1242
Znorg. Chem. 1981, 20, 1242-1247 Contribution from the Department of Chemistry, Yale University, New Haven, Connecticut 0651 1
Reactions of Aryl Isocyanates with Hydridotriosmium Carbonyl Cluster Compounds RICHARD D. ADAMS,* NANCY M. GOLEMBESKI, and J O H N P. SELEGUE
Received November 6, 1980 The reactions of aryl isocyanates with the cluster complexes H20s3(C0)9L[I, L = CO; 11, L = P(CH,),C&] are described. The major products of the reaction of I with aryl isocyanates are complexes containing N-arylformamido ligands formed by the transfer of one hydride ligand to the carbon atom of the isocyanate molecule. An X-ray crystallographic analysis of the product (p-H)(p-p-CH,C6H4NCHO)os3(co)l~ (111) was performed: space group Pi,a = 7.925 (2) A, b = 11.705 (3) A, c = 13.928 (4) A, a = 66.71 (2)O, @ = 80.17 (2)O, y = 79.18 ( 2 ) O , Z = 2, paw = 2.83 g/cm3. For 3902 reflections, R = 0.052 and R , = 0.062. 111 contains an N-p-tolylformamido ligand which is coordinated by its nitrogen and oxygen atoms across one edge of a triangular cluster of three osmium atoms. Reaction of I11 with dimethylphenylphosphine readily gives the monosubstitution product ( p - H ) ( p - p C H , C 6 H 4 N C H O ) ~ s ~ ( ~ ~ ) g [ P ( ~(V). ~ , ) 2An ~ 6X-ray H ~ ] crystallographic analysis of V was performed: space group Pi,a = 10.690 (1) A, b = 13.034 (2) A, c = 13.200 (4) A, a = 109.78 ( 2 ) O , @ = 93.05 (2)O, y = 110.25 (2)O, Z = 2, pdd = 2.28 g/cm’. For 3985 reflections, R = 0.047 and R , = 0.061. V is similar to I11 except that it contains a dimethylphenylphosphine ligand coordinated in an equatorial position on the osmium atom coordinated to the oxygen atom of the bridging N-p-tolylformamido ligand. The major product of the reaction of I1 with p-tolyl isocyanate was an isomer of V which was characterized by spectroscopic and X-ray crystallographic methods as (p-H)(p-p-CH C6H4NHCO)Os3(C0)9[P(cH,)2c6Hs] (VI): space group P&/c, a = 12.210 (2) A, b = 14.337 (4) A, c = 17.739 (4) @ = 104.49 (2)’. For reflections, R = 0.034 and R, = 0.032. VI contains an N-hydrid~N-ptolylcarboxamido ligand which is coordinated by its carbon and oxygen atoms across an edge of a triangular cluster of osmium atoms. This product was evidently formed by transfer of a hydrogen atom from the cluster to the nitrogen atom of the isocyanate. A minor product (~-H)(~L-N-~-CH~C~H~NHCO)O~~(CO)~~ (VII), which is similar to VI, was also isolated from the reaction of I with p-tolyl isocyanate. It was shown that 111 and VI1 cannot be interconverted under the reaction conditions. They are, thus, presumed to be formed by independent competing reactions. The changes in hydrogen transfer obtained when a carbonyl ligand is replaced with a dimethylphenylphosphine ligand are discussed.
