Organometallics 1983, 2, 500-505
500
full-matrix least-squares techniques with isotropic thermal parameters for all non-hydrogen atoms. The four phenyl rings are then defined as rigid groups, and the model is blocked into two molecular fragments. Each fragment is refined by counterweighted full-matrix least-squares methods with anomalous dispersion corrections (I, Fe, P), anisotropic thermal parameters for nongroup and non-hydrogen atoms and isotropic thermal parameters for group atoms to give final values of R1 = 0.066 and
. -. . - . Crystallographic Summary for MezI[sS-C6H4Fe(CO)~I]2 (1). X-ray quality crystals of 1 are obtained by slow diffusion of petroleum ether (30-60) into a CHCla solution containing 1. Pertinent crystal data and all the details of data collection are listed in Table I.I4 Least-squares refinement of the cell dimensions are based on 15 computer-centered reflections. Intensity data are collected with use of the w scans on a computer-controlled four-circle Nicolet autodiffractometer using Mo Ka radiation (A = 0.710 73 A). The intensity data are corrected empirically for absorption effects by using psi scans for five reflections having 28 between 10.35' and 30.37' and are then reduced to relative squared amplitudes, IFo12,by means of standard Lorentz and polarization corrections. Of the 5707 relfections collected 3614 are considered observed by applying the same rejection criterion as for 3b (see above). Six standard reflections monitored every 300 reflections collected show no significant variation in intensity (14)All calmlatione with the absorption-corrected intenlrity data were preformed on a Data General Eclipse 9.200 computer utilizing versions of the Nicolet E-XTL interactive crystallographic software package as modified at Crystalytics Co.
during the course of data collection. The atomic positions of all non-hydrogen atoms are located by use of direct methods program MULTAN. The hydrogen atomic positions are found by standard difference Fourier techniques or generated by using idealized sp2or sp3hybridization and a C-H bond length of 0.95 A. The structure is initially refined by full-matrix least-squares procedures with minimization of the function Cw(lFol - lFc1)2(where w = l/aF2). The final cycles of unit-weighted full-matrix least-squaresrefinement, which employ anisotropic thermal parameters for non-hydrogen atoms, isotropic thermal parameters for hydrogen atoms, and anomalous dispersion corrections (I, Fe, Si) converge to final values of 0.049 and 0.060 for R1 and R2, respectively.
Acknowledgment. We gratefully acknowledge partial support of this research by t h e donors of t h e Petroleum Research Fund, administered by the American Chemical Society, and funds obtained from NSF (Grant CHE8102918). Registry No. 1,42830-83-1;2,84521-28-8;3a, 84521-29-9;3b, 84681-03-3;4a, 84681-04-4b, 4 84581-06-5;5 (isomer 1),84581-06-6; 5 (isomer 2), 84581-07-7; (Ph0)2PC2H4P(OPh)2, 78819-34-8; [q6-C&fle(C0)2]2,38117-54-3; PPha, 603-36-0; P(OPh),, 101-02-0; C&&OH,108-95-2;C12PCH2CH2PCl2,28240-69-9;iodine, 755356-2. Supplementary Material Available: Tables of crystallographic reporb, thermal parameters,hydrogen atomic coordinates, complete bond legnthe and angles, and structure factors for 1and 3b (64 pages). Ordering information is given on any current masthead page.
