摘要:

~~Multimetallic complexes of molybdenum(n) and tungsten(@ derived from[ W12(CO){PhP(CH2CH2PPh3,-P,P'}(q2=RC,R)] (R = Me or Ph).Crystal structures of [ W12(CO){PhP(CH,CH2PPh~2-P,P'}(q2-MeC2R)](R = MeorPh)Paul K. Baker,**" Simon J. C ~ l e s , ~ David E. Hibbs,b Margaret M. Meehan" andMichael B. Hursthousea Department of Chemistry, University of Wales, Bangor, Gwynedd LL57 2UW, UKDepartment of Chemistry, University of Wales CardifJI PO Box 912, Cardiff CF13TB, UKEquimolar quantities of [W12(CO)(NCMe)(q2-RC2R'),] (R = R' = Me or Ph; R = Me, R' = Ph) andPhP(CH,CH,PPh,), (L) reacted in CH,Cl, at room temperature to give the mono(a1kyne) complexes[WI,(CO)(L-P,P')(q 2-RC2R')] in high yield. The molecular structures of mI,(CO)(L-P,P')(q2-MeC,R)](R = Me or Ph) have been crystallographically determined.There are two independent molecules in theasymmetric unit which are diastereoisomers. The co-ordination pattern about the metal atom in WI,(CO)-(L-P,P')(q2-MeC2Me)]-0.75CH2C12 1 is a distorted octahedron with two adjacent phosphorus atomsof the triphosphine, a carbonyl and an iodide ligand in the equatorial plane and an iodide and thebut-2-yne ligand occupying axial sites. The complex ~I,(CO)(L-P,P')(q2-MeC2Ph)] is also a distortedoctahedron, with identical co-ordination to that of 1, except in that the but-2-yne ligand is substituted by the1 -phenylprop- 1 -yne ligand. In 1 there is a pendant arm of the triphosphine ligand free to co-ordinate with otherspecies. The reactions of the complexes ~I,(CO)(L-P,P')(q2-RC,R)] (R = Me or Ph) as monodentatephosphine ligands with the molybdenum(rr) and tungsten(r1) complexes [MI,(CO),(NCMe),],[MI,(CO),(NCMe)L'] (L' = PPh,, AsPh, or SbPh,), [MoCl(GeC1,)(CO),(NCMe),(PPh3)] and[WI,(C0)(NCMe)(q2-RC2R),] (R = Me or Ph) were found to give a range of bi- and tri-metallic complexeswhich have all been characterised.Halogenoalkyne complexes of molybdenum(rr) and tungsten(1r)have received considerable attention over the past fifteenyears; ' * 2 in particular those containing phosphine-donorligands.Although a wide range of bimetallic complexescontaining bridging phosphine ligands such as bis(dipheny1phos-phino)methane have been reported, very few bimetallicphosphine-bridged halogenoalkyne complexes of molyb-denum(I1) and tungsten(r1) have been reported.In view of thestability of the 'four-electron' bis(phosphine) alkyne complexes[MX,(CO)L',(q2-RC,R')] (M = Mo or W; X = C1, Br or I;L' = phosphine; R, R' = alkyl or aryl),"-,, it was decided totreat the bis(a1kyne) complexes wI,(CO)(NCMe)(q2-RC,R'),] (R = R' = Me or Ph; R = Me, R' = Ph)24 with apotentially linear tridentate phosphine, PhP(CH,CH,PPh,),(L) in order to co-ordinate two of the phosphorus atoms to onemetal leaving the third free to react with other metal centres.In this paper we describe the synthesis and molecularstructures (for R = R' = Me; R = Me, R' = Ph) of[WI,(C0)(L-P,pl)(q2-RC2R')]. The reactions of wI,(CO)(L-P,P')(q'-RC,R),] (R = Me or Ph) with [MI,(CO),(NCMe),](M = Mo or W), [MI,(CO),(NCMe)L] (M = Mo or W; L =PPh,, AsPh, or SbPh,), [MoCl(GeCl,)(CO),(NCMe),-(PPh,)] and [WI,(CO)(NCMe)(q2-RC,R),] (R = Me or Ph)to give a number of new bi- and tri-metallic complexes ofmolybdenum(1r) and tungsten(r1) are also discussed.Apreliminary communication on this work has been reported.,'Results and DiscussionThe starting materials used, namely wI,(CO)(NCMe)(q ,-RC,R'),] (R = R' = Me or Ph; R = Me, R' = Ph) have beenprepared by treating the seven-co-ordinate complexes[WI,(CO),(NCMe),] with an excess of a l k ~ n e . , ~ Treatment of[WI,(C0)(NCMe)(q2-RC2R'),] with 1 equivalent of the tri-phosphine in CH,Cl, at room temperature affords the biden-tate triphosphine complexes wI,(C0)(L-P,P')(q2- RC,R')]-1-3 in high yield. Complexes 1-3 have been fully characterisedby elemental analysis (C, H and N) (Table l), IR (Table l), 'H(Table 2) and ,'P NMR spectroscopy (Table 3) and for 1 by13C NMR spectroscopy, and also for 1 and 3 by X-raycrystallography.All these complexes are readily soluble inCH,Cl, but less soluble in CHC1, and only sparingly soluble indiethyl ether. The but-2-yne complex 1 is the most soluble andthe diphenylacetylene complex the least. Complexes 1-3 arefairly stable in the solid state when stored under nitrogen forseveral weeks but much more air-sensitive in solution. Theinfrared spectra all show one carbonyl band at 1957, 1965and 1969 cm-' respectively, and alkyne stretching bands at1656, 1601 and 1587 cm-' respectively. The values of thecarbonyl stretching bands are in close agreement with thoseof the appropriate bidentate phosphine complexes [WI,-(CO)(Ph,P(CH,),PPh, )(q 2-RC2R')] (n = 1-6) previouslydescribed.2oSingle crystals of the complexes [WI,(CO)(L-P,P')(q2-MeC2Me)]*0.75CH,C1, 1 and [WI,(CO)(L-P,P')(q2-MeC,-Ph)] 3 suitable for X-ray work were grown from CH,Cl,-Et,O(4: 1) mixtures at - 17 "C. The molecular structures areshown in Figs. 1 and 2 respectively. There are two independentmolecules in the asymmetric unit which are diastereoisomers.As can be seen from Fig. 1 each molecule has the same ligandsco-ordinated in an identical way but they differ in theconfiguration about the central P atom. Selected bond lengthsand angles are presented in Table 4. The co-ordination patternabout the metal atom in complex 1 is a distorted octahedronwith two adjacent phosphorus atoms of the triphosphine, acarbonyl and an iodide ligand in the equatorial plane and aniodide and the but-2-yne ligand occupying axial sites.One ofthe end phosphorus atoms of the triphosphine is unco-J. Chem. SOC., Dalton Trans., 1996, Pages 39954002 399Me MeFig. 