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1979 547Reactivity of Cyclopalladated Complexes. Part 5.l Insertion Reactionsof Diphenylacetylene, 1 -Phenylprop-1 -yne, and Hexafluorobut-2-yne withCyclopalladated Compounds. Crystal and Molecular Structure of Chloro-{ 3-4-q-4- [ (2-d imethylaminomet hyl) phenyl] -1.4-d imethyl-2,3-d iphenyl-buta-I ,3-dienyl- CIN}pal lad ium( 11) Bromo{ 3-4-q-4- [ (2-d imethyl-aminomet hyl) p henyl] -2,4-d imet hyl-I ,3-d ip henyl buta -1.3-dienyl- PA/)-pal lad iu m( 11)andBy Ali Bahsoun, Jean Dehand," Michel Pfeffer, and Maurice Zinsius, Laboratoire de Chimie de Coordin-ation, ERA 670 du CNRS, Universite Louis Pasteur, 4 rue Blaise Pascal, 67008 Strasbourg Cedex, FranceSalah-Eddine Bouaoud and Guy Le Borgne, Laboratoire de Cristallochimie, LA 254 du CNRS, Universite deRennes, 35042 Rennes, Cedex, FranceReactions between disubstituted alkynes RC,R' (R = R' = Ph and R = Me, R' = Ph) and [(Pd(dmba)X),](dmba = NN-dimethylbenzylamine, X = CI or Br) afford bis-insertion products [Pd{(RC=CR'),CsH4CH,NMe,)X]in high yield.With MeC,Ph two isomers have been isolated, (1 bCL) and (1 bp). In order to establish their molecularstructures, a single-crystal X-ray diffraction study has been made on the chloro-derivative of (1 bB) and the bromo-derivative of (1 bJ. Crystals of (1 b,; X = Br) are monoclinic, space group P2Jc. Z = 4, with a = 15.362(13),b = 12.368(5), c = 14.886(11) A, and p = 94.86(13)". The structure has been refined to R 0.078 (R' 0.105)for 2 529 independent reflections ; the two acetylenes inserted into the Pd-C bond have a head-to-tail arrange-ment, the Pd beinga-bonded to a carbon bearing a phenyl group, Crystals of (1 bB; X = CI) are monoclinic, spacegroup P2,. Z = 2, with a = 8.227(6), b = 16.059(33), c = 8.923(9) A, and p = 99.30(12)". The structure hasbeen refined to R 0.074 (R' 0.065) for 2 077 independent reflections.The molecule shows a tail-to-tail arrange-ment for the two inserted acetylenes, the carbon o-bonded to the palladium bearing a methyl group. The corres-ponding reaction with the 8-methylquinoline palladated dimer affords a benzenoid trimer via a bis-insertion analoguewhich was isolated for R = R' = Ph. Hexafluorobut-2-yne (hfb) reacts with the above palladated dimers and thoseformed from benzo [hlquinoline and NN-dimethyl-1 -naphthylamine to give novel halide-bridged binuclear com-plexes with seven-membered rings.They are formed by formal insertion of one hfb unit into the Pd-C o bond.With the naphthylamine dimer only an organic compound was isolated. The novel dirneric complexes easily affordmonomeric derivatives by bridge-splitting reactions with pyridine or PPh,.CYCLOMETALLATED compounds formed with appropriatestabilizing ligands show some interesting properties inorganic synthesis ; 2 9 3 thus reactions of unsaturatedorganic compounds with such transition-metal complexesoften take place easily due to the lability of the metal-carbon B bond. Insertion of two molecules of disub-stituted alkyne into the M-C B bond of four-memberedmetallacycles 4 7 5 (M = Rh or Ru) affords stable products;it has been shown that hexafluorobut-2-yne (hfb) insertsquite easily into the palladium-ally1 bond.6 Recently,Stone and his co-workers' reported the formation ofsubstituted quinolin-2-ones via an isolable q-acryloylcomplex of cobalt from the reaction of hfb and tricar-bonyl(phenylazopheny1-2C,N)cobalt, the organometallicintermediate being formed by insertion of the alkyneand one carbonyl into the Co-C bond.Thompson andHeck8 and other workers9 have shown that ortho-palladation products of a-aryl nitrogen derivatives reactwith carbon monoxide, even under mild conditions, togive unusual heterocyclic compounds.3 Only theseorganic products, not the proposed organometallic inter-mediate, have been isolated. The reaction of an azo-benzene cyclopalladated dimer with isocyanide affordsthe insertion product [PdC1(CNC6Hl,),{( CNCGH,,),C6H4-NNPh}] lo in which the cyclic ring is no longer co-ordinated to the metal.However, no insertion ofacetylene into the Pd-C bond of cyclopalladated com-plexes has been previously reported.This paper reports: (i) the insertion of what is formallya four-carbon unit (two alkyne molecules) into the Pd-CCJ bond of cyclometallated compounds formed from NN-dimethylbenzylamine (dmba),ll [(Pd(dmba)X),] {or itsmonomeric derivative [Pd(dmba) (py)X] (py = pyridine,X = C1 or Br)}, and from 8-methylq~inoline,~~ [{Pd-(8Me-quin)X},], to give, with the former only stableorganometallic products and with the latter a benzenoidtrimer via an isolable organometallic intermediate ; (ii)the insertion of a two-carbon unit (one molecule of hfb)into the Pd-C bond of the above compounds withoutcleavage of the Pd,Cl, unit, to give novel chloride-bridged dimers of compounds containing a seven-membered metallacycle which afford monomeric deriv-atives by bridge splitting with neutral ligands.RESULTS AND DISCUSSIONReactions between Disubstituted Alkynes, RC-CR'(R = R' = Ph.and R = Me, R' = Ph) and Cyclopal-ladated Com@ounds.-When stoicheiometric amounts ofeither the dimer [{Pd(dmba)X),] or the monomericpyridine derivatives [Pd(dmba)(py)X] (X = C1 or Br)and diphenylacetylene were heated under reflux inmethylene chloride a deep yellow solution was formedfrom which yellow-orange crystals were obtained in highyield. The product is formulated as a bis-insertioncomplex, [Pd{ (PhC=CPh),C6H4CH,NMe,)X] (la).Thei.r. spectrum showed bands at P 620w, 1 598m, 1590m,and 1 577w cm-l due to v(C=C) and a strong band assignedto terminal v(Pd-C1) at 320 cm-l; however, for th548 J.C.S. Daltonbromo-compound the analogous vibration could not beunambiguously assigned (see below). The lH n.m.r.spectrum consisted of a multiplet at 6 6.4-7.8 p.p.m.