A,
Introduction The transfer of hydrogen atoms from metal atoms to substrates is an integral component of any catalytic cycle involving metal-hydride intermediates.’ Recently transition-metal cluster compounds have attracted considerable attention as a new source of homogeneous catalysts.* In an effort to delineate the nature of hydride transfers from cluster compounds to substrates, we have been investigating the reactivity of the hydridotriosmium carbonyl clusters H 2 0 ~ 3 ( C 0 ) 9 [I, L L = CO; 11, L = P(CH3)2C6H5]toward small unsaturated molecule^.^ These clusters are important because they are formally “electron deficient” and have been variously described ? as containing an osmium-osmium double bond4 or an OsH-Os-H four-center, four-electron bond.5 As a result they readily react with donor molecules to form “electron saturated” 1:l adducts.6J0 If the donor is an unsaturated molecule, transfer of hydrogen from the cluster to the substrate becomes a viable process. In this regard, I has been shown to be a catalyst for the hydrogenation of terminal alkenes.’ We have previously investigated the nature of hydrogen transfer from these clusters to heteronuclear unsaturated molecules although
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( 1 ) (a) Heck, R. F. “Organotransition Metal Chemistry”; Academic Press: New York, 1974; Chapter 4. (b) James, B. R. “Homogeneous
Hydrogenation”; Wiley-Interscience: New York, 1973; Chapter 11. (2) (a) Muetterties, E. L.; Band, E.; Kokorin, A.; Pretzer, W. R.; Thomas, M. G . Inorg. Chem. 1980, 19, 1552. (b) Sivak, A. J.; Muetterties, E. L. J . Am. Chem. SOC.1979, 101, 4878. (c) Thomas, M. G.; Pretzer, W. R.; Beier, B. F.; Hirsekorn, F. J.; Muetterties, E. L. Ibid. 1977, 99, 743. (d) Thomas, M. G.; Beier, B. F.; Muetterties, E. L. Ibid 1976,98, 1296. (3) (a) Adams, R. D.; Golembeski, N. M. J . Am. Chem. Soc. 1979,101, 2579. (b) Adams, R. D.; Golembeski, N . M. Ibid.1979,101, 1306. (c) Adams, R. D.; Golembeski, N. M.; Selegue, J. P. Ibid. 1979,101,5862. (d) Adams, R. D.; Selegue, J. P. Inorg. Chem. 1980, 19, 1791. (e) Adams, R. D.; Selegue, J. P. Ibid. 1980, 19, 1795. (4) (a) Mason, R.; Mingos, D. M. P. J . Orgunomer. Chem. 1973.50, 53. (b) Kaesz, H. D. Chem. Er. 1973, 344. (c) Churchill, M. R.; DeBoer, B. G.; Rotella, F. J. Inorg. Chem. 1976, 15, 1843. (5) Broach, R. W.; Williams, J. M. Inorg. Chem. 1979, 18, 314. (6) Shapley, J. R.; Keister, J. B.; Churchill, M. R.; DeBoer, B. G. J . Am. Chem. SOC.1975, 97, 4145. (7) Keister, J. B.; Shapley, J. R. J . Am. Chem. Soc. 1976, 98, 1056.
0020-1669/81/1320-1242$01.25/0
the processes were not ~ a t a l y t i c .Here, ~ we report the results of our studies of the reactions of the clusters I and I1 with aryl isocyanates. A preliminary report of this work has been published.8
Experimental Section General Informetion. Although the cluster complexes were generally air stable, reactions were routinely performed under a prepurified nitrogen atmosphere. Hexane was purified by distillation from sodium-benzophenone; other solvents were stored over 4-A molecular sieves and degassed with a dispersed stream of nitrogen. Tolyl isocyanate was vacuum distilled and stored under nitrogen. Dimethylphenylphosphine and triethylamine were distilled from sodium metal and stored under nitrogen. Osmium carbonyl was obtained commercially (Strem) or prepared from OsO,. Alumina for chromatography was Baker acid-washed aluminum oxide deactivated with 6%water, unless otherwise specified. H 2 0 s 3 ( C O ) 1and ~ H20s3(C0)9[P(CH3)2C6HS]’0 were prepared by published methods. Other reagents were used as received from commercial sources. Melting points were determined in evacuated capillary tubes with a Thomas-Hoover and are uncorrected. Infrared spectra were recorded on a Perkin-Elmer 237B