1036 Acta Cryst. (1985). C41, 1036-1038 Structure of (r/-Methylcyclopentadienyl)(tdphenylphosphine)copper(I), [Cu(CH3CsH4){P(C6Hs)3 }] BY TIMOTHYP. HANUSA, TAMARA A. ULIBARRI AND WILLIAM J. EVANS* University of California, Irvine, California 92717, USA (Received 26 November 1984; accepted 14 March 1985) Abstract. M r=404.96, monoclinic, I2/a, a---- 18.687(6), b=8-871(5), c=25.016(19)A, fl= 103.80 (5) °, V= 4028 (4)/~a, Z = 8, D x = 1.336 Mg m -a, 2(Mo Ket) = 0.71073 A, /~ = 1.167mm -1, F(000)=2832, T=297K, R=0.051 for 2105 unique observed data. The cyclopentadienyl ring is bonded in a pentahapto manner to the Cu, with Cu-C = 2.214 (6) A (ave.). The ring-centroid-Cu-P grouping forms a nearly linear array (173.1 o) for which Cu-centroid = 1.865 (9) A and Cu-P = 2.131 A. Around P, the geometry is roughly tetrahedral. Introduction. The pentahapto cyclopentadienyl ligand, although ubiquitous in most areas of organometallic chemistry, is rare among complexes of the Cu triad. For Cu itself, few structural studies are available which present information on the metal-cyclopentadienyl interaction. Only two early studies provide details pertaining to the Cu-CsH 5 unit: (q-CsHs)CuPPh 3 (Cotton & Takats, 1970) and (r/-CsHs)CuPEt 3 (Del- baere, McBride & Ferguson, 1970). Recently, a communication on the structures of two metal clusters, (r/-CsM%)3RhECu(CO) 2 and (r/-CsMes)(r/-CsHs) ~- CC6H4Me-4)PtWCu(CO)2(PMe3) 2, containing the (r/- CsMes)Cu fragment has appeared (Carriedo, Howard & Stone, 1983), but the focal point of the investigation was not the detailed structure of the cyclopenta- dienylcopper unit. This X-ray diffraction study of the title compound provides structural information on a substituted cyclopentadienyl-copper system and per- mits comparison with the known (r/-CsHs)CuPR 3 structures. Experimental. Complex prepared from reaction of Na(CH3CsH4) with PhaPCuC1 in THF (Cotton & Marks, 1970). Colorless crystals grown from hexane solution at room temperature. Crystal 0.15 × 0.35 × 0.42 mm sealed in glass capillary under N 2. Syntex P2~ diffrac- tometer, graphite-monochromated Mo Ka. Lattice parameters from setting angles of 15 reflections with 13 ° < 2 0 < 2 3 ° . Systematic absences hkl, h+k+ 14= 2n; hOl, h 4=2n. /-centered setting allowed use of smaller fl angle than that required by an A-centered cell * To whom correspondence should be addressed. 0108-2701/85/071036-03501.50 (a = 18.69, b = 8.87, c = 27.42 A, fl = 117.6°). Inten- sities of 3881 unique reflections with 0 ° < 20 < 50 ° measured in 0--20 mode with scan rate 2-12 ° min -1, scan range -1.2 ° in 20 fromKa~ to +1.2 ° from Kch. Three check reflections (806, 813, 127) monitored every 100 data indicated 7% net decay; decay correction applied. Backgrounds evaluated from 96- step peak profile. Analytical absorption correction by Gaussian integration applied (min.-max. transmission factors: 0.796-0.921) to total of 2105 unique observed reflections [I > 3o'(/)]. Structure solved by Patterson and difference Fourier techniques. Full-matrix refine- ment based on F; weights given by Corfield, Doedens & Ibers (1967) with p = 0.05. Anisotropic temperature factors for all non-hydrogen atoms; 18 H atoms located from difference maps, the rest included in fixed positions (C-H =0.95 A); none were refined. With 235 variable parameters, refinement converged to R = 0.051, wR = 0.061, S = 1.737; max. A/tr during final cycle = 0.02. Largest peak on final difference map was of height 0.89 e A -3 at 1.05 A from Cu atom. No correction for secondary extinction. Atomic scattering factors and anomalous-dispersion corrections from International Tables for X-ray Crystallography (1974). Computer programs from UCLA Crystallographic Computing Package (Strouse, 1981). Discussion. (Methylcyclopentadienyl)(triphenylphos- phine)copper(I) crystallizes in monomeric units consist- ing of an (r/-CH3CsH4)Cu fragment bonded to a PPh 3 moiety, such that the geometry around the P is roughly tetrahedral. A view of the molecule providing the numbering scheme is given in Fig. 1. Fractional atomic coordinates are listed in Table 1, and selected bond distances and angles are presented in Table 2.'t" A comparison of the structures of (CsHs)CuPPh 3, (CsHs)CuPEt 3, and (CH3CsH4)CuPPh 3 is given in Table 3. 5"Lists of observed and calculated structure factor amplitudes, anisotropic thermal parameters, equations of least-squares planes and all bond distances and angles involvingnon-H atoms have been deposited with the British Library Lending Division as Supplemen- tary Publication No. SUP 42121 (25 pp.). Copies may be obtained through The Executive Secretary, International Union of Crystal- lography, 5 Abbey Square, Chester CH 1 2HU, England. © 1985 International Union of Crystallography