1974 2027Crystal and Molecular Structure of Di-p-chloro-bis-([l -(dicarbonyl-x-cyclopentadienylferrio)-2-phenylethyne]copper( I))By Russell Clark, Judith Howard, and Peter Woodward," Department of Inorganic Chemistry, The University,The crystal structure of the title compound has been determined by conventional methods from the intensities of1578 non-zero reflections measured on a diffractometer and refined to R 0.071. Crystals are monoclinic, witha = 12.57(1), b = 18.27(2), c = 7.15(1) 8, @ = 115~3(1)', space group PZ1/a, and have two dimeric moleculesper unit cell. The dimer comprises two asymmetric units related by a centre of inversion to give a central planarring of alternating Cu and CI atoms. The Cu-CI distances are equivalent a t 2*287(3) 8 and the Cu .* . Cu distanceacross the ring is 3.069(2) 8. Each Cu atom is symmetricallyn-bonded to the C, unit of the phenylethynyl group[Cu-C 2.01 ( 2 ) A], and the CuC, moieties are coplanar with the Cu,CI, ring. The ethynyl link i s 1-23(1) 8, withFe-C-C-Ph angles of ca. 162".Bristol BS8 1TSTHE reaction between [ (x-C,H,) Fe(CO),Cl] and CuC,Phaffords a yellow-orange crystalline air-stable adductin 30% yield.1 The i.r. spectrum (in CHC1,) showstwo v ( C 0 ) bands at 2052 and 2002 cm-l, while the lHn.m.r. spectrum shows a sharp singlet at T 4-7 (C,H,)and a broad signal at T 2.7 (C,H,). The mass spectrumshows only peaks found in the spectrum of [(x-C,H,)-Fe(CO),CiCPh]. Osmometric molecular-weight de-terminations indicate that dissociation occurs in solution.EXPERIMENTALThe crystals were characterised by photographic methods.Intensities were measured on a two-circle auto-diffracto-meter according to methods described previously ; crystalaxis: c ; size of crystal: 0.1 x 0.1 x 0.5 mm; geometry:equi-inclination ; mode : o-scan ; scan speed, 1" min-l;scan interval: (2.0 + 0.3/L)O where L is the Lorentzcorrection for the reflection hkl; background count (beforeand after scan): 0.5 min; check reflection: every 20reflections; radiation: Mo-K,, with Zr filter.No. ofreflections observed 1578 [according to the criterion I >2-50 (I)].Crystal Data.-[C,,Hl,CICuFeO,I,, M = 753.8, Mono-clinic, a = 12-57(1), b = 18-27(2), c = 7.15(1) A, @ =115.3(1)", U = 1484 Hi3, D, (by flotation) 1.67, 2 = 2,D, = 1.69, F(000) = 752.Mo-K,X-radiation, A = 0.7107A, p(Mo-K,) = 25.3 cm-l. Space group P2,/a.Structure Solution apzd Refinement.-The copper and ironatoms were located from a three-dimensional Pattersonsynthesis, and the remaining atoms from electron-densityM. I. Bruce, R. Clark, Judith Howard, and P. Woodward,J. Organometallic Chem., 1972, 42, C107.C. J . Gilmore and P. Woodward, J.C.S. DaEton, 1972, 1387.difference syntheses. Least-squares refinement of thestructure (in which ZwA2 was the function minimised)made use of anisotropic thermal parameters ( Ps3 constant)TABLE 1Atomic positional and thermal parameters, withestimated standard deviations in parenthesesu x 1021Atom %la Y P zlc A2 *c u 0.4907(1) 0.4452(1) 0*3311(2) tc1 0*6227(2) 0-4666(2) 0*6696(4) iFe 0.6600(1) 0*3010(1) 0*2949(2) tC(l) 0.7576(13) 0.3366(8) 0*1322(21) 6.6(4)C(2) 0*8116(14) 0*2727(9) 0*2634(26) 8*3(4)C(3) 0.8389(13) 0*2966(9) 0*4726(22) 7-l(4)C(4) 0*8051(13) 0-3646(9) 0*4660(22) 7*6(4)C(5) 0*7574(14) 0.3919(10) 0.2622(25) 8*1(4)C(6) 0*5760(10) 0.2326(7) 0.1331(18) 4*8(3)O(6) 0.5154(9) 0.1843(6) 0-0296(16) 7*6(3)C(7) 0.6337(9) 0*2766(6) 0*6063(16) 3-8(2)O(7) 0*6134(8) 0*2617(6) 0*6466(14) 6-4(2)0-6236(9) 0*3616(6) 0*1794(15) 3*5(2) :[:; 0*4281(9) 0.3890(6) 0-0649(14) 3-3(2)C(91) 0*3197(8) 0.4045(6) -0.1166(14) 3.0(2)C(92) 0*3198(10) 0*4024(7) -0.3079(17) 4*8(3)C(93) 0.2162(11) 0*4127(8) -0*4890(19) 5*7(3)C(94) 0*1126(13) 0*4240(9) -0.4721(22) 7.0(4)C(96) 0.1081(11) 0.4289(7) -0*2769(19) 5*3(3)C(96) 0.2123(10) 