spectrophotometer. Fourier transform ‘H NMR spectra were obtained at 270 MHz on a Bruker HX270. Mass spectra were obtained at 20 eV on a Hewlett-Packard 5985 GC/MS with use of a direct-inlet, electron-impact mode. Reaction of H 2 0 ~ 3 ( C 0 ) with 1 0 p-CH3C6H4NC0. A solution of H2Ck3(CO)10(1 13 mg, 0.133 mmol) andp-CH3C6H4NC0(0.75 mL, ca. 5.3 mmol) in hexane (50 mL) was heated to reflux for 3 h and 45 min. All volatiles were removed in vacuo, and the oily yellow residue was dissolved in CDCI, and examined by ‘H NMR. This showed four metal hydride containing products (8 -1 1.26 (>90%); 8 -1 1.46, -14.27, -20.18 (-0(10) OS(3)-OS(2jP 0~(3)-0~(2)-C(4) Os(3)-Os(2)-C(5) O(lO)-OS(2)-P 0(10)-0~(2)-C(4) 0(10)-0~(2)-C(5) P-Os( 2)-C( 4) P-0~(2)-C(5) C(4)-0s(2)-C(5) Os(l)-Os(3)-C(6) Os(l)-Os(3)-C(7) O~(l)-Os(3jC(8) Os(l>-Os(3)-C(9) 0~(2)-0~(3)-C(6) Os(2)-Os(3)-C(7) Os(2)-0s(3)-C(8) 0~(2)-0~(3)-C(9) C(6)-0s(3)-C(7) C(6)-Os(3)-C(8)
59.35 (1) 59.84 (1) 60.81 (1) 81.3 (2) 94.3 (4) 142.2 (4) 121.0 (3) 94.8 (2) 85.4 (3) 83.8 (4) 177.5 (3) 174.6 (4) 94.7 (4) 87.7 (3) 90.7 (5) 92.1 (4) 96.2 (5) 81.9 (2) 114.14 (7) 99.9 (3) 150.5 (3) 92.2 (2) 170.59 (6) 94.7 (3) 92.2 (3) 79.4 (2) 172.9 (3) 90.6 (3) 93.6 (3) 92.2 (3) 91.1 (4) 84.7 (3) 154.3 (3) 93.0 (3) 101.6 (3) 91.0 (3) 94.5 (3) 84.7 (3) 162.1 (3) 88.9 (4) 175.7 (4)
C(6)-0s(3)-C(9) C(7)-0~(3>c(8) C(7)-Os(3)4(9) C(8)-0s(3)-C(9) Os(l)-NC(10) Os(l)-N-C(ll) N-C(lO)-C(lO) C(lO)-N-C(ll) NC(ll)-C(12) N-C(11)4(16) C(16)-C(ll)-C(12) C(ll)-C(12)-C(13) C(12)4(13)C(14) C(13)-C(14)4(15) C(14)-C(15)-C(16) C(15)4(16)4(11) C(13)-C(14)-C(17) C(15)-C(14)-C(17) Os(2)-P-C(31) 0~(2)-P4:(32) 0~(2)-P-C(21) C(31)-P-C(32) C(31)-P-C(21) C(32)-P-C:(21) P-C(21)-C(22) P-C(21)-C(26) C(26)-C(21)-c(22) C(21)c(24)-C(25) C(24)-c(25)-C(26) C(25)-C(26)-C(21) 0~(l)-C(l)-O(l) Os(l)-C(2)-0(2) Os(l)-C(3)-0(3) 0~(2)4(4)-0(4) Os(2)-C(5)-0(5) Os(3)-C(6)-0(6) 0~(3)-C(7)-0(7) Os(3)-C(8>-0(8) Os(3)-C(9)-0(9)
90.6 (4) 91.7 (5) 103.3 (5) 93.4 (4) 125.8 (6) 122.1 (6) 124.5 (8) 112.1 (7) 121.2 (8) 117.5 (8) 121.0 (8) 119.1 (9) 121.1 (10) 118.5 (10) 122.2 (9) 118.0 (9) 117.5 (10) 123.8 (9) 111.7 (4) 117.1 (4) 114.6 (3) 105.4 (6) 103.0 (5) 103.7 (5) 118.5 (7) 122.5 (8) 118.9 (9) 121.0 (9) 118.8 (12) 122.7 (13) 121.7 (11) 116.8 (11) 171.0 (9) 177.2 (9) 176.7 (10) 174.6 (9) 179.2 (10) 177.5 (9) 177.4 (10) 174.8 (9) 176.5 (8)
slightly longer than the osmium-osmium bond distance (2.877 (1) A) found in Os3(CO)12.13The formamido ligand is bonded in a “diaxial” coordination arrangement (Le., in two coordination positions perpendicular to the Os3plane) and bridges the Os( 1)-oS(3) edge of the cluster. The oxygen atom O(1 1) (13) Churchill, M.R.; DeBoer, B. G. Inorg. Chem. 1977.16, 878.
Inorganic Chemistry, Vol. 20, No. 4, 1981 1245
Hydridotriosmium Carbonyl Cluster Compounds
n
Table VI. Interatomic Distances (A) with Esd‘s for (vH)(r-@H3C6 H4”CO)Os3 KO), [P(CH, 1,C,H I (W
Os(l)-Os(2) Os(1j O s ( 3 ) Os(2)-Os(3) OS(l)-P Os(l)-C(l) Os(l)-C(2) Os(l)-O(lO) 0$2)-C(3) Os(2)-C(4) Os(2)-C(5) 0$2)-C(10) Os(3)-C(6) Os(3)4(7) 0~(3)-C(8) 0~(3)-C(9) C(10)-0(10) C(lO)-N N C ( 11) C(ll)-C(12) C(12)-C(13) C(13)-C(14) C(14)-C(15)
2.945 (1) 2.859 (1) 2.893 (1) 2.359 (2) 1.827 (8) 1.867 (9) 2.141 (4) 1.890 (9) 1.925 (9) 1.866 (10) 2.121 (7) 1.899 (10) 1.859 (11) 1.948 (9) 1.898 (9) 1.254 (9) 1.345 (8) 1.442 (8) 1.370 (11) 1.403 (12) 1.371 (10) 1.360 (10)
C(15)-C(16) C(16)-C(ll) C(14)4(17) PC(27) PC(28) PC(21) C(21)-C(22) C(22)-C(23) C(23)-C(24) C(24)4(25) C(25)4(26) C(26)-C(21) C(1)-0(1) C(2)-0(2) C(3)-0(3) C(4)-0(4) C(5)-0(5) C(6)-0(6) C(7)-0(7) C(8)-0(8) C(9)-0(9)
1.393 (10) 1.342 (9) 1.515 (12) 1.828 (9) 1.842 (8) 1.816 (8) 1.376 (9) 1.446 (11) 1.375 (12) 1.331 (11) 1.407 (11) 1.402 (10) 1.197 (8) 1.192 (9) 1.153 (9) 1.160 (9) 1.193 (11) 1.187 (10) 1.199 (11) 1.164 (9) 1.162 (9)
04
F i 1.