1 Crystal structure of the two diastereoisomers present in theasymmetric unit of ~12(CO)(L-P,P')(q2-MeC,Me)]~0.75CH2C1, 1,showing the atom numbering scheme: (a) molecule a; (b) molecule b(some labelling removed for clarity)c ( 2 1 ) 9 ~ ( 1 9 )C(20)Fig. 2 Crystal structure of ~I,(CO)(L-P,P')(qZ-MeC2Ph)] 3,showing the atom numbering schemeordinated and is therefore available to bind to another metalcentre.In 1989 Baker and co-workers 2o reported the synthesis andmolecular structure of the bis(dipheny1phosphino)methanecomplex [W12(CO)(Ph2P(CH2)PPh2}(q2-MeC,Me)].It and 1are both distorted octahedra with the two iodide ligands and thetwo co-ordinated phosphorus atoms cis to each other.However, the complex WI2(CO){Ph2P(CH2)PPh2}(q2-MeC,Me)] has one phosphorus atom trans to an iodide ligandand one phosphorus atom trans to the but-2-yne ligand in the(a) (b)Fig. 3 Structures of [W12(CO){Ph2P(CH2)PPh,}(qz-MeC,Me)] (a)and pI,(CO)(L-P,P')(q '-MeC2 Me)] (6)equatorial plane, whereas in 1 one phosphorus atom is trans toan iodide and one trans to a carbonyl, as shown in Fig. 3. In thecase of [W12(CO)(Ph2P(CH2)PPh2}(q2-MeC,Me)] the lengthof the alkane chain (CH,) connecting the phosphorus atoms inthe dppm ligand is shorter than the triphosphine ligand and theC(2)-W-1(1) bond angle is 107", thus allowing more space forthe but-2-yne ligand to co-ordinate.The metal-ligand bond lengths in the complexes[W12(CO)(Ph2P(CH2)PPh2}(q2-MeC2Me)] and 1 are com-parable.The IR spectrum of the former shows a carbonylstretching band at 1938 cm-', whereas that of 1 shows acorresponding band at 1957 cm-l. In the latter case there is aphosphine group trans to a carbonyl ligand. The n-acceptorphosphine ligand will compete with the CO ligand for electrondensity from the filled metal d orbitals. This may account forthe higher frequency of the carbonyl stretching band of 1 in theIR spectrum.The bend-back angles p (the angle between C=Cand C-R in an alkyne complex, <90") of the complexes~I,(CO)(dppm)(q2-MeC2Me)] and 1 are z 39 and 42.2"respectively.Complex 1 has the stereochemistry proposed for thethermodynamically favoured blue isomer of the complexWI,(CO)( Ph2P(CH2),PPh,)(q ,-MeC,Me)]. 2o The molecularstructure of [W12(CO)(L-P,Pl)(q2-MeC,Ph)] 3 is very similarto that of its but-2-yne analogue 1. From Fig. 2 it can be seenthat the co-ordination pattern about the metal atom is adistorted octahedron, identical to that of the two molecules of1, with the pendant phosphine group in a similar orientationto molecule lb.The asymmetric unit of compound 1 is comprised of twoindependent molecules, which are diastereoisomers, whereas 3contains only one of the two possible diastereoisomers observedin the solution-state 31P NMR spectrum.This is probably dueto one isomer being less soluble and hence crystallising first,however another possibility is that both isomers crystallised asdifferent crystal types with data being recorded on only onetype. The isomer of 3 that has been structurally characterised isa racemate of compound lb. It may therefore be proposed thatthe crystallographically uncharacterised diastereoisomer of 3would be a racemate of la. Attempts to separate isomers l a andl b by column chromatography proved unsuccessful, mainly dueto their instability on a variety of packing materials and indifferent solvents. Also it might be expected that the isomerswould have very similar retention times.In both complexes 1 and 3 the co-ordination pattern about themetal atom is distorted octahedral with identical co-ordination,except that in place of a but-2-yne ligand a 1-phenylprop-1-yneligand is trans to an iodide.A slight lengthening of the W-I bondtrans to the alkyne, as well as a slightly longer alkyne bond, isobserved in 3, due to the greater electron-withdrawing natureof the phenyl ligand. Table 4 shows that compound 3 exhibitsa more distorted geometry than 1 due to the larger cone angleof the 1 -phenylprop- 1 -yne ligand. The conformation of thechelating arm of the triphosphine ligand is maintained in bothcomplexes, as shown by the torsion angles of the P-CH2-CH2-Pchain [la 54.27(2); l b -54.31(2); 3 - 52.15(3)"].The IH NMR spectra of complexes 1-3 show broadmultiplets at 6 7.3-7.9 which can be assigned to the hydrogensof the phenyl groups of the triphosphine and a broad multiplet3996 J.Chem. Soc., Dalton Trans., 1996, Pages 3995-400Table 1 Physical, analytical a and IRb data for complexes 1-25Complex1 PI,(CO)( L-P,P')(q 2-MeC2Me)]-0.75CH2CI22 P I 2( CO)( L-P,P')(q 2-PhCzPh)]3 p12(CO)(L-P,P')(q2-MeC2Ph)]4 [Mo12(CO),(NCMe){(p-L-P,P')WI,(CO)(q 2-MeC2Me))]P,P')W12(CO)(q2-MeC,Me)}]p12(C0)3(NCMe){ (p-L-6 [Mo12(CO),(NCMe){(p-L-P,P') WI 2( CO)(q '-PhC ZPh))]pr2(C0)3(NCMe){(p-L-P,P')WI2(CO)(q 2-PhC2Ph)}]8 [ MoI 2 (CO), { ( p-L-P, P')WI2(CO)-(r12-MeC2Me)) 2 1(T2-MeC2Me))21h2-PhC2Ph)) 2 1(CO)(rl 2-MeC2Me))l(CO)(r12-PhC2Ph)11(W(r12-PhC2Ph))l9 pv12(co),{(p-L-P,P')w12(co)-10 [MoI~(CO),{(~-L-P,P')WI~(CO)-11 ~I,(CO),(PPh,){(p-L-P,P')WI,-12 [ M012 (CO), (PPhJ { (p-L-P,P') WI2-13 P I , ( CO),(PPh,){ (p-L-P,P') WI2-14 [MoI~(CO),(ASP~,){(~-L-P,P')WI~-15 ~I~(CO),(ASP~,){(~-L-P,P')WI~-16 [MoI~(CO),(ASP~,){(~-L-P,P')WI~-17 ~I~(CO),(ASP~,){(~-L-P,P')WI~-18 [MoI~(CO),(S~P~,){(~-L-P,P')WI~-19 ~12(CO>,(SbPh~){(~-L-P,P')WJ,-20 pI2(CO),(SbPh,){(p-L-P,P')WI2-(CO)(q 2-MeC2Me))]~0.5CH2C12(CO)(rl 2-MeC2Me))l(CO)(rl 2-PhC2Ph))l(CO)(r12-PhC2Ph))1(CO)(q 2-MeC2Me)}]~0.5CH2C12(CO)(r12-MeC2Me))]-0.5CH2C12(c0>(~2-phc2ph>)l21 [MoCl( GeCl ,)(CO) (NCMe)(PPh ,)-((p-L-P,P') WI, (CO)( q 2-MeC2 Me))]22 [MoC1(GeC13)(CO),(NCMe)(PPh,)-23 [MoCl(GeCl,)(CO),(PPh,)-{(p-L-P,P')WI,(CO)(q2-PhC2Ph))]{(p-L-P,P')W12(CO)(q2-PhC2Ph)}2]24 iy12(Co){(p-L-P,~)W12(co)(q~-PhC,Ph)),(q 2-MeC2Me)]-0.5CH2C1225 ~I~(CO){(~-L-P,P')WI~(CO)(T~~-PhCZPh)} 2(rl 2-PhC,Ph)]YieldColour (%)Blue-green 93BrightgreenGreenGreenDarkgreenBrown-blackGreenBrown-blackGreenDarkgreenGreenBlackGreenBrown-blackGreenBlackGreenBrown-blackGreenGreenGreenGreenBrown-blackGreenDarkgreen949484929088837656668581796987678447568177697788Analysis (%) IR/cm- 'C42.7(42.7)50.1(49.9)47.2(47.2)34.0(34.5)32.5(32.6)40.0(39.1)36.9(37.2)37.9(38.2)37.3(37.0)43 .O(43.3)38.5(39.2)44.2(44.8)43.3(42.8)39.1(39.5)38.9(38.3)43.9(43.8)42.0(41.9)38.0(38.5)38.5(37.7)41.8(41 .O)41.8(42.5)46.5(46.2)47.4(47.4)43.8(43.4)45.6(45.2)H N3.5 -(3.7)3.7 -(3.7)3.7 -(3.7)2.7 0.6(2.8) (0.9)2.6 0.6(2.7) (0.9)2.9 0.6(2.8) (0.8)2.6 0.5(2.6) (0.8)3.1 -(3.2)3.1 -(3.0)3.2 -(3.1)3.0 -(3.0)3.2 -(3.1)3.0 -(3.0)3.0 -(3.0)3.0 -(2.9)3.2 -(3.0)3.0 -(2.9)3.2 -(2.9)3.0 -(2.8)3.0 -(2.9)3.3 1.2(3.3) (0.8)3.3 0.5(3.3) (0.7)3.4 -(3.4)3.2 -(3.2)3.2 -(3.2)V(CI=o)1957s1965s1969s1958s, 1851m1967s, 1889m2024m, 1966s, 1904s2017s, 2007m, 1948s2023s, 1959s, 1873m2018s, 1977s, 1947s,1892m, 1866m2024w, 1966s, 1905s,1834m2016s, 1945s, 1914s2025s, 1966s2017s, 1945s, 1913m2024s, 1962s, 1998s2017s, 1945s, 1914s2024s, 1964s201 8s, 1969s, 1946s,1915s2024w, 1961s2017s, 1945s, 1913m2018s, 1968s, 1946s,1913m1953s, 1879m1954s, 1882m1969s, 188 1 m2054s, 1971s2088s, 1968sV(C=c)1656w1601w1587w1655w1659w171 lw171 lw1590w, 1551w1604w, 1550w1591w, 1550w1573w, 1550w1590w1602w1550w1578wI578w157.5~1549w1 5 5 0 ~1602w1590w1601w1601w1602w, 1550w1601w,1581w,1540w' Calculated values in parentheses.Spectra recorded in CHCI, as thin films between NaCl plates; s = strong, m = medium, w = weak.at 6 2.62.7 which can be assigned to its CH, groups. Inaddition 1 showed four but-2-yne methyl resonances at 6 3.15,3.1,2.95 and 2.9 and a resonance at 6 5.3 due to CH2C1, whichconforms with the solid-state structure having 0.75 CH,CI, inthe crystal lattice.Elemental analysis results for complex 1are also consistent with such a solvate. However, when it isobtained as a dry powder there appears to be no CH2Cl, in theNMR sample, hence stoichiometric reactions of 1 and 2 arecalculated in terms of the non-solvated complexes.Complex 3 showed two resonances at 6 3.0 and 2.9corresponding to the methyl group of the 1 -phenylprop- 1 -yneligand. Attempts to measure the barrier to but-2-yne rotation ofthe two isomers of 1 were unsuccessful since no coalescence ofthe but-2-yne resonances occurred at 60 "C.The 31P NMR spectrum of complex 1 showed five resonancesat 6 - 13.7 (m, 2P, C,H,PPh,), -2.7 (s, IP, C,H,PPh), 4.3 (s,lP, C,H,PPh), 19.5 (d, lP, Jpp = 30, C,H,PPh,) and 23.1(d, lP, Jpp = 25 Hz, C2H,PPh,).The high-field multiplet at6 - 13.7 indicates the presence of two isomers in solution, eachwith an unco-ordinated phosphorus atom and is twooverlapping doublets. It is coupled to the resonances at 6 19.5and 23.1 which could be due to the co-ordinated centralphosphorus atom of the triphosphine ligand. The resonances at6 -2.7 and 4.3 can therefore be assigned to the terminalphosphorus atoms of the triphosphine ligand co-ordinated tothe tungsten. These show no coupling and this may be due tothe two co-ordinated phosphorus atoms of the triphosphineligand being bound in an approximate cis-coplanar conforma-tion with a resultant zero coupling constant.The 31P NMRspectrum of 2 also showed five resonances (Table 3) whichcould indicate the presence of two isomers of the complex insolution. The presence of two isomers in solution is consistentJ. Chem. Soc., Dalton Trans., 1996, Pages 399.54002 399with the two isomers shown for the solid-state structure of 1[Fig. l(a) and l(b)]. The 31P NMR spectrum of 3 also has fiveresonances which also indicates the presence of two isomers insolution. X-Ray crystallography showed only one isomer in theasymmetric unit (Fig. 2). This is likely to be due to the leastsoluble isomer crystallising out of solution. All successivecrystallisations of 3 gave morphologically identical crystals.The 13C NMR spectrum of the but-2-yne complex 1 showssix resonances at 6 234,230,224,222,213 