Inorg. Chem. 1982, 21, 627-633
627
the equatorial plane of the pentagonal bipyramid is occupied The initial purple material formed from the reaction of by the two carbon atoms of coordinated acetylene and three bis(dithiocarbamato)oxomolybdenum(IV) compounds with sulfur atoms, whereas the axial positions are taken up by the (Et02C)zN2probably has the same stereochemistry as 1. This terminal oxo group and a sulfur atom from a dtc The leaves unanswered the stereochemistry of the final yellow same stereochemistry is adoptedzs by M o O ( S ~ C N P ~ ~ ) ~product with the formula M o O ( S ~ C N M ~ * ) ~ (TCNE), where TCNE is tetracyanoethylene. For DTA and (Et02CNNC02Et). Attempts to obtain suitable crystals of this yellow product for structure determination have been TCNE the latter structure is favored both by the small bite angle of the bidentate ligand and by the ?r-acceptor character unsuccessful. of these ligands. Acknowledgment. Portions of this work were supported by the National Institutes of Environmental Health Sciences Summary (Grant No. ES-00966,to J.H.E.). We thank the National X-ray structure determination shows that the deep purple Science Foundation for a grant to purchase the diffractometer. complex MOO(S,CNM~~)~(P~CONNCOP~) contains an A generous allocation of computing time from the University 0,N-coordinated dibenzoyldiazene ligand with a five-memof Arizona Computing Center is appreciated. bered chelate ring. The same stereochemistry is observed for other complexes of substituted benzoyldiazene ligands,’s-21 as Registry NO. 1, 79855-20-2. predicted by Ittel and Ibers.15 Supplementary Material Available: Listings of observed and calculated structurefactors, anisotropic thermal parameters, hydrogen positional parameters (Table VI), and least-squares planes (Table (24) Newton, W. E.; McDonald, J. W.; Corbin, J. L.; Ricard, L.; Weiss, R. VII) (15 pages). Ordering information is given on any current Inorg. Chem. 1980, 19, 1997. masthead page. (25) Ricard, L.; Weiss, R. Inorg. Nucl. Chem. Lert. 1974, 10, 217.
Contribution from the Departments of Chemistry, State University of New York at Buffalo, Buffalo, New York 14214, and The Ohio State University, Columbus, Ohio 43210
Structural Studies on Polynuclear Osmium Carbonyl Hydrides. 20.’ Crystal Structure 10(75-C5H5) and NMR Spectra of (I.~-H)~OS~CO(CO) MELVYN ROWEN CHURCHILL,*’ CLIFFORD BUENO,’ STEVEN KENNEDY,3JEFFERY C. BRICKER,’ JEFFREY S.PLOTKIN,’ and SHELDON G. SHORE*’ Received June 30, 1981
The heteronuclear species (r-H)20s3Co(CO)lo(~5-C5H5), synthesized from (p-H)20S3(C0)10 and ($-C5H,)Co(CO),, has been examined via NMR spectroscopy and a single-crystal X-ray diffraction study. This complex crystallizes in the centrosymmetric monoclinic space roup P21/n No. 141 with a = 8.193 (2) A, b = 14.641 (3) A, c = 16.341 (5) A, j3 = 90.98 (2)O, V = 1960.0 (8) and p(ca1cd) = 3.31 g cm-3 for Z = 4 and mol wt 976.75. Diffraction data were collected with a Syntex P21 diffractometer, and the structure was refined to RF = 3.5% for 1837 reflections with 3 O < 219 < 40° (Mo K a radiation). The molecule contains a tetrahedral heterometallic 0S3Co core. Each osmium atom is linked ring. The structure is completed to three terminal carbonyl ligands, while the cobalt atom is bonded to an ~5-cyclopentadienyl by an asymmetric bridging carbonyl ligand on the Os(l)-Co edge [Co-C(41) = 1.789 (14) A, Os(l)-C(41) = 2.208 (13) A] and bridging hydride ligands across the Os( 1)-0s(2) and Os(2)-Os(3) edges. The nonbridged metal-metal distances are normal [Os(l)-Os(3) = 2.778 (1) A, Os(2) 30(lF01) (T~-C,H~)CO(CO (140 ) ~ mg) was added to a two-neck 50-mL flask were RF = 2.9%, RwF = 2.8%, and GOF = 1.81. and the flask evacuated of air. Approximately 8 mL of toluene was A final difference-Fourier synthesis showed no significant features. condensed in, followed by the addition of 47 mg of H20s3(CO)lounder The function Zw(lFol showed no abnormal dependency on a stream of nitrogen gas. The solution was warmed to 90 OC and IF& (sin 8)/A, sequence number, identity, or parity class of the stirred until all of the H20s3(CO)lohad been consumed. After 48 crystallographic indices; the weighting scheme is thus satisfactory. h of reaction time the solvent and unreacted ($-C5H5)Co(C0)2 were Positional parameters are collected in Table 11; anisotropic thermal removed from the reaction mixture. The remaining dark green solid parameters are listed in Table 111. material was dissolved in methylene chloride and chromatographed Collectionof NMR Spectra. Proton N M R spectra were obtained on preparative silica gel TLC plates. Elution with an 80/20 hexon a Bruker HX-90 spectrometer operating in the FT mode at 90 ane/benzene solvent mixture yielded one major dark green band, 18 mg of (pH)20s3Co(CO)Io(~5-C5H5). Crystals of ( ~ L - H ) ~ O S ~ C O - MHz, and chemical shifts are reported relative to tetramethylsilane, (CH3),$i ( T = 10.0). Carbon-13 N M R spectra were obtained on a (CO)lo(~5-C5H5) were obtained by slowly evaporating solvent from Bruker WM-300 FT spectrometer operating at 75.5 MHz, and a CH2C12solution. chemical shifts are reported relative to (CH3)$i (0.0 ppm). Both Collection of X-ray Diffraction Data for (P-H)~O~~CO(CO)~~IH and I3C NMR spectra were obtained at temperatures ranging from (g5-C5H5).The complex was obtained in the form of opaque dark -80 to +25 "C. Deuterated dichloromethane served as the solvent (black-green) crystals of maximum dimension ca. 0.5 mm. Smaller and source of the lock signal for the 'H N M R spectra, while the 13C fragments were cleaved from these large crystals and were tested for N M R spectra were obtained in a mixture of 75% T H F of normal variation in absorbance via a series of $ scans. The crystal selected isotopic composition and 25% CD2CI2. for the X-ray diffraction experiment was rather irregular with the approximate dimensions 0.15 X 0.17 X 0.20 mm. The crystal was Description of the Structure mounted and aligned on our Syntex P21 diffractometer, and intensity The crystal consists of discrete ordered units of ( p data were collected as described previously.1° Details are given in H)20s3Co(CO)lo(q5-CsHs) which are mutually separated by Table I. The intensities were corrected for absorption by using an normal van der Waals distances. Figure 1 shows the scheme empirical method based upon 2-fold interpolation (in 28 and 4) between used for labeling atoms, while Figure 2 provides a stereoscopic $ scans of close-to-axial reflections. The reflections used, their 28 values, and their maximum-teminimum intensity ratios for a full 360" scan of $ were as follows: 243, 16.40°, 1.41:l; 252, 17.80°, 1.44:l; (1 1) 'International Tables for X-ray Crystallography"; Kynoch Press: 352, 21.01", 1.44:l; 372, 25.13", 1.42:l; 472, 28.45O, 1.43:l; 3,10,3, Birmingham, England, 1974; Vol. 4: (a) pp 99-101; (b) pp 149-150. (12) Churchill, M. R. Inorg. Chem. 1973, 22, 1213. ~ ~ l l R,F = [Cw(liol - J F C D 2 / (13) RF = [X}iFol- l ~ ~ l l / ~Xl 100 ~ w ( ~ F- ,IFc1)2/(N0 I - NV)]' (NO (10) Churchill, M. R.; Lashewycz, R. A.; Rotella, F.J. Inorg. Chem. 1977, ~ZW~F,,~~]' ~lF.1~X 1 ' 100 (%); GOF = [[ZW(~F,I 16, 265. = number of observations; NV = number of variables).
