Synthesis and reactivity of the formally co-ordinatively unsaturateddiruthenium hydride [ Ru~(~-H)(~-CO)(CO)~{~=(P~~O)~PNE~P(OPT?Z)Z] +and its co-ordinatively saturated parent [ Ru~H(CO)~{~-(PI-~O),PNEXP(OP~~,),I +Karen J. Edwards, John S. Field, Raymond J. Haines,* Beverley D. Homann, Mark W. Stewart,Jorg Sundermeyer and Stephen F. WoollamDepartment of Chemistry, University of Natal, Private Bag XOl, Scottsville, Pietermaritzburg 3209,Republic of South AfricaProtonation of the co-ordinatively unsaturated species [R~,(p,~-CO)~(CO)~(p-etipdp)~] [sb = semi-bridging,etipdp = (Pr’O),PNEtP(OPr’),] by acids of non-co-ordinating conjugate bases, e.g. HBF,*OEt,, produced[R~~(p-H)(p-CO)(CO)~(p-etipdp),] + which, as established X-ray crystallographically for the PF, - salt,contains both a bridging carbonyl and a bridging hydride ligand. This cationic species is very susceptible toattack by both neutral and anionic nucleophiles affording a range of product types.For instance, its reactionswith anions X- which are capable of functioning as monodentate bridging ligands and which preferentiallyadopt the closed bridging co-ordination mode, e.g. halide and hydrogensulfide ions, afforded products of thetype [Ru2(p-X)H(pSb-CO)(C0),(p-etipdp),] (X = C1, Br, I, SH, etc.), resulting from the substitution of acarbonyl group by the nucleophile. On the other hand, anionic nucleophiles such as H- and CN- gaveaddition products of the type [Ru,HX(CO),(p-etipdp),l (X = H, CN, etc.) in which the hydride and the X-ligand occupy equatorial sites trans disposed with respect to each other, as established in a separate study for[R~,H,(CO),(p-etipdp)~].Carbon monoxide also afforded a simple addition product, vzz. [Ru,H(CO),(p-e t i ~ d p ) ~ ] + , but the majority of the other neutral nucleophiles studied, particularly the unsaturated systems,yielded products resulting from formal insertion of the nucleophile into the Ru-H bond. Thus sulfur produced[Ru2(p-SH)(C0),(p-etipdp),] + , while unsaturated nucleophiles of general formula X‘=Y’, e.g. PhC=Nand R C S H (R = H, Ph, etc.), gave products of the type [R~~{p-X‘Y’(H)}(CO),(p-etipdp)~]+, e.g. [Ru$p-NC(H)Ph}(CO),(p-etipdp),] + or of the type [Ru2(p-q2-X’Y’(H))(C0),(p-etipdp),] +, e.g. [Ru2(p-q ’ : q -CHCHR)(CO),(p-etipdp),] + .Heterocumulenes X”=Y”=Z” such as CS, and PhNCS behaved similarlyaffording products of general formula [Ru, { p-q2-X”Y”(H)Z”}(CO),(p-etipdp),] + containing five-memberedRuX”Y”Z”Ru rings. The co-ordinatively saturated pentacarbonyl [R~,H(Co),(p-etipdp)~]PF~ gave productssimilar to those afforded by [Ru,(p-H)(p-C0)(CO),(p-etipdp),]PF6 on reaction with systems of the type XkY’and X”=Y”=Z” except that, for terminal alkynes such as PhCKH, alkenylcarbonyl-bridged products, e.g.[R~,fp-q~-0C(CH=CHPh))(CO)~(p-etipdp),]PF~, are produced. The crystal structures of the followingcompounds were determined: [Ru, (p-H)( p-CO)(CO) (p-etipdp) 2]PF6, [Ru2(p-I)H(psb-Co)( CO), (p-e tipdp) ,] ,OC(CHCHPh)} (CO),(p-e tipdp),]PF6 and [Ru, { p-rl ’-SC(H)NPh} (CO),(p-etipdp),]PF, .CRu2 (p3-N(CHPh)}(Co)4(p-etipdp),lPF,, [Ru,(p-q : qZ-CHCH2)(CO)4(pL-etipdp)2]pF6, [Ru2(p-q 2-The mechanism of activation of small molecule compounds bydi- and poly-nuclear transition-metal complexes continues to bea focus of attention in organometallic chemistry.A major aimof studies which form part of this focus is the synthesis ofcomplexes which will function as models for the chemisorptionof small molecule compounds on metal surfaces and/or whichwill themselves function as homogeneous catalysts for, inparticular, those reactions which are not catalysed bymononuclear complexes.’ Homogeneous catalytic processesmust involve at least one reaction intermediate which is co-ordinatively unsaturated and thus a prime objective in thedesign of homogeneous catalysts is the development of systemswhich readily give rise to formally co-ordinatively unsaturatedspecies or which themselves are co-ordinatively unsaturated.Such systems will provide the substrate molecules with directaccess to one or more metal atoms.’ Also, as well as beingpotential homogeneous catalysts, these systems are valuable aspotential precursors for the synthesis of generally inaccessibleproducts.In contrast to that for mononuclear systems, the range ofknown co-ordinatively unsaturated metal complexes ofnuclearity two and above is fairly limited.Low-valentunsaturated dinuclear carbonyl, cyclopentadienyl carbonyl anddiphosphorus ligand-bridged carbonyl derivatives that havereported and studied include [M2(p-H)2(CO),]2 - (M = Cr,Cr, Mo or W; cp = q5-C5H, or -C,Me,, sb = semi-[ R e ~ ( ~ 5 - C ~ M e ~ ) ~ ( ~ L , , - C O ) , o , 1 3 [Mn,(p-Mo Or w>,3 [Re2(p-H)2(Co)81,4 [M2(CP)2(psb-C0)41 (M =H)~(CO)~{J.L-(E~O)~POP(OE~)~)], 14” [Mn2(p-H)2(C0)6(p-dppm)] (dppm = Ph,PCH2PPh,), ,-* CMn 2 (c0)6 (p-dppm)12- (ref.19) and [Mn,(p-H)2(CO),(p-dppm)2].20We have established previously that [Ru,(p-CO)(CO),{ p-(RO),PNEtP(OR),),] (R = Me l a or Pr’ Ib), substitutedderivatives of diruthenium nonacarbonyl, can be decarbonyl-ated under various reaction conditions to the correspondingtetracarbonyl derivatives [Ru,(psb-Co),(Co),(p-(R0),PN-EtP(OR),),] (R = Me 2a or Pr’ 2b).,’ These unsaturatedelectron-rich species are highly reactive and react spontaneouslywith a wide range of nucleophilic as well as electrophilicreagents to afford, in the case of protonation, the dinuclearhydrides [Ru2H(p-C0)(C0>,{p-(R0),PNEtP(0R),},] + The latter are also co-ordinatively unsaturated and thus, notsurprisingly, are equally reactive, again reacting with a range ofnucleophilic and electrophilic reagents. The results of the studyJ.Chem. SOC., Dalton Trans., 1996, Pages 41 71-4181 417Results and DiscussionTable 1 Selected interatomic distances (A) and angles (") for thecomplex [Ruz(~-H)(p-Co)(Co),(CI-etipdp)~]PF, 