and 212 which may beassigned to four alkyne carbons and two carbonyl carbonsrespectively, associated with the alkyne ligands donating fourelectrons to the metal centre 26 and in accord with the 31P NMRdata and solid-state structure.It is likely that the mechanism for the formation of thecomplexes wI,(CO)(L-P,P')(q2-RC,R')] 1-3 involves initialdisplacement of acetonitrile by an end phosphorus atom of thetriphosphine ligand (see Scheme 1).Evidence to support thisproposal comes from the previously reported 2o reaction of[MoI2(CO)(NCMe)(q2-PhC2Ph),] with an equimolar amountof PPh, to give [MOI~(CO)(PP~~)(~~-P~C,P~)~]. Severalattempts to study the low-temperature (- 10 "C) reaction ofw12(CO)(NCMe)(q2-MeC2Me),] with an equimolar amountof triphosphine to give wI,(CO)(L-P)(q2-MeC,Me),] werelargely unsuccessful.Although an initial orange solution whichmay be due to this complex is formed, it rapidly turned deepgreen, and low-temperature 31P NMR spectroscopy showedonly the two diastereoisomers due to complex 1. In order toTable 2 Proton NMR data 6* for complexes 1-25Complex 6123456789101112131415161718192021222324257.9-7.3(m,25H,Ph),5.3(~, 1.5H,CH2CI2),3.15,3.1,2.95,2.9 (4s, 6 H, C,Me), 2.5-2.4 (m, 8 H, PhPCH,)7.9-7.33 (br m, 35 H, Ph), 2.7-2.5 (br m, 8 H, PhPCH,)7.9-7.3 (m, 30 H, Ph), 3.0,2.9 (2.3, 3 H, C,Me), 2.6-2.4 (m,8 H, PhPCH,)7.9-7.3 (br m, 25 H, Ph), 3.15, 3.1, 3.0,2.9 (4s, 6 H, C,Me),2.7-2.5 (8 H,PhPCH2),2.3(s, 3 H,NCMe)7.9-7.3 (br m, 25 H, Ph), 3.1, 3.0, 2.9, 2.85 (4s, 6 H, C,Me),2.6-2.3 (br m, 8 H,PhPCH2),2.1 (s, 3 H,NCMe)7.7-7.3 (br m, 35 H, Ph), 2.1 (s, 3 H, NCMe), 2.8-2.4 (br m,8 H, PhPCH,)7.9-7.4 (br m, 35 H, Ph), 2.4 (s, 3 H, NCMe), 2.8-2.4 (br m,8 H, PhPCH,)7.7-7.3 (br m, 50 H, Ph), 3.0, 2.9 (2s, 12 H, C,Me), 2.9-2.7(br m, 16 H, PhPCH,)7.7-7.3 (m, 50 H, Ph), 3.0, 2.95 (2s, 12 H, C,Me), 2.88-2.5(m, 16 H, PhPCH,)7.9-7.3 (br m, 70 H, Ph), 2.6-2.5 (br m, 16 H, PhPCH,)7.9-7.3 (m, 40 H, Ph), 3.1,2.85 (2s, 6 H, C,Me), 2.6-2.4 (m,8 H, PhPCH,)7.9-7.3 (m, 50 H, Ph), 2.6-2.4 (m, 8 H, PhPCH,)7.9-7.3 (br m, 50 H, Ph), 2.6-2.4 (br m, 8 H, PhPCH,)7.9-7.3 (m, 40 H, Ph), 5.3 (s, 1 H, CH,CI,), 3.1, 2.85 (2s,6 H, C,Me), 2.6-2.4 (m, 8 H, PhPCH,)7.9-7.3 (m, 40 H, Ph), 3.0, 2.9 (2s, 6 H, C,Me), 2.8-2.5 (m,8 H, PhPCH,)7.9-7.3 (br m, 50 H, Ph), 2.6-2.4 (br m, 8 H, PhPCH,)7.9-7.3 (br m, 50 H, Ph), 2.6-2.4 (br m, 8 H, PhPCH,)7.7-7.3 (m, 40 H, Ph), 5.3 (s, 1 H, CH,CI,), 3.1,3.0 (2s, 6 H,C,Me), 2.62.4 (m, 8 H, PhPCH,)7.9-7.3(m,40H,Ph),5.3(s,1H,CH,CI2),3.1,2.9(2s,6H,C,Me), 2.6-2.4 (m, 8 H, PhPCH,)7.7-7.3 (br m, 50 H, Ph), 2.6-2.4 (br m, 8 H, PhPCH,)7.9-7.3 (br m, 40 H, Ph), 3.1, 2.9 (2s, 6 H, C,Me), 2.6-2.4(br m, 8 H, PhPCH,), 2.2 (s, 3 H, NCMe)7.7-7.3 (br m, 50 H, Ph), 2.8-2.7 (br m, 8 H, PhPCH,), 2.3(s, 3 H,NCMe)7.9-7.3 (br m, 85 H, Ph), 2.8-2.5 (br m, 16 H, PhPCH,)7.9-7.3 (m, 70 H, Ph), 5.3 (s, 1 H, CH,CI,), 3.C2.8 (br m, s,6 H, C,Me), 2.7-2.5 (m, 16 H, PhPCH,)7.9-7.3 (m, 80 H, Ph), 2.6-2.4 (m, I6 H, PhPCH,)* Spectra recorded in CDCl, (+ 25 "C) and referenced to SiMe,: s =singlet, br = broad, d = doublet, m = multiplet.account for the formation of the two diastereoisomers as shownin Figs.1 and 2, it is statistically likely that after co-ordinationof one end of the triphosphine ligand there will be 50% of theunco-ordinated phosphine group pointing up and a 50% chanceof it pointing down. After final co-ordination of the centralphosphorus atom an equal chance of the formation of eachstereoisomer shown in Fig. l(a) and l(b) is observed in both thesolution and the solid state.Two unsuccessful attempts to co-ordinate the unattachedphosphorus atom in complex 1 were made.Refluxing a CH,Cl,solution of 1 for 24 h gave only the starting complex afterworking up the reaction mixture. Also, after reaction of 1 withan equimolar amount of ONMe,-2H20 in NCMe for 12 h onlystarting materials were recovered. Trimethylamine N-oxide hasbeen previously shown to react with, for example, [M(CO),] inNCMe to give the carbonyl-displaced products [M(CO),-(NCMe)] and C02.27 It may be that the steric crowding of thetriphosphine and but-2-yne ligands hinders attack by theONMe, on the carbonyl ligand in complex 1.The reactions of [WI,(CO)(L-P,P')(q2-RC,R)] (R = Me 1or Ph 2) with molybdenum(I1) and tungsten(r1) complexes areextensive and summarised in Scheme 2. Reactions with 1equivalent of [MI,(CO),(NCMe),] (M = Mo or W)28 inCH2Cl, at room temperature gave the bimetallic complexes[MI, (CO) (NCMe) { (p- L- P, P') W I , (CO)( q ,-RC, R) >] 4 7 inhigh yield.These and other multimetallic complexes 8-25.CAC,Me MeiI.CCC,Me MeScheme 1Scheme 2 L" = [WI,(CO)(L-P,P')(q2-RC,R)] (R = Me or Ph). Allreactions were carried out in CH,Cl, at room temperature. (i) L withan equimolar quantity of [MI,(CO),(NCMe),] (M = Mo or W) for24 h; (ii) 2 L with [MI,(CO),(NCMe),] (M = Mo or W) for 24 h; (iii)[MI,(CO),(NCMe),] (M = Mo or W) with an equimolar quantity ofL' (L' = PPh,, AsPh, or SbPh,) for 1,3 or 5 min respectively, followedby an in situ reaction with L for 10 min; (iu) L" with an equimolarquantity of [MoC~(G~C~,)(CO),(NCM~)~(PP~,)] for 24 h; (u)[MoCI(GeCI,)(CO),(NCMe),(PPh,)] with 