Preparation of Trinuclear Ruthenium Clusters with Capped Sulfide

Organometallics 1995, 14, 5367-5376

5367

Preparation of Trinuclear Ruthenium Clusters with Capped Sulfide Ligand, [(Cp*Ru)3(lc3-S)(lc3-C1)], [(Cp*Ru)s(lc3-S)(/r3-SiPr)l, and [(Cp*Ru)3(lc3-S)2(lc2=H)I (Cp* = q5-C5Me5), and Reactivities of [(Cp*Ru)3(lc3-S)(lc3-C1)] toward CO and Alkynes Kohjiro Hashizume, Yasushi Mizobe, and Masanobu Hidai* Department of Chemistry and Biotechnology, Graduate School of Engineering, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113, Japan Received May 5, 1995@ Treatment of [(Cp*Ru)4@3-C1)4](1;Cp* = r5-C5Me5)with either LizS alone or a mixture of LizS and NaS'Pr in THF at 50 "C afforded trinuclear clusters with a n equilateral triangular core [(CP*RU)~OC~-S)OC~-C~)] (2) and [(Cp*Ru)3OC3-S)OC3-SiPr)l (31,respectively, while a n analogous reaction of 1 with (Me3Si)zS resulted in the formation of a mixture of 2 and [(Cp*Ru)3013-S)zOCz-H)](4). Cluster 2 dissolved in THF reacted with CO at 50 "C to give trinuclear carbonyl clusters [(CP*RU)~OC~-S)OCZ-CO)ZOCZ-C~)I (5) and [(CP*RU)~OC~-S)OCZ-CO)~ICl(8). In 5, two Ru-Ru bonds are each bridged by a CO ligand, and one Ru-Ru edge without direct bonding interaction is bridged by the C1 atom, whereas 8 has a n equilateral RUBcore with three CO ligands bridging each Ru-Ru bond. It has also been demonstrated that reaction of 2 with excess HCECCOOMe in THF at 50 "C results in the almost quantitative formation of cyclic trimers of the alkyne C6H3(COOMe)3in a 1,3,5-and 1,2,4-isomers ratio of 4258. In contrast, from a reaction mixture of 2 with MeC=CCOOMe under the similar was conditions a dinuclear complex [C~*R~~Z-SCM~C(COOM~)CM~C(COOM~)}RUC~*I(~O) isolated. Detailed structures of 2-5,8, and 10 have been determined by X-ray crystallography.

Introduction Our current interest has been centered on the exploitation of novel chemical transformations catalyzed by dinuclear and polynuclear complexes. Significant emphasis has been placed upon the studies on the synthesis and reactivities of sulfur-bridged multimetallic compounds, since these are expected to provide a relatively robust metal framework facilitating the substrate transformation accessible only a t the multimetallic reaction site with retention of its high nuclearity.l Recently we have reported that the reactions of dimeric or tetrameric Ru complexes with Cp* ligand [Cp*RuCl(u2-Cl)~RuCp*ClI,[(Cp*Ru)4(,~3-C1)41 (l),and [Cp*Ru(uz-OMe)~RuCp*l (Cp* = r5-C5Me5)with various thiolate sources afford a series of diruthenium complexes with two or three bridging thiolate ligands. The bimetallic sites in these complexes have proved t o exhibit numerous intriguing reactivities toward the substrates including alkynes, CO, isocyanide, Hz, and alkyl halides.2 Interestingly, it has also been demonstrated that the reaction of 1 with LizS instead of thiolate compounds results in the formation of a triangular cluster with a capped sulfide ligand, [(Cp*Ru)3&3-S)&3-C1)](2). Furthermore, treatment of 1 with a thiolate compound NaS'Pr in the presence of LinS has also led t o the formation of a related triruthenium @Abstractpublished in Advance ACS Abstracts, October 1, 1995. (1)(a)Rakowski DuBois, M. Chem. Reu. 1989,89,1. (b) Adams, R.

D. Polyhedron 1986,4 , 2003. (2) (a) Hidai, M.; Mizobe, Y.; Matsuzaka, H. J . Organomet. Chem. 1994,473, 1 and references therein. (b) Homig, A.; Rietmann, Chr.; Englert, U.; Wagner, T.; Koelle, U. Chem. Ber. 1993,126, 2609.

0276-7333/95/2314-5367$09.00/0

cluster [(Cp*Ru)3(u3-S)(u3-SiPr)1 (3).3In this paper, we wish to report the details of 2 and 3 along with the another triruthenium cluster [(Cp*Ru)3(u3-S>z(un-H)1 (4) isolated from the reaction of 1 with (Me3Si)zS. Reactivities of 2 toward CO and alkynes are also described.

Results and Discussion Reactions of 1 with Li2S Alone or a Mixture of LizS and NaS'Pr. Previously we have reported that treatment of 1 with excess NaSR in THF at room temperature gives dinuclear Ru(I1) complexes with two thiolate bridges [Cp*Ru(uz-SR)zRuCp*I(R = iPr, tBu, 2,6-Me~CeH3).~ Now we have found that treatment of 1 with LizS instead of the thiolates as a sulfur source results in the formation of a trinuclear Ru(I1) cluster 2. Thus, when 1 was reacted with LizS in THF at 50 "C in a Ru:S atomic ratio of 2:1, 2 was isolated from the reaction mixture as dark brown crystals in 50% yield based on Ru atom (eq 1). Reactions with excess LizS also afforded 2 as the only isolable Ru-containing product.

THF/%'C

(3)Mizobe, Y.;Hashizume, K.; Murai, T.; Hidai, M. J. Chem. SOC., Chem. Commun. 1994,1051. (4) Takahashi, A.; Mizobe, Y.; Matsuzaka, H.; Dev, S.; Hidai, M. J. Organomet. Chem. 1993,456,243.

1995 American Chemical Society

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On the other hand, when the reaction of 1 with LizS was performed in the presence of NaS'Pr, a trinuclear sulfido-thiolato Ru(I1) cluster 3 was obtained as dark brown crystals (eq 2). Although the reaction of these three substrates in a stoichiometric Ru:S2-:SiPr- ratio of 3:l:l afforded a mixture of 2 and 3, change in the ratio to 3:1:2 gave 3 exclusively, which was isolated in 63% yield. Preparation of a SPh analogue of 3 from the reaction of 1 with a LizS-NaSPh mixture was unsuccessful under these conditions. It should be noted that treatment of 2 with excess NaS'Pr in THF at 50 "C resulted in the almost quantitative recovery of 2, which may suggest that the formation of 3 from 1 does not proceed via 2 as an intermediate stage.

C30 C

Figure 1. Molecular structure of 2 with atom numbering scheme.

intensity ratio, and the hydride resonance is observed a t -22.3 ppm as a singlet. This spectral feature is 3 consistent with the structure containing a p2-H ligand determined by the X-ray analysis (vide infra). The lH NMR spectrum of 2 shows a singlet at 1.83 The related reactions giving ruthenium sulfide clusppm assignable to the Cp* methyl protons, while that ters include formation of a triangular Ru(I1) cluster of 3 recorded at 40 "C exhibits a singlet a t 1.92 ppm [{(P-cymene)Ru)3cu3-S)2l2+(6) by treatment of a Ru(I1) due to the Cp* methyl protons as well as one septet and dimer [(p-cymene)RuC1212with either (MesSi)sS,methaone doublet a t 4.06 and 1.97 ppm which are ascribed to nolic NaSH, or aqueous Na2S7 and synthesis of a the methine and methyl protons of the SiPr group, cubane-type Ru(II1) cluster [(Cp*Ru)4@3-S)41from 1 and respectively. These data are indicative of the equivalent NaSH.8 nature of three Cp*Ru units in both 2 and 3 in solutions. Reaction of 1 with (MesSi)&. When 1 was treated It is not clear how the trinuclear cores in 2-4 are with (Me3Si)zS in place of Li2S under the similar produced from the tetraruthenium cluster 1. Formation of a closed t@angular Ru cluster from 1 has recently conditions, a mixture of 2 and another triruthenium been observed in the reaction with MezC=CHCHO, cluster 4 having two capped sulfide and one hydride yielding a p3-cyclopentenyl complex [(Cp*Ru)&s-CO)ligands was obtained. The lH NMR spectrum of the (&-MeCCHCH)l together with a mononuclear complex evaporated reaction mixture residue dissolved in C& indicates the formation of these two products in ca. 1:2 [ C ~ * R U ( C O ) ( ~ ~ - C H ~ C M ~InCthe H ~ above ) ~ . ~ reactions ratio (eq 31, which was almost reproducible in the to give 2-4, however, mononuclear Ru species are not repeated runs. The hydrogen source of 4 seems t o be detectable in the reaction mixtures. Assembly of a the adventitious moisture present in THF, since the triangular (Cp*Ru)3 cluster from dinuclear complexes reaction of 1 and (Me3Si)aSin the presence of H20 gave is also precedented; these examples are preparation of 4, while that using D20 in place of H2O resulted in the C(CP*RU)~~U~-OM~)~][PF~] from reaction of [Cp*Ru@zformation of a deutride analogue of 4.5 Clusters 2 and OMe)zRuCp*I with NH4PF6 in MeOHlO and synthesis 4 were inseparable by either fractional crystallization of [ ( C ~ * R U ) ~ ~ ~ ~ - O(R ) ~=~'Pr, -OR ) I by treatment tBu) or chromatography. However, by treatment with CO with NaO'Pr in of [C~*RU@~-H)~(LQ-OCOCF~)~RUC~*I in THF the mixture of 2 and 4 was converted into a HO'PrmHF or KOtBu in THF.ll mixture of a carbonyl cluster [(C!~*RU)~@~-S)@Z-CO)~-X-ray Structures of 2-4. To clarify the detailed h2-Cl)l (5) derived from 2 (vide infra) and unreacted 4 structures of the new sulfide clusters, X-ray analyses in solution,6 from which pure 4 was able to be isolated have been carried out using single crystals of 2-4. in 14% yield by fractional crystallization because of its ORTEP drawings of these clusters are shown in Figures much higher solubility into THF than 5. 1-3, while important bond distances and angles are listed in Table 1. As suggested by the IH NMR spectrum, 2 consists of an essentially equilateral triangular Ru3 core capped by both the p3-S and p&1 ligands. The Ru-Ru distances in the range of 2.874(2)-2.9014