(Ph, 24 H) and sharp singlets at 2.76 and 2.70 (5 H) andon the following considerations: (i) the two highest-field peaks were assigned to C-methyl groups, in accordwith those observed for the complexes [(Pd[(CMe=CMe),Cl]Cl},] l3 and [Pd( CBut=CMeCMe=CButCl) (acac)] l4(acac = pentane-2,kdionate) in which one end of theolefinic chain bearing methyl substituents is linked tothe metal by a Pd-C Q bond; (ii) the assignments ofC-methyl groups [6 1.60 (MeCH=) and 2.08 p.p.m.(C-MeC=C)] for (1 E ,32)-1-deuterio-2-methyl- 1,3-di-phenylpenta- 1,3-diene 16 (PhDC=CMePhC=CHMe) canbe closely related to those observed for isomer (lba)(6 1.56 and 2.16 p.p.m.); (iii) no drastic differences inchemical shifts should be expected for the N-methylgroups from one isomer to the other.In order to establish unambiguously the molecularstructure of these two isomers a single-crystal X-rayBrC(26)FIGURE 1 ORTEP drawing of compound (lba; X = Br)2.32 p.p.m.(3 H). The two equally intense singlets at2.70 and 2.32 p.p.m. are assigned to inequivalent N-methyl groups and that at 2.76 p.p.m.corresponds to themethylene protons.The corresponding reaction of either [{Pd(dmba)X),] or[Pd(dmba)(py)X] with the unsymmetric acetylenePhC,Me afforded an isomeric mixture of two bis-insertion products (lba) and (lbs) which have beeneasily isolated. The i.r. spectra of the two isomerswere nearly identical ; however, differences were observedmainly in the bands due to v(C=C) (1 594m cm-l for thea form and 1 615m and 1 600m cm-l for the p form) andin the 700-800 cm-l region (see Experimental section).The lH n.m.r. spectrum of each form showed, in addi-tion to aromatic proton resonances, four sharp singletsof equal intensity attributed to non-equivalent methylgroups (NMe, CMe), and signals corresponding to methy-lene protons which were split into an AB quartetW(H-H) 14 €I21 or were broadened and ill definedfrom extensive overlapping of lines (6 1.5-3.0 p.p.m., 14H) .Accordingly, assignments were made tentativelydiffraction study was made on a bromo-derivative of oneisomer and on a chloro-derivative of the other. Theresults of this study are given in Tables 3-8 and areillustrated in Figures 1 and 2 which also show thecrystallographic numbering system. For both struct-ures the atoms directly bonded to the palladium atoms[C(7), N, X(C1 or Br)] and A [the middle of the C(10)C(17) vector] are almost coplanar, although the devi-ations from these planes are rather large as shown inTables 7 and 8. The C(lO),C(17) vector is nearly per-pendicular to these planes, the distances Pd-C(10) andPd-C( 17) however being significantly different.ThePd-C(7) distance is shorter in the chloro- than in thebromo-compound presumably because of the different Rgroups attached to these carbons. The Pd-N distancesare quite large compared to other palladacyclic com-pounds 1 ~ 6 and this is probably due to the larger transeffect of a a-bonded carbon [C(7)] than Br or CO(CO),.~~The Pd-Cl distance is normal whereas the Pd-Br oneseems to be short [2.449(2); lit.,17 2.58 A]. Thereforewe could not assign the v(Pd-Br) vibrations for the bis1979 549insertion products to any i.r. absorption consistent withthis short Pd-Br length. However, for these bromo-compounds, we observe an intense i.r.absorption inthe range 150-156 cm-l, which is absent for the cor-responding chloro-compounds. These wavenumbers arefar too low for a terminal Pd-Br stretching frequency,the bromine being trans to an olefinic bond {v(Pd-Br) isin the range 207-222 cm-l for [Pd(diene)Br2]}.l8 Theyare possibly a combination of different vibration modes,but they certainly contain some v(Pd-Br) character.On the other hand, the v(Pd-C1) frequencies are ingood agreement with those found for related com-pounds .18In contrast to the preceding reaction of [{Pd(dmba)-@ C(26)FIGURE 2 ORTEP drawing of compound (lbg; X = C1)XI,] with acetylene, the reaction of [(Pd(8Me-quin)X),]with PhC,Ph afforded two products separated by frac-tional crystallization. The first, containing 1 mol oftoluene of crystallization per mol of compound, wasobtained in rather poor yield.Its elemental analysisand spectroscopic features are consistent with the illus-trated structure (2a) , i.e. a bis-insertion compound forPh Phwhich the methylene protons appeared as a four-lineAB pattern [J(H-H) 15 Hz] in the lH n.m.r. spectrum.A singlet corresponding to the methyl group of thetoluene of crystallization occurs at 2.34 p.p.m. Thesecond product was hexaphenylbenzene, identified byits elemental analysis and mass spectrum. The yieldof (2a) depended on the reaction time, suggesting thatthis compound is an intermediate in the cyclo-oligo-merization of diphenylacetylene.The reaction of [ (Pd(8Me-quin) X),] with PhC,Meafforded two products analogous to (2a) and the benzen-oid trimer.We could not isolate a pure metallacyclefrom the crude yellow mixture (very poor yield - 0.5%).Microanalytical data were erratic but not far from thevalues calculated for a bis-insertion product. The lHn.m.r. spectrum showed a very complex pattern in themethyl region which was not analyzable. By analogywith (2a), however, we suggest that this compound is amixture of isomers, each of which has the same basicskeleton as that of (2a). The major product whichseparated as a white crystalline compound was a mixtureof lJ2,4-trimethy1-3,5,6-triphenylbenzene and lJ3,5-tri-methyl-2,4,6-triphenylbenzene (7 : 3, see Experimentalsection for 1H n.m.r. data). The mixture was identifiedby elemental analysis and by its mass, and particularlyIH n.m.r.spectra. The last spectrum unequivocallygave the proportion of each isomer formed, with theassignment according to Maitlis and his co-workers l3who have previously separated isomers of this benzene-noid trimer.It will be noted that only bis-insertion products wereisolated when the reaction was carried out in the presenceof an excess of acetylene. Attempts to produce mono-insertion complexes with PhC,Ph or PhC,Me, either byshortening the reaction time or by carrying out thereaction with less than a stoicheiometric amount ofacetylene, failed. No reaction takes place betweenPhC,Ph and cyclopalladated compounds formed fromben~o[h]quinoline,~~ azobenzene,19 or NN-dimethyl-1-napht hylamine .llThese reactions can be related to similar reactions ofcyclometallated compounds with acetylene affordingbis-insertion products, e.g.