2L" for 24 h; (ui)~I,(CO)(NCMe)(q2-RC,R),] (R = Me or Ph) with 2 L for 24 h3998 J.Chem. SOC., Dalton Trans., 1996, Pages 3995-400described were characterised by elemental analysis (C, H andN) (Table I), IR (Table l), 'H NMR (Table 2) and in selectedcases by "P NMR spectroscopy (Table 3). Complexes 14, 18,19 and 24 were confirmed as 0.5CH2C1, solvates by repeatedelemental analysis and 'H NMR spectroscopy. In the case of 6FAB mass spectral data were also obtained. The complexes 4-7Table 3 Phosphorus-3 1 NMR data for selected complexes *Complex12345679101415161719202425aia6( JIHz)- 13.7 (m, 2 P, C,H,PPh,), -2.7 (s, 1 P, C,H,PPh), 4.3(s, 1 P, CZH4PPh), 19.5 (d, 1 P, J p p = 30, C,H,PPhZ), 23.1(d, 1 P, Jpp = 25, C2H,PPh2)- 13.3 (m, 2 P, C,H,PPh,), -4.0 (s, 1 P, C,H,PPh), -3.5(s, br, 1 P, C,H,PPh,)- 13.5 (m, 2 P, C,H,PPh,), - 1.2 (s, 1 P, C,H,PPh), 7.2(s, 1 P, CZH4PPh), 19.8 (d, 1 P, J p p = 30, CZH,PPh,), 26.1(s, 1 P, CZHdPPh), 19.6 (d, 1 P, Jpp = 35, CZHdPPh,), 22.7(d, 1 P, J p p = 24, C,H,PPh,)2.16 (d), 4.37 (s), 21.27 (m), 39.7 (s)- 2.1 (d), 4.1 (d), 22.0 (m), 39.0 (s)- 3.7 (m), 19.4 (s), 24.3 (m), 26 (d), 39 (s)-4.2 (m), -2.2 (d), 22.8 (m), 27.0 (m)- 2.6 (d), 4.0 (d), 22.0 (m)- 3.5 (m), 4.24 (d), 21.9 (m)- 3.4 (m), 21.5 (m), 23.6 (d)-7.3 (s), -3.95 (m), 21.0 (m)- 3.6 (m), 11.3 (s), 24.9 (d)-3.0 (m), 21.0 (d), 22.1 (d)- 2.0 (m), 3.9 (m), 22.5 (m)- 3.7 (d), 4.24 (d), 20.9 (m)- 3.9 (d), 21.3 (d), 26.9 (m)- 4.0 (d), - 3.4 (m), 20.4 (m)-3.5 (s, br), 21.2 (m), 25.2 (d, br)-4.0 (d), 21.0 (d), 24.7* Spectra recorded in CDCl, referenced to H,PO,.are all fairly soluble in dichloromethane and chloroform butonly sparingly in diethyl ether. However, 1-3 are more solublethan 4-7.These complexes are fairly stable in the solid stateunder nitrogen for a few days but less stable than 1-3.The infrared spectra of the complexes [MI,(CO),-(NCMe){(pL-P,PI)WI,(CO)(q2-MeC,Me)}] (M = Mo 4 orW 5) show alkyne stretching bands at 1655 cm-' and 1659 cm-',respectively, i.e. at much lower wavenumbers compared to thoseof unco-ordinated but-2-yne. These complexes also show threecarbonyl stretching bands as opposed to the four predicted,indicating that some of the bands may be masked.The IRspectra for 4 and 5 show broad carbonyl stretching bands at1958 and 1967 cm-' respectively, which can be assigned tothe carbonyl group co-ordinated to wI,(C0)(L-P,PI)(q2-MeC,Me)] 1 which would not be expected to shift very muchwhen its unco-ordinated phosphorus atom coordinates toanother metal centre. Complexes 4-7 all show an acetonitrilestretching band in the region of 2300 cm-'. The FAB massspectrum of [Mo12(CO),(NCMe){p-L-P,P')WI,(CO)(q~-PhC,Ph)}] 6 shows a peak at m/z 1147 which could beassigned to a mass peak of M - I,.The 'H NMR spectra of complexes 4-7 conform with thestoichiometry proposed. The 31P NMR data (Table 3) show noresonance at 6 -13 indicating that the unco-ordinatedphosphorus atom of the complexes w1,(C0)(L-P,P')(q2-RC,R)] had attached to another metal centre.Severalunsuccessful attempts were made to grow single crystals forX-ray crystallography. Several unsuccessful attempts werealso made to obtain 13C NMR spectra for these and othermultimetallic complexes described later. This is almost certainlydue to poor solubility and instability in solution over the longperiod of time required to obtain 'Reaction of 2 equivalents of wI,(CO)(L-P,P')(q ,-RC,R)](R = Me 1 or Ph 2) with 1 equivalent of [MI,(CO),(NCMe),]NMR spectra.Table 4 Selected bond lengths (A) and angles (") for the two diastereoisomers of compound 1 and for 31.970( 1 1)2.025(8)1.997(8)2.470( 2)2.556(2)2.8 15(2)2.851(4)I .302( 1 1)1.502(11)1.535( 12)1 1 1.4(4)73.8(4)37.8(3)96.1(3)87.5(2)94.5(2)164.7(3)83.4(2)121.2(2)80.25(7)89.6(3)1 03.5(2)100.4(2)164.99(5)90.68(6)79.6(3)163.9(2)15 1.9(2)79.50(6)85.12(6)87.89(4)137.8(8)136.3(7)2.0 1 q 1 0)2.086( 10)2.005(8)2.492(2)2.569(2)2.808(2)2.849(2)1.307( 12)1.434( 12)1.507(12)109.1(3)72.1(3)37.2(3)96.4(2)87.8(2)95.0(2)168.0(3)82.4(3)119.6(2)80.58(7)88.0(2)102.9(2)98.5(2)166.45(5)92.47(6)82.7(3)1643 3)153.9(2)80.74(5)85.34( 5 )87.15(3)140.5(9)133.5( 8)Compound 32.012( 10)2.024( 10)2.044( 9)2.49 1 (2)2.557(2)2.803 7( 7)2.861 5(7)1.324( 13)1.489( 1.444( 12) 13)113.0(3)76.1(3)38.0(4)93.9(3)86.4(3)97.6(3)16432)8 1 4 3 )118.9(3)80.97(7)79.0(2)162.3( 3)154.7(3)79.6 1 (6)85.66(6)90.2(3)105.5(3)97.7(3)1 64.73( 6)91.30(6)86.73(2)134.0(9)139.1(9)J. Chem.SOC., Dalton Trans., 1996, Pages 3995-4002 399(M = Mo, R = Me or Ph; M = W, R = Me) in CH,Cl,at room temperature gave the trimetallic complexes[M12(CO)3((p-L-P,P')W12(CO)(q2-RC2R)}2] 8-10 in highyield. These complexes are all fairly soluble in dichloromethaneand chloroform, but only sparingly in diethyl ether. However,they are less soluble than the monosubstituted complexes 4-7.They are fairly stable in the solid state when stored undernitrogen for a few days, but much less stable in solution, andless stable than complexes 1-3.The infrared spectra of complexes 8-10 all show alkynestretches in the region of 1600 cm-'.They show a broadcarbonyl stretching band in the region of 1950 cm-' which canbe assigned to the