-
Polynuclear Osmium Carbonyl Hydrides
Inorganic Chemistry, Vol. 21, No. 2, 1982 629
Table 11. Final Positional and Isotropic Thermal Parameters for (~-H),0s,Co(CO),,(q5-C5H5) atom OS(1) OS(2) Os(3 co O(11) O(12) o(13) atom C(11) C(12) C(13) C(21) C(22) C(23) C(31) C(32) C(33) C(41) C(1)
X
Y
0.23718 (7) 0.4 8066 (6) 0.52035 (7) 0.29116 (21) 0.0281 (12) -0.0271 (14) 0.3847 (12)
0.34 134 (4) 0.31 895 (4) 0.24237 (4) 0.18409 (12) 0.2349 (9) 0.4816 (9) 0.4629 (7)
z
X
Y
z
0.1054 (16) 0.0652 (18) 0.3336 (16) 0.6165 (16) 0.6218 (16) 0.3401 (16) 0.6889 (17) 0.4186 (17) 0.6479 (18) 0.1312 (16) 0.3532 (19)
0.2786 (9) 0.4299 (11) 0.4167 (9) 0.2333 (10) 0.4195 (9) 0.3373 (9) 0.1545 (10) 0.1779 (10) 0.3175 (10) 0.2617 (10) 0.0481 (11)
0.4886 (8) 0.5928 (9) 0.4836 (8) 0.7577 (8) 0.7293 (8) 0.7915 (8) 0.5578 (8) 0.4500 (9) 0.4715 (9) 0.6681 (8) 0.5986 (9)
0.56727 (3) 0.70005 (3) 0.53995 (3) 0.64266 (10) 0.4454 (6) 0.6099 (7) 0.4345 (6) B, A* atom 3.0 (3) 4.1 (3) 3.1 (3) 3.1 (3) 2.8 (3) 2.9 (3) 3.4 (3) 3.4 (3) 4.1 (3) 3.2 (3) 4.3 (4)
C(2) C(3) C(4) C(5) H(12) H(23) H(1) H(2) H(3) H(4) H(5)
Y
atom
X
O(21) O(22) O(23) O(31) O(32) O(33) O(41)
0.6971 (13) 0.7055 (12) 0.2579 (13) 0.7832 (13) 0.3622 (13) 0.7289 (14) 0.0160 (12)
0.1802 0.4768 0.3462 0.0971 0.1386 0.3634 0.2754
Y
X
0.1826 (20) 0.1324 (21) 0.2700 (20) 0.4070 (20) 0.371 (10) 0.637 (11) 0.418 0.111 0.019 0.270 0.520
0.0624 (12) 0.0804 (13) 0.0820 (12) 0.0650 (11) 0.388 (6) 0.302 (7) 0.03 1 0.059 0.09 1 0.094 0.065
Z
(7) (7) (7) (8) (8) (8) (8) Z
0.7908 (6) 0.7481 (6) 0.8466 (6) 0.5660 (7) 0.3966 (6) 0.4325 (7) 0.7107 (6) B, A’
0.6010 (10) 0.6756 (11) 0.7280 (10) 0.6817 (10) 0.643 (5) 0.644 (6) 0.552 0.553 0.692 0.786 0.701
5.1 (4) 5.7 (4) 5.3 (4) 5.0 (4) 0.6 (20) 2.0 (25) 5.3 6.2 6.8 6.4 6.0
Q
Figure 2. Stereoscopic view of the (~-H)20s3Co(CO)lo($-C5H5) molecule (ORTEP-11 diagram).
view of the molecule. Interatomic distances and their esti(q5-CsH5),l6and 2.825 (2)-2.827 (2) A in (P-H)~OS,Wmated standard deviations (esd’s) are collected in Table IV; (CO)ll(q5-C5H5).17The observed osmium-cobalt distances interatomic angles are listed in Table V, while information on are fairly similar to those found’ in ( ~ - H ) , O S , C O ( C O ) ~ ~ molecular planes and dihedral angles is provided in Table VI. (OS-CO = 2.690 (1)-2.698 (1) A). The molecule is based upon a closed tetrahedral Os3C0 (b) “Long” Osmium-Osmium Bond Lengths. The Os( 1)cluster. There are the usual 60 valence electrons associated Os(2) and Os(2)-Os(3) distances are 2.940 (1) and 2.870 (1) with a tetrahedral array (three ds Os(0) atoms, one d9 (Co(0) A, respectively. (The difference in these must be attributed atom, one electron from each hydride ligand, two electrons to their different environment-vide infra.) They are from each carbonyl group, and five electrons from the q5lengthened appreciably relative to the nonbridged Os( 1)-Os(3) cyclopentadienyl system). Each osmium atom is linked to distance of 2.778 (1) A. This is entirely consistent with their three terminal carbonyl ligands, and the cobalt atom is bound being bridged by p-hydride 1 i g a n d ~ ’ (as ~ J ~shown directly by to the q5-C5H5ligand; the structure is completed by a rather the diffraction study) and is a result of the Os(p-H)Os system asymmetric bridging carbonyl group across the Os( l)-Co bond being held together by an electron-deficient two-electron, and by bridging hydride ligands (which were located in the three-center bond. course of the structural analysis) across the Os(l)-Os(2) and Hydride-bridged Os-Os distances