3P( l)-Ru( 1)-P(2)P( 1)-Ru( 1)-C(2)P(I)-Ru(I)-H(~)P(2)-Ru( 1)-C(2)P(2)-Ru( I)-H( 1)C( 1 >-Ru( 1 kC(3)C(2tRu( 1 F ( 3 )C(3tRu(lFH(l)P( 3)-Ru(2)-C(3)P(3)-Ru(2)-H( 1)C(3kRum-HU)2.816(1)2.349( 1 )1.899(5)1.81(4)2.31 3(1)1.854(6)177.7(1)89.2(2)92m8 8.S( 2)90(2)165.9(2)99.7( 2)896.5(1)85(2)89(2)P( l)-Ru( 1 )-C( 1)P( I)-Ru( 1)-C(3)P(2)-Ru(l)-C(I)P(2)-Ru( 1)-C(3)C(1 kRu( 1 kC(2)C(1 )-Ru(l )-W)C(2 ~ R u ( I)-H( 1)P(3)-Ru(2)-P(4)P(3)-Ru(2)-C(4)C(3)-Ru(2)-C(4)C(4)-Ru(2)-H(1)2.346(1)1.935(6)2.158(5)2.325( 1)1.954(5)1.76(4)92.0(2)90.4( 1)8 9.2( 2)88.9(1)94.3(2)W2)179(2)169.9( 1)90.9(2)102.4(3)1 69(2)Cf28IFig. 1PF, 3 showing the atom labelling schemeStructure of the cation in [R~~(p-H)(p-CO)(CO)~(p-etipdp)~]-I,co I cooc- - coI 0 IEtof the reactivity of the tetraisopropoxy diphosphazane-bridgedspecies [Ru, H(p-Co)(Co),(p-etipdp),]PF, [etipdp = (Pr'-O),PNEtP(OPr'),] towards various neutral and anionicnucleophiles as well as that of the saturated pentacarbonyl[Ru,H(CO),(p-etipdp),]PF, towards unsaturated systems ofthe type XkY' and X"=Y"=Z are reported here; because of thedifficulty in s yn thesising [Ru, H( p-CO)( CO), (p-e tmdp) ,] PF,[etmdp = (MeO),PNEtP(OMe),] in a pure state in high yieldsits reactivity towards various nucleophiles was not investigatedin any detail.Some of the results have been communicatedp r e v i o ~ s l y . ' ~ , ~ ~Synthesis and structure of [ Ru2(p-H)(p-CO)(CO),-As reported previously,21 treatment of the formally co-ordinatively unsaturated compound [Ru~(~,,,-CO),(CO)~(~-etipdp)'] 2b with HBF,-OEt, or aqueous HPF, leads to theformation of the dinuclear cationic hydride [Ru,(p-H)(p-CO)(CO),(p-etipdp),] + 3, isolated as either the BF,- or PF, -salt, and which, according to its IR spectral data, contains abridging as well as terminal carbonyl groups [v(C-0): 2059s,2006s, 1956s (br) and 1757ms cm-', measured in CH,Cl,].Thepresence of a quintet of chemical shift 6 - 9.69 in the 'H NMRspectrum of this species was initially interpreted in terms of thepresence of a terminal hydride ligand and the cation adopting astructure analogous to that of the parent pentacarbonyl lb.21However, this chemical shift may also be interpreted in terms ofthe hydride adopting a bridging co-ordination mode and, as aconsequence, the crystal structure of the PF,- salt wasdetermined.The stereochemistry of compound 3 is illustrated in Fig.1;selected interatomic distances and angles are listed in Table 1.The two ruthenium atoms, separated by a distance of 2.816( 1) A,are linked, not only by two bridging diphosphazane ligands anda bridging carbonyl group, but by a bridging hydride ligand aswell; the hydrogen was reliably located in a difference electron-density map and its position refined. The co-ordination abouteach ruthenium atom is completed by two terminal carbonylgroups on Ru(1) and a single terminal carbonyl on Ru(2). Asshown Ru( 1) adopts an approximate octahedral geometry withthe angles subtended by the ligands at the metal atom rangingfrom 8 l(2) [C(3)-Ru( 1 )-HI through 90.4( 1) [p( 1)-Ru( 1)-C(3)]to 99.7(2)0 [C(2)-Ru( 1)-C(3)]. On the other hand Ru(2) adoptsan approximate square-pyramidal geometry with C(3) occupy-ing the apical position [C(3)-Ru(2)-H 89(2), C(3)-Ru(2)-P(4)and P(4), C(4), P(3) and H occupying the basal positions(p-etiPdp),l PF,93(2), C( 3)-Ru(2)-C(4) 102.4( 3), C( 3)-Ru(2)-P( 3) 96.5( 1 )"I[P(3)-Ru(2)-P(4) 169.9( l), C(4)-Ru(2)-H 169(2), P(4)-Ru(2)-C(4) 89.9(3), C(4)-Ru(2)-P(3) 90.9(2), P(3)-Ru(2)-H 85(2),P(4)-Ru(2)-H 92(2)"].This difference in stereochemistry forthe two ruthenium atoms can be interpreted in terms of Ru( 1)having a formal oxidation state of + 2 and of Ru(2) one of zero.In this context it is worth noting that distances associated withRu(2) are without exception less than the correspondingdistances for Ru(1). For instance the distances for Ru(2)-P(3)and Ru(2)-P(4) are 2.325( 1) and 2.313( 1) 8, respectively, whereasthoseforRu( 1)-P( 1)and Ru( l)-P(2)are 2.346( 1) and2.349(1)&respectively. Also the carbon of the bridging carbonyl issubstantially closer to Ru(2) [Ru(2)-C(3) 1.954(5) A] than toRu( 1) [Ru( l)-C(3) 2.158(5) A].The ruthenium-rutheniumdistance of 2.816(1) 8, corresponds to a formal bond. However,molecular orbital calculations on the formally co-ordinativelyunsaturated species [ O S ~ ( ~ - H ) ~ ( C O ) ~ ~ ] and [M,(p-H)*-(CO),]"- (n = 2, M = Cr, Mo or W; n = 0, M = Mn orRe), all of which have been postulated to contain a metal-metaldouble bond, have indicated small or practically non-existentdirect metal-metal bonding with the interaction occurringthrough the hydrogen bridge^.^^,^' It is assumed that a similarsituation holds for the cation 3 and that the bonding betweenthe two ruthenium atoms is best explained in terms of closedRu-H-Ru and Ru-C(0)-Ru bridge bonding.The cation isessentially eclipsed as evidenced by the P( 1 )-Ru( 1 )-Ru(2)-P(4)and P(2)-Ru( l)-Ru(2)-P(3) torsion angles of 1.9 and 9.4"respectively. A consequence thereof is that the four carbonylgroups and the hydride ligand are basically coplanar, with theprojected distances of C(4), Ru(2), H, C(3), Ru(l), C(1) andC(2) from their least-squares plane being 0.01 5 , 0.032, 0.005,0.017,0.017,0.017 and 0.005 8, respectively.The 31P-{ IH} NMR spectra of both the PF,- and BF,- salts4172 J. Chem. SOC., Dalton Trans., 1996, Pages 41 71418Et- Et(P40)2P~N'P(oPrj21.8, I coI rc0 OC- RU 'H' RU.EtEt+EtI co I CN oc - RU'- RU'- coH' I&' IScheme 1 Reaction of [Ruz(p-H)(p-C0)(CO),(CI-etipdp),] + withvarious anionic nucleophiles: (i) Li(C=CH)-H,NC,H,NH, or Li(CrCPh) in acetone at - 15 O C ; (ii) X- in acetone at room temperature(r.t.) (X = C1, Br or I); (iii) SH- in methanol added to 3 in acetone atr.t.; (iu) NaBH, in acetone at r.t.; (u) CN- in acetone at r.t.CW)Fig.2 Molecular structure of [R~,(p-I)H(p,~-CO)(CO)~(p-etipdp),]6 