[Rh((PhC=CPh),C,H,PPh,)-(PPh,)] ,4 the structure of which was established by X-rayanalysisJ20 and [Ru{(CF3C=CCF,),C,H,PPh,)~~-C,H5)] .5In each of these an eight-membered ring is formed,chelating via M t P and M-C (M = Rh or Ru) G bonds. Incontrast , the metallacyclic structure we observe consistsof a nine-membered ring (which is somewhat uncommonfor palladium complexes) chelating via P d t N and aPd-C 0 bond and a trans arrangement of the halogenatom with respect to the metal-olefin x bond.Reactions between HexafEzlorobut-2-yne and Cyclo-palladated Compounds.-In order to obtain further evi-dence in support of insertion of acetylenes bearing elec-tron-withdrawing substituents into the Pd-C o bond, wehave investigated the reaction between hfb and dimersformed from NN-dimethylbenzylamine, 8-methylquino-line , benzo[h] quinoline , and NN-dimethyl-1-naphthyl-amine. With the exception of the latter, the reactionsproceeded to give a new type of compound for whichelemental analyses and spectroscopic features indicateJ.C.S.DaltonTABLE 1Analytical data, colours, and i.r. dataAnalysis (yo) 1.r. bands (cm-l)h-.\ -X ' cC1 70.16(70.26)Br 66.40(66.66)C1 63.9(63.8)C1 63.6(63.8)Br 68.65(58.65)Br 68.6(68.66)Cle 74.26(73.8)Br 69.25(69.66)C1 36.6(36.6)Br 32.45(32.36)C1 36.6Br 34.8(34.26)C1 42.6(42.36)56.8(66.8)C1 41.6(41.8)Br 38.7(38.46)C1 63.1(63.16)Br 60.1(49.96)C1 43.0(43.46)C1 64.16(64.25)(37.7)H6.00(6.06)4.80(4.76)6.60(6.60)6.45(6.60)4.90(6.05)4.96(6.06)6.66(4.90)4.65(4.66)2.76(2.76)2.60(2.60)2.20(1.80)2.06(1.66)2.85(1.66)2.75(2.86)3.16(3.30)3.10(3.06)3.65(3.86)3.46(3.66)2.40(2.60)3.30(3.25)H2.262.26(2.06)2.66(2.76)2.96(2.76)2.66(2.65)2.60(2.66)2.162.00(1.80)3.10(3.20)3.00(2.90)3.30(3.15)3.06(2.86)3.16(2.90)4.36(4.40)6.40(6.40)6.00(6.00)2.162.106.26(6.36)2.16(2.20)(1.90)(2.00)(1.90)(2.00)F26.26(26.06)23.36(23.65)24.3(26.65)23.15(23.25)22.3(22.06)21.0(20.3)16.36(16.3)16.0(16.3)21.86(21.7)16.7(16.1)X7.45(7.00)13.6(14.46)8.36(8.10)16.15(16.6)8.2516.7(16.3)(7.95)6.66(6.85)13.9(14.25)6.30(6.06)10.56( 10.7 5)6.90(6.76)6.30(6.00)ColourDeep yellowLight orangeLemon- yellowGolden- yellowDark yellowYellowYellowYellowYellowDeep yellowPale yellowLemon- yellowTanRedPale yellowPale yellowPale yellowPale yellowWhitePale yellowv(Pd-X)3 20vsb305vs306vsbb312sb320s, 270s197s, 168s317vs, 255ms202m.5, 158m170m315s, 266s305vs182vs306vs202s309vs312vsv(c=C)162Ow, 1598m,1 590mJ 1577w1 694m, 1577w1616m, 1599m, 1575w1594m, 1576w1615m, 1690m, 1578w1629vw, 1 597m,1583w1617, 1606sh,1576w1642s, 1619vw,1598m1645m, 1 622ms1586w, 1 573m1630s, 1 691mJ 1576s11608s, 1677vw1 611m, 1 573vw1 634m, 1 609m,d 1 601w1633m.1600w, 1577wQ Calculated values are given in parentheses. See text. e One molecule of toluene of crystallization per mol of compound.d v(C=C) + v(C=N) from co-ordinated py. Strong v(C-F) between 1 080 and 1 280 cm-1 for all fluoro-compounds.the presence of one hfb molecule per Pd atom in a halide-bridged binuclear complex.( 3 1r(5 1Thus [(Pd(dmba)X),] reacted over a period of severalhours at 60 "C with hfbindichloromethane to yield a yellowcrystalline product [ (Pd[ (CF,C=CCF,) C,H,CH,NMe,]-X>J (3). In the i.r. spectrum several bands are assign-able to v(C=C) (see Table 1) and strong absorptionsbetween 1280 and 1100 cm-l are typical of v(C-F)vibrations.In the metal-halide stretching region twostrong bands, involving bridging Pd-X bonds in thebinuclear Pd,X, unit,18p21,22 are observed at 320 and 270cm-l and at 197 and 168 cm-l for X = C1 and Br respect-ively. The 1H n.m.r. spectrum showed, apart from reson-ances indicative of phenyl protons (6 7.2-7.6 p.p.m.,8 H), a four-line AB pattern associated with one methy-lene group and a complex pattern arising from theremaining protons (6 2.3-3.0 p.p.m., 14 H) : four sharpsinglets of equal intensity at 2.91 and 2.75 p.p.m. and at2.47 and 2.45 p.p.m. (A8 4.5 Hz) assigned to non-equivalent pairs of N-methyl groups in each half of thedimer, plus a broadened multiplet assigned to thesecond methylene group. The 19F n.m.r.spectrumcontained two equally intense resonances at 49.0 (9)and 59.07 (9) p.p.m. (upfield from CFCI,) and two some-what overlapped signals at 49.4 (q) and 49.6 p.p.m.(broad multiplet). The high value of the couplingconstant [5](FbFb) 13.8 Hz] suggested the presence of acis-CF,C=CCF, group 23 in each half of the dimer. Thes1979 551data strongly suggest the presence of the following twoisomers in a 1 : 1 ratio: *The corresponding reactions of the 8-methylquinolineand benzo[h]quinoline dimers with excess of hfb affordedthe binuclear analogues (4) and (5) respectively. Theseproducts were not fully characterized due to their veryCom-pound X(lb) [' a Br(2a) C1(la) a :;P Br(3) c1(7a) C1(7b) C1(8a) C1(8b) C1(6)with an excess of hfb (in situ) to yield a mixed orhomogeneous bis-insertion compound respectively.Di- p-chloro-bis(NN-dimet hyl- 1 -napht hylamine-C8N) -dipalladium reacted with an excess of hfb at roomtemperature in dichloromethane with a change in colourfrom yellow to deep orange, but decomposition occurredeven under an inert atmosphere.However, red crystalsof an organic product were isolated from pentaneextracts, The identification of the latter as (6) followedfrom its molecular weight and spectroscopic data. Themass spectrum contained a parent ion at m/e 317together with other ions at m/e 302 [P - Me]+ and 288TABLE 2Hydrogen-1 and 1BF n.m.r. data in CD,Cl,aNMel NMe2 CH, 2J(CH2)/Hz CMel CMe2 H aromatic2.70s2.97s, 3 H2.77s2.96s2.76s2.91s2.47s2.93s, 3 H2.88d,f 3 H2.32s, 3 H2.64s2.60s, 3 H2.71s2.68s2.75s2.45s2.78s, 3 H2.78d,g 3 H4.27d, 1 H7.05d.1 H4.10d, 1 H6.4761, 1 H3.22q,' 3 H6.4-7.8m, 24H14 2.16s, 3 H 1.58s, 3 H 6.8-8.0m, 14 H1414 2.15s, 3 H 2.32s, 3 H 6.8-8.0m, 14 H142.16s, 3 H 1.54s, 3 H 6.8--8.0m, 14 H14 2.16s, 3 H 2.47s, 3 H 6.8-8.1m, 14 H1415 2 . 