(Ph)=CH2)(CO)SPPh3 (623) through its I3C N M R spectra, crystal structure, and deuterium-labeling experiment. A preliminary account of this work has appeared.2c Experimental Section and Results Solvents and reagents were purchased and, except for tetrahydrofuran described below, used as received. Tetrahydrofuran was dried by reflux
0 1990 American Chemical Society
Xue et al.
1826 J . Am. Chem. Soc., Vol. 112, No. 5, 1990 Table I. Carbonyl Absorptions formula
compd
absorption/cm-’
2079 (s), 2050 (vs), 2009 (s), 2003 (s), 1986 (m), 1981 (w), 1975 RU~{~-~=C(NM~~),~-U,T-*C(P~)=*C(P~)H)(CO)~~~~~~ 3 (w), 1506 (vw) 2058 (w), 2052 (vs), 2004 (s), 1991 (m), 1973 (w), 1944 (w), 1939 (W)d 2051 (vs), 2040 (w), 2030 (w), 2002 (s), 1989 (m), 1969 (m)$ 1939 Ru~{~-O=C(NMe2),p-u,~-C(Ar)=C(Ar)HJ(CO)5PPh,c Sa, Ar = Ph (m), 1505 (w) Sb, Ar = p-to1 2050 (vs), 2040 (w), 2030 (w), 2000 (s), 1988 (s), 1968 (m), 1938 (m), 1510 (w), 1504 (w) Ru21p-O=C(NMe2),r-o,*-C( Ph)=CHzJ(CO)5PPh,bf 6a 2061 (vs), 2055 (s), 2005 (s), 1996 (s), 1990 (s), 1972 (m), 1964 (s), 1947 (m), 1936 (w), 1512 (vw), 1504 (vw) “*C = ”CC-enriched.b l n hexane solution. CThemaxima for this complex follow closely those of the unenriched material,’ which are observed at (cm-I, hexane) 2080 (m), 2049 (s), 2008 (m), 2002 (m), 1986 (m), 1981 (w), 1975 (w), and 1507 (w). dSample of insufficient concentration to observe u(O=CNMe2). C l n CCI4 solution. /Mixture of oic and gem isomers (see Table 11).
Ru$~-O=C(NMez),p-o,~-*C(Ph)=*C(Ph)H)(CO)~PPh3a~ 4
Table 11. IH NMR Soectral Data“ compd resonance: b/ppm (J/Hz) 2.86 and 3.22 (6 H, N(CH,),), 4.63 (dd, 1 H, Hvinyl, J*C+ = 157.6, J * e . C - H = 2.7), 6.81-7.21 (m, IO H, Ph) 36 46 2.78 and 3.30 (6 H, N(CH,),), 4.21 (1 H, Hvinylr J v - H = 154.4% 6.69-7.74 (m, 25 H, Ph) Sab 2.79 and 3.31 (6 H, N(CH3)2), 4.23 (d, 1 H, Hvinyl, J p H = 2.4) 6.68-7.54 (25 H, Ph) Sbbsd 2.20 and 2.32 (6 H, p-CH3-C6H,), 2.80 and 3.32 (6 H, N(CH3)2), 4.26 (d, 1 H, finny’, JpH= 3.8), 6.63-7.95 (m, 23 H, Ph) oic-6a 2.51 and 3.01 (6 H, N(CH,),), 2.83 and 4.39 (d, H,’ Jp-H = 7.6), 7.01-7.64 (m, 20 H, Ph) 2.64 and 3.28 (6 H, N(CH,),), 2.83 and 3.91 (Hvinyl),7.01-7.64 (m, 20 H, Ph) gem& “CDzC12 solution, 23 OC, Bruker WP-200, 200.133 MHz, singlets unless otherwise designated; d = doublet; m = multiplet. *C = ”C-enriched. ‘uic and gem isomers are observed as one averaged set of coalescing signals. CDoublet seen as two peaks of A q l 2 = 10 Hz, consisting of the unresolved couplings: P-Ru-C(Ph)=C(Ph)H and *C(Ph) = *C(Ph)H. Jeol90. ~~
Scheme 11. Reaction of Ru,(p-D, r-O=C(NMe2))(CO),, (1 b) with Phenylacetylene, PhCECH ,me2
,mq
//o=c \ ,Ru(CO)~ /
(OC)3Ru,
,Ru(CO)j
(a) excess PhC.CH/hexane,
18 h/23 ‘C
(b) filter solution, add PPh3, 18 M23
D
‘L
o\c\ Ph3P-Ruc’ C‘ 0’
fRu(C0)3
Ph’ ‘C-Ll
I
I