ligand present in the complexes [WI,(CO)-(L-P,P')(q'-RC,R)] (R = Me 1 or Ph 2). The 'H NMRspectra conform with the stoichiometry of the complexes.The ,'P NMR spectra of complexes 8-10 all show threeresonances, which indicates the organometallic phosphinesw12(CO)(L-P,P')(q2-RC2R)] are equivalent, and it has oftenbeen observed that seven-co-ordinate complexes are fluxionalat room temperature.' It appears that the diastereoisomersobserved in 1 are not seen when the complex acts as amonodentate phosphine and co-ordinates to another metalcentre.Reaction of 1 equivalent of [MI,(CO),(NCMe),] (M = Moor W) with an equimolar quantity of L' (PPh,, AsPh, orSbPh,) for 1, 3 and 5 min respectively followed by in situreaction with an equimolar amount of [WI,(CO)(L-P,P')(q2-RC,R)] (R = Me 1 or Ph 2) afforded the complexesPPh,, M = W, R = Me; M = Moor W, R = Ph; L' = AsPh,,M = Mo or W, R = Me or Ph; L' = SbPh,, M = Mo or W,R = Me; M = W, R = Ph).They are all fairly soluble indichloromethane and chloroform but only sparingly in diethylether. These complexes are fairly stable in the solid stateunder nitrogen for a few days, but much more air-sensitive insolution.The infrared spectra of complexes 11-20 showed carbonylstretching bands in the region of 1950 cm-', which could beassigned to the carbonyl group of the monodentate phosphineligand [WX,(CO>(L-P,P')(q'-RC,R)] (R = Me 1 or Ph 2).Allshowed an alkyne stretching band in the region of 1590 cm-',and three or four carbonyl stretching bands indicating thatsome of these may be masked. The 'H NMR spectra (see Table2) are consistent with their conformation as bimetalliccomplexes. The ,'P NMR spectra for selected AsPh, andSbPh, complexes show three phosphorus resonances whichagain indicates the complexes are likely to be fluxional.'Treatment of complexes 1 and 2 with an equimolar amountof [MoCl(GeCl,)(CO),(NCMe),(PPh,)] in CH2C12 at roomtemperature gave [MoCl(GeCl,)(CO), (NCMe)(PPh 3) {(p-L-P,P')WI,(CO)(q'-RC,R))] 21 and 22. Reaction of 2equivalents of 2 with 1 equivalent of [MoCl(GeCl,)(CO),-(NCMe),(PPh,)] in CH,Cl, at room temperature yielded[MoCl(GeCl,)(CO) ,(PPh,) ((p-L-P,P') WI '(CO)(q '-PhC2-Ph)),] 23.As expected these complexes are soluble indichloromethane and chloroform but only sparingly in diethylether. All are far less soluble and less stable than complexes 1-20, 24 and 25. These complexes are stable in the solid stateunder nitrogen for a few days but much less stable in solution.The infrared spectra of complexes 21 and 22 show broadcarbonyl stretching bands at 1953 and 1879 and 1954 and I882cm-' respectively. The higher-frequency bands at 1953 and1954 cm-' are as expected, in a similar position to those ofthe phosphine ligands 1 and 2. The IR spectrum of complex 23shows two carbonyl stretching bands at 1969 and 1881 cm-'.The band at 1969 cm-l is broad and may mask the carbonylband of complex 2 which is at 1965 cm-l.No acetonitrile bandswere observed indicating that both ligands have been displaced.The 'H NMR spectra of 21-23 are consistent with theformulation of the complexes proposed. Since complex 1[MI~(CO)~L'((~-L-P,P')WI~(CO)(~2-RC~R)}] 11-20 (L' =contains a 'four-electron' alkynez6 it is unlikely the alkynestretching bands will differ significantly, since the complexes areall of the type w12(CO)L,(q2-alkyne)].Reaction of pI,(CO)(NCMe)(q'-RC,R),] (R = Me orPh) with 2 equivalents of LWI,(CO)(L-P,P')(q'-PhC,Ph)] 2 inCH2C12 at room temperature gave the complexesand 25 in good yield. Both are soluble in dichloromethane andchloroform but only sparingly in diethyl ether.These complexesare fairly stable in the solid state under nitrogen but less stablein solution. The infrared spectra showed weak alkyne stretchingbands at 1602, 1550 cm-' for 24 and 1601,1581 and 1540 cm-'for 25. Since the structures of four bis(phosphine) complexes[MoB~,(CO)(PE~,),(~~-P~C,H)],'~ [MoBr,(CO)(PMePh,),-(q2-MeC'Me)] 2 2 and [WCl,(CO)L',(q2-PhC2Ph)] (L' =PPh, or PMe,Ph) ' have been crystallographically determinedand have trans-phosphine ligands, it is very likely thatcomplexes 24 and 25 have this structure as shown in Fig. 4.Several unsuccessful attempts to grow suitable single crystals of24 and 25 for X-ray crystallography were made. The ,'P NMRspectra both show three phosphorus resonances which indicatesthat the attached organotungsten phosphorus ligands 1 and 2are equivalent and conforms with the structure shown in Fig.4.Again it appears that the diastereoisomers of complex 1 are lostafter co-ordination to the tungsten centre of the 'free'phosphorus atom in 1.In conclusion, the novel monodentate phosphinesw12(CO)(L-P,P')(q2-RC,R)] (R = Me 1 or Ph 2) areexcellent precursors to prepare a number of new bi- and tri-metallic complexes of molybdenum(I1) and tungsten(@.