J. Am. Chem. SOC.1985, 107, 1671-1679 apdized by a sine-bell function, zero-filled, and Fourier-transformed, and the absolute value was taken and symmetrized. The resolution was 1.75 Hz in each dimension. The data were plotted with a Zeta plotter. The total time for data processing and plotting was about 1 h. Two-Dimensional IH-lH J-Correlated Spectrum of 21. The data were acquired by using the UCB-200 N M R spectrometer (Cryomagnet Systems Inc. superconducting magnet operating on 201.9-MHz proton frequency, Nicolet 1180 computer, Nicolet 293A' pulse programmer) and processed with a Nicolet 1180E computer. Nicolet's correlated spectrum (COSY) experiment was used to provide the pulse program. The 90" 'H pulse was 7.7 ps. The fixed delay was 7.0 ps to emphasize couplings less than 35 Hz. The incremental delay was equal to the dwell time of 500 ps. The sweep width was 1000 Hz. The spectrometer frequency was set at the left edge of the spectrum, 5.3 ppm. Single-phase detection was used. The pulse delay was 2 s. When a 0.1 M solution of 21 in C6D6 was scanned, 16 1K transients were collected for each of the 256 incremental spectra. The total time for data acquisition was less than 3 h. The data were apodized by a sine-bell function and Fourier-transformed. After transposing the matrix, the data were apodized by a sine-bell function, zero-filled, and Fourier-transformed, and the absolute value was taken and symmetrized. The resolution was 1.95 Hz in both dimensions. The data were plotted with a Zeta plotter. The total time for data processing and plotting was about 1 h. Two-Dimensional "C-IH Chemical Shift Correlation Map of 21. The data were acquired by using the UCB-250 N M R spectrometer (Cryomagnet Systems Inc. superconducting magnet operating on 250.8-MHz proton frequency, Nicolet 1180 computer, Nicolet 293A' pulse programmer) and processed with a Nicolet 1180E computer. Nicolet's chemical shift correlation map (CSCM) experiment was used to provide the pulse program. The 90" IH pulse from the decoupler was 36 ps. The 180' I3C pulse was 37 ps. The two fixed delays were 3.0 and 2.5 ms. The incremental mixing delay was 227 ps to give a proton spectral width of 4.4 ppm. Single-phase detection was used. The decoupler frequency
1671
was set at the left edge of the proton spectrum at 4.9 ppm. The spectrometer frequency was set at the left edge of the carbon region, 103 ppm. The sweep width was 88 ppm. The pulse delay was 1.3 s. When a 0.5 M solution of 21 in C6D6was scanned, 72 4K transients were collected for each of the 256 incremental spectra. The total time for data acquisition was 7.5 h. The data were apodized by a sine-bell function and Fourier-transformed in the carbon dimension. After the matrix was transposed to the proton dimension, the data were apodized by a sine-bell function, zero-filled, and Fourier-transformed, and the absolute value was taken. The resolution was 1.4 Hz in the carbon dimension and 2.2 Hz in the proton dimension. The data were plotted with a Zeta plotter. The total time for data processing and plotting was about 2 h.
Acknowledgment. W e a r e grateful t o R. Nunlist a n d D r . I Holden for discussions concerning 2D NMR experiments. This work was supported by t h e NIH G M - 2 2 4 7 9 . E. D. was t h e recipient of a Fulbright/Ministerio d e Universidades e Investigacion ( M U I ) , Spain, Scholarship (1981-1983), R.L.H. of a University of California Regents' Fellowship (1982-1984), a n d K.P.C.V. of a Camille a n d H e n r y Dreyfus Teacher-Scholarship (1978-1983).