0*4186(7) -0.1029(17) 4.6(3)* B = 8x2U.t Anisotropic thermal parameters in the formexp{ - 2X2(h2a*2U,l + k2b*2U2a + Pc*2U3, + hka*b* U,, +hZa*c* U,, + kZb*c* U,,)) with parameters ( x lo2) :Atom u11 u22 u33 u12. u,, u23CU 3.71(8) 3*66(9) 3.35 0.29(6) 1*16(6) -0.38(6)C1 4.44(16) 4.36(18) 4.15 1.27(13) 1.07(12) -0*37(12)Fe 2-90(8) 3.07(10) 2.82 0.38(6) 0.97(5) -0.06(6)for Cu, C1, and Fe in the final stages, and separate scalefactors for each reciprocal layer. The final weightin2028 J.C.S. Daltonscheme, chosen to keep the variation of AF with rangesof F and of (sin 8/A) to a minimum, was: l/w = op2 +0.01251F,12, in which op is the standard deviation derivedfrom counting statistics.2 All computational work wascarried out with the ‘ X-Ray System ’ on an Atlas com-puter.3 Final atomic positional and thermal parameterswith their standard deviations are in Table 1, bond lengthsTABLE 2Bond lengths (A) and bond angles (”) *Cu-cl 2.283 (3) cu-C(9) 2*003( 10)1-234( 13)1 - 906 ( 10) cu-CU‘ 3-06 9 (2)Cl-cl’ 3.392 (4) C(9)-C(91) 1-447 ( 11)cu-C(S)Fe-C ( 6) 1 -725( 1 1) Fe-C( 7) 1.73 2 (1 3)C(6)-0 (6) 1*192(15) C(7)-0(7) 1.1 74(17)(a) DistancesCu-cl’ 2*291(3) y-;y)2 * 0 1 6 ( 1 2)Carbonyl groupsCyclopentadienyl ring1*47(2)1-44(2)1.33 (2)1.40( 2)1-3 7 (2)2*12(2) C(l)-C(2)2.08 (2) C(2)-C(3)2*06( 1) C( 3)-C(4)2.06(1) C(4)-C(5)2.13 ( 2) C(5)-C(1)Fe-C(l)Fe--C(2)(Mean 1.40);zg; Fe-C ( 5 )(&lean 2.09)Phenyl groupC( 9 1)-C( 92) 1*38(2) c (94)-c ( 95) 1 -43 (2)C(92)-C( 93) 1*41(1) C( 95)-C (96) 1*38( 1) c (93)-c (94) 1*36(2) C (96)-C( 9 1) 1 -4 1 (2)(Mean 1.38)( b ) AnglesCu-cl-CU’ 84.3(1) C( 93)-C( 94)-C( 95) 122 (1)C1’-cu-Cl 95*7( 1) C( 94)-C( 95)-C( 96) 11 7 (1)Fe-C ( 8)-C ( 9) 164*3(9) C( 95)-C(96)-C( 91) 122( 1)C ( 6)-Fe-C ( 7) 96.0(6) C(96)-C(91)-C(92) 119(1)C ( 7)-Fe-C( 8) 93-1(5) Fe-C(6)-0(6) 176(1)C( 6)-Fe-C( 8) 8 7.2 ( 5 ) Fe-C( 7)-O( 7) l78( 1)C(8)-C(9)-C(91) 161(1) C(l)-C(2)-C(3) 106(1)C(9)-C(91)-C(92) 119( 1) C(2)-C(3)-C(4) 108(1)C( 9)-C( 9 1)-C( 96) 123 ( 1) C(3)-C(4)-C(5) 112(l)C( 91)-C( 92)-C( 93) 12 1 (1) C(4)-C(5)-C( 1) 108( 1)C(92)-C(93)-C(94) 119( 1) C(5)-C(l)-C(2) 107(l)* Estimated standard deviations include cell parametererrors.TABLE 3Equations of some least-squares planes in fractional co-distances (A) of relevant atoms ordinates, x , y , z ;from these planes are given in square bracketsPlane (1) : Cyclopentadienyl ring C(1)-(5)11.909~ + 5 .4 5 5 ~ - 2.157~ = 10.581[C(1) -0.008, C(2) 0.004, C(3) 0.002, C(4) -0.008, C(5) 0*010]Plane (2) : Phenyl ring C(91)-(96)2 . 1 8 1 ~ + 17.977~ - 0.2692 = 8.011[C(91) -0.010, C(92) 0.004, C(93) 0.009, C(94) -0.016, C(95)0.009, C(96) 0-004]Plane (3): Central planar portion of dimer: Cu, CI, Fe C(8),C(9), C(91), Cu’, Cl’, Fe’, C(8’), C(9’), C(91’)8 . 9 1 1 ~ -i- 11.380~ - 4.308~ = 7.991[CU 0.021, C1 -0.131, FC 0.045, C(8) 0.016, C(9) -0.030,C(91) -0.0421and angles in Table 2, and some least-squares planes inTable 3.Observed and calculated structure factors arelisted in Supplementary Publication No. SUP 21088(10 pp., 1 microfiche).* Atomic scattering factors arethose of ref. 4.* For details see Notice t o Authors No. 7 in J.C.S. Dalton, 1973,Index issue.DISCUSSIONThe crystal structure of the title compound shows thatit is dimeric in the solid state, of molecular formulaC,,H,,Cl,Cu,Fe,O, with two asyinmetric units relatedby a centre of inversion (see Figure 1, which also showsthe atom numbering sequence). The Cu,Cl, ring isplanar, with angles a t Cu 95.7(1) and at C1 84.3(1)”.The Cu-C1 distances are not significantly different,mean 2.287(3) A. Across the ring the Cu - - - Cudistance is 3.069(2) A. Each copper atom is sym-metrically bonded to the C, unit of the phenylethynylgroup, the CuC, moieties being coplanar with the Cu,Cl,ring (Table 3).Cu’ vector bisects