showing the atom labelling schemeof compound 3, measured in (CD,),CO at -80 OC, exhibit asymmetrical set of resonmces of AA'BB' pattern, centred at 6142.0, as predicted for the structure established crystallographi-cally.However, the corresponding room-temperature spectracontain a broad singlet at 6 138.9. This is interpreted in terms of3 being involved in some fluxional process, as establishedpreviously for [Ru, H(C0) { p-(RO) ,PNEtP(OR) , } 2] +Reactivity of [ R~~(p-H)(p-CO)(CO)~(p-etipdp)~] PF, towardsvarious nucleophilesBeing cationic and formally co-ordinatively unsaturated,compound 3, is, not unexpectedly, very susceptible to attack byanionic nucleophiles. Thus treatment with NaBH, in acetone atroom temperature was shown to lead to the ready formation ofthe known dihydride, [Ru,H,(CO),(p-etipdp),l 4, previouslysynthesized by reaction of [R~,(p~,-CO),(CO),(p-etipdp)~]with H,.,' As established X-ray crystallographically,21 the twohydride ligands in this complex adopt equatorial positions,essentially trans disposed with respect to each other.A product related to 4 and characterised as the neutralcyanohydride [Ru2H(CN)(C0),(p-etipdp),l 5 was obtained byreaction of 3 with NaCN in CH,Cl, at room temperature.Attempts to produce single crystals of this species, suitable for acrystal structure determination, were not successful but thestructure of the compound could nevertheless be ascertainedfrom the spectroscopic data.In particular the 31P-{ 'H} NMRspectrum, measured in C6D, at room temperature, exhibited anAA'BB' pattern of peaks, indicative of an asymmetric structure,while the 'H NMR spectrum revealed a quintet at 6 -7.58,more readily assigned to a terminal rather than a bridginghydride ligand.The IR spectrum in the C-0 stretching regioncontained peaks corresponding to terminal carbonyls only.These data are consistent with the structure shown in Scheme 1;the sites of co-ordination of the hydride and cyanide ligandscould not be established unequivocally but they are presumedto occupy equatorial positions trans disposed with respect toeach other on the basis that these are the co-ordination sitesoccupied by the hydride ligands in 4 (see above).Halide ions also react spontaneously with compound 3 insolution at room temperature but significantly the productsformed were found to result from carbonyl substitution ratherthan from simple addition and were characterised as [Ru2(p-X)H(pSb-Co)(p-Co),(p-etipdp),] 6 (X = C1, Br or I).The "P-('H} NMR spectra of these compounds were found to containsingle AA'BB' patterns while their 'H NMR spectra eachcontained a triplet corresponding to the hydride ligand, ofchemical shift more readily assigned to a bridging rather than aterminal hydride. Three peaks of distinctive band pattern wereobserved in the C-0 stretching region of their IR spectra. Theseresults could be interpreted in terms of a structure based on thatof the parent cation 3 in which the bridging carbonyl has beenreplaced by a bridging halide ligand. Alternatively the structurecould be based on that of [Ru,(pX)(CO),(p-etipdp),l+ (X =C1, Br or I)26 with the hydride occupying a site of one of theterminal carbonyls.With the object of establishing unequivocally the structureof these species the crystal structure of [RU2(p-I)H(psb-CO)(CO),(p-etipdp),] 6 (X = I) was determined.Thestereochemistry of the complex is illustrated in Fig. 2; selectedinteratomic distances and angles are given in Table 2. As well asbeing bridged by two diphosphazane ligands, trans disposedwith respect to each other, the two ruthenium atoms are linkedthrough an essentially symmetrically disposed bridging iodide[Ru(l)-I 2.795(1), Ru(2)-I 2.754(1) A]. One of the carbonylgroups bonded to the Ru(1) atom is, to a first approximation,collinear with the ruthenium-ruthenium vector, whereas theother functions as a semi-bridging carbonyl to Ru(2)[Ru( 1)-C(2) 1.92(2), Ru(2)-C(2) 2.53(2) A]. The hydride ligand,the position of which was reliably located, was shown to co-ordinate terminally which contrasts with what is observed forthe hydride ligand in the parent cation 3, as discussed above.Similar to that for the situation in 3, the two ruthenium atoms in6 (X = I) adopt different local geometries.Thus, while Ru( 1) isJ. Chem. SOC., Dalton Trans., 1996, Pages 41 71-4181 417Table 2complex [R~,(p-I)H(CO),(p-etipdp)~] 6Selected interatomic distances (A) and angles (“) for the l+ EtRu( 1)-I 2.795( 1) Ru(2)-1 2.754( 1)Ru( 1 )-Ru(2) 2.821(1) Ru( 1 )-P( 1) 2.318(3)Ru( 1)-P(2) 2.3 17(4) Ru( I)-C( 1) 1.84(2)Ru( 1 t C ( 2 ) 1.92(2) Ru(2)-P( 3) 2.306( 3)Ru(WT4) 2.308(4) Ru( 2)-C(2) 2.5 3( 2)Ru(2)-C(3) 1.77(2) Ru(2)-H( 1) 1.40(8)I-Ru( 1)-P( 1)I-Ru( 1 )-C( 1 )P( 1)-Ru( 1)-P(2)P( I)-Ru( 1)-C(2)P(2)-Ru( 1 )-C(2)I-Ru( 2)-P( 3)1-R~(2)-C(2)I-Ru(~)-H( 1 )P( 3)-Ru(2)-C(2)P(3)-Ru(2)-H( 1)P(4)-Ru(2)-C( 3)C(3)-Ru(2)-H( 1)C(2)-Ru(2)-C(3)89.1(1)130.2(5)176.6( 1)92.0(3)91.4(3)88.0( 1)101.7(3)W3)93.8(3)84(3)92.1(4)87.4(5)8x3)I-Ru( 1 )-P(2)I-Ru( 1)-C(2)P( 1 )-Ru( 1 )-C( 1 )P(2)-Ru( 1)-C( 1)C( 1 )-RN 1 )-C(2)I-Ru( 2)-P(4)I-Ru( 2)-C( 3)P(3)-Ru(2)-P(4)P( 3)-Ru(2)-C( 3)P(4)-Ru( 2)-C( 2)P(4)-Ru(2)-H( 1)C(2)-Ru(2)-H( 1)89.7( 1)1 19.9(4)89.0(4)89.4(4)1 09.9( 6 )88.9(1)170.8(4)1 74.1 (1)90.2(4)91.8(3)9 1(3)172(3)essentially trigonal bipyramidal with the iodine, the carbon ofthe semi-bridging carbonyl and the carbon of the terminalcarbonyl adopting the equatorial positions [I-Ru( 1)-C( 1)Ru(2) is essentially square pyramidal or octahedral if thecarbon of the bridging carbonyl is accepted as a sixth site withthe hydrogen occupying the apical position for the square-pyramidal geometry.The ruthenium-ruthenium distance of2.821(1) A is again consistent with a formal Ru-Ru bond but asfor 3 the bonding between the two ruthenium atoms isundoubtedly more appropriately explained in terms of closedRu-1-Ru