3 4 ~ , ~ 3 H 6.5-8.3m, 30 H15 9.77dd, 1 H1111.41212121214141414} 7.2-7.6m, 8 H7.2-7.8m, 7 H8.38dd, 2 H7.1-7.6m, 19 H7.3-8.0m, 7 H8.3dd, 1 H8.8m, 2 H9.75dd, 1 H6.9-8.0m, 19 H8.35dd, 1 H9.57m, 1 H7.0-7.40m, 5 H6.40d,"' 1 H1 i49.0qe 59.07q 13.849.8q 57.8q 15.048.01dq i 58.66q 13.850.63q 58.53q 14.553.33q 59.95q 14.051.26m 60.27m 13.056.90q 59.50q 15.3Chemical shifts (6) downfield from SiMe, and upfield from CFC1, (0.00 p.p.m.) respectively; lH (90 and/or 250 MHz), 'OF [250MHz and, for (7a) 90MHzI.s = Singlet; d = doublet; dd = doublet of doublets; q = quadruplet; dq = doublet of quadruplets;m = multiplet. Unresolved integration. C AB quartet overlapped with NMe signals. d From toluene of crystallization. Be-sides overlapped signals at 49.4q and 49.6m p.p.m.; the bromo-analogue affords only two CF, resonances a t 48.lm and 58.6q p.p.m.,"J(FaFb) 15 Hz, lSF (90 MHz). f ,J(P-Me') 2.7 Hz. ,J(P-MeZ) 2.0 Hz. h ,J(P-H1) 6.4 Hz. i 4J(F&P) 8.0 Hz. f Mixture ofstereoisomers, the quartets a t 50.63 and a t 58.53 p.p.m.correspond to the predominant form (see text). Two overlapping quartets.,J(F+P) 6.5 and 'J(Fb-P) 19.6 Hz. 5J(F-H) 2.2 Hz. m 3J(H-H) 7.8 Hz.low solubility in common solvents. However, themetallacyclic structures (4) and (5) depicted are sup-ported by (2) elemental analysis, (ii) i.r. spectra contain-ing strong absorptions typical of v(C-F) vibrations, newbands due to v(C=C), and two strong bands due to v(Pd-X) stretching vibrations, (iii) products of bridge-splittingreactions with neutral ligands (see below). An asym-metric Pd,Cl, unit in compounds (3)-(5) is suggestedby a difference in v(Pd-C1) of 50-60 cm-l in each case.18For palladated compounds where the bridge is sym-metrical two bands in close proximity are generallyobserved.24 The lH and 19F n.m.r.data from product(3) are also in agreement with a low-symmetry structure.It is noteworthy that these dimeric compounds did notreact either with an equivalent amount of PhC,Ph or* We thank one of the referees for this suggestion.[P - NMe]+. The i.r. spectrum showed typical strongv(C-F) vibrations between 1080 and 1300 cm-l andbands at 1 630s, 1 591ms, and 1 576s cm-l due to v(C=C).The lH n.m.r. spectrum revealed, in addition to aromaticproton resonances, a broadened quartet at 6 3.22 p.p.m.(3 H), assigned to the N-methyl group. The 19F n.m.r.spectrum consisted of two equally intense 1 : 3 : 3 : 1quartets centred at 56.90 and 59.60 p,p.m. ; the quartetsare slightly broadened due to a further small couplingwith the N-methyl protons. Chemical shifts andcoupling constants (Table 2) are consistent with thepresence of a cis-CF,C=CCF, All attempts toisolate what we believe to be a metallacyclic precursorfailed, and the structure depicted for (6) is favoured.It is interesting to note the loss of one of the N-methylgroups for the ligand bearing nitrogen as donor atom.This feature has been observed in the reaction of th552 J.C.S.DaltonNN-dimet hylbenzylamine palladated dimer on carbonyl-ation which affords a demethylated product, i.e. 2-met hylnaphthylamine.Bridge-splitting Reactions with Group 5 Donor-atomLigands.-This type of reaction is well known withhalide-bridged cyclometallated complexes ; l8, 22p 239 25 thuswe have restricted our investigation to some cleavagereactions with neutral unidentate ligands such as tri-phenylphosphine and pyridine (py).The seven-membered metallacyclic dimers (3) and (4) easily undergobridge-splitting reactions in CH2C12 with py and PPh, toproduce high yields of the monomeric species (7) and(8) respectively. These are more soluble than the cor-responding dimeric compounds and accordingly thederivatives of (4), which is insoluble, were more amenableto spectroscopic study.MeThe i.r. spectrum of the monomeric derivativesshowed, besides typical absorptions of co-ordinated pyor PPh,, strong absorptions due to w(C-F) vibrations,bands due to w(C=C), and one strong band assigned toterminal w(Pd-X). The range of w(Pd-X) frequencies,at ca.305-310 and 182-202 cm-l for X = C1 and Brrespectively, is consistent with X trans to the carbon CJbonded to the metal. These values are somewhatshifted to higher wavenumbers compared to thoseobserved for pyridine or phosphine monomeric deriv-atives 22p 25 of compounds containing only five-memberedrings where X is trans to alkyl or phenyl groups and forwhich w(Pd-X) frequencies occur a t 280-299 (X = C1)and 160-172 cm-1 (X = Br). This behaviour can berationalized in terms of a smaller trans influence exertedby an alkenylic carbon than by alkyl or phenyl carbons.13The lH n.m.r. spectrum of complexes (7a) or (7b)showed, in addition to aromatic proton resonances, twosignals of equal intensity assigned to non-equivalentN-methyl groups, and the signals from (7b) were con-sistently split into doublets due to a small coupling of theN-methyl protons with phosphorus; the protons asso-ciated with the methylene group of most derivativesgave rise to the