In the lH NMR spectrum of 4, the Cp* methyl protons appear as two singlets at 1.92 and 2.07 ppm in a 2:l (5) The reaction of 1 with (Me3Si)zSin the presence of HzO did not give 2. The 'H NMR spectrum of the reaction mixture revealed the formation of other product(s) in addition to 4, one of which has been characterized to be [(Cp*RuCl)z(p-SH)~lby the preliminary X-ray results. Details will be reported subsequently.

(6)A small amount of the tricarbonyl cluster 8 (vide infra) was also formed, which was almost insoluble in THF. (7)Lockemeyer, J. R.; Rauchfuss, T. B.; Rheingold, A. L. J. Am. Chem. SOC.1989, 11I , 5733. (8)Houser, E.J.; Dev, S.; Ogilvy, A. E.; Rauchfuss, T. B.; Wilson, S.R. Organometallics 1993, 12,4678. (9) Trakampruk, W.; Arif, A. M.; Emst, R. D. Organometallics 1994, 13, 2423. (10) Keolle, U.; Kassakowski, J.: Boese, R. J. Orpanomet. Chem. 1989,378, 449. I

(11)Suzuki,

H.;Kakigano, T.; Igarashi, M.; Usui, A,; Noda, K.;

Oshima, M.; Tanaka, M.; Moro-oka, Y . Chem. Lett. 1993, 1707.

Preparation of Pinuclear Ruthenium Clusters

Organometallics, Vol. 14,No. 11, 1995 5369

Table 1. Selected Bond Distances (A)and Angles (den) in 2-4

Ru(l)-Ru(2) R~(2)-Ru(3) Ru(l)-Cl( 1) Ru(2)-C1(1) Ru(3)-Cl( 1)

Compound 2 Bond Distances 2.877(2) Ru(l)-Ru(3) 2.874(2) 2.359(5) Ru(l)-S(l) 2.358(5) Ru(2)-S(l) 2.370(4) Ru(3)-S(l)

2.901(2) 2.300(5) 2.287(5) 2.288(5)

Bond Angles R u ( ~ ) - R u ( ~ ) - R u ( ~ )60.59(5) Ru(l)-Ru(3)-Ru(2) R u ( ~ ) - R u ( ~ ) - R u ( ~ )59.66(5) Cl(l)-Ru(l)-S(l) C U ~ ) - R U ( ~ ) - S ( ~ ) 88.8(2) Cl(l)-Ru(3)-S(1) Ru(l)-Cl(l)-Ru(2) 75.2(2) Ru(l)-C1(1)-R~~(3) R~(2)-Cl(l)-Ru(3) 74.9(1) Ru(l)-S(l)-Ru(2) R~(l)-S(l)-Ru(3) 78.4(2) Ru(2)-S(l)-Ru(3) *22

C32


Ru( 1)-Ru( 2) Ru(2)-Ru(3) Ru(l)-S(l) Ru(2)-S( 1) Ru(3)-S(1) S(2)-C(l)

Compound 3 Bond Distances 2,9449(8) Ru(1)-Ru( 3) 2.944(1) 2.281(2) Ru(l)-S(2) 2.287(2) Ru(2)- S( 2) 2.280( 2) Ru(3)-S(2) 1.818(8)

Ru(l)-Ru(B)-Ru(3) Ru(B)-Ru(l)-Ru(S) S(~)-RU(~)-S(~) Ru(l)-S(l)-R~(2) Ru(2)-S(l)-Ru(3) Ru(l)-S(2)-R~(3) Ru(l)-S(2)-C(I) Ru(~)-S(~)-C(I)

Ru(l)-Ru(2) Ru(2)-Ru(3)

59.75(5) 88.5(2) 88.5(2) 75.7(1) 77.7(2) 77,8(2)

2.9599( 9) 2.249(2) 2.240(2) 2.247(2)

Bond Angles 60.34(2) R u ( ~ ) - R u ( ~ ) - R u ( ~ )59.84(2) 59.82(2) S(l)-Ru(l)-S(B) 82.37(7) 82.46(7) S(l)-Ru(3)-S(2) 82.43(7) 80.29(6) Ru(l)-S(l)-Ru(3) 80.92(6) 80.29(6) Ru(l)-S(2)-Ru(2) 82.00(6) 82.33(6) R u ( ~ ) - S ( ~ ) - R U ( ~ ) 82.02(6) 131.2(3) Ru(2)-S(2)-C(l) 130.6(3) 130.2(3)

Compound 4 Bond Distances 2.806(3) Ru(l)-Ru(3) 2.798(2)

2.851(3)


C19* C18*

C18 C19

Figure 4. Molecular structure of 6-THF with atom numbering scheme. (2)A are indicative of the presence of the Ru-Ru single bonds. The Cp* ligands coordinate to Ru atoms perpendicularly t o the RUBplane, the dihedral angles of which vary from 84"to 88". Two atoms capping the RUB basal plane almost symmetrically could not be assigned unambiguously due to the small difference in electron densities between the S and C1 atoms. However, the

distances between these two atoms and the Ru atoms differ significantly, and the atom having the shorter bonds with the Ru atoms has been assigned as S, while the other has been characterized to be C1. Indeed, the Ru-S distances at 2.287(5)-2.300(5) A in 2 are in good agreement with the Ru-S(su1fide) lengths in 3 (vide infra). Analogous assignment of the p3-S and p3-c1 ligands based on the differences between the M-S and M-C1 bond distances has been done, for example, for [Mo3NizS4C14(PEt3)51.l2 It is t o be noted that the Ru-S bonds in 2 are slightly shorter than those in the lower valent Ru3 cluster [(Ru(C0)3}3013-CO)013-S)1(2.334(2)2.361(2) but are slightly longer than those in the Ru(I1) triangular cluster 6 (2.263(2)-2.272(1) The Ru-C1 distances in 2 fall in the range of 2.358(5)-2.370(4) A, which are much shorter than those previously reported for the p3-Cl ligands in the complexes without (12)Saito, T.; Kajitani, Y.; Yamagata, T.; Imoto, H. Znorg. Chem. 1990,29,2951. (13)Adams, R. D.; Babin, J. E.; Tasi, M. Organometallics 1988,7, 219.