bridge bonding. As for 3, the compound adopts analmost eclipsed configuration with the P( 1 )-Ru( l)-Ru(2)-P(4)and P(2)-Ru( l)-Ru(2)-P(3) torsion angles being 0.1 and 2.6”respectively. The molecular geometry of 6 (X = I) is similar tothose reported for [R~~(p-I)I(CO),(p-etipdp)~] 27 and [Ru,-(p-I)I(CO),(p-dppm)2] 28 although a close examination of thethree structures reveals that that adopted by [Ru2(p-I)-I(CO),(p-etipdp)2] is in effect a ‘frozen’ transition state in thetransformation of the structure as adopted by cR~~(p-1)-(CO),(p-etipdp)2] + (ref.27) to that as exhibited by 6 .Addition of an equimolar amount of NaSH to a solution ofcompound 3 was found to result in the formation of a productcharacterised as [R~~(p-sH>H(p,~-Co)(CO),(p-etipdp)~] 7with a structure analogous to that of 6 on the basis of itsspectroscopic data and, in particular, the band pattern of theC-0 stretching peaks in its IR spectrum being almost identicalto that found for 6. This hydrogensulfido-bridged derivativehas been synthesised previously by reaction of [Ru,(p,,-CO),(CO),(p-etipdp),] with H2S.21 Significantly, while theroom-temperature ‘P-{ ‘H} NMR spectrum of this species,measured in [2H8]toluene, exhibits a broad singlet at 6 158.8,the corresponding spectrum measured at - 32 “C exhibits twooverlapping sets of peaks with one set having a definite AA‘BB’pattern.This observation is interpreted in terms of thiscompound existing in two isomeric forms in solution with thetwo isomers rapidly interconverting at room temperature by aprocess which results in the phosphorus atoms being equivalenton the NMR timescale. Treatment of 3 with the acetylideanions HC-C- and PhC=C- led, on the other hand, to theformation of the neutral parent complex [Ru2(p-CO)(CO),(p.-etipdp),] lb29 as the only identifiable product, the alkynesH C S H and PhCKH presumably being eliminated and a CObeing scavenged during the elimination process.The compound [R~,(p-H)(p-Co>(Co),(p-etipdp)~]PF, isalso highly reactive towards neutral nucleophiles. For instancepassage of carbon monoxide through a solution of this130.2(5), I-Ru( 1)-C(2) 1 19.9(4), C( l)-Ru( 1)-C(2) 109.9(6)”],I co I co oc - RU’- RU’- coH’ loc’ Il+ EtEt(iv l2Et--I+ I Et(Pri0)ZP ”\ P(OPf92I I10 l+ Et 13(Pri0)2P 0N\P(oPri)2I IScheme 2 Reaction of [R~~(p-H)(p-CO)(CO),(p-etipdp).J + withvarious neutral nucleophiles: (i) CO in acetone at r.t.; (ii) S, in tolueneadded to 3 in acetone at r.t.; (iii) CS2 in acetone at r.t.; (iu) PhNCS inacetone at r.t.; (u) PhCN in acetone at r.t.; (ui) RC&H (R = H or Ph)in CH2C12 or acetone at r.t.species leads (Scheme 2) to the immediate formation of[R~,H(cO),(p-etipdp)~]PF,, also obtained directly by proton-ation of l b with aqueous HpF,.26 Significantly sulfur alsoreacts spontaneously with 3 at room temperature to givethe hydrogensulfido-bridged cationic product [Ru&sH)(Co),(p-etipdp),]PF, 9, previously synthesised by deproto-nation of [R~,(C0),(H,S)(p-etipdp)~][PF,], or by proton-ation of [Ru2(p-S)(C0),(p-etipdp),l with HPF,.30 The IRspectrum of this species exhibits a distinctive pattern of peaks inthe C-0 stretching region typical of cationic species of the type[Ru2(p-A)(C0),(p-etipdp),] + while its ‘H NMR spectrumcontains a quintet at 6 0.63 corresponding to the hydrogen ofthe hydrogensulfido group.Significantly the 31P-(1H) NMRspectrum revealed an AA’BB’ pattern of peaks which isexplained in terms of the hydrogen of the hydrogensulfidogroup being outside of the plane defined by the sulfur and thetwo ruthenium atoms.Not surprisingly compound 3 is very susceptible to attack byunsaturated neutral nucleophiles and, in particular, by those of4174 J. Chem. SOC., Dalton Trans., 1996, Pages 41 71-418Fig. 3 Structure of the cation in [Ruz{p-N(CHPh))(C0)4(p-etipdp),]PF, 10 showing the atom labelling schemeTable 3complex [Ru, {p-N(CHPh)}(CO),(p-etipdp), JPF, 10Selected interatomic distances (A) and angles (") for theRu( 1 )-Ru( 2) 2.7 16( 1) Ru( 1 k P ( 1) 2.334( 1 )Ru(l W ( 4 ) 2.328( 1) Ru(lFN(3) 2.097(4)Ru( 1 )-C( 1 ) 1.884(6) Ru( 1 FC(2) 1.903(5)Ru(2)-P(2) 2.344(1) Ru(2)-P(3) 2.349( 1 )Ru(2)-N( 3 ) 2.09 I(3) Ru(2)-C(3) 1.903(5)R@)-C(4) 1.891(6) N3)-C(33) 1.272(6)C(33)-C(34) 1.468(8)P( l)-Ru( 1 )-P(4)P( I)-Ru( 1 )-C( 1 )P(4)-Ru( 1 )-N(3)P(4)-Ru( 1)-C(2)N(3)-Ru( 1)-C(2)P(2)-Ru( 2)-P(3)P( ~)-Ru( 2)-N( 3)P(3)-Ru(2)-C(4)P(2)-Ru(2)-C(3)N(3)-Ru(2)-C(3)175.7(1)89.1(2)87.7(1)87.3( 1)1 1 6.1 (2)176.3( 1)93.0(1)88.7(2)86.2(2)148.4(2)95.3(1)88.6(1)90.2(2)1 43.7(2)100.0(2)93.0(1)92.1(2)8 8.7(2)114.8(2)96.5(3)type X-Y.Thus addition of an equimolar amount ofbenzonitrile to a solution of the compound results in animmediate colour change and the formation of a productcharacterised as [R~,(p-N(CHPh))(C0),(p-etipdp)~]PF, 10.The structure of this species has been established by X-raycrystallography and is illustrated in Fig.3; selected interatomicdistances and angles are listed in Table 3. The cation adopts aconfiguration more eclipsed than staggered [P(4)-Ru( 1)-Ru(2)-P(3) 9.1, P(l)-Ru(l)-Ru(2)-P(2) 8.3'1 with the tworuthenium atoms, separated by a distance of 2.716(1) A,corresponding to a formal ruthenium-ruthenium bond, beingbridged by an azavinylidene group as well as by twodiphosphazane ligands; the N(3)-C(33) distance of 1.272(6) A,corresponding to a nitrogen-carbon double bond, theN(3)-C(33)-C(34) angle of 128.1(7)' and the essentialcoplanarity of Ru(l), Ru(2), N(3), C(33) and C(34) [projecteddistances of C(33) and C(34) from the plane defined by Ru(l),Ru(2) and N(3) are 0.001 and 0.017 8, respectively] providedconfirmatory evidence of the N(CHPh) group functioning as anazavinylidene ligand.The group co-ordinates solely through thenitrogen atom giving rise to a three-membered dimetallahetero-cyclic ring and is produced as a result of the formal insertion ofthe benzonitrile into the ruthenium-hydrogen bond. A relatedtrinuclear compound [Ru, (p-N(CHPh)}(CO), 0] has beensynthesized previously by treatment of [Ru3(CO) 2] withbenzonitrile in the presence of acetic acid 31 or by reaction of[RU,(CO)~,] with PhCN in ligroin at 130 "C under anatmosphere of hydr~gen.