four lines of an AX system, with theexception of those of (7b) for which one proton is furthercoupled with phosphorus.The 19F n.m.r. spectrum ofeach derivative revealed unambiguously that the split-ting reactions had occurred with retention of the cis-CF,C=CCF, group. The spectrum of (8a; X = C1)showed more clearly than the far-i.r. spectrum thatthis pyridine complex occurs as a mixture of two stereo-isomers, i.e. the py is either cis or trans to the nitrogenatom of the metallacyclic ring (ratio of isomers 8.5 : 1.5).Nevertheless, both the far-i.r.and 19F n.m.r. data indi-cate that the trans derivative (X trans to Pd-C Q bond)predominates. The relatively simple 19F n.m.r. spectraof the phosphine derivatives (7b) and (8b) indicated thatonly one isomeric form occurred in these products,namely the trans isomers. Phosphorus-fluorine coup-ling was observed for both CF, groups of (8b), but onlyfor the most proximal CF, in (7b). Chemical shifts andimportant coupling constants are listed in Table 2.EXPERIMENTALMicroanalysis was carried out by the C.N.R.S. Micro-analytical Service. The i.r. spectra (400-4 000 cm-l) inKBr pellets were recorded on a Beckman IR 12 spectro-meter. Spectra in the range 50-420 cm-l were run inpolyethylene discs, using a Polytec FIR 30 interferometer.N.m.r.spectra were obtained on Bruclter W.H. 90 (90RIHz) and/or Cameca (250 MHz) spectrometers usingdichlorodeuteriornethane as the solvent.Cyclopalladated compounds formed from NN-dimethyl-benzylamine,l' 8-methylquinoline,12 benzo[hjquinoline,'Zazobenzene,lg and NN-dimethyl-1-naphthylamine l1 wereprepared by published methods. Diphenylacetylene, 1-phenylprop-1-yne, hexafluorobut-2-yne, pyridine, and tri-phenylphosphine were used as obtained.Reactions of [{Pd(dmba)X},] and [Pd(dmba) (py)X].-(a)With diphenylucetylene. A mixture of [{Pd(dmba)X),](X = C1; 0.22 g, 0.4 mmol) and diphenylacetylene (0.30g, 1.7 mmol) in dichloromethane (60 cm3) was heated underreflux for 24 h, with rapid stirring. The orange reactionmixture was filtered and then evaporated to dryness inZ~UCUO.The resulting solid was exhaustively extracted(Soxhlet) with pentane (200 cm3) affording a yellow solutionwhich on evaporation a t room temperature (r.t.) yieldedyellow crystals of ( l a ; X = CI). For X = Br the reactiontime was shorter (7-8 h) and the crude product was re-crystallized from dichloromethane-pentane mixtures toyield light orange crystals of ( l a ; The yieldbased on Pd was 90% in each case.( b ) With 1-phenylprop-1-yne. The 'compound [{ Pd-(dmba)X),] (X = Cl, 0.46 g, 0.83 mmol) and I-phenyl-prop-1-yne (0.4 g, 3.4 mmol) were heated under reflux indichloromethane (60 cm3) for 20-24 h after which time thesolution turned dark orange. After all the solvent hadbeen removed, the crude product was transferred to a fritand quickly extracted with several portions of pentane(ca.20 cm3) until the last filtrate was colourless or very paleyellow. The combined filtrates afford on standing a t r.t.the isomeric 01 form (lb,) as small lemon-yellow crystals(yield 35-40~0). Extraction of the remaining residue inthe frit with acetone-pentane (1 : 1) yielded, upon concen-X = Br)1979 553tration of the solution, a dark yellow product. Furtherpurification was achieved by recrystallization from pureacetone and cooling to -20 OC, affording golden-yellowcrystals of the isomeric form (lbp) (X = C1, yield 15-20y0), which were collected, washed with excess of pentane,and dried in vucuo.For the bromo-analogues, the crude product was washedtwice with pentane (ca.20 cm3), then extracted and re-peatedly recrystallized from dichloromethane-pentane(15 : 85) to yield yellow crystals of (lbp; X = Br), whichwere collected, washed with portions of cold pentane (ca.5 cm3), and dried in vucuo. The combined filtrates wereevaporated to dryness in vucuo, affording a product whichupon repeated recrystallization from acetone-diethyl etherand then from pure acetone yielded dark yellow crystals ofthe a isomer.Separation of the two isomers was followed by i.r.analysis. For the bromo-isomers for instance the i.r.peaks in the range 700-800 cm-l are as follows: (Iba)785m, 769vs, 745w, 738w, 707vs; (lbp) 774(sh), 767s,752vs, 741s, and 699vs cm-l.With the monomeric complexes [Pd(dmba) (py)X] asstarting material the procedure was essentially the sameexcept that an excess (20% over the stoicheiometric amount)of acetylene was used.Reactions of [{ Pd(8Me-quin)X},].-(a) With diphenyl-acetylene.A suspension of [(Pd(8Me-quin)Cl),] (0.46 g,0.8 mmol) and diphenylacetylene (0.61 g, 3.4 mmol) washeated under reflux in dichloromethane (60 cm3) for 4 d.After evaporation t o half-volume the dark orange-redreaction mixture was filtered to remove the insolubleTABLE 3Atomic positional parameters (fractional co-ordinates)( x lo4) with estimated standard deviations in paren-theses for compound (lba; X = Br)X Y Z3 102.9(0.9) 9 504.3(1.0) 7 1 3.8( 0.8)3 506.3(1.7) 7 992.0(1.6) -228.4(1.4)3 743(11) 10 192(12) - 1 609(11)3 877( 13) 10 138( 14) -2 513(12)3 199(13) 10 324( 14) - 3 150( 11)2 243(12) 10 616( 16) - 1 958( 11)2 941(11) 10 419(13) - 1 322( 10)2 807(10) 10 501(14) - 325(10)1878(15) 12 296(15) - 240 ( 1 2)2 398( 14) 10 550(18) - 2 865( 11)2 376(11) 11 283(14) 88(10)2 497(10) 11 032(12) 1 088(10)1 630(11) 10 887( 14) 1 525( 11)985(12) 10 177(16) 1 144(13)184(15) 10 033(22) 1544(18)57(15) 10 594(21) 2 351(16)685(12) 11 333(18) 2 724(13)1478(12) 11 496(16) 2 311(12)3 315(10) 11 061(12) 1 544(10)4 083( 11) 11 572(14) 1 108(11)3 487(10) 10 938(12) 2 545( 10)3 313(11) 10 008(13) 3 055(10)3 644( 13) 9 993(14) 3 963(13)4 054(12) 10 867(15) 4 404( 11)4 159(11) 11 797(14) 3 920( 11)3 872(10) 11 820(13) 2 993(10)2 759(11) 9 051(13) 2 717(10)4 