Organotransltion-Metal Metallacarboranes. 1. Iron Complexes Derived from C8H& Structure of (77'-CsHi dFe[ 293-(CHd2C2B4H4 1 Richard B. Maynard, Robert G. Swisher, and Russell N. Grimes" Department of Chemistry, University of Virginia, Charlottesville, Virginia 2290 1 Received November 1. 1982
The reaction of the C8Hs2-(cyclooctatetraenide) dianion with FeCl, and the (C2H5),,CzB4H5-carborane ion in THF produces a 1,3,5-cyclooctatriene complex, (qa-C Hlo)Fe[(C2HS)2C2B4H4] (I), in 50% yield as a red, air-stable solid, together with two minor products, (qt-C6H6)Fe(C2H)2C B4H4and (C16H18)Fe(C2H5),C2B4HH4. Compound I has been characterized from IR and mass spectra, l!B, ?H, and 13Chigh-resolution FT NMR, and an X-ray diffraction study of ita C,C'-dimethyl homologue and contains a 1,3,5-cyclooctatriene ligand. Compound I is the f i s t metallacarborane complex of a C8-ring ligand to be structurally characterized complex whose by X-ray diffraction and is apparently only the third qe-cyclooctatriene-transition-metal crystal Rtructure has been determined. The metallacarborane portion of the molecule consists of a seven-vertex FeC2B4pentagonal-bipyramidal cage similar to previously reported MC2B4systems. The geometry of the qe-1,3,5-C&lo ligand claely resembles that of the previously reported complexes (q6-C8Hlo)Fe(q4-C8Hlo) and (q6-C8Hlo)Cr(C0),;the six metal-coordinated carbon atoms are nearly, but not quite, coplanar, and the two noncoordinated (methylene) ring carbons are bent well out of the plane, away from the metal. The NMR data are consistent with a nonfluxional structure. Crystal data: (C8Hlo)Fe[(CHJ2C2B4H4],M, = 264, s ace group C2/c, 2 = 8, a = 31.403 (7) A, b = 7.098 (3) A, c = 12.348 (7) A, p = 100.61 (3)O, V = 2706 R = 0.048 for 1805 reflections having F: > 3a(F;).
i3,
Introduction Metallacarboranes bearing exopolyhedral hydrocarbon ligands form a large family of well-characterized compounds,2 b u t t h e hydrocarbon in nearly all cases is cyclo-
pentadienide, C5H,-. Its role is usually passive, in that i t serves as a "capping" ligand, completing t h e valence coordination of the metal and stabilizing the complex. T h e relative inertness and bulk of the tightly coordinated C5H5-
(1)Reported in part at the 182nd National Meeting of the American Chemical Society, New York, Aug 1981;American Chemical Society: Washington, DC, 1981;Abstract INOR-11.
(2) Grimes, R. N. In "Comprehensive Organometallic Chemistry"; Wilkinson, G., Stone, F. G. A., Abel, E., Eds.; Pergamon Press: Oxford, 1982;Volume 1, Chapter 5.5,pp 459-542.
0276-7333/83/2302-0500$01.50/00 1983 American Chemical Society
Organotransition-Metal Metallacarboranes
Organometallics, Vol. 2, No. 4, 1983 501
Table I. 360-MHz 'H FT NMR Data (C6D6Solution) compd
relative to Si(CH,),b
relative area
5.56 m [H(3,4)1, 5.16 dd [H(2,5)1, 4.68 m [H(l,6)], 1.95 m (CH,), 1.72 m (CH,), 1.68 m [H(7,8), endol, 1.06 t (CH,), -0.20 m [H(7,8), e x o ] 5.92 s (C,H,), 3.10 m (CH,), 2.76 m (CH,), 1.62 t (CH,) 6.10 d, 5.22 t, 5.07 m, 4.67 q, 4.01 m, 2.78 m, 2.02 m (C,H,), 1.83 m (C,H,), 1 . 6 8 m (C,H,), 1.22 q, 1.07 m (C,H,), 0.90 m, 0.27 m, -2.87 m
2, 2, 2, 2, 2, 2, 6, 2
6
(~6-C,H,o)Fel(C,H,),CzB,H,](I)" (~6-C6H,)Fe[(C2H,)zC~B,H,l (11) .
(C,,H,,)Fe[(C,H,),C,B,H,] (111)
6, 2, 2, 6 1, 1, 2, 2, 1, 191, 2, 1, 2, 6, 2, 1, 1
Legend: m = multiplet, d = doublet, t = triplet, q = quadruplet, dd = doublet of doublets.
Acetone-d, solution.
Table 11. "C FT NMR Data (C,D, Solution)" compd (r)
6-C8H,o)Fe[(CZH,12c2B,H,I (1)
( r ) 6 - C 6 H 6 )Fe[(CZHS
)2C2B4H41
(C16H18)Fe[(C2H5)2C2B4H41
a
6
Obtained at 90.80 MHz.