~'The alkynes, ethyne and phenylethyne, the latter beingisoelectronic with benzonitrile, were also found to react readilywith compound 3 in solution at room temperature.In the caseof ethyne the product was characterised crystallographicallyas well as by conventional methods as [Ru2(p-q1 :q2-CHCH,)(CO),(p-etipdp),]PF, 11 (R = H) containing abridging vinyl group. The stereochemistry of the cation isillustrated in Fig. 4; selected interatomic distances and anglesare listed in Table 4. In contrast to 10, the cation adopts aconfiguration that is more staggered than eclipsed as reflectedby the P( 1)-Ru( 1)-Ru(2)-P(4) and P(2)-Ru( l)-Ru(2)-P(3)torsion angles of 1 1.3 and 16.2" respectively. The a-carbon ofthe vinyl group is nearly symmetrically disposed with respect tothe two ruthenium atoms [Ru( 1)-C(33) 2.098(8), Ru(2)-C(33)2.267(8) A] whereas the P-carbon has only one ruthenium atomwithin bonding distance [Ru(2)-C(34) 2.32( l), Ru( 1)-C(34)3.16( 1) A].Furthermore the latter carbon lies well outside of theplane defined by the two ruthenium atoms and C(33), thedihedral angle between this plane and that defined by Ru(2),C(33) and C(34) being 45.4". Two of the carbonyls are almostcollinear with the Ru-Ru vector [Ru(2)-Ru( 1 )-C( 1) 161.6(3),Ru(l)-Ru(2)-C(3) 174.5(3)"] whereas the other two are almostorthogonal to it [C(2)-Ru(l)-Ru(2) 101.0(3), C(4)-Ru-(2)-Ru( 1) 82.7(3)"]. The ruthenium-ruthenium distance of2.802(1) A corresponds to a formal metal-metal bond. Thegeometry of the bridging vinyl group in this compound is verysimilar to that adopted by the bridging vinyl groups in[MZ(cp),(p-ql : q2-CHCH2)(p-CO)(CO)2]BF4 (M = Fe orRu, cp = q5-C5H5).33'34 The 31P-(1H} NMR spectrum of thiscomplex contains an ABCD pattern of peaks which isconsistent with the structure established for the solid state whilethe 13C-{1H} NMR spectrum exhibits a triplet at 6 158.7corresponding to the methyne carbon and a broad triplet at 668.2 corresponding to the methylene carbon, these assignmentsbeing based on a distortionless enhancements of polarisationtransfer (DEPT) analysis; a multiplet centred at 6 8.10associated with the hydrogen of the a-carbon and multiplets at 65.02 and 4.27 corresponding to the hydrogens of the I)-carbonare observed in the 'H NMR spectrum.The product isolated from the reaction involving phenyl-ethyne was also found to result from the formal insertion ofthe alkyne into the ruthenium-hydrogen bond of compound 3,being characterised as the styryl-bridged product [Ru2(p-q1 : q2-CHCHPh)(CO),(p-etipdp),]PF, 11 (R = Ph).The 13C-{'H} NMR spectrum exhibits two quintets at 6 144.0 and 94.7with a DEPT analysis establishing the presence of a singlehydrogen on each of the two carbon atoms associated withthese quintets. The 'H NMR spectrum reveals two doubletsof quintets at 6 8.31 and 5.53, the integral of each setcorresponding to a single hydrogen and assigned to thehydrogen bonded to the a- and P-carbons respectively.However, the room-temperature 'P-{'Hf NMR spectrumexhibits a well resolved AA'BB' pattern of peaks at 6 135.6. Fora structure analogous to that of the vinyl-bridged speciesdiscussed above an ABCD pattern of peaks is predicted and onthis basis some fluxional process is assumed, possibly involvingin a formal sense a windscreen-wiper motion of the CHPhmoiety about an axis defined by the a-carbon of the styryl groupand the ruthenium atom closest to the P-carbon of the latter.Not surprisingly compound 3 is also very susceptible toattack by the heterocumulenes CS, and PhNCS affording[Ru2{p-q2-SC(H)S)(C0),(C1-etipdp),lPF, 12 and [Ru, { p-q2-sC(H)NPh}(Co),(p-etipdp),]PF, 13 respectively.As for theproducts from the corresponding reactions involving benzo-nitrile, ethyne and phenylethyne a formal insertion of theheterocumulene into the Ru-H bond occurs in the formationof these species.However, in contrast to [Ru,(p-N(CHPh)}(CO),(petipdp),]PF, and [Ru,(p-q ' : q2-CH-J. Chem. SOC., Dalton Trans., 1996, Pages 41714181 417Table 4 Selected interatomic distances (A) and angles (") for thecomplex [Ru2(p-q : q2-CHCH,)(CO),(p-etipdp),]PF6 11Ru( 1 )-Ru(2) 2.802(1) Ru(1 )-P(l) 2.338(2)Ru( 1 )-P(2) 2.328(2) Ru( 1 )-C( 1) 1.89(2)R W kC(2) 1.91(1) Ru( 1 )-C( 3 3) 2.098(8)Ru(2)-P(3) 2.348(3) Ru(2)-P(4) 2.325(4)RW-C(3) 1.91(1) Ru(2)-C(4) 1.91( 1)Ru(2)-C( 3 3) 2.267(8) Ru(2)-C(34) 2.32(1)C( 33)-C( 34) 1.41(1)176.4( 1)93.5(3)89.7( 3)92.5(2)1 08.8(4)88.3( 3)103.1(2)89.9( 3)79.3(2)102.3(5)99.1(4)15734)88.0(3)85.6(2)89.6(3)97.4( 5 )177.5(1)90.5(3)83.2(2)88.2(3)157.5(4)128.4(4)127.2(4)W9)Fig. 4 Structure of the cation in [Ru,(p-ql : q2-CHCH,)(CO),(p-etipdp),]PF6 11 showing the atom labelling schemeFig.5etipdp),]PF, 13 showing the atom labelling schemeStructure of the cation in [Ru2{p-q2-SC(H)NPh)(CO),(p-CH,)(CO),(p-etipdp),]PF,, the cations of these productscontain five-membered dimetallaheterocyclic rings, as estab-lished crystallographically. The stereochemistry of [Ru,{ p-q ,-Table 5 Selected interatomic distances (A) and angles (") for thecomplex [Ru, ( p q ,-SC(H)NPh) (CO),(p-etipdp),] PF, 13Ru(2)-Ru( l)-P(l)Ru(2 )-Ru(1)-SRu(2)-Ru( 1 )-C(2)P(1)-Ru(1)-SP( 1 )-Ru(l )-wP(2)-Ru(l)-C(2)S-Ru( 1 )-C(2)Ru( l)-Ru(2)-P(3)Ru( 1 )-Ru(2)-N(3)Ru( l)-Ru(2)-C(4)P( 3 )-R U( 2)-N( 3)P( 3)-Ru(2)-C( 3)P(4W uWN(3)P(4)-Ru(2)-C(4)N(3)-Rm-C(4)89.3(1)85.3( 1)87.6(1)89.2( 1)88.7(1)9 4 4 1)172.6(1)89.4( 1)86.0( 1)179.0( 1)89.1(1)89.0( 1)9 1.6( 1)92.7(1)94.9(2)87.7(1)176.7( 1)175.5( 1)92.9( 1)90.0( 1)92.3( I)94.9(2)86.8( 1)88.1(1)176.2( 1)89.1(1)91 .O( 1)89.9( 1)1 73.8(2)91.0(2)EtEt Et15 16SC(H)NPh}(CO),(p-etipdp),] + is illustrated in Fig.5; selectedinteratomic distances and angles are listed in Table 5. Asurprising feature of the structure of this cation is that unlike[R~~(p-q~-OB(F)OH}(CO),(p-etrndp),]+~~ and [Ru2{p-q2-OC(Ph)O)(CO),(p-etipdp),] +,35 this cation adopts a configur-ation that is substantially staggered [P( 1)-Ru( l)-Ru(2)-P(4)26.5, P(2)-Ru( I)-Ru(2)-P(3) 22.2'1. As a consequence theRuNCSRu ring is puckered.This puckering is interpreted interms of localised n-orbital overlap involving the carbon andnitrogen ring atoms, as opposed to delocalised n-orbital overlapinvolving the carbon, nitrogen and sulfur ring atoms. The ringC-N [ 1.294(6) A] and C-S [ 1.698(5) A] distances are consistentwith this interpretation. Related diiron and triosmiumcompounds have been isolated from the reactions of [Fe2{p-(CO), 0] with CS2 and PhNCS respectively. 