[WI,(CO){(~-L-P,P')WI,(CO)(r\'-PhC,Ph)}~(~'-RC~R)} 24ExperimentalAll reactions were carried out at room temperature under astream of dry nitrogen using standard vacuum Schlenk-linetechniques. The complexes [MI,(CO),(NCMe),] (M = Mo orW),,* [WI,(CO)(NCMe)(q'-RC,R),] (R = Me or Ph) 24 and[MoCl(GeC1,)(CO),(NCMe),(PPh3)] 29 were prepared bypublished methods.Dichloromethane and diethyl ether weredried and distilled before use. All chemicals were obtained fromcommercial sources.Elemental analyses (carbon, hydrogen and nitrogen) weredetermined using a Carlo Erba Elemental Analyser MOD 1106(using helium as the carrier gas). Infrared spectra were recordedas CHCl, films between NaCl plates on a Perkin-Elmer 1600series FTIR spectrophotometer, 'H, 'C (referenced to SiMe4)and ,'P NMR (85% H3PO4) spectra on a Bruker AC 250 NMRspectrometer. Fast atom bombardment mass spectrometry wascarried out by the EPSRC service at University CollegeSwansea, on a VG-Autospec instrument, using Cs' ions at 25kV as bombarding ions and samples dissolved in a 3-nitro-benzyl alcohol matrix target.For low-resolution measurementsthe resolution was set at about 3000 and the result wasthe average of about 20 scans using an external calibration.Preparations[WI,(CO)(L-P,PI)(q2-MeC2Me)] 1. To a solution of[WX,(CO)(NCMe)(q'-MeC,Me),] (2.01 g, 3.27 mmol) dis-solved in CH,Cl, (30 cm3) at room temperature was added thetriphosphine (1.75 g, 3.27 mmol) and the reaction mixture wasstirred for 24 h. The resulting green solution was filtered, andthe solvent removed in uacuo giving a blue-green crystallinepowder of [WI,(CO)(L-P,P')(q2-MeC,Me)] 1 which wasrecrystallised by cooling a CH,Cl,-diethyl ether (4 : 1) solutionof the complex at - 17 "C to yield single crystals of 1, suitablefor X-ray crystallography.Yield 3.40 g, 93%.Similar reactions of [WI,(CO)(NCMe)(q2-RC2R'),] (R =R' = Ph; R = Me, R' = Ph) with 1 equivalent of triphosphinein CH'CI, gave the bright green crystalline products4000 J. Chem. SOC., Dalton Trans., 1996, Pages 3995-400Ph [ MoCl(GeCl,)( CO),(NCMe)(PPh,)((p-L-P,P')W12(C0)(q2-MeC,Me)}] 21. To a solution of w12(C0)(L-P,P')(q2-MeC,Me)] (0.15 g, 0.14 mmol) dissolved in CH,Cl, (30 cm3) atroom temperature was added [MoCl(GeCl,)(CO),(NCMe),-(PPh,)] (0.10 g, 0.14 mmol) and the reaction mixture wasstirred for 24 h. The solvent was removed in vacuo giving a greencrystalline powder of [MoCl(GeCl,)(CO),(NCMe)(PPh,)( (p-L-P,P')WI,(CO)(q2-MeC2Me)}] 21 which was recrystallisedby cooling a CH,Cl,-diethyl ether solution of the complex at- 17 "C.Yield = 0.19 g, 81%.A similar reaction of [WI,(CO)(L-P,P')(q2-PhC,Ph)] with 1at room temperature gave the complex CMoCl(GeC1,)-(CO),(NCMe)(PPh,){(p-L-P,P')WI2(CO)(q2-PhC,Ph))] 22.\ , sPh Ph--C41e 0.. I ..,,lIIFig. The likely structure Of C w 1 2 ~ c 0 ~ ~ ~ c I ~ L ~ p ~ p ' ~ w 1 2 ~ c 0 ~ ~ ~ 2- equivalent of [MoCl(GeC1,)(CO), (NCMe) ,(PPh ,)I in CH,C1, PhC2Ph)}2(qZ-RC2R)] (R = Me 24 or Ph 25)wI,(CO)(L-P,P')(q2-RC2R')] 2 and 3. Suitable single crystalsof 3 for X-ray crystallography were obtained by cooling aCH,Cl,diethyl ether (4: 1) solution of the complex at - 17 OC.See Table 1 for physical and analytical data.Reactions of [ W12(CO)(L-P,PI)(q2-RC,R)] (R = Me 1 or Ph2)[ MoI,( CO),(NCMe){(p-L-P,P')W12(CO)(q2-MeC2Me)}) 4.To a solution of [WI,(CO)(L-P,P')(q2-MeC,Me)] (0.21 g, 0.19mmol) dissolved in CH,Cl, (30 cm3) at room temperature wasadded [MoI,(CO),(NCMe),] (0.1 g, 0.19 mmol) and thereaction mixture was stirred for 24 h.The resulting greensolution was filtered, and the solvent removed in vacuo giving agreen crystalline powder of [MoI,(CO),(NCMe){(p-L-P,P')W I , (CO)(q ,-MeC,Me) >] 4 which was recrystallised bycooling a CH,Cl,-diethyl ether (4 : 1) solution of the complex at- 17 "C. Yield = 0.25 g, 84%.Similar reactions of ~I,(CO)(L-P,P')(q2-RC,R)] (R =Me or Ph) with 1 equivalent of [MI,(CO),(NCMe),] (M =Mo or W) in CH,Cl, at room temperature gave the complexes[MI,(CO),(NCMe){(p-L-P,P')WI,(CO)(q2-RC,R)}] 5-7.[ MoI,(CO)3{(p-L-P,P')W12(C0)(q2-MeC2Me)}2] 8.To asolution of [WI,(CO)(L-P,P')(q2-MeC,Me)] (0.3 g, 0.28mmol) dissolved in CH,CI, (30 cm3) at room temperature wasadded [MoI,(CO),(NCMe),] (0.07 g, 0.14 mmol) and thereaction mixture was stirred for 24 h. The resulting greensolution was filtered, and the solvent removed in vacuo giving abrown-black crystalline powder of [MoI,(CO),{(p-L-P,P')-WI,(C0)(q2-MeC,Me)>2] 8 which was recrystallised bycooling a CH,Cl,-diethyl ether solution of the complex at- 17 "C. Yield = 0.29 g, 83%.Similar reactions of 2 equivalents of wI,(CO)(L-P,P')(q ,-RC,R)] with 1 equivalent of [MI,(CO),(NCMe),] (M = W,R = Me; M = Mo, R = Ph) in CH,Cl, at room temperaturegave the complexes [M12(CO),{(p-L-P,P')W12(CO)(q2-RC,R)},] 9 and 10.[WI2(CO),(PPh3)((p-L-P,P')WI2(C0)(q2-MeC2Me)}) 11.To a solution of [WI,(CO),(NCMe),] (0.12 g, 0.20 mmol)dissolved in CH,Cl, (30 cm3) at room temperature was addedPPh, (0.05 g, 0.20 mmol) and the reaction mixture was stirredfor 1 min, after which time [WI,(CO)(L-P,P')(q2-MeC,Me)](0.22 g, 0.20 mmol) was added in situ and the reaction stirredfor 10 min.The solvent was removed in vacuo giving agreen crystalline powder of [WI,(CO),(PPh,){(p-L-P,P')WI,(CO)(q'-MeC,Me)}] 11 which was recrystallised bycooling a CH,Cl,-diethyl ether solution of the complex to- 17 "C. Yield = 0.25 g, 66%.Similar reactions of [MI,(CO),(NCMe),] (M = Mo or W)with an equimolar amount of L' (L' = PPh,, AsPh, andSbPh,) for I , 3 or 5 min respectively followed by an in situreaction with 1 equivalent of ~12(CO)(L-P,P')(q2-RC,R)](R = Me or Ph) in CH,Cl, at room temperature gavecomplexes 12-20.