Registry No. 4, 94732-58-8; 5, 94732-59-9; 6, 94732-60-2; 7, 8722659-3; 8, 87226-60-6; 9, 94732-61-3; 10, 94732-62-4; 11, 94732-63-5; 12, 94751-08-3; 13, 94732-64-6; 14, 94732-65-7; 15, 94732-66-8; 16, 94751-09-4; 17, 94732-67-9; 18, 94732-68-0; 19, 94732-69-1; 20, 94751-10-7; 21, 94751-11-8; 22, 94732-70-4; 23, 94751-12-9; 24, 94732-71-5; 25, 94751-13-0; 26, 94732-72-6; 27, 94751-14-1; CPCO(CO),, 12078-25-0; (CH3)3SiCH2MgCI,13 170-43-9; 1,6-heptadiyne, 2396-63-6; 3-bromopropanal ethylene acetal, 18742-02-4; 4-bromo- 1butene, 5162-44-7; 1,7-octadiyne, 871-84-1; (chlcromethy1)trimethylsilane, 2344-80- I ; methyl-d3-triphenylphosphoniumiodide, 1560-56-1.
Reaction of the Samarium-Hydrogen Bond in [ (C5Me5)2SmH]2with Carbon Monoxide: Formation, Isomerization, and X-ray Crystallographic Characterization of cis- and trans-{(C5Me5),[(C6H5)3PO]SmJ2(~-OCH=CH0)1~2 William J. Evans,*3 Jay W. Grate, and Robert J. Doedens Contribution from the Department of Chemistry, University of California, Irvine. California 9271 7 . Received July 30, 1984 Abstract: [(CSMes)2SmH], (I) reacts with CO in arene solvents to form a product, 11, which generates crystals of cis{ ( C S M e 5 ) , [ ( C 6 H s ) , P O ] ~ m ~ ( p - ~ ~ H(IIIa) = ~ H when ~ ) (C6HS),P0 is added. IIIa crystallizes from toluene under hexane diffusion in space group P I with unit cell dimensions a = 18.673 (7) A, b = 17.641 (6) A, c = 13.973 (5) A, a = 102.40 (3)O, /3 = 93.57 (3)', y = 93.15 (3)O, and Z = 2 (with six toluene molecules of crystallization per unit cell) for D, = 1.27 g ~ m - ~Least-squares . refinement on the basis of 6427 observed reflections led to a final R value of 0.065. IIIa isomerizes to the trans isomer IIIb at room temperature in hours to days depending on sample concentration. IIIb crystallizes from toluene under hexane diffusion in space group P 2 , / n with unit cell dimensions a = 14.678 (2) A, b = 17.424 (3) A, c = 28.736 (4) A, /3 = 100.67 (l)", and 2 = 4 for D, = 1.34 g Least-squares refinement on the basis of 8312 observed reflections led to a final R value of 0.051. In both IIIa and IIIb, (CsMes)2Sm[OP(C6H5)3]units are connected by a bridging -OCH=CHOmoiety. The two C5Me5ring centroids, the OPPh3 oxygen atom, and the enediolate oxygen atom describe a distorted tetrahedral coordination geometry around each samarium center. The enediolate bridge is best resolved in the cis isomer IIIa and has the following bonddistances (A): Sm-0, 2.147 ( I O ) and 2.179 (IO); C-0, 1.319 (19) and 1.352 (18); C=C, 1.324 (22). 0-C=C angles of 132.51 (18)' and 128.4 (18)" were observed. In the trans isomer IIIb there is an apparent rotational disorder of the bridging group about the Sm-0 bonds.
C a r b o n monoxide is o n e of t h e most extensively investigated ligands in organometallic chemistry. I n recent years,, t h e desire t o use CO a s a feedstock h a s encouraged research on both t h e homogeneous a n d heterogeneous conversion of CO/H, mixtures (1) Part 7 of the series Organolanthanide and Organoyttrium Hydride Chemistry. Part 6: Evans, W. J.; Meadows, J. H.; Hanusa, T. P. J . Am. Chem. SOC.1974, 106, 4454-4460. (2) Presented in part at the Industrial Associates Conference on Recent Trends in Heterogeneous and Homogeneous Catalysis, California Institute of Technology, March 21-23, 1984.