5370 Organometallics, Vol. 14, No. 11, 1995 C13

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Table 2. Selected Bond Distances (A) and Angles (dea) in 5 and 8

Ru(l)-Ru(2) Ru( l)-S( 1) Ru( l)-C( 1) C( 1)-O( 1)

Compound 5 Bond Distances 2.7973(7) Ru(l)-C1(1) 2.311(1) Ru(2)-S(l) 2.010(5) Ru(2)-C(l) 1.179(5)

2.480(1) 2.285(2) 2.089(5)

Bond Angles Ru( 1)-Ru(~)-Ru( 1)* 76.80(2) Ru(2)-Ru( l)-C1( 1) 88.3l ( 4 ) Ru(2)-Ru(l)-S(l) 52.08(4) Ru(l)-Ru(B)-S(l) 52.94(3) Ru(l)-Ru(B)-C(l) 45.8(1) Ru(B)-Ru(l)-C(l) 48.2(1) Cl(l)-R~(l)-S(l) 83.16(5) Cl(l)-Ru(l)-C(l) 85.6(1) S(l)-Ru(l)-C(l) 99.5(1) S(l)-Ru(2)-C(l) 98.0(1) Ru(l)-Cl(l)-Ru(l)* 88.97(6) Ru(l)-S(l)-Ru(l)* 97.48(7) Ru(l)-S(l)-R~(2) 74.97(5) Ru(l)-C(l)-Ru(2) 86.1(2) RU(l)-C(l)-O(l) 140.4(4) Ru(2)-C(l)-O(l) 133.4(4)

Figure 5. Structure of the cation in 8. The C1 anion and the solvating CHzClz molecule are omitted for clarity. Ru(l)-Ru(2)

Compound 8 Bond Distances 2.769(1) Ru(l)-Ru(3) 2.771(1) Ru(l)-S( 1) 2.276(3) Ru(3)-S(l) 2.056(10) Ru(l)-C(2) 2.03(1) Ru(2)-C(3) 2.02(1) Ru(3)-C(3) 1.18(1) C(2)-0(2) 1.21(1)

2.769(1)

Ru(2)-Ru(3) 2.287(3) Ru-Ru interactions such as 1 (2.513(3)-2.537(3) All4 Ru(2)-S(l) 2.285(3) and [Cp*3R~3@3-Cl)@2-C1)2(1;1~-p2-HCCSiMe3)1 (7;2.559Ru(l)-C(l) 2.066(9) (2) A (mean)).15 The Ru-S-Ru and Ru-C1-Ru angles Ru(2)-C(l) 2.01(1) Ru(3)-C(2) 2.047(10) in 2 are in the ranges of 77.7(2)-78.4(2)' and 74.9(1)C(1)-0(1) 1.18(1) 75.7(1)", respectively. C(3)-0(3) Cluster 3 also contains an equilateral Ru3 triangle Bond Angles with the Ru-Ru bond distances at 2.944(1)-2.960(1) A, R u ( ~ ) - R u ( ~ ) - R u ( ~ )59.99(3) R u ( ~ ) - R u ( ~ ) - R u ( ~ )59.96(3) which are slightly longer than those in 2. The Cp* and R u ( ~ ) - R u ( ~ ) - R u ( ~ )60.04(3) RUBplanes are almost perpendicular with the dihedral S(l)-RU(l)-C(l) 99.3(3) S(l)-Ru(l)-C(2) 99.3(3) angles of 81-85'. Both S atoms coordinate to the R u ~ S(l)-Ru(2)-C(l) 100.6(3) S(l)-Ru(2)-C(3) 100.2(3) plane symmetrically and the Ru-S(sulfide1 distances S(l)-Ru(3)-C(2) 100.8(3) S(l)-Ru(3)-C(3) 98.6(3) R~(l)-S(l)-Ru(2) 74.70(8) Ru(l)-S(l)-Ru(3) 74.56(9) (2.280(2)-2.287(2) 8,) are comparable to those in 2. Ru(2)-S(l)-Ru(3) 74.81(8) Ru(l)-C(l)-Ru(2) 85.4(4) Interestingly, the Ru-S(thio1ate) bonds at 2.240(2)Ru(l)-C(2)-Ru(3) 85.4(4) R u ( ~ ) - C ( ~ ) - R U ( ~ ) 86.3(4) 2.249(2)8, are slightly shorter than the Ru-S(sulfide1 Rdl)-C(l)-O(l) 135.4(9) Ru(2)-C(l)-O(l) 139.1(9) bonds. This contrasts to the feature observed in the R ~ ( l ) - C ( 2 ) - 0 ( 2 ) 135.2(9) R~(3)-C(2)-0(2) 139.3(8) related oxo-alkoxo complex [(Cp*Ru)3(~~-0)@3-0~Pr)l,R~(2)-C(3)-0(3) 138.8(8) R~(3)-C(3)-0(3) 134.8(8) which consists of the Ru-O(a1koxide) bonds (2.14(1)the rapid rotation of the 'Pr group around the S-C bond 2.16(1)A) longer than the Ru-O(oxide) bonds (2.03(1)in a solution state. 2.09(1) A).11 The thiolate ligand coordinated to a Ru3 In 4, there exists a triangular RUBcore capped by two face was observed previously in e.g. [(~3-1;1~-C7H7)- p3-S ligands from both sides. The Ru-S distances fall Ru3(C0)6@3-StBu)I which has the Ru-S bonds at in the range of 2.278(6)-2.302(6) A. For the RUBcore 2.272(1)-2.274(1) The p2-thiolate ligands bound t o in 4, all three Ru-Ru distances are diagnostic of the a Ru-Ru single bond in a Ru3 triangular array are more Ru-Ru single bond interaction, and the coordination precedented, e.g. [Ru~(~~-H)@~-SCHZCOOH)(CO)~OI,~~ geometry around the Ru atoms is analogous for the [RU~@~-H)@~-SP~)(CO)S(P~~PCH~PP~~)I,~~ and [(Cpthree Ru atoms. However, the Ru(l)-Ru(3) bond at Ru)3@2-SnPr)31(Cp = q5-C5H5),19which contain slightly 2.851(3)A is significantlylonger than the other two Ruor substantially longer Ru-S bonds of 2.387(6) and Ru bonds (2.806(3)and 2.798(2) which is indicative 2.388(3)A,2.395(1) and 2.387(1) A, and 2.286(1)-2.304of the presence of the hydride as a p2-bridge between (1) A, respectively, than 3. The Ru-S(su1fide)-Ru and the Ru(1) and Ru(3) atoms, although the position of the Ru-S(thio1ate)-Ru angles are 80.29(6)-80.92(6)" and hydride could not be found in the final Fourier map. The 82.00(6)-82.33(6)", respectively. The S-C bond in the hydride-bridged Ru-Ru single bonds longer than the SiPr ligand is almost perpendicular to the basal palne unsupported Ru-Ru single bonds in a triangular RUB (Ru-S-C angles: 130.2(3)-131.2(3)") and two methyl cores have been demonstrated previously for the clusters groups are oriented toward the directions so that the (2.879(1) and 2.882such as [@~-H)~(RU(CO)~}~@~-S)I C(2)-C(l)-S(2) and C(3)-C(l)-S(2) planes bisect the (1)A us 2.760(1)A),20[(Dz-H){Ru(CO)~)~@~-S)M~(CO)~Ru-Ru vectors. Appearance of the all Cp* methyl (MeCN)21(2.848(1)A us 2.784(1) and 2.770(1)A),21and protons as one singlet in lH NMR spectrum suggests [@2-H){Ru(CO)3}3(u4-S)Ru(CO)3(q2-CH2CMe2NHCNHtBu)l (2.8935(6)A us 2.750(1) and 2.757(1) Ahzz Three (14) Fagan, P. J.; Mahoney, W. S.;Calabrese, J. C.; Williams, I. D. Cp* planes are almost perpendicular to the Ru3 basal Organometallics 1990, 9, 1843. plane with the dihedral angles of 88.5-90.0". (15) Campion, B. K.; Heyn, R. H.;Tilley, T.D. Orgurwmetullics 1990, 9 -, iinfi Reactivities of Sulfide Capped Trinuclear Clus(16)Howard, J. A. K.; Kennedy, F. G.;Knox, S.A. R. J . Chem. SOC., ters. Reactivities on the trimetallic sites surrounded Chem. Commun. 1979, 839.

A.

A),

(17)Jeannin, S.; Jeannin, Y.; Lavigne, G. Inorg. Chem. 1978, 17, 2103.

(18) Fompeyrine, P.; Lavigne, G . ;Bonnet, J.-J.J . Chem. SOC.,Dalton Trans. 1987, 91. (19) Shaver, A,;Plouffe, P.-Y.;Liles, D. C.; Singleton, E. Znorg. Chem. 1992, 31, 997.

(20)Adams, R. D.; Katahira, D. A. Organometallics 1982, 1, 53. (21)Voss, E. J.; Stern, C. L.; Shriver, D. F.Inorg. Chem. 1994,33, 1087. (22) Bodensieck, U.; Stoeckli-Evans,H.;Suss-Fink, G. J. Chem. SOC., Chem. Commun. 1990, 267.

