Polyhedron Vol. 12, No. 22, pp. 2749-2151, 1993 0277-5387/93 $6.00+ .MJ Printed in Great Britain 0 1993 Pergamon Press Ltd

COMMUNICATION

SYNTHESIS AND X-RAY CRYSTAL STRUCTURE OF THE Sm-YLIDE COMPLEX, [(C5H&SmCH2P(Me)Ph2]

WAI-KWOK WONG*

Department of Chemistry, Hong Kong Baptist College, Kowloon, Hong Kong

and

JINGWEN GUAN, JINSONG REN and QI SHEN

Laboratory of Rare Earth Chemistry and Physics, Changchun Institute of Applied Chemistry, Academia Sinica,

109 Stalin Street, Changchun 130022, P.R.C.

WING-TAK WONG*

Department of Chemistry, University of Hong Kong, Pokfulam Road, Hong Kong

(Received 16 June 1993 ; accepted 11 August 1993)

Abstract-The interaction of (C5H5),SmC1* LiCl with one equivalent of Li[(CH,)(CH,) PPhJ in refluxing tetrahydrofuran gives the yellow complex [(CgH5)3SmCH2P (Me)Ph2] in 30% yield. The compound has been fully characterized by analytical, spectro- scopic and X-ray diffraction methods.

Phosphorus ylides have been shown to possess an extensive coordination chemistry with main group and transition metal atoms and to form metal- carbon a-bonds of unusual stability.’ Schumann2 and Gilje3 have extended the ylidic chemistry to lanthanide and actinide metals, respectively. Gilje and co-workers have further demonstrated that the phosphorus ylidic ligand, depending on the reaction conditions, can act either as a monodentate or a bidentate ligand as shown below.3a

M=CH-PRR

I CH,

M/cH2\pm,

‘CH’ 2

*Authors to whom correspondence should be addressed.

Recently we have described the preparation, solu- tion dynamics and reactivities of a series of phos- phorus ylidic organolanthanide complexes of the general formula Cp’,M[(CH,)(CH2)PRR1 - (LiC1)2, (Cp’ = C5Me,; M = Sm, Nd).4 We are interested in examining the factors that affect the mode of coordination of the phosphorus ylidic ligand, particularly the steric and electronic effects of sub- stituents of the cyclopentadienyl rings on the mode of coordination. In this communication, we report the result of the reaction of (C5H5),SmC1* LiCl with Li[(CH,)(CH,)PPh,].

The interaction of (C,H,),SmCl - LiCl with one equivalent of Li[(CH,)(CH,)PPhJ in refluxing tetrahydrofuran for 16 h, work up gave yellow crystals of stoichiometry (C,H,),Sm[(CH,)(CH,)

2749

2750 Communication

PPh,] *CdHBO, (l),* in 30% yield after recrys- tallization from a tetrahydrofuran-toluene mix- ture. Other than the resonances due to the tetra- hydrofuran protons, the ‘H NMR of 1 exhibits a broad singlet, a multiple& a doublet (Jr+ = 13.5 Hz), and a doublet (.&_n = 8.0 Hz) of relative inten- sity 15, 10, 3 and 2 for the protons of the three Cp rings, the two phenyl rings, the methyl group,

and the methylene group at 6 10.36, 7.17-7.60, 2.08, and 0.80 ppm, respectively. The 3’P{‘H) NMR spectrum of 1 exhibits a singlet at 6 21.2 ppm. The 3’P chemical shift is consistent with a ylide complex.’ Based on the above spectroscopic data, 1 can be formulated as [(CSHS)3SmCH2P (Me)Ph,], a ylide complex having structure A as

shown below.

- /CH2\& Cp$m

CH’ 2 3

A

A similar structure has been proposed for [(C5H5)3LuCH2PPh3].5 The structure of 1 was established by an X-ray diffraction study.t Crystals of stoichiometry [(CSH,)$mCH2P(Me)Ph,1 * C4H,0 suitable for X-ray diffraction study were grown from a solution of tetrahydrofuran. A per- spective drawing and selected bond lengths and bond angles of 1 are shown in Fig. 1 and its caption.