0002-7863/85/ 1507-167 1$01.50/0
("syn-gas")
carbons."12
t o reduced, homologated oxygenates a n d hydroO n e reaction that has been studied to model hydrogen
(3) Alfred P. Sloan Research Fellow. (4) Ponec, V. Catul. Reu.-Sci. Eng. 1978, 18, 151-171. (5) Masters, C. Adu. Organomet. Chem. 1979, 17, 61-103 and references therein. (6) Kung, H. H. Cutul. Reu.-Sci. Eng. 1980, 22, 235-259. (7) Klier, K. Adu. Cur. 1982, 243-313. (8) Dombek, B. D. Adu. Car. 1983, 32, 325-416 and references therein. (9) Muetterties, E. L.; Stein, J. Chem. Reo. 1979, 79, 479-490.
0 1985 American Chemical Society
1672 J . Am. Chem. SOC.,Vol. 107, No. 6, 1985
Evans, Grate, and Doedens
reduction of C O is the reaction of a metal hydride with C O to form a formyl complex12(eq 1). The formation of metal formyl MH + CO MC(=O)H (1)
derived from carbon monoxide and a metal hydride. In addition, the isomerization of the cis enediolate bridge is a reaction with little precedent in the literature.
complexes by this route has been synthetically difficult because thermodynamic considerations generally favor the reverse reaction, namely, decarbonylation of the formyl to C O and a metal hydride.l2-l4 Oxophilic metals, such as the early transition metals, lanthanides, and actinides can be used to advantage in this regard, since intermediate formyls can be stabilized by coordination of both C and 0 to the metal center. n MC(=O)H - M+:CO-H
Experimental Section
-+
The complexes described below are extremely air and moisture sensitive. Therefore, both the syntheses and subsequent manipulations of these compounds were conducted under nitrogen with rigorous exclusion of air and water using Schlenk, vacuum line, and glovebox (Vacuum/ Atmospheres HE-553 Dri Lab) techniques. Materials. Hexane was washed with sulfuric acid, dried over MgS04, and distilled from potassium benzophenone ketyl solubilized with tetraglyme. Toluene and T H F were distilled from potassium benzophenone ketyl. Benzene, THF-d,, benzene-d6, and toluene-d, were vacuum transferred from potassium benzophenone ketyl. CO (99.99%, Liquid Indeed, hydrides of early transition metals have displayed an Carbonic) and triphenylphosphine oxide (Aldrich) were used as received. extensive chemistry with CO'03113'33'53'6and actinide hydrides react (CSMe5),Sm(THF), was prepared from SmI, and KC5Me5.26 rapidly with C O to give spectroscopically observed $-formyl ((C5Me5)2SmH]2(I) was prepared from (C5MeS)2Sm(THF)2,dicomplexes at low temperature." phenylacetylene, and H 2 as described in ref 23. However, the product Our previous studies of the reaction of C O with ( C S H 5 ) 2 L ~ - was collected as the precipitate from the hydrogenolysis reaction in al(t-C,H,)(THF) to form (CsH5),Lu(COCMe3) and kane solvent, rinsed with alkane, and dried in vacuo. It was not exposed [(C5Hs)2Lu]2(C0)4(CMe3)2 (eq 2; Cp = C5H5,R = CMe3)I8as to arenes, with which it reacts slowly (over days), until it was used. Powdered I isolated in this manner can be stored for weeks at -25 "C R in a well-sealed vial in the glovebox. Physical Measurements. Infrared spectra were obtained on a Perkin-Elmer 283 spectrometer as previously described.,] 'H N M R spectra were obtained on a Bruker WM-250 spectrometer at 295 K unless othR (2) erwise noted. Chemical shifts were assigned relative to C6D,H, 7.15 ppm, for spectra in benzene-d,, or relative to C6D5CD2H,2.15 ppm, for spectra well as the observed reaction of C O with (CSMes)2Sm(THF)2'9 in toluene-d,. Complete elemental analyses were obtained from Analyindicated that organolanthanide complexes display interesting tische Laboratorien, Engelskirchen, West Germany. Magnetic suscepchemistry with CO. Reactions of organometallic lanthanide tibilities were determined by the Evans method on the 250-MHz spechydrides and C O have not previously been reported primarily tr~meter.