Preparation of Trinuclear Ruthenium Clusters

Organometallics, Vol. 14, No. 11, 1995 5371

Table 3. Selected Bond Distances (A)and Angles (deg) in 10 Ru(l)-Ru(2) Ru(1)-S Ru(l)-C(3) Ru(l)-C(8) Ru(2)-C(8) C(3)-C(7)

Figure 6. Molecular structure of 10 with atom numbering scheme. by cyclopentadienyl ligands in 2-4 is of particular interest. It should be noted that the unique C-C bond cleavage of cyclopentadiene facilitated on a RUBsite provided by [(C~*RU)~@~-H)~CU~-H)~I has been reported recently.23 Coordination of certain n-acceptor molecules to a trimetallic site capped by a p3-S ligand has been demonstrated most extensively for Co clusters [(CpCo)s@3-S)@s-L)],where L = C0,24CS,25and CNR.26 Reactions of CO, isocyanides, and alkynes with the Ru3 clusters obtained here have therefore been investigated. Among three clusters 2-4, cluster 2 may exhibit higher reactivity than 3 and 4 toward these molecules, since the former has the C1 ligand which is probably more labile than the S'Pr and S ligands. Indeed, 2 has proved to react with CO at 50 "C to give carbonyl clusters, while neither 3 nor 4 reacts with CO under the same conditions. Reactivities of 2 with n-acceptor molecules have therefore been studied in detail, which are described below. Reactions of 2 with CO and Isocyanides. Cluster 2 dissolved in THF reacted with CO gas a t 50 "C to give a dicarbonyl cluster 5 as the major product. A small amount of the cationic tricarbonyl cluster [(Cp*Ru)3@3S)@2-C0)31Cl(8) was also formed as byproduct, which was easily separated from the reaction mixture by filtration because of its low solubility into THF (eq 4). 2

CO c

THF I50 "C

5

E

As expected, treatment of the isolated 5 with CO a t 50 (23)Suzuki, H.; Takaya, Y.; Takemori, T. J. Am. Chem. SOC.1994, 116,10779. (24)(a) Otsuka, S.; Nakamura, A.; Yoshida, T. Ann. Chem. 1968, 719,54.(b)Frisch, P.D.; Dahl, L. F. J . Am. Chem. SOC.1972,94,5082. Leonhard, K. Angew. Chem. 1979,91,663.(b) (25)(a)Werner, H.; Werner, H.;Leonhard, K.; Kolb, 0.; Rottinger, E.; Vahrenkamp, H. Chem. Ber. 1980,113,1654. (26)(a) Fortune, J.;Manning, A. R.; Stephens, F. S. J . Chem. Soc., Chem. Commun. 1983,1071. (b) Manning, A. R.; O'Dwyer, L.; McArdle, P. A.; Cunningham, D. J. Organomet. Chem. 1996,474,173.

Bond Distances 2.786(3) 2.341(6) Ru(2)-S 2.14(2) Ru(l)-C(7) 2.11(2) Ru(2)-C(2) 2.05(2) C(2)-C(3) 1.39(2) C(7)-C(8)

Ru( 1)- S-Ru(2) Ru( ~ ) - R u (1)- S Ru(2)-Ru(l)-C(7) S-Ru( 1)-C(3) S-Ru(l)-C(8) Ru(l)-Ru(2)-C(8) S-RU(~)-C(~) Ru(2)-C(2)-C(3) C(2)-C(3)-C(7) C(3)-C(7)-C(6) Ru(~)-C(~)-C(~) C(7)-C(8)-C(9)

2.245(6) 2.14(2) 1.98(2) 1.52(2) 1.46(2)

Bond Angles 74.8(2) Ru(l)-Ru(2)-S 51.0(1) Ru(2)-Ru(l)-C(3) 73.0(5) Ru(2)-Ru(l)-C(8) 68.2(5) S-RU( 1)-C(7) 94.3(4) Ru(l)-Ru(2)-C(2) 48.8(7) S - R U ( ~ ) - C ( ~ ) 98.7(6) C ( ~ ) - R U ( ~ ) - C ( ~ ) 114(1) C(2)-C(3)-C(4) llO(1) C(4)-C(3)-C(7) 128(1) C(3)-C(7)-C(8) 114(1) Ru(2)-C(8)-C(9) 118(1)

54.2(1) 72.6(5) 47.2(4) 97.8(5) 64.7(6) 46.4(5) 79.7(7) 125(1) 121(2) 113(1) 121(1)

"C resulted in the formation of 8, although uptake of the third CO molecule proceeded only slowly under these conditions and most of 5 was recovered unreacted after 15 h. However, 8 once formed is considerably stable and 8 dissolved in polar solvents under N2 or in vacuo did not regenerate 5. For clusters 3 and 4, no reactions took place with CO under these conditions. In 5, coordination of two CO ligands to the Ru3 core resulted in the cleavage of one Ru-Ru single bond forming an open cluster core, along with the change in the coordination mode of the C1 ligand from a sixelectron-donating p3 type t o a four-electron donating p2 one, while 8 consists of a cation containing three p2-CO ligands coordinated to a closed Ru3 core together with a discrete C1 anion (vide infra). The IR spectra exhibit intense v(C0) bands a t 1777 cm-l for 5 and at 1778 and 1823 cm-l for 8, respectively. In the lH NMR spectra, the Cp* methyl protons of 5 dissolved in C6D6 appear as two singlets a t 1.65 and 1.87 ppm in a 2:l intensity ratio, while those of 8 in CDC13 were observed as one singlet a t 1.92 ppm. Reactions of 2 with an excess amount of isocyanides such as tBuNC and 2,4,6-Me3CsHzNC have also been attempted. However, the products could not be characterized satisfactorily. lH NMR spectra of the crude products suggest that degradation of the Ru3 core to give mononuclear complexes may be taking place in both reactions. On the other hand, treatment of 2 with various alkenes such as ethylene, isoprene, and CH2CHCOOR at 50-80 "C in THF or toluene resulted in the quantitative recovery of 2. X-ray Structures of 5 and 8. To clarify the detailed structures of these two clusters, X-ray analysis has been performed by using the single crystals of 5 T H F and 8.CH2C12. ORTEP drawings of 5 and 8 are shown in Figures 4 and 5, respectively, while important bonding parameters in these clusters are summarized in Table 2. Cluster 5-THFcrystallized in monoclinic space group P21Im with two molecules in the unit cell and the molecule consists of a crystallographically imposed mirror plane defined by the Ru(2), S(l),and Cl(1) atoms. The Ru3 core in 5 has only two Ru-Ru bonds and the nonbonding Ru-Ru vector is bisected by this mirror plane. A sulfide ligand coordinates to all three Ru atoms as a p3 bridge and each Ru-Ru bond at 2.7973-

5372 Organometallics, Vol. 14, No. 11, 1995

Hashizume et al.

Table 4. X-ray Crystallographic Data for 2,3,4, S*THF,8.CH2C12, and 10 2

5THF

4

3

8.CHvC19

10

(a1 Crvstal Data

formula fw cryst system space group cryst color cryst dimens, mm a,A b, A C,

A

a, deg P, deg Y , deg

v. A3

2'

Dcalcrg F(OOO),electrons p(Mo Ka), cm-I

diffractometer monochromator radiation (A, A) temperature 2OmaX, deg scan type scan rate, deg min-' reflctns measured no. of unique reflctns absorption correctns transmission factors data used (Z > 30(Z)) no. of variables R RVJ max residual, e A-3

C~OH~~SC~RU~ 776.4 triclinic monoclinic P21/n (No. 14) P1 (No. 2) dark brown dark brown 0.3 x 0.5 x 0.6 0.3 x 0.5 x 0.7 11.588(2) 11.149(3) 22.517(4) 17.795(4) 12.443(2) 9.041(1) 90.00 90.05(2) 101.90t2) 102.09(2) 90.00 89.33(2) 3176(1) 1754.0(6) 4 2 1.623 1.545 1560 828 15.75 14.14

+h, +k, il 7483 0.545-1.00 3750 316 0.077 0.110 1.7

+h, fk,f l 8055

orthorhombic Pbca (No. 61) dark brown 0.1 x 0.1 x 0.3 18.576(7) 22.277(4) 15.392(9) 90.00 90.00 90.00 6369(4) 8 1.614 3120 15.53 (b) Data Collection Rigaku AF'C7R graphite Mo Ka (0.7107) room temperature 55 W-26 16

monoclinic P21/m (No. 11) dark red 0.2 x 0.3 x 0.7 8.788(2) 18.518(2) 11.317(1) 90.00 90.42(1) 90.00 1841.6(5) 2 1.631 916 13.77

+h, +k, +I

+h, +k, %1 7996 4385 +scans 0.789-1.00 0.655-1.00 0.861-1.00 (c) Solution and Refinement 4964 2700 3365 343 316 208 0.044 0.079 0.038 0.045 0.050 0.032 1.5 1.8 0.66