H
H
vic
lb
over potassium benzophenone ketyl and freshly distilled under nitrogen. Although the organometallic clusters were generally air-stable, reactions, filtrations, and recrystallizations were routinely carried out under a purified nitrogen atmosphere with Schlenkware techniques! Chromatographic separations and handling of the complexes can be done in air if exposure is limited to a few hours. All chromatographic separations were carried out on a 20 X 2 cm column of 60-200-mesh silica gel (EM Reagents). Complexes l a and l b were made with modified procedures described be lo^.^.^ 2a and 2b were synthesized according to the cited literature procedures,2 while synthesis of the I3C-enriched complex 3 in reduced scale is reported in the supplementary material. The transformations undertaken in the 13C-labelingstudy are summarized in Scheme I.’-” Preparation of B was carried out on the same scale as in the cited literature.’ Preparations of C,8 D? E,Io F,” And GIi were originally reported for unenriched materials on a relatively large scale. These reactions were scaled down for the isotopically enriched material in the present study. Detailed syntheses of B-C are given in the supplementary material. ‘H and I3C NMR spectra were obtained on Bruker AF 200, Bruker
(4) Shriver, D. F.;Drezdzon, M.A. The Manipulation of Air-senritiue Compounds, 2nd ed.; John Wiley & Sons: New York, 1986. (5) Szostak, R.; Strouse, C. E.; Kaesz, H. D. J. Organomet. Chem. 1980, 191, 243. (6) Mayr, A.; Lin, Y.C.; Boag, N. M.;Kaesz, H. D. Inorg. Chem. 1982, 21, 1704. (7) Braden, G. A.; Hollstein, U.J. Labelled Compd. Radiopharm. 1976, 12, 507. (8) Four, P.; Guibe, F. J . Org. Chem. 1981, 46, 4439. (9) Adam, R.; Marvel, C . S. OrganicSynfheses;Wiley: New York, 1941; COlkXt. - ...... VOl. - I. -.D 94. (IO) Clarke, H. T.;Dreger, E. E.OrganicSyntheses; Wiley: New York, 1941; Collect. Vol. I, p 87. ( I 1) Cope,A. C.; Smith, D. S.; Cotter, R. J. Organic Syntheses; Wiley: New York, 1963; Collect. Vol. IV, p 377.
gem
6b AM500, and Jeol FX-90 spectrometers. IR spectra were measured either in hexane or in CCll solution and recorded by a Nicolet MX-1FT IR spectrometer. Elemental analyses were obtained from Galbraith Laboratories, Knoxville, TN, and Schwarzkopf Microanalytical Laboratory, Woodside, NY. Spectroscopicdata for the new compounds are presented in Tables 1-111. Individual spectra are presented in Figures 1 - 6 . R ~ ~ { p - l p - ~ ( N M e , ) l ( C (L 0 ) =~ H , ,la; L = D,lb).5*6A typical procedure is given here for la. The synthesis of la was first reported in ref 5. A modified method reported below was used in this research. To R U , ( C O ) ~(5.00 ~ g, 7.82 mmol) in a Schlenk flask under N2 is added 2 L of THF. A quantity of C(NMe2)4(1.47 g, 7.82 mmol) is