in other tetranuclear Os(2)-Os( 3) bonds. osmium carbonyl clusters have similar values: 2.941 (2) A The intermetallic distances within the cluster fall into three in (p-H)30sW(CO)l,(q5-C5H5),17 2.932 (2) 8, in (p-H)sets. (Note that the designations “short”, “normal”, and Os3W(CO)12(q5-C5H5),16 2.956 (1)-2.971 (1) A in ( p “long” are used in a local, comparative sense.) H)40s4(CO)11(CNMe),1S and 2.893 (1)-2.909 (1) A in ( p (a) “Normal” Metal-Metal Bond Distances. The Os( 1)H)30s3Co(C0)13.7It is worth noting that the three p-hydride Os(3) bond length of 2.778 (1) A and the distances Os(2)-Co ligands in this last complex, ( p - H ) 3 0 ~ 3 C ~ ( C 0 )again 1 3 , span = 2.672 (2) A and Os(3)-Co = 2.680 (2) are considered the Os-Os vectors, rather than the O s 4 0 vectors. Presumably to be normal, since there are no bridging ligands present on M-H-M bridges involving two third-row metal atoms are these tetrahedral edges that might interfere with the metalenergetically favored over M-H-M’ bridges involving a metal bond order. Although the Os( 1)-Os(3) bond length of first-row and a third-row transition metal. 2.778 (1) A is 0.099 A shorter than the mean value of 2.877 (c) A Rather “Short”O s m i d o b a l t Bond. The Os(l)-Co , ~ ~to the (3) A in the triangular species O S ~ ( C O )it~is~close bond length of 2.645 (2) A, the shortest osmium-cobalt disunbridged osmium-osmium distances in neutral tetrahedral cluster complexes: viz., 2.822 (1) A in (p-H)40~4(CO)11- (15) Churchill, M. R.; Hollander, F. J. Inorg. Chem. 1980, 19, 306. (CNMe),15 2.784 (2)-2.799 (2) 8, in ( ~ - H ) O S ~ W ( C O ) ~ ~(16) - Churchill, M. R.; Hollander, F. J. Inorg. Chem. 1979, 18, 843. (14) Churchill, M. R.;DeBoer, B. G. Inorg. Chem. 1977, 16, 878.
(17) Churchill, M. R.; Hollander, F. J. Inorg. Chem. 1979, 18, 161. (18) Churchill, M. R. Adu. Chem. Ser. 1978, No. 167, 36. (19) Churchill, M. R.; DeBoer, B. G.; Rotella, F. J. Inorg. Chem. 1976,15, 1843. (See, especially, discussion on pp 1848-1852.)
Churchill et al.
630 Inorganic Chemistry, Vol. 21, No. 2, 1982 Table IV. Selected Interatomic Distances (A) for the ~-H),Os,Co(CO),,(qS-C,H,) Molecule (A) Metal-Metal Distances 2.940 (1) Os( 2)-Os(3) 2.778 (1) Os( 2)-CO 2.645 (2) Os(3)Xo
Os( 1)-0s(2) Os( 1)-Os(3) Os(l)-Co
2.870 (1) 2.672 (2) 2.6 80 (2)
(B) Metal-Carbonyl Distances Os(l)-C(ll) Os(l)-C( 12) Os(l)-C(13) Os( 2)-C( 2 1) Os( 2)-C( 22) Os(2)-C(23) Os(3)-C( 3 1) Os(3)-C(32) 0~(3)-C(33)
1.902 (13) 1.965 (15) 1.935 (13) 1.914 (13) 1.927 (13) 1.922 (13) 1.906 (14) 1.924 (14) 1.895 (15)
Os(l)-*O(ll) Os(1)***0(12) 0~(1)*.*0(13) Os(2)*-0(21) 0~(2)*-0(22) Os(2)--0(23) 0~(3)-0(31) 0~(3)***0(32) Os(3)*-*0(33)
O~(l)-H(12) 0~(2)-H(12)
(C) Metal-Hydride Distances 1.78 (8) OS(2)-H(2 3) 1.63 (9) 0~(3)-H(23)
3.036 (1 1) 3.073 (12) 3.070 (10) 3.062 (10) 3.049 (10) 3.062 (10) 3.051 (11) 3.061 (11) 3.041 (11) 1.61 (10) 2.12 (10)
(D) Distances Involving the q 5 S s H s Ligand 2.181 (16) C(l)-C(2) 2.100 (17) C(2)-C(3) 2.077 (18) C(3)-C(4) 2.053 (17) C(4)-C(5) 2.080 (17) C(5)-C(1) 1.732
1.414 (23) 1.321 (24) 1.403 (24) 1.387 (23) 1.443 (22)
C(l1)-O(11) C(12)-0(12) C(13)-0(13) C(21)-0(21) C(22)-0(22)
(E) Carbon-Oxygen Distances 1.138 (17) C(23)-0(23) 1.110 (19) C(31)-0(31) 1.136 (17) C(32)-0(32) 1.149 (17) C(33)-0(33) 1.122 (17)
1.140 (16) 1.147 (18) 1.137 (18) 1.147 (19)
Co-C(41) Os( 1)-C(4 1)
(F) Bridging Carbonyl Distances 1.789 (14) Co***0(41) 2.208 (13) C(41)-0(41)
COC( 1) C0-W) co-C(3) Co-C(4) CO-C(S) co-*cp=
a
2.862 (10) 1.199 (16)
Cp is the centroid of the q 5 C , H , system.