36-38P(C6H1 1)2}(~-H)(~-Co)(C0)4(~-dPPm)l and C0s3(p-H)2-Reactivity of [ Ru2H(C0),(p-etipdp),1 PF, towards variousnucleophilesThe pentacarbonyl hydride [Ru2H(CO),(p-etipdp),]PF6 8affords, in general, products analogous to those produced by[R~,(p-H)(p-Co)(Co)~(p-etipdp)~]PF~ in its reaction withvarious nucleophiles but more forcing reaction conditions arerequired.Thus reactions of this compound with benzonitrile,4176 J. Chem. SOC., Dalton Trans., 1996, Pages 41 71-418Fig. 6etipdp),]PF, 14 showing the atom labelling schemeStructure of the cation in [Ru2{pq’-0C(CHCHPh)}(CO)&Table 6complex [Ru,{ p-q’-OC(CHCHPh)}(CO),(p-etipdp),]PF, 14Selected interatomic distances (A) and angles (“) for theRu(~)-Ru( 1)-P(1)Ru(~)--Ru( 1)-C( 1 )Ru(~)-Ru( I)-C(5)P(I)-Ru( l)-C(l)P( 1 )-Ru( 1 )-C( 5 )P(4)-Ru( 1)-C(2)C( I)-Ru( 1 )-C(2)C(2)-Ru( 1 )-C( 5 )Ru(l)-Ru(2)-P(3)Ru( l)-Ru(2)-C(3)P(2)-Ru(2)-P(3)P(2)-Ru(2)-C( 3)P(3)-Ru( 2)-O( 5 )P(3)-Ru( 2)-C(4)0(5)-Ru( 2)-C(4)2.782(1) Ru( 1 )-P( 1 ) 2.31 l(2)2.3 1 9(2) Ru( 1)-C( 1) 1.923(9)1.884(9) Ru( 1)-C(5) 2.079(5)2.3 3 2( 2) Ru(2)-P(3) 2.3 3 5( 2)2.126(5) Ru(2)-C(3) 1.919(8)1.857(8) 0(5)-C(5) 1.252(9)1.458(1 I ) C(6)-C(7) 1.38( 1)1.47( 1)91.6(1)95.0(3)67.2(2)90.9(3)90.6(2)89.3( 3)101.9(4)95.9( 3)90.2( 1)169.0(2)178.3( 1)88.9( 2)89.7(1)91.7(4)16 1.8(3)Ru(~)-Ru( 1)-P(4)Ru(~)-Ru( 1 )-C(2)P( 1 )-w 1 FP(4)P( 1 FRu( 1 )-C(2)C( 1 )-Ru( 1 )-C(5)P(4)-Ru(2)-C( 1 )P(4)-Ru( 1)-C(5)Ru( 1 )-Ru(2)-P(2)Ru( l)-Ru(2)-0(5)Ru( 1 )-Ru(2)-C(4)P(2)-Ru(2)-0( 5 )P( 2)-R ~(2)-C(4)P( 3)-Ru(2)-C( 3)C( 3)-Ru(2)-C(4)0(5)-Ru(2)-C(3)91.7(1)163.1(3)176.6( 1)87.8(3)88.1(3)9 1.4(2)162.2(3)90.8(1)70.0( 1)91.8(3)91.8(1)87.0(3)90.3(2)99.0(3)99.2(3)carbon disulfide and phenyl isothiocyanate in 1,2-dichIoro-ethane under reflux give 10,12 and 13 respectively.However, theproduct isolated from the reaction with phenylethyne under thesame conditions was shown to be the styrylcarbonyl-bridgedproduct [Ru, { p-q 2-OC(CHCHPh)} (CO),(p-etipdp),]PF, 14and not the styryl-bridged derivative 11 (R = Ph).The characterisation of this complex was achieved X-raycrystallographically as well as by conventional methods. Thestereochemistry of the cation is illustrated in Fig. 6; selectedinteratomic distances and angles are given in Table 6. Thecation adopts an almost eclipsed configuration [P( 1)-Ru( 1)-Ru(2)-P(2) 0.3, P(3)-Ru(2)-Ru( 1)-P(4) 0.2’1 with the tworuthenium atoms being separated by a distance of 2.782( 1) A,corresponding to a formal ruthenium-ruthenium bond.Thesalient structural feature is the presence of a four-membereddimetallaheterocyclic ring comprising the two rutheniumatoms and a carbonyl group, with a styryl group bonded to thering carbon atom. Related diruthenaheterocyclic ring systemsand in particular diruthenium compounds containing bridgingacyl groups have been reported previously 3’) with the reactionof [Ru~{~-~~-OC(R)}(~-H)(CO)~~], synthesized from thetriruthenium anionic hydride [RU~(~-H)(~-CO)(CO)~~] -,with ethene affording [Ru, {p-q2-OC(R)) (p-q 2-OC(Et)}-(CO),] (R = Et, Pr, e t ~ ) . ~ ” ~ ~ The atoms comprising the‘acyl group’ are approximately coplanar, with the projecteddistances of Ru(2), 0 ( 5 ) , C(5), Ru(l), C(6), C(7) and C(8) fromthe least-squares plane of Ru(2), 0 ( 5 ) , C(5), C(6) and Ru(1)being 0.030, 0.034, 0.018, 0.010, 0.032, 0.1 14 and 0.019 8,respectively.The benzenediazonium cation PhN2 + is isoelectronic withbenzonitrile and phenylethyne and thus might be expected togive rise to a product analogous to 10 on reaction with 8.However, while no reaction was found to occur at roomtemperature, a monocationic product, which could not becharacterised, was formed in the reaction in 1,2-dichloroethaneunder reflux.On the other hand the dicationic phenyldiazenespecies, [Ru, (N , HPh)(CO) (p-etipdp) ,] ’ + 15, is readilyproduced by treatment of [Ruz(p-CO)(C0),(p-etipdp),] with[PhN,]PF, in methanol at room t e m p e r a t ~ r e .~ ~Mechanism of formation of various productsThe reactions of CS2 with both [ R U ~ ( ~ - H ) ( ~ - C O ) ( C O ) ~ ( ~ -etipdp),] + and [Ru,H(CO),(p-etipdp),] + were monitored bymeans of 31P-{1H) NMR spectroscopy and significantly acommon intermediate in the formation of [Ru,{p-q2-SC(H)S}(CO),(p-etipdp),]+ 12 and which exhibited anAA’BB’ pattern of peaks was observed for both reactions. Onthe basis of this evidence it is concluded that the intermediate isa tetracarbonyl species of asymmetric structure and is proposedto be [R~,H(CS,)(CO),(p-etipdp)~] +; migration of thehydride ligand on to the co-ordinated CS2 would afford aspecies which would be predicted to rearrange spontaneouslyto 12. The formation of 14 in the reaction of 8 with PhCzCHcould be interpreted in terms of this reaction occurring via apentacarbonyl intermediate but the intermediate observed onmonitoring the reaction by means of 31P-(1H3 NMRspectroscopy exhibited an AA‘BB‘ pattern of peaks identicalin shape and chemical shift to the set of peaks afforded bythe product obtained