061(12) 8 021(15) 2 195(13)2 514(13) 7 607(15) 1 770(14)3 143(9) 8 450( 11) 1945(9)starting material.The resulting filtrate was evaporated tolow volume affording yellow crystals which on recrystalliz-ation from toluene and cooling to -20 "C yielded (2a;X = C1) (14%). The combined filtrates were evaporatedTABLE 4Atomic positional parameters (fractional co-ordinates)( x lo4) with estimated standard deviations in paren-theses for compound (lbp; X = C1)X Y3 241(6) -114(7)3 968(15) -2 612(24)-3 213(14)3 991(16) -3 069(13)3 485( 16) -2 351(21)3 209( 16) -1 673(16)3 451(14) - 1 810(10)3 819(16) - 947( 10)5 170(18) - 1 410( 11)2 525.9(1.5) 04 265(17)3 195(16) - 1 102(10)2 154(16) - 333(9)- 662( 17)352(13) -485(9)- 1 012(10)-2 324(17) -1 164(10)-2 918(17) - 789( 10)- 1 873(16) - 373(8)-211(15) -82(17)2 823( 17) 422(10)4 739( 15) 536(11)1859(16) 1244(9)554( 17) 1587(9)-92(22) 2 369(15)561(22) 2 781(10)1839(21) 2 413(11)2 530(16) 1670(9)-433(15) 1154(10)1254(20) 1 718(10)- 601 (20) 494(13)598( 13) 928(8)Z836.5 ( 1.3)3 471(4)- 1 506(10)- 2 523(9)- 4 092( 10)- 4 620( 10)-3 265(15)- 2 062(8)-1 091(15)- 1 559( 13)- 2 347( 13)- 1 667(16)-2 356(19)- 3 732( 16)- 4 433( 14)-3 709(13)- 1 493(15)- 1 378(16)- 2 063( 14)- 1 517( 14)- 2 056( 19)-3 140(20)-3 745(17)- 3 229(15)- 428(14)438( 15)1 501(15)1 905(16)1 126(12)2 OOO(l8)to dryness to leave a brown solid.This was dissolved in asmall volume of dichloromethane and addition of excess ofpentane afforded a yellowish precipitate which on recrystal-lization from acetone yielded colourless crystals of hexa-phenylbenzene (25%) identified by its elemental analysisand mass spectrum (molecular ion a t wz/e 534).Repetitionof the above experiment using a shorter reaction time gavethe bis-insertion product (2a) in variable yield (2 d, 10% ;3 d, 23%).The bromo-analogue (2a; X = Br) was obtained bymetathesis of the chloro-product with an excess of lithiumbromide in acetone.The procedure was essen-tially the same. However, after removal of the insolublecyclopalladated complex , the filtrate was evaporated todryness. Extraction with several portions of pure acetoneafforded a yellow filtrate and a whitish residue.The latterwas dissolved in hot acetone and on cooling yielded amixture of isomers of trimethyltriphenylbenzene identifiedby its elemental analysis and its mass (molecular ion a t m/e348) , and particularly lH n.m.r. spectra [methyl resonancesobserved as two equally intense signals a t 6 2.00 (s),1.675 (s), and 1.66 (s) p.p.m. (A8 1.5 Hz)].An attempt to isolate a pure bis-insertion product fromthe yellow filtrate in acetone failed. On evaporation todryness and recrystallization from toluene of the resultingproduct, the yellow crystals obtained gave rather unsatis-factory analyses (Found: C, 63.9; H, 5.25; N, 2.75.C,,H,,ClNPd requires C, 65.2; H, 4.5; N, 2.70%). Theyield was very poor (0.5-1%).Reactions of Hexafluorobut-2-yne.-(a) With the NN-(b) With l-phenylprop-l-yne554dimethylbenzylaminepalladium dimer.The complex [{ Pd-(dmba)X},] (X = C1 or Br, ca. 0.5-0.6 mmol) dissolved indichloromethane (50 cm3) was sealed in a thick glass tubewith hexafluorobut-2-yne (ca. 1.6-2.0 g, 10-12 mmol,condensed a t - 196 "C) and heated to 60 "C (12-15 h) witha change in colour from yellow to clear orange. The filteredsolution afforded, on evaporation a t r.t., a deep yellow pro-duct which on recrystallization from dichloromethane-pentane mixtures (1 : 1) yielded yellow crystals of (3) (80-goo/, based on Pd). These were collected, washed withlight petroleum, and dried in vacuo.Similarly (b) W i t h the 8-unethylquinolinepaZladium dimer.TABLE 5Bond lengths (A) and angles (") for compound (lb,; X = Br)(a) DistancesPd-BrPd-C (7)Pd-C ( 1 0)Pd-C ( 1 7)Pd-NPd * - * C(8)Pd .. . AC(l)-CP)C(2)-C(3) c ( 3)-c ( 4)C(4)-C(5)C(5)-C(6) c (61-C (1)c ( 6)-c (7)C(7)-C(8)C(8)-C(9)C( 10)-C( 11)C(8)-C( 10)C ( 10)-C ( 17)(b) AnglesBr-Pd-C ( 7)Rr-Pd-NBr-Pd - * AC(7)-Pd-NC( 7)-Pd - - * AN-Pd * * * AC (7)-Pd-C ( 10)C( 10)-Pd-C( 17)C( 1)-C(6)-C(7)C(5)-C(6)-C(7)C( 2)-C( 1)-C( A)C( 1)-c (2)-C( 3)C( 2)-c(3)-c( 4)C(3)-C(4)-C(5)C (4)-C (5)-C (6)C (5)-C( 6)-C( 1)C ( 6)-C ( 7)-PdC (6)-C ( 7)-C (8)C( 8)-C( 7)-PdC( 7)-C ( 8)-C ( 1 0)C ( b) -C (8) -C ( 10)C(7)-C@)-C(9)C (8)-C ( 10) -C ( 1 1)C(8)-C( 10)-C( 17) c(ll)-c(lo)-c( 17)2.449(2)1.999( 15)2.199(15)2.295(14)2.247 (12)2.603 ( 1 6)2.1271.379(25)1.368 (25)1.3 64( 29)1.393( 24)1.390(22)1.3 6 7 (23)1.519( 2 1)1.350(23)1.5 2 6 (25)1.517( 21)1.54 1 (23)1.3 7 7 ( 20)94.6(0.4)91.g(0.3)166.816 7,9 (0.6)75.399.6SS.O(O.6)3.56(0.5)12 1.3 (1.4)1 19.6 ( 1.0)12 1.9( 1.6)118.2( 1.4)123.0(1.9)1 17.7 ( 1.5)120.0(1.1)1 19.0( 1.0)1 3 2.4 (0.5)127.3( 1.3)100.2 (0.6)1 34.0( 1.5)106.0(1.0)119.9( 1 .O)113.6(0.9)C(l1)-C(12)C( 12)-C( 13)C( 13)-C( 14)C( 14)-C( 15)C ( 1 5)-C ( 16)C(16)-C(ll)C(17)-C( 18)C( 1 7)-C ( 19)C(19)-C(20)C(2O)-C(21)C(2 1)-C(22)C( 22)-C( 23)C( 23)-C( 24)C( 24)-C( 19)C (2 5)-C( 20)N-C(25)N-C(26)N-C(27)C( 11)-C( 12)-C( 13)C(12)-C(13)-C( 14)C ( 1 3)-C( 1 4)-C ( 1 5)C( 14)-C( 15)-C( 16)C( 15)-C( 16)-C( 11)C(l6)-C(ll)-C(12)C ( 1 O)-C ( 1 7)-C ( 1 8)C(lO)-C( 17)-C( 19)C( 18)-C(17)-C(19)C( 17)-C( 19)-C( 20) c ( 17)-c ( 19)-c (24)C( 19)-C( 20)-C( 25)C( 19)-c(20)-c(21)C( 20)-C( 2 1)-C( 22)C( 2 1)-C( 22)-c (23)C(21)-C(20)-C(25)C.