(7)A is further bridged by a p2-CO ligand. On the other hand, the Ru(1) and Ru(l)* atoms separated by 3.48 A are connected by a p2-Cl ligand. The Ru(2)-S(l) bond length at 2.285(2)A, being slightly shorter than the Ru(l)-S(l) distance of 2.311(1) A, is comparable to the Ru-S(sulfide) bond lengths in 2-4. It is to be noted that the p3-S ligand in the previously reported RUB clusters with only two Ru-Ru bonds such as [{(pcymene)Ru13013-S)d7and [Ru3(CO)~o13-S)~2-H)2~2-C1).. (SnCl3)I (9Izohas the longer Ru-S bonds in the range of 2.328(2)-2.351(2) A and 2.361(2)-2.411(2) A, respectively. As for the p2-Cl ligand bridging the nonbonded Ru atoms, the Ru-C1 distance at 2.480(1) 8, is comparable to those in the analogous pz-Cl ligands in 7 (2.445(2)-2.496(2) A) and 9 (2.443(2)-2.469(2) A). However, it is considerably longer than the Ru-C1 lengths for the C1 ligands bridging the Ru-Ru single bond in [(Cp*Ru)301z-Cl)z01z-H)013-CH)l[BF41(2.416(1) and 2.363(1) AIz7 as well as that capping the Ru3 core with three Ru-Ru single bonds in 2, and is shorter than those for the pugC1 ligands bound to nonbonded Ru3 cores in 1 and 7 (vide supra). The Ru-Ru-C( 1)and Ru-Ru-C1 planes are not coplanar with the Ru3 basal plane and folded to the direction opposite to the p3-S ligand. The cationic part of cluster 8 contains a triangular core of three mutually bonded Ru atoms with the RuRu distances a t 2.769(1)-2.771(1) A, which is capped by a p3-S ligand. The Ru-S bond lengths varying from 2.276(3) to 2.287(3) A are not different from those in the other clusters reported here. Each Ru-Ru bond is (27) Kakigano, T.; Suzuki, H.; Igarashi, M.; Moro-oka, Y. Organometallics 1990,9, 2192.

orthorhombic P212121 (NO.19) dark purple 0.2 x 0.3 x 0.7 17.611(2) 19.977(2) 10.682(3) 90.00 90.00 90.00 3758.0(10) 4 1.671 1896 14.91

+h, +k, +1

C~OH~ZO~SRUZ 700.9 triclinic P1 (No. 2) dark green 0.2 x 0.2 x 0.3 11.094(4) 16.128(7) 8.774(5) 91.16(4) 106.87(4) 101.20(3) 1468(1) 2 1.585 716 11.32

4832

f h , fk,11 6747

0.912-1.00

0.699- 1.00

3206 397 0.043 0.028 1.0

2791 (Z 334 0.092 0.064 2.3

>

4dZ))

bridged by a p2-CO ligand almost symmetrically and the C(l)-, C(2)-, and C(S)-Ru-Ru planes are bent from the Ru3 basal plane by the angles of 117.8", 118.4",and 119.5", respectively, toward the other side of the capped S ligand. These three planes are almost coplanar with the corresponding Ru-Ru-S(l) planes; dihedral angles m o u n d the Ru(l)-Ru(2), Ru(l)-Ru(3), and Ru(2)-Ru(3) bonds are 178.3", 178.0", and 176.5", respectively. Three Cp* ligands bind to the Ru3 plane almost perpendicularly by the angles of 82.0-82.9". Reactions of 2 with HCECCOOMe and MeOCOCrCCOOMe To Give Cyclic Alkyne Trimers. It has been demonstrated that 2 readily reacts with excess HCWCOOMe in THF at 50 "C to give the alkyne trimers in high yield (eq 5). Thus, in the reaction using

3HC=COOMe

THFISO'C d a w 2

ORRo +

(5)

R

R

R = COOMe

180 equiv of the alkyne per mole of 2, all the alkyne charged has been consumed, and the 'H N M R study has disclosed that the reaction mixture after 15 h contains 1,3,5- and 1,2,4-CsH3(COOMe)3along with 2 as the sole organic and organometallic species detectable by lH NMR criteria. The alkyne trimers were isolated in 95% combined yield, and the 1,3,5- and 1,2,4-isomers ratio has been determined to be 42:58 by the lH NMR and GLC studies. Reaction of MeOCOCWCOOMe with 2 proceeded analogously t o give Cs(CO0Me)sexclusively,



Table 5. Coordinates of Non-Hydrogen Atoms in 2 atom

X

0.1538(1) 0.2853(1) 0.0886(1) 0.0856(4) 0.2602(4) 0.028(2) 0.090(2) 0.209(2) 0.228(2) 0.114(2) -0.102(2) 0.025(3) 0.305(3) 0.344(3) 0.094(3) 0.467(2) 0.432(2) 0.360(2) 0.349(2) 0.412(2) 0.553(3) 0.481(3) 0.304(3) 0.266(3) 0.421(4) -0.065(2) 0.040(2) 0.087(2) 0.006(2) -0.083(2) -0.139(3) 0.086(3) 0.189(3) 0.012(3) -0.183(3)

Y

z

0.09130(7) 0.09841(7) 0.17679(7) 0.0717(2) 0.1696(2) 0.068(1) 0.018(1) 0.0238(10) 0.0790(8) 0.1094(6) 0.081(1) -0.037(1) -0.020(1) 0.099(2) 0.174(1) 0.0844( 10) 0.1306(9) 0.095( 1) 0.038(1) 0.028(1) 0.098(2) 0.186(2) 0.125(2) -0.006(2) -0.03 1(1) 0.2329(9) 0.2690(8) 0.2572(10) 0.2184(9) 0.204(1) 0.231(2) 0.311(2) 0.291(1) 0.203(2) 0.168(1)

-0.2055(1) -0.3775(1) -0.3820(1) -0.3941(4) -0.2533(4) -0.107(2) -0.125(2) -0.080(2) -0.036(2) -0.048(2) -0.132(2) -0.178(2) -0.075(3) 0.029(3) -0.002(3) -0.353(2) -0.434(2) -0.520(2) -0.494(2) -0.387(2) -0.244(3) -0.446(4) -0.634(3) -0.568(3) -0.329(3) -0.375(2) -0.368(2) -0.470(2) -0.534(2) -0.477(2) -0.294(3) -0.272(3) -0.495(4) -0.649(2) -0.523(3)

but that of p-MeCsH4CsCH resulted in the complete recovery of the alkyne under the similar conditions. Our recent studies on the reactions of various terminal alkynes H C W R with the dinuclear Ru(I1) complex [Cp*Ru@2-SiPr)2RuCp*lhave disclosed the formation of either ruthenacyclic compounds (R = COOMe, p-MeC&, cyclohexenyl) or a n-alkyne complex (R = MesSi) in which two or three alkyne molecules are coupled and incorporated a t the diruthenium centers.28 However, cyclotrimerization of the alkynes does not proceed in none of these systems. Transition metal-catalyzed cyclotrimerization of alkynes t o give benzene derivatives has been studied extensively, and numerous catalyst systems promoting this reaction have been reported.29 However, reactions catalyzed by Ru species have been relatively poorly studied.30 Moreover, most of the systems reported to date involve mono- and dinuclear complexes and those using metal clusters as catalysts or catalyst precursors are still limited,31 e.g. [Fe3(C0)121 and [Coq(CO)1o(PhCCPh)] for P ~ C E C P [Ni4(CNtBu)71 ~,~~ for HCsCH (28) (a)Matsuzaka, H.; Mizobe, Y.; Nishio, M.; Hidai, M. J. Chem. Soc., Chem. Commun. 1991, 1101. (b) Nishio, M.; Matsuzaka, H.; Mizobe, Y.; Hidai, M. Ibid. 1993, 375. (c) Nishio, M.; Matsuzaka, H.; Mizobe, Y.; Tanase, T.; Hidai, M. Organometallics 1994, 13, 4214. (d) Koelle, U.; Rietmann, Chr.; Tjoe, J.; Wagner, T.; Englert, U. Ibid. 1995, 14, 703. (29) (a) Schore, N. E. Chem. Rev. 1988,88, 1081. (b) Winter, M. J. In The Chemistry ofMetal-Carbon Bond; Hartley, F. R., Patai, S., Eds.; John Wiley & Sons: Chichester, 1985; Vol. 3, p 259. (30) Formation of arene complexes from coupling of three alkyne molecules in the coordination sphere of Ru was previously observed. See, for example: (a) Lucherini, A.; Porri, L. J. Organomet. Chem. 1978, 155, C45. (b) Burt, R.; Cooke, M.; Green, M. J. Chem. SOC.(A) 1970, 2981. ( c ) Reference 15. (31)Suss-Fink, G.; Meister, G. Adu. Organomet. Chem. 1993, 35, 41.