(I1) (I1')
[relative to Si(CH,),]
100.37 d [C(3,4)], 91.59 d [C(2,5)], 86.40 d [C(l,6)], 32.91 t [C(7,8)], 22.81 t [C,H,], b14.76 q [C,H,I 93 [carborane C], 83.91 d [C6H6],24.82 t [CH,], 15.24 q [CH,] 105.79 d, 95.98 d, 93.22 d, 88.90 d, 87.75 d, 84.10 d, 77.54 d, 59.81 d, 26.61 t
Broad, weak singlet.
group tend to protect the metal from attack, so that such complexes are usually poor candidates for homogenous catalysts or catalyst precursors. Consequently, efforts to develop metallacarborane catalysts have centered on complexes with more easily displaceable ligands such as
phosphine^.^^^ Since arene and larger cyclic hydrocarbon ligands in transition-metal complexes are often more labile than C5H5-, we have begun a systematic examination of the synthesis and chemistry of (C,H,)metal(carborane) complexes where n I6, with the objective of preparing species having displaceable hydrocarbon ligands and relatively active metal centers. Our chosen carborane ligand, pyramidal R2C2B4H42-, is readily a ~ c e s s i b l e and ~ * ~ tightly binds to metal ions, forming stable seven-vertex MC2B4 polyhedral cages on which metal-centered reactions can be conducted without disruption of the cage framework. Several metallacarboranes having six- or eight-membered cyclic hydrocarbon ligands have been reported previously, in which the organic group is C8Ha2- (cyclooctatetraenide),5 1,5-C8Hl2 (cyclooctadiene),B CgH6y7 1,3,5-C6(CH3)3H3,7bCH~C~HS:C ~ ( c H 3 ) 6 Xylene,78 ,~~ or CloH8 ( n a ~ h t h a l e n e ) . ~Of~ these, ~ ~ X-ray structure determinations have been reported only for [C6(CH3),H3]and $6Fe(C2BgHi1),7b(C6H5CH3)Fe[(CH3)2C2BgHgl,7a H5CH3)Fe[(C2H5)2C2B,H4].9In this article we report the reaction of the C8Ha2-ion with (C2H5)2C2B4H5and FeC12 and the structural characterization of a (1,3,5-cyclo0ctatriene)iron carborane complex (v6-CaHlo)Fe[ (C2H5)2C2B4H4].The following paperlo describes the (3) (a) Paxson, T.E.; Hawthorne, M. F. J . Am. Chem. SOC.1974,96, 4674. (b) Delaney, M. S.; Knobler, C. B.; Hawthorne, M. F. Znorg. Chem. 1981,20, 1341 and references therein. (c) Grimes, R. N. In "Metal Interactions with Boron Clusters", Grimes, R. N., Ed.; Plenum Press: New York, 1982, Chapter 7, and references therein. (4) (a) Maynard, R. B.; Borodinsky, L.; Grimes, R. N. Znorg. Synth., in preas. (b) Hosmane, N. S.; Grimes, R. N. Znorg. Chem. 1979,18,3294. (5)Salentine, C. G.; Hawthorne, M. F. Inorg. Chem. 1976, 15, 2872. (6)Green, M.; Spencer, J. L.; Stone, F. G. A.; Welch, A. J. J. Chem. Soc., Dalton Tram. 1975, 179. (7) (a) Garcia, M. P.; Green, M.; Stone, F. G. A.; Somerville, R. G.; Welch, A. J. J . Chem. SOC.,Chem. Commun. 1981,871. (b) Hanusa, T. P.; Huffman, J. C.; Todd, L. J. Polyhedron 1982, 1, 77. (8)Salentine, C. G.; Hawthorne, M. F. J. Am. Chem. SOC. 1975, 97, 6382. (9) Sneddon, L. G.,Workshop on Main-Group Chemistry, Keystone, Colorado, June, 1982; Sneddon, L. G., private communication. Micciche, R. P.; Sneddon, L. G. Organometallics, in press. (10) Swishar, R. G.; Sinn, E.; Grimes, R. N., following article in this issue.
Table 111. 115.5-MHz "B FT NMR Data 6 ( J , Hz)" re1 area solvent compd CDCl, I 10.65 (141), 6.22 (160), 1, 1, 2 3.10 ( 1 4 9 ) 11 C,D6 12.47,b 6.61 (140), 3.53b 1, 1, 2 I1 (CD,),CO 6.21 (158), 4.62 (158), 1, 1, 2 1.14 (134) I11 C6D6 12.54,b 6.56,b 3.23b 1,1,2 a BF,~O(CzH,), shift is 0;positive shifts downfield. J not measurable.
conversion of the latter species to several (arene)iron(carborane) complexes and X-ray crystallographic studies on three prototype compounds.
Results Reaction of FeC12, (C2H5)2C2B4H