( 22)-C( 23)-C( 24)C(23)-C(24)-C(19)C(24)-C(19)-C(20)C( 20)-C( 25)-NC( 25)-N-C(26)C ( 2 5)-N-C ( 2 7 )1.407( 24)1.423( 31)1.4 15 (36)1.407 (31)1.425(27)1.427 (24)1.530(23)1.499 ( 20)1.41 6( 22)1.403 (23)1.388(25)1.375( 24)1.412(21)1.385( 21)1.5 1 9 ( 22)1.528(20)1.522(22)1.523 (23)121.0(1.7)1 18.7( 1.4)120.9( 1.9)120.3( 1.4)119.0( 1.1)120.0( 1.2)120.4( 1.1)124.3( 1.1)112.7(0.9)126.1(0.9)1 15.6( 1.4)125.6( 0.9)117.1 (1.5)117.3( 1.5)1 23.9 ( 1.5)11 8.2( 1.3)1 19.3 ( 1.0)122.6 ( 1.6)118.3( 1.1)1 1 2.8 (0.8)113.2(0.9)102.8( 1.3)1 20.6 ( 1.1 j c(26 j-~-c (1 7 j io9.7ji.4j1 25.5 (0.9) Pd-N-C( 25) 110.2(0.9)Pd-N-C(26) 1 1 1.3 (0.8)C ( 1 O)-C( 1 1)-C ( 1 2) 1 20.5 ( 1.2) Pd-N-C (2 7) 109.3 ( 1.0)C(lO)-C(ll)-C(l6) 119.5(0.9)a suspension of [(Pd(8Me-quin)Cl},] (0.26 g, 0.46 mmol) andhexafluorobut-2-vne (1.6 E.10 mmoll in toluene (60 cm3\J.C.S. Daltonwas heated to 60-65 "C (7d) after which time the super-natant solution turned orange. The pale yellow filteredTABLE 6Bond lengths (A) and angles (") for compound( l b p ; X = C1)(a) DistancesPd-ClPd-C( 7)Pd-C ( 10)Pd-C( 17)Pd-NP d - . . Pd - - - cd8'CW-C(2)C(2)-c(3) c ( 3)-c (4)C(4)-C(5)C(5)-C(6)C(6)-C(1)C(W-C(S)C(7)-C(8)C(7)-C(9)C( 10)-C( 11)C( 8)-C ( 10)C(lO)-C(17)(b) AnglesCl-Pd-C( 7)C1-Pd-NC1-Pd * * * AC( 7)-Pd-NC( 7)-Pd * * - AC( 7)-Pd-C( 10)C( 1 0)-Pd-C ( 1 7)C(17)-Pd-NN-Pd * * * AC(l)-C(6)-C(8)C(5)-C(6)-C(8)C(l)-C(2)-C(3)C(2)-C(3)-C(4) c (3)-c (4)-c (5)C(4)-C(5)4(6)C(5)--C(6)-CP)C (6)-C ( 1)-C (2)C (8)-C ( 7)-PdC(9)-C( 7)-PdC (8)-C (7)-C (9)C( 6)-C( 8)-C( 10)C ( 7)-C ( 8)-C ( 1 0)Pd-N-C( 25)Pd-N-C ( 26)Pd-N-C ( 2 7)C(20)-C (25)-NC( 25)-N-C(26)C ( 25)-N-C ( 2 7)C (26)-N-C( 27)C ( W w ) - C (7 12.33 7 (4)1.922( 15)2.176( 11)2.237 (1 3)2.588 (14)2.1041.3 7 2 (32)1.400( 12)1.289 (35)1.446(33)1.394( 15)1.42 1 (38)1.466(20)1.400( 18)1.53 2 ( 19)1.523 ( 19)1.554(15)1.328 (20)2.222( 11)93.9 (0.4)90.2 (0.3)166.2168.3(0.5)76.267.6( 0.5)35.0 (0.5)95.3 (0.5)101.4124.1 (1.2)117.3( 1.2)118.8(0.9)121.9(1.6)12 1.5( 1.7)118.9(0.9)118.6(1.1)10 1.2 (0.6)129.6(1.0)129.2(1.4)130.5(1.0)126.6(0.8)103.0( 1.3)110.6(0.8)114.2(0.6)106.6 (0.5)114.0(0.8)108.7(1.0)105.1 (1.1)11 1.3( 1.1)120.2( 1.1)C( 1 1)-C( 12)C( 12)-C( 13)C(13)-C( 14)C( 14)-C( 15)C( 15)-C( 16)C( 16)-C(ll)C( 17)-C( 18)C( 17)-C(19)C( 19)-C(20) c ( 20)-c ( 2 1) c ( 2 1)-c ( 2 2)C (2 2)-C (23)C( 23)-C(24)C( 24)-C ( 19)C ( 20)-C ( 25)N-C( 25)N-C(26)N-C( 2 7)C(8)-C( 10)-C(l1)C(8)-C(lO)-C( 17)C( l l ) - C ( lo)+( 17)C( 10)-C( 11)-C( 16)C( 16)-C(ll)-C( 12)C(12)-€(13)-C(14)C(14)-C(15)-C(16)C( 15)-C ( 1 1 ) 16)-C(C( 1 0)-C ( 1 7)-C( 18)C(18)-C( 17)-C( 19)C( lo)<( 1 1 2 ) l)-c(C( 11)-C( 12)-C( 13)C(13)-C(14)-C(15)C(10)-C(17)-C(19)C( 1 7)-C( 19)-C( 20)c ( 2 1 )-C( 20)-c ( 25)c ( 24)-c ( 2 0 ) 19)-C(c (20)-c (2 1)-c (22)C(22)-C(23)-C( 24)C(23)-C(24)-C( 19)C(17)-C(19)-C(24)C( 19)-C(20)-C(25)C( 19)-C(20)-C(21)C(21)-C( 22)-C( 23)1.394( 19)1.427(18)1.384(21)1.4 1 1 ( 20)1.447 ( 17)1.389( 19)1.574(19)1.58 1 (20)1.364( 20)1.41 7 (26)1.353(27)1.3 89 (26)1.369(22)1.429( 19)1.530(20)1.547(15)1.504( 19)1.522(21)11 6.7( 1.2)121.4( 1.1)11 9.5(0.8)118.8(0.9)12 1.7( 1.3)121.1( 1.2)121.1 (1.2)119.0(0.9)119.7(0.9)121.7( 1.3)1 16.7 (1.5)1 2 0 4 1.1)124.4 ( 1.0)1 1 1.7 ( 1.0)127.2( 1.1)113.7(0.8)124.9(0.9)114.2( 1.1)119.0(0.8)120.7(1.2)120.4(1.2)118.9( 1.1)122.6( 1.7)118.3( 1.1)solid (similar to the starting material) was heated withexcess of lithium chloride in acetone (25 cm3).The resultingsolution was concentrated to low volume and upon additionof water yielded the pale yellow product (4; X = C1) whichwas washed with small portions of ethanol and then withlight petroleum and dried (yield 80%). The bromo-analogue (4; X = Br) was obtained by metathesis of (4;X = Cl) with excess of LiBr in acetone.(c) With the benzo[h]quinolinepaZladium dimer. Themocedure was essentially the same as for (b) except that th1979 555solvent was dichloromethane and the reaction time shorter(2 d).The tan product ( 5 ; X = C1) was obtained in ratherpoor yield (17yo). A deep orange filtrate resulting fromseparation of the reaction mixtures yielded orange crystalswhich were not identified.TABLE 7Some least-squares planes * for compound (lb,; X = Br)and distances (A) of atoms from planes in squarebracketsPlane (2): Pd, Br, C(7), N and A, the middle of the C(lO)-C(17)vector[Pd 0.00010, Br -0.0049, C(7) 0.2533, N 0.1170, A-0.9540X - 0.2508Y - 0.16432 + 7.5883 = 0- 0.025521Plane (ii): Pd, C(17), C(19), C(20), C(25), N-0.9777X + 0.2012Y - 0.05912 - 2.2694 = 0[Pd 0.0005, C(17) 0.0996, C(19) -0.1544, C(20) -0.1057,C(25) 0.4756, N -0.27911Plane (iii): Pd, C(7), C(8), C(10)-0.8877X - 0.4415Y - 0.13092 + 9.4855 = 0[Pd 0.0002, C(7) -0.0558, C(8) 0.0711, C(10) -0.03841* X, Y , and 2 are fractional co-ordinates (A) in the orthogonalsystem a, c* x a, c*.(d) W i t h the NN-dimethyl-l-naphthylaminepalladiumdimer.A solution of the chloride dimer (0.63 g, 1 mmol) indichloromethane (50 cm3) was degassed in a glass tube;hexafluorobut-2-yne (1 .O g, 6.2 mmol) was then condensedTABLE 8Some least-square planes * for compound (lbb; X = C1)and distances (A) of atoms from planes in squarebracketsPlane ( 2 ) : Pd, C1, C(7), N, A-0.7123X - 0.7014Y - 0.02682 + 1.4323 = 0[Pd 0.018, C1 -0.063, C(7) 0.297, N 0.126, A -0.1971Plane (ii): Pd, C(17), C(19), C(20), C(25), N0.5517X - 0.7049Y - 0.44582 + 1.4358 = 0[Pd 0.028, C(17) 0.144, C(19) -0.170, C(20) -0.137, C(25),0.460, N -0.2381Plane (iii): Pd, C(7), C(8), C(10)0.8066X + 0.5687Y - 0.16142 - 1.4800 = 0[Pd -0.020, C(7) 0.075, C(8) -0.085, C(l0) 0.0481* X, Y, and 2 are fractional co-ordinates (A) in the orthogon-al system a, c* x a, c*.(- 196 "C) into the tube which was sealed in vacuo.Re-action takes place a t r.t. (10-12 h) with a change in colourfrom yellow to dark orange but decomposition occurred(formation of PdO). The orange-red filtered solution wasevaporated to dryness in vacuo. Pentane extraction of thecrude mixture, under an oxygen-free atmosphere, affordeda deep yellow solution from which red crystals of (6) wereisolated by crystallization at - 20 "C (variable yield).Reactions between (3) or (4) and Neutral Ligands (L = py,OY PPh,) .