X

0.26648(5) 0.32250(5) 0.06525(5) 0.2208(2) 0.2148(2) 0.2098(9) 0.337(1) '0.1 16(1) 0.4172(7) 0.3144(8) 0.2218(8) 0.2669(7) 0.3913(7) 0.5384(8) 0.309(1) 0.0992(8) 0.1994(10) 0.4779(10) 0.488(1) 0.504(1) 0.423(2) 0.354(1) 0.396(1) 0.572(2) 0.602(2) 0.402(3) 0.256(1) 0.354(2) -0.1228(6) -0.0979(6) -0.0707(6) -0.0789(7) -0.1110(7) -0.1666(8) -0.1083(8) -0.0415(9) -0.0635(9) -0.1437(10)

Y

z

-0.15937(3) -0.32166(3) -0.26954(3) -0.24969(10) -0.25037(10) -0.2514(5) -0.2346(7) -0.1916(6) -0.0835(4) -0.0510(4) -0.0380(4) -0.0596(4) -0.0887(4) -0.1023(5) -0.0280(6) -0.0017(5) -0.0494(5) -0.1113(5) -0.3742(7) -0.3574(6) -0.397(1) -0.4378(7) -0.4246(7) -0.346(1) -0.3084(8) -0.404(2) -0.4943(8) -0.458(1) -0.2305(5) -0.2418(5) -0.3191(5) -0.3555(5) -0.3023(6) -0.1600(6) -0.1826(5) -0.3566(6) -0.4392(5) -0.3205(8)

-0.18462(7) -0.17183(7) -0.23066(7) -0.0269(2) -0.3584(2) -0.5606(9) -0.586(1) -0.634(1) -0.181(1) -0.285(1) -0.20 1( 1) -0.0490(10) -0.036(1) -0.222(2) -0.444(1) -0.262(1) 0.078(1) 0.104(1) -0.209(2) -0.059(2) -0.002(2) -0.120(3) -0.244(2) -0.308(3) 0.024(3) 0.152(2) -0.109(4) -0.396(2) -0.311(1) -0.1503(10) -0.123(1) -0.264(1) -0.379(1) -0.393(1) -0.035(1) 0.034(1) -0.284(2) -0.542(1)

and dialkyla~etylenes,~~ and [Ru3(C0)12yL(L = PPh3, P"Bu3, P(OPh)S, and PPhzCl) for HCWCOOMe.34 If compared with the latter [Ru~(CO)~ZI based system, the present reaction using 2 may be featured by the much higher yield of the cyclic trimers (95% us 26-58%) and the lower reaction temperature for effective catalysis (50 "C us 130 "C). Difference in the 1,2,4- and 173,5-isomer ratio between these systems is also noteworthy (2: 1.4; [RU~(CO)~&L: 1.7-3.4). Although detailed studies on the mechanism of the cyclotrimerization of alkynes have appeared already, these are limited mostly to the reactions using monon u ~ l e a or r ~b i~n~~ ~c l~e a rcatalysts, ~ ~ > ~ ~ and few mechanistic studies are available associated with the trimerization facilitated at the trimetallic site.37,40In this (32)Hiibel, W.; Hoogzand, C. Chem. Ber. 1960, 93, 103. (33) Thomas, M. G.; Pretzer, W. R.; Beier, B. F.; Hirsekorn, F. J.; Muetterties, E. L. J. Am. Chem. SOC.1977, 99, 743. (34) Ren, C. Y.; Cheng, W. C.; Chan, W. C.;Yeung, C. H.; Lau, C. P. J. Mol. Catal. 1990, 59, L1. (35) See also, for example: (a) Bianchini, C.; Caulton, K. G.; Chardon, C.; Doublet, M.-L.; Eisenstein, 0.;Jackson, S. A.; Johnson, T. J.; Meli, A.; Poruzzini, M.; Streib, W. E.; Vacca, A.; Vizza, F. Organometallics 1994,13,2010. (b)Smith, D. P.; Strickler, J. R.; Gray, S. D.; Bruck, M. A.; Holmes, R. S.; Wigley, D. E. Ibid. 1992,11, 1275. (c)Wakatsuki, Y.; Nomura, 0.;Kitaura, K.; Morokuma, K.; Yamazaki, H. J.Am. Chem. Soc. 1983, 105, 1907. (d) Maitlis, P. M. Acc. Chem. Res. 1976, 9, 93. (36) (a)Dickson, R. S.; Fraser, P. J. Adu. Organomet. Chem. 1974, 12, 323. (b) Polyi, G.; Varadi, G.; Marko, L. In Stereochemistry of Organometallic and Inorganic Compounds; Bernal, I., Ed.; Elsevier: Amsterdam, 1986; p 358. (37) Coordination of alkynes to the triangular RUBcore has been and [Pt3well defined previously, e.g. [{RU(CO)~}~~C~-S)(CC~-HCCP~)I~~ R U ~ ( C O ) ~ ~ ~ C ~ - H ) ~ C ~ - HSee ) ~also: ~ ~ -Sappa, P ~ C CE.; P ~Tiripicchio, )I.~~ A.; Braunstein, P. Chem. Rev. 1983,83, 203.

5374 Organometallics, Vol. 14,No. 11, 1995

Hashizume et al.

Table 7. Coordinates of Non-Hydrogen Atoms in 4 atom Ru(l)

X

Y

z

0.2607(1) 0.18407(8) 0.33456(8) 0.2627(3) 0.2575(3) 0.214(2) 0.289(2) 0.328(2) 0.285(2) 0.207(2) 0.154(1) 0.314(1) 0.409(1) 0.302(2) 0.142(1) 0.068(1) 0.081(1) 0.121(1) 0.131(2) 0.089(2) 0.022(1) 0.061(1) 0.143(2) 0.161(1) 0.088(1) 0.416(2) 0.380(2) 0.403(2) 0.440(1) 0.450(1) 0.421(2) 0.344(2) 0.383(2) 0.468(2) 0.492(1)

0.06934(7) 0.15005(9) 0.15508(10) 0.0775(2) 0.1718(2) 0.030(1) 0.037(2) 0.006(1) -0.023(2) -0.012(1) 0.053(1) 0.0777(9) 0.003(2) -0.0698(10) -0.041(1) 0.153(2) 0.129(1) 0.171(2) 0.225(2) 0.209(2) 0.127(2) 0.069( 1) 0.164(2) 0.283(2) 0.263(2) 0.158(2) 0.216(2) 0.235(1) 0.186(2) 0.144(2) 0.118(2) 0.250(2) 0.297(1) 0.197(2) 0.087(2)

0.1367(1) 0.0316(2) 0.0320(2) -0.0117(3) 0.1465(3) 0.252(2) 0.271(2) 0.213(2) 0.161(2) 0.185(2) 0.309(2) 0.347(1) 0.203(2) 0.087(2) 0.146(2) 0.049(2) -0.028(3) -0.087(2) -0.033(3) 0.048(3) 0.115(2) -0.064(2) -0.177(2) -0.063(2) 0.110(2) -0.074(2) -0.065(3) 0.024(3) 0.060(2) 0.007(3) -0.154(2) -0.139(2) 0.042(3) 0.153(2) 0.019(3)

Table 8. Coordinates of Non-Hydrogen Atoms in 5*THF ~~

X

0.13232(5) 0.26607(6) -0.0629(2) 0.2992(2) 0.0133(4) 0.604(2) 0.0900(5) 0.2401(8) 0.226(1) 0.068(1) -0.0103(6) 0.1004(8) 0.389(1) 0.358(2) 0.003(2) -0.1774(8) 0.067(1) 0.3121(9) 0.3818(6) 0.4937(5) 0.196( 1) 0.3547(8) 0.6084(6) 0.7449(9) 0.638(1)

_ _ _ _ ~ ~ ____

~~

Y

0.15617(2) 0.2500 0.2500 0.2500 0.1526(2) 0.2500 0.1744(3) 0.0790(3) 0.0463(4) 0.0404(4) 0.0716(3) 0.0947(3) 0.0913(5) 0.0095(5) 0.0027(5) 0.0756(5) 0.1281(4) 0.2500 0.1879(3) 0.2118(3) 0.2500 0.1116(4) 0.1651(4) 0.2104(5) 0.1877(4)

z

0.21659(4) 0.38087(5) 0.1774(2) 0.1808(2) 0.4655(3) 0.879(1) 0.3883(4) 0.0995(8) 0.2062(8) 0.2321(6) 0.1365(7) 0.0558(5)

0.038(1) 0.271(1) 0.3346(8) 0.120(1) -0.0616(6) 0.5745(6) 0.5265(5) 0.4468(4) 0.6686(8) 0.5664(5) 0.3837(5) 0.7248(7) 0.8107(9)

respect, the present reaction using 2 is of particular interest. However, all attempts t o isolate or detect the

Table 9. Coordinates of Non-Hydrogen Atoms in 8.CH2C12 atom

X

Y

z

0.14773(4) 0.05150(4) 0.02440(4) 0.1955(2) 0.1207(3) 0.2192(3) 0.1032(1) 0.0985(4) 0.0638(4) -0.0660(3) 0.0973(5) 0.0715(5) -0.0179(6) 0.2437(4) 0.2224(5) 0.2222(5) 0.2424(5) 0.2558(5) 0.2599(5) 0.2115(6) 0.2091(5) 0.2517(6) 0.2843(5) 0.0052(6) 0.0738(5) 0.0806(5) 0.0203(7) -0.0279(6) -0.0276(6) 0.1232(6) 0.1450(6) 0.0063(6) -0.1030(5) -0.0582(6)