by protonation of [Ru,(p-C=CHPh)(CO),(p-etipdp),] 16.Furthermore compound 14was formed, albeit in low yield, in the reaction of 3 withphenylacetylene.ExperimentalThe compounds [Ru,(ps,-CO)2(CO)z(p-etipdp)2] and[Ru,H(CO),(p-etipdp),]X (X = BF, or PF,) were synthesisedaccording to literature procedures. ‘ v Z 6 All reactions andmanipulations were carried out under an atmosphere ofnitrogen using Schlenk techniques. Solvents were purified anddried using standard literature methods.The IR spectra weremeasured on a Perkin-Elmer 457 spectrometer, P-{ ’ H} NMRspectra on a Varian FT 80A instrument and ‘H NMR spectraon a Varian Gemini 200 spectrometer. Relevant spectroscopicdata are summarised in Table 7 .Syntheses[R~~(p-II)(p-CO)(CO)~(p-et.ipdp)~] BF,. A solution of anexcess of HBF,-OEt, (0.4 cm3, 54% in diethyl ether) in ether (3cm3) was added dropwise to a stirred solution of [Ru2(pSb-CO),(CO),(p-etipdp),] (0.25 g, 0.24 mmol) in ether (20 cm3) atroom temperature. The solution turned orange and an orangemicrocrystalline material separated which was isolated, washedwith ether and pentane and dried. Recrystallisation fromacetone-ether afforded orange crystals. Yield: 70% (Found: C,35.6; H, 6.5; N, 2.2.Cak. for C3,H,,BF,N2012P,Ru2: C, 35.5;H, 6.2; N, 2.6%).J. Chem. Soc., Dalton Trans., 1996, Pages 4171-4181 417Table 7 Infrared and ,'P-{ 'H) nuclear magnetic resonance spectroscopic dataCompound 3(CO) "/cm-'2059s, 2006s, 1956s (br), 1757ms2064w, 2031s, 2000vs, 1995 (sh), 1975 (sh)d1997m, 1935s, 1 8 8 6 ~ '1952s, 1888s, 1850w (br)'1950s (br), 1890s (br), 1 8 3 7 ~ '1951s (br), 1888vs (br), 1812w (br)"1946s (br), 1889s (br), 1838 (sh)'2028m, 2001ms, 1994 (sh), 1952s (br)'2030s, 1997vs, 1966s, 1946s2041 s, 2007vs, 1977s, 1958s2033s, 2001vs, 1973s, 1951sd2033s, 2003vs, 1977s, 1957s2021 vs, 1996vs, 1966s, 1945s *2036s, 2006vs, 1986s, 1970s *2033s, 2004vs, 1979s, 1963s*31P-{'H) NMRb138.9 (s, br)'-/137.7 (s) e*h159.3 ( s ) k153.0 (AA'BB')15 1.8 (AA'BB')149.5 (AA'BB')k158.8 ( s ) ~1 50.4 (AA'BB')136.2 (AA'BB')'143.5 (ABCD)'."135.6 (AA'BB')'143.4 (ABCD)y135.4 (AA'BB') '133.1 (s)'139.6 (AA'BB')'a Includes v(Ru-H) where appropriate; v = very, s = strong, m = medium, w = weak, br = broad.* 6 scale in ppm relative to H,PO,; s = singlet,d = doublet, t = triplet, qnt = quintet, m = multiplet, br = broad, AA'BB' = centre of an AA'BB' pattern of peaks. 'H NMR: -9.69 (qnt,I2JpH + 2Jp.HI = 14.8 Hz, 1 H, Ru-H-Ru); in (CD,),CO at r.t. In CH,CI,. Low-temperature 31P-{'H} NMR: 6 142.0(AA'BB'); in (CD,),CO at -80 "C. 31P-{'HJ NMR, in(CD,),CO at -90 "C: 6 144.9 (AA'BB') and 151.0 (AA'BB'). 'H NMR: 6 -8.39 (qnt, I2JpH + ,JpfHI = 11.1 Hz, 2 H, RuH); in C,D, at r.t.' Inhexane. In C6D6 at r.t. 'H NMR: 6 -9.39 (t, br, ,JPH = 18.1 Hz, 1 H, RuH); in C,D, at r.t. 'H NMR: 6 -9.60 (t, br, ,JPH = 17.8 Hz, 1 H,RuH); in C6D6 at r.t. " 'H NMR: 6 - 10.17 (t, br, 2JpH = 17.2 Hz, 1 H, RuH); in C,D, at r.t. ' In CHCI,. 'H NMR: 6 - 10.03 (t, br, ' J = 17.8, 1 H,RuH) and - 1.67 (,JpH = 13.8 Hz, 1 H, SH); in [2H,]toluene at r.t. In [2H,]toluene at r.t. Low-temperature 31P-{1H} NMR: two overlapping setsof peaks of apparent AA'BB' pattern; in [2H,]toluene at - 32 "C. 'H NMR: 6 -7.58 (t, br, 'JpH = 21.6 Hz, 1 H, Ru-H); in C,D, at r.t. P(CN)2098w cm-', in hexane. 'H NMR: 0.63 (qnt, ,JpH = 13.9 Hz, 1 H, SH); in CDCI, at r.t. In CDCI, at r.t. NMR: 'H, 6 8.10 (m, 1 H, CHCH,), 5.02(m, 1 H, CHCH,) and 4.27 (m, 1 H, CHCH,); '3C-{1H), 6 158.7 (t, Jpc = 13.7, CHCH,) and 68.2 (t, br, Jpc = 7.4 Hz, CHCH,); measured in(CD,),CO at r.t.' Highest-intensity peak of an ABCD pattern. NMR: 'H, 6 5.53 (d of qnt, 1 H, CHCHPh) and 8.31 (overlapping d of qnt, 1 H,CHCHPh); 13C-('H}, 6 144.0 (qnt, CHCHPh) and 94.7 (9, CHCHPh); in CDCI, at r.t. = 15.2, '.IpH = 2.5, 1 H,CHCHPh) and 8.54 (overlapping d of qnt, ,JHH = 15.2, ,JpH = 7.7 Hz, 1 €3, CHCHPh); in (CD,),CO at r.t. Centre of an ABCD pattern; in(CD,),CO at -40 "C. Variable-temperature data: 0 "C, ABCD pattern centred at 6 142.7; 30 OC, two broad peaks; 44 k 3 OC, coalescencetemperature; 80 "C, s, br at 140.5; 130 OC, s at 140.0. v(CN): 2220w cm-', in 1,2-dichloroethane. * In 1,2-dichloroethane. ' In CD,C12 at r.t. * 'HNMR: 6 11.35 (qnt, ,JpH = 2.2 Hz, 1 H, SCHS); in CDC1, at r.t.9 'H NMR: 6 8.85 (qnt, ,JpH = 1.8, 1 H, SCHNPh); in (CD,),CO at r.t.In (CD,),CO at r.t.'H NMR: 6 -7.57 (qnt, ['.IpH + ,Jp,HI = 10.4 Hz, 1 H, RuH); in (CD,),CO at r.t.'H NMR: 6 5.66 (d of qnt,[Ru2(p-H)(p-Co)(Co),(p-etipdp),]PF6. A solution of anexcess of HPF, (0.5 cm3, 60% in water) in water (3 cm3) wasadded to a stirred solution of [R~~(p~~-COj,(CO),(p-etipdp)~](0.25 g, 0.24 mmol) in CH,Cl, ( 5 cm3) at room temperatureand the resultant two-phase mixture stirred vigorously for 2 h.The organic layer was separated from the aqueous layer,evaporated to dryness and the residue crystallised fromacetone-ether to afford orange crystals. Yield: 75% (Found: C,34.1; H, 5.5; N, 2.1. Calc.for C,,H,,F,N,O,,P,Ru,: C, 33.7;H, 5.9; N, 2.5%).[R~,(p-X)H(p,~-CO)(CO)~(p-etipdp)~] (X = C1, Br or I). Anequimolar amount of NBu",CI (0.02 g, 0.09 mmol), NBu",Br(0.03 g, 0.09 mmol) or NBu",I (0.03 g, 0.09 mmol) was added toa stirred solution of [R~~(p-H)(p-CO)(CO)~(p-etipdp)~]PF~(0.10 g, 0.09 mmol) in acetone (10 cm3) and the solution stirredfor 30 min. The solvent was removed under reduced pressure toafford a yellow residue which was extracted with toluene.Addition of MeCN to the toluene solution resulted in theseparation of the required compound in crystalline form. Yield:70% (Found: C, 36.9; H, 6.8; N, 2.8. Calc. for C3,H6,C1N,-O,,P,Ru,: C, 37.1; H, 6.7; N, 2.8. Found: C, 35.7; H, 6.3; N,2.6. Calc. for C,,H,,BrN,O,,P,Ru,: C, 35.5; H, 6.4; N, 2.7.Found: C, 34.6; H, 6.2; N, 2.6.Calc. for C,,H,,IN,O, ,P,Ru,:C, 34.1; H, 6.2; N, 2.6%).