~' Apparatus and Methods for the CO Reactions. Reactions were carried because molecular lanthanide hydride complexes were not known out in 3-02 Lab-Crest (Fischer-Porter) glass pressure reaction vessels. until recently.20,21 We now have a variety of well-characterized The stainless steel coupling to the glass vessel was equipped with a organolanthanide and organoyttrium hydrides in hand, including pressure-relief valve, a pressure gage, a bellows valve, and a VCO cou[(C5H4R)2Ln(THF)(pH)]222 (R = H, CH,; Ln = Tb, Er, Lu, pling. With the bellows valve closed, the contents of the reactor were Y), [ ( C ~ M ~ S ) Z S ~[H ( CI SZ H, ~S ~) Z E ~ H I ~[C( C~ S- ,H~S~) Z L ~ H I ~ H - sealed from the atmosphere. For N M R experiments, an N M R tube was (Ln = Y, Er, Lu),1*24,25 and ([(CH3CsH4)2YH]2[(CH3C5H4)2loaded with a solution of [(C5Me5)2SmH]2(I) in benzene-d6 or toluene-d, ZrHIHJ,' and have begun a study of their reactivity with CO. and then placed inside the reaction vessel. For preparative reactions the In this report we describe the rapid reaction of [(C5Me5),SmH], solutions were loaded directly into the glass pressure vessel and a Teflon with C O to generate a product which can be isolated as a tristir bar was added. The reactor was sealed and placed on a metal vacuum line via the VCO coupling. Carbon monoxide was delivered to phenylphosphine oxide (TPPO) adduct. In this system, carbon the line via a Matheson high-purity regulator. The line, which was monoxide is both reduced and dimerized to yield a bridging enconnected to a Schlenk line via a plug valve, could be vented via another ediolate ligand with cis geometry. We describe here the synthesis plug valve and a bubbler and was equipped with a pressure-relief valve. of this complex, the full details of its structure determined by X-ray Before initiating a reaction, the metal vacuum line from the C O cylinder crystallography, the isomerization of the cis enediolate ligand to valve to the reactor bellows valve was purged of air by using the Schlenk the trans isomer, and the characterization of the trans isomer by line, evacuated, and pressurized to 90 psi CO. The bellows valve was then X-ray crystallography. These studies have provided the first direct opened to pressurize the reaction. Nitrogen was removed from the restructural information on an unsubstituted enediolate ligand action vessel by venting the line to 1 atm through the bubbler, represswing, venting, etc. CAUTION: Glass pressure vessels should be protected with a wire mesh and a shield. Reaction of I with C O is essentially (10) Bercaw, J. E.; Wolczanski, P. T. Acc. Chem. Res. 1980, 13, 121-127 as rapid as mixing, based on the color change, but most reactions were and references therein. left a t 90 psi for 1-2 h. (Mixing in unstirred N M R tubes is slow.) (1 1) Erker, G.Arc. Chem. Res. 1984, 17, 103-109 and references therein. Reaction also occurs at 1 atm, but reaction at 90 psi is rapid and con(1 2) Gladysz, J. A. Adu. Orgummet. Chem. 1982,20, 1-38 and references therein. venient. When reactions were complete, the line was vented to 1 atm, (13) Manriquez, J. M.; McAlister, D. R.; Sanner, R. D.; Bercaw, J. E. J. the bellows valve was sealed, and the reactor under 1 atm of CO was Am. Chem. SOC.1978, 100, 2716-2724. returned to the glovebox for