-The products of bridge-splitting, (7) and (8),were obtained in high yield (ca.75-85y0) from the followinggeneral procedure. The dimer (3) or (4) (ca. 1 mmol) wastreated with a 15-20y0 excess ( > 2 mmol) of L (py orPPh,) in dichloromethane (30 cm3) with stirring a t r.t.until the solid dissolved (ca. 2-3 min). The clear solutionwas evaporated to low volume at r.t. and addition of lightpetroleum yielded a fine precipitate of the product. Purific-* For details see Notices to Authors No. 7, J.C.S.Dalton, 1978,Index issue.ation was accomplished by recrystallization from dichloro-methane-light petroleum.Crystal-structure Determination of [Pd(CMe=CPhCPh=CMeC,H,CM,NMe,)Cl] ( l b ~ ; X = C1) and of [Pd(CPh=CMeCPh=CMeC,H,CH,NMe,)Br] (lb,; X = Br) .-Crystal-lographic data were recorded at room temperature (20 "C)on a Nonius CAD-4 automatic diffractometer, using graph-ite-monochromated Mo-K, radiation (A 0.710 69 A).Wechose sufficiently small crystals so that the X-ray absorptioncorrections could be neglected. The unit-cell parameterswere obtained from the setting angles of 15 reflections, andintensity data were collected in the range 2 < 8 < 30°,using an 0-28 scan of width S = (1.20 + 0.30tan0)" anda counter aperture D = (3.00 + O.ltan8) mm.16 Datareduction was performed with the program MAXE .26CrystaE data. C,,H,,BrNPd, M = 552.8, Monoclinic,94.86(.l3)", U = 2 818 pi3, 2 = 4, D, = 130 g cm-,,~(Mo-K,) = 21.6 cm-l, F(000) = 1 112, space group P2,/c(no.14), 2 529 independent reflections, where o ( I ) / I < 1/3,retained for the the structure refinement.C,,H2,ClNPd, M = 508.4, Monoclinic, a = 8.227(6),1 163.4 pi3, 2 = 2, D, = 1.45 g ern-,, ~(Mo-K,) = 9.7 cm-l,F(000) = 520, space group P2, (no. 4), 2 077 independentreflections with o ( I ) / I < 1 retained for the structurerefinement.The molecular struc-tures were solved from Fourier-difference synthesis, follow-ing location of the heavy atoms (Pd and X = C1 or Br) andseveral carbon atoms with the program MULTAN,27The refinement of the atomic co-ordinates together withthe thermal parameters, isotropic at first then anisotropic,of the 30 atoms (excluding hydrogen) of the molecule gavethe final values of R [= C(lFoI - KIF,I)/XIF,I] of 0.074and 0.078 and of R' { = [Cw(lFol - KIF,])2/XwlFo~2]~} of0.065 and 0.105 for (lbb; X = C1) and (lba; X = Br) re-spectively.We used a weighting scheme of the Ibers type.With the exception of those of the methyl groups, all thehydrogen atoms were located on difference-Fourier syn-thesis and included in their calculated positions, but notrefined in the latter stages of refinement. They wereassigned isotropic thermal parameters equivalent to thoseof the carbon atoms to which they were bonded. Theleast-squares refinements were performed using SFLS-5.28Atomic positional parameters are in Tables 3 and 4,interatomic distances and angles in Tables 5 and 6, andselected least-squares planes in Tables 7 and 8.Observedand calculated structure factors, all the thermal parameters,the shortest intermolecular distances, and details of thephenyl-ring planes are listed in Supplementary PublicationNo. SUP 22416 (22 pp.).*[7/1214 Received, 11th July, 19773u = 15.362(13), b = 12.368(5), c = 14.886(11) A, p =b = 16.059(33), G = 8.923(9) A, p = 99.30(12)", U =Structure solution and refinement.REFERENCESM. Zinsius, Inorg. Chem., 1976, 15, 2675.327.Part 4, J. Dehand, J. Fischer, M. Pfeffer, A. Mitschler, andJ. Dehand and M. Pfeffer, Co-ordination Chem.. Rev., 1976,18,M. I. Bruce, Angew. Chem., 1977, 89, 75.W. Keim, J . Organometallic Chem., 1969, 16, 191.M. I. Bruce, R. C. F. Gardner, and F. G. A. Stone, J.C.S.6 T. G. Appleton, H. C. Clark, R. C. Poller, and R. J. Pudde-7 M. I. Bruce, B. L. Goodall, and F. G. A. Stone, J.C.S. Dalton,Dalton, 1976, 81.phatt, J . Organometallic Chem., 1972, 39, C13.1975, 1651556a J. M. Thompson and R. F. Heck, J . Org. Chem., 1975, 40,2667.H. Takahashi and J . Tsuji, J . Organometallic Chem., 1967,10, 511; D. Medena, R. Van Helden, and C. F. Kohll, Inorg.Chim. Acta, 1969, 3, 255.lo J. F. Van Baar, J. M. Klerks, P. Overbosch, D. J. Stufkens,and K. Vrieze, J . Organometallic Chem., 1976, 112, 95.l1 A. C. Cope and E. C. Friedrich, J . Amer. Chem. SOC., 1968,90, 909.l2 G. E. Hartwell, R. V. Laurence, and M. J. Smas, Chem.Comm., 1970, 912.l3 H. Dietl, H. Reinheimer, J. Moffat, and P. M. Maitlis, J .Amer. Chem. SOC., 1970, 92, 2276.l4 E. A. Kelly, P. M. Bailey, and P. M. Maitlis, J.C.S. Chem.Comm., 1977, 289.l6 N. S. Bhacca, D. P. Hollis, L. F. Johnson, and E. A. Pier,Varian Spectra Catalog, vol. 2, Varian Associates, 1963, spectrumno. 674.l6 G. Le Borgne, S. E. Bouaoud, D. Grandjean, P. Braunstein,J. Dehand, and M. Pfeffer, J . Organometallic Chem.. 1977, 136,375.l7 E. Forsellini, G. Bombieri, B. Crociani, and T. Boschi, Chem.Comm., 1970, 1203.J.C.S. Daltonla B. Crociani, P. Uguagliati, T. Boschi, and U. Belluco, J .Chem. SOC. ( A ) , 1968, 2869.lo A. C. Cope and R. W. Siekman, J . Amer. Chem. SOC., 1965,87, 3272.2o J. S. Ricci and J. A. Ibers, J . Organometalbic Chem., 1971, 27,261.21 J. Dehand, M. Pfeffer, and J. Shamir, Spectrochim. Acta,1977, A33, 1101.22 B. Crociani, T. Boschi, R. Pietropaolo, and U. Belluco, J .Chem. SOC. ( A ) , 1970, 531.23 H. C. Clark and W. S. Tsang, J . Amer. Chem. SOC., 1967, 89,633; P. M. Treichel, E. Pitcher, and F. G. A. Stone, Tnorg. Chem.,1962, 1, 511.24 M. S. Lupin, J. Powell, and B. L. Shaw, J . Chem. SOC. ( A ) ,1966, 1410.25 J. Dehand, M. Pfeffer, and M. Zinsius, Inorg. Chim. Ada,1975, 13, 229.26 J. Y. Le Marouille, These de 3e Cycle, Rennes, 1972.27 G. Germain, P. Main, and M. M. Woolfson, Acta Cryst., 1971,28 C. T. Prewitt, SFLS-5, Report ORNL-TM-305, Oak RidgeA27, 368.National Laboratory, 1966

ISSN:1477-9226    

DOI:10.1039/DT9790000547

出版商:RSC    

年代:1979

数据来源: RSC