Organometallics 1983, 2, 183-184
183
Laboratoire de Chimie de Coordination was supported by the CNRS (Greco-CO). Registry No. 1, 83704-63-6; 3, 83704-64-7; 4, 83704-65-8; 5, 83704-66-9; Co, 7440-48-4; Mo, 7439-98-7; [PdCldppmIz,8370467-0; NaCo(CO)4, 14878-28-5;NaMo(CO)&p, 12107-35-6;NaW(CO)&p, 12107-36-7;~FWIS-P~[MO(CO)~CP]~(P~CN)~, 83704-681; PtCl,(dppe), 14647-25-7;W, 7440-33-7; Pd, 7440-05-3; Pt, 744006-4. Supplementary Material Available: Tables of the positional and thermal parameters and their estimated standard deviations for compounds 1 and 5 (6 pages). Ordering information is given on any current masthead page.
Basic Cluster Reactions. 3.' Hetero Site Reactivities in Ru,Co,(CO),,
Figure 1. Molecular structure of H , R U ~ C O ~ ( C(1): O ) ~small ~ circles, CO ligands. H atoms were located but not refined. Bond lengths (pm): Rul-Ru2 = 290.4 ( l ) , Rul-Col = 266.6 (l), Rul-Co2 = 266.3 (l), Ru2-Col = 264.3 (l),Ru2-Co2 = 265.3 (l), C0l-C02 = 254.6 ( l ) , Rul-H1 = 190, Ru2-Hl = 177, Ru2-H2 = 196, Col-H2 = 173, C02-H2 = 180.
isolated in 76% yield by cooling the solution to 4 "C. 3-Hexyne reacted equivalently. Znstitut fur Anorganische Chemie der Universitat Freiburg H2RuzCoz(CO)i2 RU~CO~(CO)~~(P~&~) 0-7800 Freiburg, Germany 1 2 Received July 8, 1982 The compositions of both new clusters were determined by FD mass spectra. The reaction sites were deduced for Summary: Two metal-specific reactions have been ob1 from NMR data" and established for 1 and 2 by crystal served for the tetrahedral cluster Ru,CO,(CO),~ under very structure analyses.12 The hydrogen positions in 1 were mild conditions. Hydrogen reacts at the ruthenium atoms located from difference Fourier maps as well as by Orpen's to form H,Ru,Co,(CO),. Alkynes insert between the coH searching program.13 Figures 1 and 2 give the overall balt atoms to form Ru,Co,(CO),,(R,C,). molecular structures and important bond lengths. The cluster core geometries and ligand distributions are normal The advantages of mixed-metal clusters in studying in both cases. There is a striking similarity (including unit cluster reactivity and molecular dynamics as well as their cell dimensions) between 1 and Co4(CO)1214 or HFeCo3catalytic potential due to the their possible different site (CO)12,15whereas 2 is intermediate between CO~(CO)~,-,reactivities have been ~ t r e s s e d . ~However, ?~ few reactions (R2C2)16and Ru4(CO)12(R2C2). l7 of mixed-metal clusters have been found yet to underline The structures show that the preferred reaction sites thk2y4 In particular, we are not aware of such a cluster have been used. The acetylene in 2 has been inserted for which reactions with simple substrates a t different between the two cobalt atoms, thereby opening the cluster specific locations in the cluster core have been r e p ~ r t e d . ~ and forming a closo Ru2C02C2core. The hydrogen atoms We have now observed that the ternary metal carbonyl in 1 are associated with the ruthenium atoms. one of them R U ~ C O ~ ( Cpossesses O ) ~ ~ ~hetero site reactivity. The two reagents chosen were hydrogen and internal (10) RuZCo2(CO)ll(Ph2C2)(2): green-black crystals; mp 194 "C dec; acetylenes, both well established in cluster chemistry.'~~ IR (cyclohexane) 2090 (w), 2052 (vs), 2047 (s), 2019 (m), 2006 (w), 1881 (w). 