workup. (14) But see: Wayland, B. B.; Woods, B. A. J . Chem. SOC.,Chem. ComInitial Product of the [(C,Me,),SmH],/CO Reaction, 11. In the mun. 1981,700-701. Wayland, B. B.; Woods, B. A,; Pierce, R. J . Am. Chem. glovebox, [(C,Me,),SmH], (I) (0.175 g, 0.207 mmol) was dissolved in SOC.1982, 104, 302-303. I O mL of toluene to give an orange solution, which was placed in the glass (15) Fachinetti, G.;Floriani, C . ; Roselli, A.; Pucci, S. J . Chem. SOC., pressure apparatus with a Teflon stir bar. The apparatus was attached Chcm. Commun.1978, 269-270. to the metal vacuum line and pressurized to 90 psi with CO. The solution (16) Gell, K. I.; Schwartz, J. J . Organomet. Chem. 1978, 162, Cll-C15. (17) Fagan, P. J.; Moloy, K. G.;Marks, T. J. J . Am. Chem. SOC.1981, turned red-brown after CO was admitted and stirring began. After 103, 6959-6962 and references therein. returning the solution to the glovebox, removal of the toluene left a tacky, (18) Evans, W. J.; Wayda, A. L.; Hunter, W. E.; Atwood, J. L. J . Chem. red-brown solid which was dissolved in hexane. Removal of the hexane SOC.,Chem. Commun.1981, 706-708. left a drier, glassy solid. I R spectra were run both as a KBr pellet and (19) Evans, W. J.; Bloom, I.; Hunter, W. E.; Atwood, J. L. J . Am. Chem. as a neat film deposited on a salt plate with hexane (which evaporated). SOC.1981, 103, 6507-6508. Evans, W. J.; Grate, J. W.; Hughes, L. A,; These spectra were essentially identical, and in each case, the base-line Zhang, H.; Atwood, J. L., submitted for publication. rose to medium intensity from 1660 to 900 cm-I, capped with peaks from (20) Evans, W. J. Adu. Orgummet. Chem., in press, and references therein. 1580 to 980 cm-l. IR (neat) 2955 (s), 2906 (s), 2858 (s), 1589 (w), 1563 (21) Evans, W. J.; Meadows, J. H.; Hunter, W. E.; Atwood, J. L. J . Am. Chem. SOC.1984, 106, 1291-1300 and references therein. (w), 1544 (m). 1530 (m), 1492 (m), 1436 (s), 1378 (m), 1267 (m), 1228 (22) Evans, W. J.; Meadows, J. H.; Wayda, A. L.; Hunter, W. E.; Atwood, (m), 1187 (m), 1160 (m), 1134 (m), 1110 (m), 1018 (m), 981 (m), 810 J. L. J . M.Chem. SOC.1982, 104, 2008-2014. (23) Evans, W. J.; Bloom, I.; Hunter, W. E.; Atwood, J. L. J . Am. Chem. SOC. 1983, 105, 1401-1403. (26) Evans, W. J.; Grate, J. W.; Bloom, I.; Choi, H. W.; Hunter, W. E.; (24) Evans, W. J.; Meadows, J. H.; Wayda, A. L.; Hunter, W. E.; Atwood, Atwood, J. L. J . Am. Chem. SOC.,in press. J. L. J . Am. Chem. SOC.1982, 104, 2015-2017. (27) Evans, D. F. J . Chem. SOC.1959,2003-2005. Becconsall, J. K. Mol. (25) Evans, W. J.; Meadows, J. H., unpublished results. Phys. 1968, 15, 129-139.
Reaction of the Samarium-H Bond in ((CSMes)#mH], Table I. Crystal Data and Summary of Intensity Data Collection and Structure Refinement for C~~-I(C~M~~)~[(C~H~),PO]S~}~(~OCH=CHO) (IIIa) compd Sm2P2C78H9204 1456.3 Mr space group Pi cell constants 18.673 (7) a, A 17.641 (6) b, A 13.973 (5) c, A 102.40 (3) a , deg 93.57 (3) i%deg 93.15 (3) 7 7 deg cell VOI, A3 4476 (3) molec/unit cell 2, 6 toluene 1.27 p(calcd), g r(calcd), cm-' 13.87 transmsn factor 0.840-0.883 range radiatn Mo K a X = 0.71073 8, graphite monochromator max cryst dimens, 0.35 X 0.31 X 0.25 mm scan width -1.2' in 20 from Karl to +1.2" from Ka2 scan rate, deg min-l variable, 2-12 (20, 0-35"), 4-12 (20, 35-45') std reflcns 2,1,1 2,-1,l -2,1,3 decay of std 16%, isotropic reflcns measured 11758 20 range 0-45' obsd reflcns 6427 (>3a) bkgd counting bkgds evaluated from 96-step peak profile no. of params varied 595 2.25 GOF R 0.065 0.087 Rw temo 24 OC
J . A m . Chem. Soc., Vol. 107, No. 6,1985