A
O3
ORTEP diagram of (JL-H)(JL-pCH3C~CHO)Os3(CO)lo (111) showing 50% probability ellipsoids. The hydrogen atom H I is shown in an idealized position.
Table MI. Interatomic Angles (Deg) with Esd’s for OI-H)(~-~-CH,C,H,NHCO)OS~ (CO), [P(CH,),C6H I I (VI)
0 ~ ( 1 ) - 0 ~ ( 2 ) - 0 ~ ( 3 ) 58.63 (1) 0~(1)-0~(3)-0~(2) 61.59 (1) 0~(2)-0~(1)-0~(3) 59.78 (1) OS(2)-0s( 1)-P 109.53 (5) 0 ~ ( 2 ) - O ~ ( l ) - C ( l ) 112.5 (3) 0 ~ ( 2 ) - 0 ~ ( l ) - C ( 2 ) 144.8 (3) 0~(2)-0~(1)-0(10) 68.0 (1) os(3)-os( 1)-P 168.99 (5) Os(3)-0s(l)-C(l) 92.5 (3) 92.9 (3) Os(3)-Os(l)-C(2) 0 ~ ( 3 ) - 0 ~ ( 1 > 0 ( 1 0 ) 90.3 (1) P-Os( l)-c( 1) 94.4 (3) P-OS(l)-C(2) 95.8 (3) P-Os( 1)-0(10) 82.6 (1) 88.6 (4) C(l)-Os(l)-C(2) C(l)-Os(l)-O(lO) 176.9 (3) C(2)-0S(l)-0(10) 92.5 (3) OS(1)-Os(2)-C(3) 118.3 (3) 0 ~ ( 1 ) - 0 ~ ( 2 ) C ( 4 ) 107.3 (3) W ~ ) - O S ( ~ ) - C ( ~ ) 137.5 (3) OS(~)-OS(~)~X~O ) (2) 65.2 Os(3)-Os(2)4(3) 176.7 (3) Os(3)-0$2)-C(4) 91.6 (2) 0 ~ ( 3 ) - 0 ~ ( 2 ) C ( 5 ) 84.3 (3) 0 ~ ( 3 ) - 0 ~ ~ 2 ) 4 ( 1 0 )87.9 (2) C ( ~ > - O S ( ~ ) C ( ~ ) 90.7 (4) C ( ~ ) - O S ( ~ ) C ( ~ ) 98.0 (4) c(3)-OS(2)wO) 89.5 (3) C ( ~ ) - O S ( ~ ) - C ( ~ ) 92.7 (4) C(4)-OS(2)C(lO) 171.3 (3) C ( ~ ) - O S ( ~ ) - C ( ~ O ) 95.9 (3) 0~(1)-0~(3)-C(6) 86.7 (3) O S ( ~ ) - O S ( ~ ) - C ( ~ )161.2 (3) 0~(1)-0~(3)-C(8) 85.0 (3) O S ( ~ ) - O S ( ~ ) - C ~ ( ~98.2 ) (3) 0 ~ ( 2 ) - 0 ~ ( 3 ) C ( 6 ) 85.2 (3) 0~(2)-0~(3)-C(7) 99.6 (3) 0~(2)-0~(3)-C(8) 88.8 (3) O S ( ~ ) - O S ( ~ ) - C ( ~ 159.5 ) (3) C ( ~ > - O S ( ~ ) - C ( ~ ) 92.2 (4) C(6)-0~(3)-C(8) 171.4 (4)
C(6)-0~(3)4(9) C(7)-0~(3)4(8) C(7)-0~(3)-C(9) C(8)-0s(3)-C(9) 0~(2)-C(10)-0(10) 0~(2)4(10)-N 0~(1)-0(10)-C(lO) C(lO)-N