*[(CgHS),SmCH,P(Me)Phd*C,H,O: Yellow crystals, m.p. 18&183”C. Found: C, 63.0; H, 6.1; Cl, 0.0; Sm, 23.6. Calc. for C3,H,,0PSm: C, 62.8; H, 6.0; Cl, 0.0; Sm, 23.8%. IR (cm- ‘, in Nujol) : 3087m, 3049m, 2883~ 284&s, 2721w, 1589w, 1576w, 1437s 1416w, 1338w, 1317m, 1298w, 1157m, 1121m, 1109m, 107Ow, 1010s 994m, 93lw, 898s 886s, 846w, 773~s 752~s 738~s 706m, 692s 677w, 665~. “P{ ‘H} NMR (d,-THF) : 21.2(s) ppm. ‘H NMR (ds-THF): Cp protons, 6 10.36 (15H, br s) ppm; phenyl protons, 6 7.17-7.60 (lOH, m) ppm ; methyl protons, 6 2.08 (3H, d; JPmH = 13.5 Hz) ppm ; methylene protons, 6 0.80 (2H, d; .&, = 8.0 Hz) ppm; THF protons, 6 3.54(m) and 1.70(m) ppm.

t Crystal data : C*,H,,PSm * C,H,O, F,,, = 632.01, triclinic, Pi (No. 2) a = 10.760(6), b = 11.999(4), c = 12.441(6) A, CI = 74.84(3), fl = 68.21(4), y = 85.43(3), V = 1439.3 A’, 2 = 2, F(OOO) = 642, DC = 1.458 g cm- ‘, p = 21.23 cm- ‘. Crystal dimensions : 0.32 x 0.42 x 0.44 mm. Intensity data were collected on an Enraf-Nonius CAD4 diffractometer with grapahite monochromated MO-K, radiation (1 = 0.71073 A) using w-20 scans

(2&n,, = SO”). The structure was solved by a combination of Patterson and direct methods (DIRDIF) after an absorption correction ($-scan method) was applied and refined by full-matrix least-squares to give R = 0.035, R, = 0.044 for 4085 independent observed reflections [I > 3a(Z)].

Fig. 1. A perspective view of the structure of [Cp,SmCH,P(Me)Ph,]. Selected bond lengths (A) and bond angles (“) : Sm-C(6), 2.622(6); P-C(6), 1.734(6);

P-C(7), 1.811(6); P-C(4A), 1.817(6); P-C(SA), 1.811(5); Sm-C(6)--P 138.2(2) ; C(6FP--C(7), 112.2(3) ; C(6)-P-C(4A), 114.3(2) ; C(6)-P-C(5A), 113.3( 1) ; C(7>-P-C(4A), 104.9(3) ; C(7)-P--C(5A),

106.5(2); C(4AtP-C(SA), 105.0(3).

The solid state structure of 1 is consistent with the spectroscopic data and can be described as a distorted tetrahedron if one considers that the metal coordinated to the centroid of the cyclopentadienyl rings. The cyclopentadienyl rings are bonded in a q5-fashion with Sm-C bond lengths ranging from 2.725(9) to 2.827(7) A. The mean Sm-C distances for the three Cp rings are 2.75, 2.78, and 2.79 A. These values are slightly longer than that of [(MeC5H4)$mC=CCMe312 (2.71 and 2.72 A)” and (C9H7)3Sm (2.75 A),’ and similar to that of (CSH,),Sm(C,H,N) (2.75, 2.77, and 2.78 A)” and [(CSH,),Sm(&I)Sm(CsH,),l- (2.77 A).‘This is an agreement with structure A where a negative charge is delocalized on to the Sm metal. The Sm-C(6) distance is 2.622(6) 8, and is longer than the Sm-C terminal distance in (C,Me,),Sm(R)(THF) [R = Me, 2.484(14) A;‘” R = Ph, 2.511(8) A;” R = CH,Ph, 2.528(g)” 8, and shorter than the Sm-C bridging distance in (C,Me,),Sm(p- Et),AlEt, [2.662(4) A].” This is consistent with the fact that the Sm-C(6) bond is a dative bond which should be weaker than a Sm-C o-bond as in (C,Me,),Sm(R)(THF) and stronger than an elec- tron-deficient three centre-two electron Sm-C bridging bond as in (C,Me,),Sm(p-Et),AlEt,. The P-C distances for the P-CH2 and P-CH3 groups are 1.734(6) and 1.81 l(6) A, respectively. These