1613
Table 11. Crystal Data and Summary of Intensity Data Collection and Structure Refinement for trans-((CSMe5)2[(CaH5)3PO]Sm]2(pOCH=CHO) (IIIb) compd Sm2P2C78H9204 1456.3 Mr space group PWn cell constants 14.678 (2) a, A 17.424 (3) b, A 28.736 (4) c, 8, 100.67 (1) deg 7222 (2) cell VOI,.A3 4 molec/unit cell 1.34 p(calcd), g cm-3 17.10 fi(calcd), cm-' transmsn factor range 0.716-0.742 Mo K a X = 0.71073 8, radiatn graphite monochromator max cryst dimens, mm 0.42 X 0.54 X 0.51 scan width -1.2" in 20 from K a , to +1.2' from Ka2 scan rate, deg mi& variable, 4-12 0,-2,-2 2,0,0 2,0,-4 std reflcns 7.0%, isotropic decay of std reflcns measured 13799 20 range 0-50' obsd reflcns 8312 (>30) bkgd counting bkgd evaluated from 96-step peak profile 523 no. of params varied 2.29 GOF 0.051 R 0.085 Rw 24 'C temp
indicated triclinic symmetry, which was confirmed by a Delaunay reduction. The lower limit of the variable scan rate was increased after 20 = 35' because of decay of standards, which were measured every 100 reflections. Data were collected by the 8-28 scan technique in bisecting geometry. The p factor in the expression29for the standard deviation of (m) cm-I; IH N M R (benzene-d,) S -0.7 (br, w l j 2= 16 Hz) ppm. At 253 the observed intensities was given a value of 0.05. Crystal data and K the signal broadened to a half-width of approximately 250 Hz and at experimental parameters are summarized in Table I. 233 K it disappeared into the base line. New signals began to appear All computations were carried out with a local version of the UCLA at 223 K, and at 213 K the principle features of the spectrum were broad Crystallographic Computing Package.)O The space group PT was insignals at 2.8 and -3.8 ppm, with two small broad satellites placed dicated by intensity statistics and was confirmed by the successful soluasymmetrically about the latter peak. At 193 K the satellites disaption and refinement of the structure. Data collection was terminated at peared, and I1 had peaks at 3.0 (half-width = 20 Hz) and -3.5 ppm 20 = 45' because only a small fraction ( 3 u(l). The [Ag3Li2Ph6]-cluster closely resembles the [Cu5Ph6]-cluster mentioned earlier, having the same basic trigonal-bipyramidal geometry with lithium atoms in axial positions. The [Li6Br4(EtzO)lo]2+ cation is extremely unusual: it consists of a [Li6Br4I2’salt-like core surrounded by a shell of ten ether molecules.
Organocopper complexes have been used in organic synthesis for many years.’ This interest has been extended to organosilver compounds for its possible use in organic synthesisZas well as its ability to provide some insight into the chemistry of group 11 elements in general. As an extension of our studies on the phenylcopper s y ~ t e mphenylsilver ,~ complexes have been investigated. (1) Posner, G. H. “An Introduction to Synthesis Using Organocopper 1. (2) Westmijze, H.; Kleijn, H.; Vermeer, P. J. Organomel. Chem. 1979, 172, 377.
Reagents”:Wiley: New York, 1980; Chapter
0002-7863/85/1507-1679$01SO/O
This paper describes the preparation and structure of one such complex, the [Ag3LizPh6]-anion. The susceptibility of the silver-carbon bond to oxidation and hydrolysis has hindered many early attempts at isolating and characterizing arylsilver compound^.^ It was only in 1972 that (3) Edwards, P.G.; Gellert, R. W.; Marks, M. W.; Bau, R. J . Am. Chem. SOC.1982, 104, 2072. (4) (a) Krause, E.; Schmitz, M. Chem. Ber. 1919, 52, 2159. (b) Krause, E.: Wendt, B. Chem. Ber. 1923,56, 2064. (c) Reich, R. C. R. Hebd. Seances Acad. Sci. 1923, 177, 322.
0 1985 American Chemical Society