1861 (w) cm-': 'H NMR (CDC1,) multiolet centered at 7.07 m m . From their different reactivities toward simple clusters of And. Calcd for [C;5H10C02011R~2]: 37.24; H, 1.25. Found: C, g6.94; cobalt and ruthenium one could expect that hydrogen H, 0.80. would prefer the ruthenium sites and acetylenes would (11) Upon cooling of CDzClzsolutions of 1 the broad 'H NMR resoprefer the cobalt sites in a mixed cobalt-ruthenium cluster. nance sharpens and moves to high field. At -60 O C when the low solubility of 1 limits further cooling there is a sharp signal at -20.36 ppm This was observed. Both reactions proceeded in n-hexane which we associate with a Ru-Ru edge bridging hydrogen because of the a t 45-50 "C. Stirring of R U ~ C O ~ ( Cfor O )3 ~h~under an strong broadening effect of the quadrupolar cobalt nuclei. The second atmosphere of H2 produced black 1: isolated in 78% yield signal to be expected to the low field side of this which would have to be with a Ru/Co or Co/Co bridging hydrogen is too broad to be by crystallization from toluene. Reaction of R U ~ C O ~ ( C O ) ~associated ~ observed. with diphenylacetylene for 4 h yielded dark green 2,1° (12) Crystals of 1 were obtained from toluene and those of 2 from Eckehart Roland and Heinrich Vahrenkamp'
e,
(1)Part 2: Vahrenkamp, H.; Wolters, D. Organometallics 1982,1,874. (2) Gladfelter, W. L.; Geoffroy, G. L. Adu. Organomet. Chem. 1980, 18, 207. (3) Vahrenkamp, H. Philos. Trans. R. SOC. London, in press. (4) Cf. Richter, F.; Vahrenkamp, H. Organometallics 1982, 1, 756. (5) Among the few reactions of mixed-metal clusters with different substrates are the nonspecific reactions of H2FeRu3(C0)13with Hz and alkynes: Knox, S. A. R.; Koepke, J. W.; Andrews, M. A.; Kaesz, H. D. J.Am. Chem. SOC. 1975,97,3942. Fox, J. R.; Gladfelter, W. L.; Geoffroy, G. L.; Tavanaiepour, I.; Abdel-Mequid, S.; Day, V. W. Inorg. Chem. 1981, 20, 3230. (6) Roland, E.; Vahrenkamp, H. Angew. Chem. 1981,93,714;Angew. Chem., Int. Ed. Engl. 1981,20,679. (7) Humphries, H. P.; Kaesz, H. D. Prog. Inorg. Chem. 1979,25,145. (8) Deemine, A. J., In "Transition Metal Clusters": Johnson, B. F. G., Ed.; Wiley: New York, 1980; p 391. (9) HzRuzCoz(CO)lz(1): black crystals; m p 175 OC dec; IR (CHClJ 2082 (s), 2058 (vs), 2050 (sh), 2032 (sh), 1880 (w), 1868 (sh) 2112 (vw), cm-'; 'H NMR (CD,Cl,) broad resonance at -18.8 ppm. Anal. Calcd for [C12H2C02012R~2]: C, 21.90; H , 0.31. Found: C, 22.22; H , 0.08.
hexane. The crystal quality was checked by Weissenberg photographs; all other measurements were done on a Nonius CAD 4 diffractometer. 1: monoclinic, space group R 1 / c , 2 = 4, a = 930.4 (1) pm, b = 1153.0 (2) pm, c = 1664.2 (4) pm, fi = 91.28 (2)'. 2: monoclinic, space group PZ1/c, 2 = 4, a = 922.6 (4) pm, b = 1168.8 (1)pm, c = 2398.1 (3) pm, p = 93.77 (2)". The structures were solved by direct methods. Full matrix refinement (anisotropic for all non-hydrogen atoms, phenyl groups in 2 as rigid bodies with H atoms isotropic, H atoms in 1 located but not refined) using unit weights resulted in R values of 0.040 for 1 and 0.036 for 2. All details of the crystallographic work are documented in the supplementary material: Table A contains all crystallographic data, Tables B and C list all atomic parameters, Tables D and E all bond lengths and angles for both compounds, Tables F and G give the FJF, listings, and Figures A and B show the detailed molecular structures and atom numbering schemes. (13) Orpen, A. G. J . Chem. Soc., Dalton Trans. 1980, 2509. (14) Wei, C. H. Inorg. Chem. 1969,8, 2384. (15) Cf. Huie, B. T.; Knobler, C. B.; Kaesz, H. D. J . Am. Chem. SOC. 1978, 100, 3059. (16) Dahl, L. F.; Smith, D. L. J. Am. Chem. SOC.1962, 84, 2450. (17) Johnson, B. F. G.; Lewis, J.; Reichert, B. E.; Schorpp, K. T.; Sheldrick, G. M. J. Chem. SOC.,Dalton Trans. 1977, 1417.
0276-7333/83/2302-0183$01.50/0 0 1983 American Chemical Society