Communication 2751

bond lengths are in very good agreement with comparable bond lengths in (C,Me,),Lu[(CHJ (CH2)PMe2]2a [P-CH,, 1.769(16) and 1.782(15) A; P-CH,, 1.816(22) and 1.823(23)x] and (C,

Me,),U(Cl)[(CH,)(CH,)P(Me)Ph] [P-CH,, 1.74( 1) and 1.74( 1) 8, ; P-CH j, 1.77( 1) A].3b

In contrast to (C,Me,),SmCl * LiCl which reacted with Li[(CH,)(CH,)PPh,] to give the expected cyc- lic ylidic complex (C,Me,)2Sm(CH,)(CH,)PPh,,4 interaction of (CSH,),SmCl .LiCl with Li[(CH,) (CH2)PPh2] gives the unexpected ylide complex [(C,H,),SmCH,P(Me)Ph2]. The result suggests that the nature of the products of the above reaction may be influenced by the substituents of the Cp rings. We are in the process of examining this effect.

Acknowledgement-W.-K. Wong thanks the Hong Kong Baptist College, the Hong Kong Research Grant Council, and the Croucher Foundation for financial sup- port. W.-T. Wong thanks the Hong Kong Research Grant Council and the University of Hong Kong for financial support.

REFERENCES

1. H. Schmidbaur, Act. Chem. Res. 197.5,8,62 and refs therein.

2.

3.

4.

5.

6.

7.

8.

9.

10.

11.

12.

(a) H. Schumann, I. Albrecht, F. W. Reier and E. Hahn, Angew. Chem. Int. Ed. Engl. 1984, 23, 522 ; (b) H. Schumann and F. W. Reier, Inorg. Chim. Acta

1984, 95,43 and refs therein. (a) J. W. Gilje. R. E. Cramer, M. A. Bruck, K. T. Higa and K. Panchanetheswaran, Inorg. Chim. Acta 1985, 110, 139; (b) R. E. Cramer, S. Roth, F. Edel- mann, M. A. Bruck, K. C. Cohn and J. W. Gilje, Organometalfics 1989, 8, 1192 and refs therein. W. K. Wong, H. Chen and F. L. Chow, Polyhedron 1990,9, 875.

H. Schumann and F. W. Reier, J. Organomet. Chem. 1984, 269, 2 1. W. 7. Evans, I. Bloom, W. E. Hunter and J. L. Atwood, Organometallics 1983, 2, 709. J. L. Atwood, J. H. Burns and P. G. Laubereau, J.

Am. Chem. Sot. 1973,95, 1830. G. B. Deacon, B. M. Gatehouse, S. N. Platts and D. L. Wilkinson, Aust. J. Chem. 1987,&I, 907. H. Schumann, S. Nickel, J. Loebel and J. Pickardt, Organometallics 1988,7, 2004. W. J. Evans, L. R. Chamberlain, T. A. Ulibarri and J. W. Ziller, J. Am. Chem. Sot. 1988, 110, 6423. W. J. Evans, I. Bloom, W. E. Hunter and J. L. Atwood, Organometallics 1985,4, 112. W. J. Evans, L. R. Chamberlain and J. W. Ziller, J.

Am. Chem. Sot. 1987,109,7209.