tance in the molecule, is contracted by 0.031 A from the mean "normal" Os-Co distance of 2.676 [6]A. This presumably is a result of the asymmetrically bridging carbonyl group associated with this tetrahedral edge [Cd(41) = 1.789 (14) A, Os(l)*-*C(41)= 2.208 (13) A, C(41)-0(41) = 1.199 (16) A, LCo-C(41)-0(41) = 145.9' (1,')l LOs(l).-*C(41)-0(41) = 131.9 (lo)']. The p-hydride ligands were located directly from a difference-Fourier synthesis, and their positions were optimized by least-squares refinement (vide supra). Atom H(12) bridges Os( 1) and Os(2), with Os( 1)-H(12) = 1.78 (8) A, Os(2)-H(12) = 1.63 (9)A, and ~Os(l)-H(12)-0~(2) = 119.2(50)'; H(23) bridges Os(2) and Os(3),with Os(2)-H(23) = 1.61 (10) A, Os(3)-H(23) = 2.12 (10)A, and ~Os(2)-H(23)Os(3) = 99.6 (47)'. While the hydride ligands are located with rather poor precision (as expected, with Z(H)= 1 vs. Z(Os) = 76), one may easily observe their effects on the ligand distribution about the tetrahedral metal cluster. We have previously commented" that bridging hydride ligands in tetrahedral clusters can occur at various angles about the bridged metal-metal vector. Obvious symmetrical possibilities include (a) the case. where an M1-H-M2 plane bisects the exterior angle between the M1-M3-M2 and M1-M4-M2 tetrahedral faces meeting at Ml-MZ (see I) and (b) cases
I
H
I1
111
where the M,-H-M2 plane is coplanar with one of the two triangular faces meeting at the M1-M2 edge-either with M1-M3-M2 (as in 11) or with Ml-M4-M2 (as in 111). A
continuum of less symmetrical locations between these extremes is, in principle, possible. (Note that I1 and I11 will be equivalent only when M 3and M4 are identical metal atoms in the same ligand environment.) Figure 3 shows portions of the molecule projected, in turn, onto each of the four triangular faces of the tetrahedral cluster. Atom H(12) lies only 0.23 (8) A above (relative to Figure 3A) the Os(l)-Os(2)-Co plane, whereas it is 0.70 (9) A above (relative to Figure 3B) the Os(l)-Os(2)-0~(3) plane. The appropriate dihedral angles20 are [Os(l)-Os(2)-Co] / [Os(l)-H(l2)-Os(2)] = 16' and [Os(l)-Os(2)-Os(3)]/[Os(l)-H(12)4~(2)] = 5'. The near coplanarity of H(12) with the Os( l)-Os(2)-Co plane would appear to be associated with the expanded equatorial Os-Os-CO angles in Figure 3A [Os(1)-Os(2)-C(22) = 119.6 (4)' and Os(2)-Os( l)-C(13) = 107.7 (4)'] as compared to those in Figure 3B [Os(2)Os(1)-C(12) = 113.4 (4)' and Os(l)-Os(2)-C(23) = 98.6 (4)'l. However, this correlation is not carried over to the second bridging hydride ligand. Atom H(23) lies 0.66 (10)8,above the Os(l)-Os(2)-Os(3) plane (Figure 3B) and 0.64(10)8,above the Os(2)-Os(3)