then added against a flow of N2. The solution is stirred at 23 OC for 2 h. The solvent is then removed in vacuo. The solid is dissolved in 100 mL of CH2C12 under N2, and 1.3 g of HBF4.Et20 (1.09 mL, 8.03 mmol) is added drop by drop to the solution against a N2flow. The volume of the solution is then reduced and put onto a silica gel column. Eluting first with petroleum ether gives two fractions, a yellow band of R U ~ ( C O )(450 ~) mg, 0.704 mmol, 9%) and an orange band of H4Ru4(CO)lo(54 mg, 0.078 mmol, 1%). Elution with petroleum ether/CH2Cl2 (8/2) next gives an orange band consisting of l a (4.32 g. 6.58 mmol, 84%). Reaction of R~,(p-o=C(NMe,),a-o,r-C(Ar)=C(Ar)H)(co)~(Ar = Phenyl, 2a. Ar = p-Tolyl, 2b) and 3 with Tripbenylphosphine. A typical procedure is given here for 2a. Finely powdered triphenylphosphine (1 15 mg, 0.438 mmol) is placed in a Schlenk flask equipped with a magnetic stirring bar. To this is added hexane (50 mL), and the mixture is stirred until the triphenylphosphine is completely dissolved. A quantity of 2a (258 mg, 0.393 mmol) is added and the stirring continued. A yellow precipitate begins to form in about 50 s, and stirring is continued for 1 h. The supernatant solution is removed and the solid washed with hexane (IO mL) and dried under vacuum to give Ru2(p-O=C(NMe2),r-u,~-C(Ph)=C(Ph)HI(CO)SPPh3 (Sa; 168 mg, 0.196 mmol, 50% based on 2a). Anal. Calcd. for Sa: C, 56.14; H, 3.77. Found: C, 56.19; H, 3.77. Ru2(p-O=C(NMe2),p-u,n-*C(Ph)=*C(Ph)H)(CO)sPPh3 (4) is similarly prepared from Ru2(p-O=C(NMe2),p-o,r-*C(Ph)=*C(Ph)H)(CO)$’Ph, (3).
J. Am. Chem. SOC.,Vol. 1 1 2, No. 5, 1990
Characterization of Diruthenium ( ~Vinyl , r Complexes
1827
CD2C12
Pnenyl region
c9 I
I'
J (13C- I3C) = 39.0 HZ J (I3C- I3C) = 39.0 HZ
CIO
6 = 102.9 ppm J (13C- I3C) = 39.0HZ
CIO
S = 77.9 ppm J (I3C- I3C) = 39.0 HZ
Figure 2. Vinyl carbon region, 13C(1H)NMR at 125.8 MHz of RU~(~-O=C(NM~~),~~-~,X-*C(P~)=*C(P~)H)(CO)~ (3), -50 "C, CDzC12solution: upper scan, C9 resonance; lower scan, C10 resonance. Table 111. 13C NMR Spectral Data'
comd ~~
ois-3' gem-3* uic-4' gem-4'
35.4 and 40.8 (N(CH3)2), 35.4 and 40.8 (N(CH3)2), 34.6 and 40.2 (N(CH3)2), 194.6-207.7 (CO) 34.6 and 40.2 (N(CH3)2),
resonance: b l m m (JIHz) 102.9 (de, =*C(Ph)H), 125.7-152.0 (m, Ph), 187.4 (de, R u - * e ) , 191.3-204.9 (CO) 77.9 [de, =*C(Ph)H), 125.7-152.0 (m, Ph), 193.5 (de, Ru-*C=), 191.3-204.9 (CO) 97.8 (d, =*C(Ph)H, J.c-.c = 41.1), 124.3-150.6 (m, Ph), 186.0 (dd, Ru-*C=, J.c-.c = 41.1, JPaC= 10.8), 76.3 (d, =*C(Ph)H, J.c-.c = 37.8), 124.3-150.6 (m, Ph), 197.6 (d, Ru-*C=, J.c-.c = 37.8), 194.6-207.7
(CO)
Sad 34.6 and 40.2 (O=CN(CH3)2), 76.3 [=C(Ph)H), 124.3-150.6 (m, Ph), 195.3-205.7 (Ru-C= and CO) gem-6ac 33.5 and 39.1 (O=CN(CH3)2), 59.2 (ddd, =a2, JC-" = 160.7 and 151.2, J+Ru