[ MoCl(GeCl,)( CO),(PPh3){(p-L-P,P')WI2( CO)(q2-PhC,-Ph)},] 23.To a solution of WI,(CO)(L-P,P')(q ,-PhC,Ph)](0.19 g, 0.16 mmol) dissolved in CH,Cl, (30 cm3) atroom temperature was added [MOC~(G~C~~)(CO)~(NCM~),-(PPh,)] (0.06 g, 0.08 mmol) and the reaction mixture wasstirred for 24 h. The solvent was removed in vacuo giving abrown-black crystalline powder of [MoCl(GeCl,)(CO),(PPh,)-{(p-L-P,P')WI,(C0)(q2-PhC2Ph)},] 23 which was recrystal-lised by cooling a CH,Cl,diethyl ether solution of thecomplex at - 17 "C. Yield = 0.17 g, 69%.[ WI,(CO){ (p-L-P,P')WI,(CO)(q2-PhC2Ph)}2(q2-MeC2Me)]0.5CH,C12 24. To a solution of [WI,(CO)(NCMe)(q2-MeC,Me),] (0.09 g, 0.14 mmol) dissolved in CH,Cl, (30 cm3)at room temperature was added Dy12(C0)(L-P,P')(q2-PhC,Ph)] (0.33 g, 0.28 mmol), and the reaction mixture wasstirred for 24 h.The resulting green solution was filtered andthe solvent removed in vacuo giving a green crystallinepowder of wI,(CO)((p-L-P,P')WI,(CO)(q ,-PhC,Ph)} ,(q ,-MeC,Me)]~O.SCH,Cl, 24 which was recrystallised from aCH,Cl,-diethyl ether solution of the complex at - 17 "C.Yield = 0.33 g, 77%.A similar reaction of wI2(CO>(NCMe)(q2-PhC,Ph),] with2 equivalents of wI,(CO)(L-P,P')(q2-PhC,Ph)] in CH,Cl, atroom temperature gave the dark green product [WI,(CO){(p-L-P,P')W12(CO)(q2-PhC2Ph)}2(q2-PhC2Ph)] 25.X-Ray crystallographyCrystals of complexes 1 and 3 were grown as described in theExperimental section.Information concerning the crystal dataand structure refinement is given in Table 5.Data were recorded on a FAST TV area detectordiffractometer, with a molybdenum target [h(Mo-Ka) =0.710 69 813, equipped with an Oxford Cryosystems cryostat anddriven by MADNES software operating on a MicroVAX 3200computer, following previously described procedures. 30 Thestructures were solved via heavy-atom methods (SHELXS),3and then subjected to full-matrix least-squares refinement onFo2 (SHELXL 93).,, There are two independent molecules inthe asymmetric unit for compound 1. Non-hydrogen atomswere made anisotropic, with hydrogens in calculated positions(C-H 0.96 81, with U,,, tied to U,, of the parent atoms).Thesolvent molecules in 1 were freely refined with partialoccupancy (75%). Absorption corrections were applied usingDIFABS.,, The R indices are defined as wR2 = pw(Fo2 -Fc2)2/E(wF02)2]~ { w = 1/[a2(FO2) + (0.0715P)2] where P =[max.(Fo2) + 2(Fc2)]/3} and R1 = Z(Fo - Fc)/E(Fo). Sourcesof scattering factor data are given in ref. 32. Diagrams weredrawn with SNOOPI,34 and the coordinates of lb inverted so asto show the similarities in stereochemistry between the twomolecules.Atomic coordinates, thermal parameters, and bond lengthsand angles have been deposited at the Cambridge Crystallo-graphic Data Centre (CCDC). See Instructions for Authors,J. Chem. SOC., Dalton Trans., 1996, Pages 3995-4002 400Table 5 Crystal data and structure refinement for compounds 1 and 3111 16.05120(2)TriclinicPf10.056(5)1 7.884( 8)24.91 5(9)105.77(3)94.83(3)1 02.4 1 (2)41 63(3)41.7814.49621460.2 x 0.14 x 0.14C3,H3d,0P3W*C0.,5H1 .5c11 .51.79-25.04- 10 to 10, -20 to 13, -28 to 2710 09599060.02930.823, 1.1759901,8890.930R1 = 0.0392wR2 = 0.1031 (8194 reflections)R1 = 0.0509wR2 = 0.11242.807 and -0.7623Empirical formulaFormula weightT/KCrystal systemSpace groupalAblAC I Aa/"P/"Y/" u pzD,/Mgm-3p1rnrn-lm o o )Crystal size/mm0 range for data collection/"hkl RangesReflections collectedIndependent reflectionsAbsorption correction factorsData parametersGoodness of fit on PFinal R indices[ I ' 2 m 1(all data)RintLargest difference peak and hole/e A3C44H41 120p3w11 16.33150(2)KOrthorhombicPna211.062(2)22.240( 2)16.927(3)4 1 64.4( 10)41.7814.40421520.28 x 0.32 x 0.321.83-25.10"- 13 to 13, -24 to 20, - 19 to 1917 186627 10.06410.908, 1.1936271,4611.005R1 = 0.0388wR2 = 0.0859 (5442 reflections)R1 = 0.0479wR2 = 0.08733.233 and -0.917J.Chem. SOC., Dalton Trans., 1996, Issue 1. Any request to theCCDC for this material should quote the full literature citationand the reference number 1 86/ 16 1.AcknowledgementsM. M. M. thanks the European Social Fund and EPSRC for aresearch studentship. We also thank Dr. M. Ballantine at theEPSRC Mass Spectrometry Services (Swansea) and Dr. 0. W.Howarth at the EPSRC NMR Service (Warwick) for importantdata and the EPSRC for support of the crystallography servicein Cardiff.References1 J.L. Templeton, A h . Organomet. Chem., 1989,29, 1.2 P. K. Baker, Adu. Organomet. Chem., 1996,40,45.3 A. Blagg, A. T. Hutton, P. G. Pringle and B. L. Shaw, J. Chem. Soc.,4 J. A. Iggo and B. L. Shaw, J. Chem. Soc., Dalton Trans., 1985,1009.5 A. Blagg, B. L. Shaw and M. Thornton-Pett, J. Chem. Soc., DaltonTrans., 1987,769.6 T. G. Schenck, J. M. Downes, C. R. C. Milne, P. B. Mackenzie,H. Boucher, J. Whelan and B. Bosnich, Inorg. Chem., 1985, 24,2334.7 G. B. Jacobsen, B. L. Shaw and M. Thornton-Pett, J. Chem. 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ISSN:1477-9226    

DOI:10.1039/DT9960003995

出版商:RSC    

年代:1996

数据来源: RSC