the twomultiple bonds orthogonally: the distances Cu-C(8)and Cu-C(9) are not significantly different [mean% O l ( l ) A]. The multiple bond C(8)-C(9) is of length1-23(1) A. Atom C(9) is o-bonded to a phenyl groupThe Cu -FIGuim 1 View of the dimeric molecule, showing the atoninumbering sequenceC(91)-C(96) at a distance of 1.45(1) A, while C(8) iso-bonded to the iron atom of a (x-C,H,)Fe(CO), unitat a distance of 1.91(1) A; both bonds are coplanarwith the whole central portion of the molecule. TheC(91)-C(9)-C(8)-l;-e sequence is coplanar but non-linear, with angles at C(9) and C(8) of 161(1) and164( 1)’.The geometry of the (r-C,H,)Fe(CO), groupclosely resembles that found in many other compoundscontaining i t ; the iron atom can be considered to takeup an octahedral configuration, with the cyclopenta-dienyl ring occupying three facial positions. Figure 2shows the packing of the moleculcs in the inonoclinicunit cell.The structure of the title compound is generallysimilar to that of Pt(PPh,),(C,Ph,),5 but differs from3 J. M. Stewart, 17. A. Kundell, and J. C. Baldwin, X-Raj-System of Crystallographic Prograins for any Computer, Com-puter Science Centre, University of Maryland, Rcport TK 67 58,revised 1970.4 H. P. Hanson, F. Herman, J . TI. Lea, and S. Skillman, AdaCryst., 1964, 17, 1040.5 J. 0. Glanville, J. &I. Stewart, and S.0. Grim, J . 07gano-metallic Cltcm., 1967, 7, PO1974 2029it in having a transition metal a-bonded to the acetylene.The length of the carbon-carbon multiple bond inPt(PPh,),(C,Ph,) was not very accurately measured(1.32 & 0.09 A), so little can be deduced from its magni-tude] but the angles between the C-C bond and theC-Ph bonds were ca. 140" (no a given). The C-Cstretching frequency is lowered considerably, to the range1750-1770 cm-l, and the co-ordination around thePt atom is substantially planar. The diphenylethynylconfiguration and the bond lengths suggest that exten-sive delocalisation occurs, involving both metal atoms,the acetylenic fragment, and possibly the phenyl group.This feature, which probably involves back-bondingfrom filled orbitals on the Cu atom into X * orbitalson the acetylene, must contribute to the enhancedstability of the complex over that of the free acetylide.6The Fe-C(8) distance [1.906(10) A] is somewhat shorterthan expected for an Fe-C(s@) single bond,'.* but isFIGURE 2 Contents of one unit cell, seen in projection down b, looking towards the originligand in Pt(PPh,)2(C,Ph,) is thus most simply formu-lated as divalent and bidentate.On the other hand,the simple acetylide (n-C,H,)Fe(CO),(C,Ph), the struc-ture of which is reported in the preceding paper, showsbond angles at the C, unit which do not differ signi-ficantly from 180" and has a C-C bond length of 1.201(9)A. The title compound is intermediate between thesetwo situations in that the C-C bond is of length 1-233(13)and the angles at the C atoms are ca. 162". Both the* A. I. Gusev and Yu. T. Struchkov, J . Struct. Chenz., 1970,11,340.M. R. Churchill, Pevspectives in Structural Chem., 1970, 3, 91. * V. G. Adrianov, B. P. Riryukov, and Yu. T. Struckhov, J .Struct. Chem., 1969, 10, 1014.closely similar to that found for Ni-C in two separatedeterminations 9910 of the crystal structure of trans-Ni(C,Ph),(PEt,), [1.87(1) and 1.847(11) A].We thank Miss Sheila Lindsay for some preliminarymeasurements on the crystal which was provided by Pro-fessor M. I. Bruce, and the S.R.C. for financial supportand for facilities at the Atlas Computer Laboratory,Chilton, Berkshire, where help was given by Mrs. CarolHirst.[4/516 Received, 15th March, 197419 G. R. Davies, R. H. B. Mais, and P. G. Owston, J . Chem.10 W. A. Spofford, P. D. Garfagna, and E. L. Amma, Inorg.Soc. ( A ) , 1967, 1760.Chem., 1967, 1653 and Errata, 2677