0.05648(8) -0.10793(8) 0.04186(9) 0.2902(4) 0.6527(6) 0.6424(6) -0.1125(3) 0.0951(7) 0.2912(6) 0.0691(7) 0.042(1) 0.1838(9) 0.0239(9) 0.0780(9) 0.196(1) 0.195(1) 0.076(1) 0.0022( 10) 0.041(1) 0.307(1) 0.309(1) 0.030(1) -0.131(1) -0.176(1) -0.218(1) -0.296(1) -0.308( 1) -0.236(1) -0.097(1) -0.366(1) -0.190(1)

C(25) C(26) C(27) C(28) C(29) C(30) C(31) C(32) (333) C(34)

0.05001(4) 0.10345(5) -0.02126(4) 0.7420(2) 0.7636(3) 0.8769(4) -0.0117(1) 0.2100(4) 0.0447(4) 0.1154(4) 0.1514(6) 0.0324(5) 0.0841(5) 0.1141(6) 0.0879(6) 0.0058(6) -0.0181(6) 0.0488(6) 0.1950(5) 0.1370(7) -0.0418(7) -0.1008(6) 0.0492(7) 0.2102(6) 0.2089(7) 0.1458(7) 0.1072(7) 0.1468(6) 0.2703(6) 0.2713(7) 0.1268(7) 0.0425(6) 0.1330(7) -0.0698(6) -0.1153(6) -0.1469(5) -0.1209(6) -0.0739(6) -0.0321(7) -0.1353(6) -0.2036(6) -0.1428(6) -0.0448(7) 0.824(1)

0.0004(5)

0.0165(5) -0.0309(6) -0.0778(5) -0.0958(6) 0.0328(6) 0.0716(6) -0.0348(6) -0.1394(5) 0.163(1)

-0.3938(10) -0.231(1) 0.159(1) __ - .

0.175(1) 0.058(1) -0.034(1) 0.031(1) 0.259(1) 0.298(1) 0.030(1) -0.171(1) -0.028(1) 0.56%1)

intermedate stages were unsuccessful.41 The lH NMR spectra of the mixtures at the various stages of the reaction demonstrated only the presence of 2 as the Cp*containing Ru species, and 2 was actually recovered almost quantitatively after catalysis. However, the rate of the trimerization did not increase linearly with increase in the concentration of 2.42Thus, the trimerization might be catalyzed by a small amount of monoor dinuclear Ru species generated in situ during the reaction.43 It should also be noted that reactions of HCECCOOMe and MeOCOCECCOOMe with the dicarbonyl cluster 5 under Nz also proceeded analogously to that with 2, giving cyclic trimers selectively, and after catalysis 6 was recovered quantitatively with both CO ligands intact. Reaction of 2 with MeCGCCOOMe. To isolate or detect the intermediate stages involved in the cyclotri-

(41)The NMR studies of the reaction mixtures under various conditions (changing the reaction time, temperature, and substrate/ (38) Adams, R. D.; Babin, J. E.; Tasi, M.; Wolfe, T. A. Organomecluster ratio) revealed only the presence of either the cyclic trimers tallics 1987, 6 , 2228. and 2 or these together with the unreacted alkyne. (39) Adams, R. D.; Li, 2.; Swepston, P.; Wu, W.; Yamamoto, J. J. (42)The rates of the formation of the trimers observed in the three Am. Chem. SOC.1992,114, 10657. independent runs with the cluster concentration of 5.0,10.8, and 13.4 (40)Transformation of HCrCPh into 1,3,5-Ph3C& using a cluster mM are 0.42, 0.60, and 0.51 mmol min-', respectively. The initial [CpzMozRu&3-S)(C0)~1 has been shown to proceed through an interconcentration of HC=CCOOMe in these runs is about 0.39 M. mediate [C~~MOZRU(U~-S)(CO)Z(U~-~~-CHCP~CHCP~CHCP~)]: Adams, (43) Even if a monometallic Ru complex [Cp*Ru(PMePhz)zCl]was R. D.; Babin, J. E.; Tasi, J. E.; Wang, J.-G. Organometallics 1988, 7, used, the trimerization of HCWCOOMe occurred under these condi755. tions, although the yield and selectivity of the cyclic trimers were poor.



merization, reactions of more diversified alkynes with 2 were attempted. This has led to the finding that treatment of 2 with excess MeCGCCOOMe in THF at 50 "C results in degradation of the Ru3 core, and diruthenium complex [Cp*Ru@z-SCMeC(CO0Me)CMeC(COOMe)}RuCp*1(10)has been isolated from the reaction mixture in moderate yield (eq 6). Other fragmentation product(s) presumably containing a Cp*RuCl moiety could not be isolated. The GC-MS study of the reaction mixture has shown that the alkyne trimers are produced also in this reaction but the yields are quite low. Reaction of this alkyne with 5 did not occur under the similar conditions. Cook

Cook 10

The structure of 10 has been determined unambiguously by X-ray crystallography; ORTEP drawing is shown in Figure 6 and selected bond distances and angles are listed in Table 3. Complex 10has two Cp*Ru units connected by a Ru-Ru single bond (2.786(3) A). Two Cp* ligands are mutually cis, the dihedral angle between two Cp* planes being 59.1". In 10, four C atoms of two alkynes linked in a head-to-tail manner comprise a five-membered ring together with one Ru atom, of which the three C atoms further coordinate to the other Ru atom in a n-allyl manner. The bonding parameters around the C(3), C(7), and C(8) atoms are consistent with this feature. Relating pz-ruthenacyclopentenyl cores have been demonstrated recently for the products from the reactions of [Cp*Ru~z-S'Pr)zRuCp*I with TolCECH, cyclohexenylacetylene,z*band HCECCOOMe.28CThe sulfur atom bridging the two Ru atoms is further bound to the a-C atom involved in the fivemembered ruthenacycle.

Experimental Section General. All manipulations were performed under a n atmosphere of nitrogen using standard Schlenk techniques. Solvents were dried by common procedures and degassed before use. Compound 1 was prepared according to the literature method,44 while NaS'Pr was obtained from the reaction of HSiPr with NaH in THF. Lithium sulfide was used as received, while alkynes commercially obtained were degassed and stored over molecular sieve 4 A. IR spectra were recorded on a Shimadzu FTIR-8100M spectrometer, and lH NMR spectra were obtained by a JEOL EX-270 spectrometer. GLC analysis was performed using a Shimadzu GC-14A gas chromatograph equipped with a HiCap-CBPlO-M25-025capillary column, while GC-MS study was carried out by the use of a Shimadzu GCMS-QP2000 spectrometer. Elemental analyses were done by a Perkin-Elmer 240011 CHN analyzer (for C, H, and N) or a t the Elemental Analysis Laboratory, Department of Chemistry, Faculty of Science, The University of Tokyo (for C1 and S). Preparation of 2. A suspension of 1(104 mg, 0.096 mmol) and LizS (10 mg, 0.21 mmol) in THF (5 mL) was stirred a t 50 "C for 15 h. The resultant brown solution was filtered, and (44) Fagan, P. J.; Ward, M. D.; Calabrese, J. C. J.Am. Chem. SOC. 1989,111,1698.


X

Y

2

0.1989(2) 0.4334(2) 0.3504(5) -0.042(2) 0.096(1) 0.243(1) 0.313(1) 0.346(2) 0.315(2) 0.173(2) 0.069(2) O.OOO(2) 0.033(2) 0.156(2) 0.266(2) 0.269(2) 0.321(2) 0.1982) 0.090(2) 0.026(2) 0.098(2) 0.206(2) 0.288(2) 0.031(2) -0.111(2) 0.059(2) 0.300(2) 0.593(2) 0.572(2) 0.594(2) 0.634(1) 0.631(2) 0.599(2) 0.562(2) 0.612(2) 0.683(2) 0.659(2)

0.2336(1) 0.2791(1) 0.3618(3) 0.336(1) 0.431(1) 0.0872(9) 0.0635(9) 0.438(1) 0.358(1) 0.316(1) 0.358(2) 0.478(2) 0.179(1) 0.234(1) 0.195(1) 0.113(1) -0.016(1) 0.217(1) 0.248(1) 0.179(2) 0.116(1) 0.142(1) 0.272(2) 0.313(2) 0.169(2) 0.030(2) 0.091(1) 0.205(1) 0.224(1) 0.300(2) 0.352(1) 0.287(2) 0.124(1) 0.163(1) 0.352(1) 0.446(1) 0.297(2)

-0.1480(2) -0.2129(2) -0.0792(6) -0.447(2) -0.280(2) -0.542(2) -0.292(2) -0.367(2) -0.280(2) -0.337(3) -0.366(3) -0.287(3) -0.532(3) -0.402(2) -0.333(3) -0.409(2) -0.344(3) 0.095(2) O.OlO(3) -0.086(3) -0.089(3) 0.040(2) 0.242(2) 0.046(3) -0.218(3) -0.183(3) 0.101(2) -0.130(3) -0.278(3) -0.304(3) -0.156(3) -0.038(2) -0.063(3) -0.428(3) -0.448(2) -0.093(3) 0.139(3)

the filtrate was concentrated in vacuo. Dark brown crystals precipitated after storage at -20 "C were filtered off and dried (50 mg, 50%yield based on Ru atom). lH NMR (C6D6): 6 1.83 (s, Cp*). Anal. Calcd for C ~ ~ H ~ E S C C, ~ R46.41; U ~ : H, 5.84; S, 4.13; C1, 4.57. Found: C, 45.96; H, 5.84; S, 4.51; C1, 5.14. Preparation of 3. A suspension containing 1 (174 mg, 0.160 mmol), LizS (10 mg, 0.21 mmol), and NaS'Pr (42 mg, 0.43 mmol) in THF (10 mL) was stirred a t 50 "C for 15 h. The resultant brown solution was filtered, and the concentrated filtrate was kept at -20 "C. Dark brown crystals deposited were collected by filtration and dried in vacuo (116 mg, 68% yield based on Ru atom). lH NMR (CsD6): 6 1.92 (s,45H, cp*), 1.97 (d, J = 6.8 Hz, 6H, SCHMe2), 4.06 (sep, J = 6.8 Hz, l H , SCHMez). Anal. Calcd for C ~ ~ H ~ Z S C, ~ R48.56; U ~ :H, 6.42; S, 7.86. Found: C, 47.85; H, 6.38; S, 8.35. Preparation of 4. Into a suspension of 1 (133 mg, 0.122 mmol) in THF (10 mL) was added (Me3Si)zS (218 pL, 1.23 mmol), and the mixture was stirred at room temperature for 15 h. Carbon monoxide gas was passed through the resultant yellow-brown solution for 2 min, and then the mixture was continuously stirred a t 50 "C under CO atmorphere for 15 h. Red precipitate of 8 was removed by filtration, and the storage of the filtrate a t -20 "C afforded additional amount of 5. After separating the precipitate by filtration, the filtrate was concentrated and cooled t o -20 "C, giving 4 as brown crystals (14 mg, 14%). 'H NMR (C6D6): 6 1.92 (S,30H, cp*), 2.07 (8, 15H, Cp*), -22.3 (s, l H , RuHRu). Anal. Calcd for C3oH46S2RUB: C, 46.55; H, 5.99; S, 8.28. Found: C, 46.28; H, 6.12; S, 7.81. Preparation of 5. After dissolving 2 (32 mg, 0.041 mmol) in THF (12.5 mL), CO gas was bubbled through the solution for 2 min, and the mixture was stirred continuously under CO for 15 h a t 50 "C. The initial brown solution changed in color to red-purple, and formation of a small amount of red solid

5376 Organometallics, Vol. 14,No.11, 1995 was observed, which was characterized to be 8 by its IR spectrum. After removing the solid by filtration, the filtrate was concentrated in vacuo and stored at -20 "C. Dark red crystals of 5.THF were filtered off and dried (27 mg, 74%). 'H NMR (CsDs): 6 1.65 (s, 30H, Cp*), 1.87 (s, 15H, Cp*), 1.45 and 3.60 (m, 4H each, THF). IR (KBr disk, cm-l): 1777s (v(CO)). Prolonged drying under high vacuum resulted in complete loss of the solvating THF, which was confirmed by the NMR spectrum of the residue. Anal. Calcd for C32H4502SClRu3: C, 46.17; H, 5.45; S, 3.85; C1, 4.26. Found: C, 46.40; H, 5.41; S, 3.62; C1, 4.45. Preparation of 8. Carbon monoxide gas was passed through the solution of 5.THF (56 mg, 0.062 mmol) in THF (10mL) for 2 min, and the mixture was stirred for 15 h at 50 O C under CO. A red solid precipitated was filtered off and crystallized from CHzClz-ether (5-10 mL), yielding dark purple crystals of 8.CHzC12 (5.0 mg, 8.6%). Most of the unreacted 5 was recovered from the filtrate of the reaction mixture. 'H NMR (CDC13): 6 1.92 (s, 45H, Cp*), 5.30 (s, 2H, CH2C12). IR (KBr disk, cm-l): 1823s and 1778s (v(C0)). Anal. Calcd for C34H4703SC13Ru3: C, 43.20; H, 5.01. Found: C, 42.57; H, 5.02. Reaction of HCECCOOMe with 2. To a solution of 2 (42 mg, 0.055 mmol) in THF (5 mL) was added HCSCCOOMe (823 mg, 9.78 mmol), and the mixture was stirred a t 50 "C for 15 h. The GLC analysis of the reaction mixture showed t h a t the alkyne has been consumed completely during this period. The resultant solution was dried up in vacuo, and the residue was subjected to Kugelrohr distillation, giving a mixture of 1,3,5and 1,2,4-CsH3(COOMe)a(95%). The ratio of these isomers determined by GLC as well as 'H NMR spectrum was 42:58. The products were characterized by GC-MS, IR, and lH NMR spectra. Reaction of 2 with MeOCOC=CCOOMe and t h a t of 5 with HC=CCOOMe or MeOCOC=CCOOMe were carried out similarly. Reaction of 2 with MeC=CCOOMe Forming 10. A solution containing 2 (64 mg, 0.082 mmol) and MeC=CCOOMe (61 mg, 0.62 mmol) in THF (5 mL) was stirred a t 50 "C for 15 h. The resultant yellow-green solution was dried up and the residue was extracted with hexane (15 mL). Green crystals (45) teXsan: Crystal Structure Analysis Package, Molecular Structure Corp. (1985 and 1992). (46)PATTY: Beurskens, P. T.; Admiraal, G.; Beurskens, G.; BosSmits, J. M. M.; Smykalla, man, W. P.; Garcia-Granda, s.;Gould, R. 0.; C . (1992). The DIRDIF program system: Technical Report of the Crystallography Laboratory, University of Nijmegen, The Netherlands.

Hashizume et al. precipitated from the concentrated extract were filtered off and dried (25 mg, 0.44 mol of lO/mol of 2). 'H NMR ( c a s ) : 6 1.66 and 1.80 (s, 15H each, Cp*), 3.60 and 3.71 (s, 3H each, COOMe), 1.43 and 2.48 (s, 3H each, CMe). IR (KBr disk, cm-l): 1689s (v(C0)). Anal. Calcd for C30H4204SRu2: C, 51.41; H, 6.04. Found: C, 51.43; H, 6.26. X-ray Diffraction Studies. Single crystals of the studied complexes prepared as described above were mounted in glass capillaries under Nz and transferred to a Rigaku AFC7R diffractometer. Diffraction studies were performed a t room temperature by using graphite-monochromatized Mo Ka radiation. Orientation matrices and unit cell parameters were determined by least squares treatment of 25 reflections with 25 < 28 < 40". The intensities of three check reflections were monitored every 150 reflections during data collection, which revealed no significant decay for all crystals. Intensity data were corrected for Lorentz and polarization effects and for absorption (ly scans). Details of crystal and data collection parameters are shown in Table 4. Structure solution and refinements were carried out by using the teXsan program package.45 The heavy atom positions were determined by Patterson methods program (DIRDIFPATTY),46and remaining non-hydrogen atoms were found by subsequent Fourier syntheses. All non-hydrogen atoms were refined anisotropically by full-matrix least-squares techniques, while hydrogen atoms were placed a t calculated positions and included in the final stages of refinements with fxed parameters. Structure solution and refinements of 3 and 10 by selecting space group P1 instead of P1 were unsuccessful. For 8, refinements of the structure with an opposite polarity did not result in the lower R values. Coordinates of non-hydrogen atoms in 2,3,4,5sTHF, 8.CHzC12, and 10 are listed in Tables 5-10, respectively.

Acknowledgment. We are grateful to the Ministry of Education, Science, and Culture of Japan for financial support and to Ms Tohko Murai for experimental assistence. Supporting Information Available: Tables containing hydrogen atom coordinates, anisotropic temperature factors of non-hydrogen atoms, and extensive bond distances and angles and figures showing the full views including hydrogen atoms for 2, 3, 4, 5*THF, 8-CHzC12, and 10 (65 pages). Ordering information is given on any current masthead page. OM950328E

Preparation of Trinuclear Ruthenium Clusters with Capped Sulfide

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