[Ru,H(CN)(CO),(p-etipdp),] . An equimolar amount of solidKCN (0.01 g, 0.18 mmol) was added to a stirred solution of[Ruz(p-H)(p-Co)(Co),(p-etipdp),]PF, (0.20 g, 0.18 mmol) inacetone (15 cm3) and the solution stirred for 30 min. Thesolvent was removed under reduced pressure to afford a yellowresidue which was extracted with hexane. Removal of thesolvent from the hexane extract afforded a residue which wascrystallised from toluene-MeCN. Yield: 75% (Found: C, 38.8;H, 6.7; N, 4.0. Calc. for C,3H6,N,0,,P,Ru,: C, 38.7; H, 6.6;N, 4.1 %).[ Ru,{p-N(CHPh)}(CO),(p-etipdp),] PF,. (i) A solution of anequimolar amount of PhCN (0.01 cm3, 0.09 mmol) in acetone (3cm3) was added dropwise to a stirred solution of [Ru,(p-H)(p-CO)(CO),(p-etipdp),]PF, (0.10 g, 0.09 mmol) in acetone (10cm3) at room temperature resulting in an immediate changefrom orange to yellow. The solvent was removed under reducedpressure and the residue washed with hexane and crystallisedfrom MeCN-hexane to afford white crystals.Yield: 70%.(ii) A solution of [Ru,H(CO),(p-etipdp),]PF, (0.35 g, 0.30mmol) and PhCN (0.15 g) in 1,2-dichIoroethane (25 cm3) washeated at reflux for 90 min. The solvent was removed underreduced pressure and the resultant oil washed with hexane toremove the excess of PhCN. The solid residue was crystallisedfrom MeCN-Et,O-hexane (1 : 8 : 1) to afford white needles.Yield: 90% (Found: C, 37.9; H, 6.1; N, 3.6.Calc. forC3,H,,F,N30,,P,Ru,: C, 37.6; H, 5.8; N, 3.4%).[ Ru2(p-ql : q'-CHCH,)(CO),(p-etipdp),l PF,. A stream ofethyne was passed slowly through a solution of [Ru,(p-H)(p-Co)(Co),(CL-etipdp),]PF, (0.25 g, 0.22 mmol) in acetone (7cm3) at room temperature for 30 min. The resulting yellowsolution was concentrated to ca. 3 cm3 and toluene added toafford a pale yellow crystalline material. Yield: 60% (Found: C,35.2; H, 5.7; N, 2.5. Calc. for C34H69FSN2012P5R~2: C, 35.0;H, 6.0; N, 2.4%).[Ru,(p-q' : $-CHCHPh)(CO),(p-etipdp),lBF,. A solution ofan excess of PhC=CH (0.10 g, 1 .O mmol) in CH,Cl, (2 cm3) wasadded dropwise to a stirred solution of [Ru,(p-H)(p-CO)(CO),(p-etipdp),]BF, (0.20 g, 0.18 mmol) in CH,Cl, (1 5cm3) and the resulting mixture stirred for 15 min.The solventwas removed under reduced pressure and the pale yellowresidue crystallised from CHC1,-pentane to afford crystals ofthe required compound. Yield: 80% (Found: C, 40.6; H, 6.3;N, 2.3. Calc. for C,,H,3BF,N,0,,P,Ruz: C, 40.5; H, 6.2; N,2.4%).4178 J. Chem. SOC., Dalton Trans., 1996, Pages 4171-418Table 8 Crystallographic dataY$ t,FormulaMCrystal systemSpace groupa/AblA 4.I"PI"rl" u/A3zDJgF(OO0)plcrn-'Crystal size/mmMeasured reflectionsIndependent reff ec tion sObserved reflections [ I > 3a(I)]No. variablesg in weighting schemeRR'A / a (maximum)Aple A-33 6C32H67F6NZ012P5RU21142.89Monoclinic11.361(2)32.020(2)1 4.459( 1)f%lc98.97(2)5 195( 1)41.46023447.960.61 x 0.19 x 0.127709635 152165950.00060.0370.0420.930.40c3 lH67INZ0I lPdRu21096.82OrthorhombicPbca17.366(2)22.6 3 3( 2)25.234(2)99 18(2)81.469444814.010.15 x 0.15 x 0.087542526728184650.00020.0360.0340.050.47Weighting scheme: w = l/[02(F) + g p ] , R = C(lFoI - IFc~)/Z~FJ, R' = Zw*(lFol - (F,()/Cw*F,.101246.0 1Monoclinic11.512(2)24.955(3)20.479(2)C39H72F6N301 2P5Ru2m l c108.444(9)5581( 1)41.48325607.500.52 x 0.31 x 0.1210 048886571226070.00040.0410.0450.190.73111168.93OrthorhombicPna216.377(2)22.287(3)14.433(4)C34H69F6N201 ZPSRU25268( 2)41.47424007.880.49 x 0.29 x 0.204098353 I29705520.00040.0340.0340.1 10.3[ Ru2{p-q2-OC(CHCHPh)}(CO),(p-etipdp),] PF,.An excessof PhCsCH (0.09 g, 1.0 mmol) was added to a solution of[Ru,H(CO),(p-etipdp),]PF, (0.35 g, 0.30 mmol) in tetrahydro-furan (thf) (25 cm3) and the mixture heated at reflux for 4 h.The solvent and unreacted PhCSH were removed in vacuo andthe yellow oil which remained was washed with warm hexane(2 x 20 cm3, 50 "C). The residue was crystallised from acetone-Et,O-hexane (1 : 2 : 3) to afford yellow crystals. Yield: 85%(Found: C, 38.4; H, 5.8; N, 2.2. Calc. for C41H73F6N2013-P,Ru,: C, 38.7; H, 5.8; N, 2.2%).[ Ru2{p-q2-XC(H)S)(CO),(p-etipdp),] PF, (X = S or NPh).(i) A solution of an excess of CS, (0.08 g, 1 .O mmol) or PhNCS(0.02 cm3, 0.2 mmol) in acetone (2 cm3) was added dropwise toa stirred solution of [R~~(p-H)(p-CO)(CO)~(p-etipdp),]PF~(0.1 g, 0.1 mmol) in acetone (10 cm3) and the solution stirredfor 30 min to 2 h.The solvent was removed under reducedpressure to afford a yellow-orange residue which wascrystallised from acetone-hexane (1 : 1) (for the CS, reaction) orfrom acetone-Et,O-hexane (1 : 1 : 1) (for the PhNCS reaction).Yield: 85-95%.(ii) A solution of [Ru,H(CO),(p-etipdp),]PF, (0.35 g, 0.3mmol) and CS, (0.5 cm3) or PhNCS (0.05 g, 0.4 mmol) in 1,2-dichloroethane (30 cm3) was refluxed for 1.5-2 h. The solventwas removed under reduced pressure to afford a yellow-orangeresidue which was crystallised as above. Yield: 80-90% (Found:C, 32.7; H, 5.7; N, 2.5. Calc. for C3,H,,F,N20,,P,Ru,S2: C,32.5; H, 5.5; N, 2.3.Found: C, 36.8; H, 5.7; N, 3.2. Calc. forC,,H,,F,N,O,,P,Ru,S; C, 36.6; H, 5.6; N, 3.3%).Reactions of [ R~~(p-H)(p-CO)(CO),(p-etipdp)~] PF,With sodium tetrahydroborate. An equimolar amount of solidNaBH, (0.01 g, 0.18 mmol) was added to a stirred solution of[R~,(p-H)(p-Co>(Co)~(p-etipdp)~]PF, (0.20 g, 0.18 mmol) inacetone (15 cm3) and the solution stirred for 30 min. Thesolvent was removed under reduced pressure and the yellowresidue extracted with hexane. The hexane extract wasevaporated to afford a yellow microcrystalline material whichwas identified as the neutral dihydride [Ru,H,(CO),(p-etipdp),12' by means of IR and NMR spectroscopy. Yield:75%.With sodium hydrogensulfide. A solution of an equimolaramount of NaSH (0.01 g, 0.18 mmol) in methanol (2 cm3) wasadded dropwise to a stirred solution of [Ru,(p-H)(p-Co)(Co),(p-etipdp),]PF, (0.20 g, 0.18 mmol) in acetone (1 5cm3) and the solution stirred for 30 min.The solvent wasremoved under reduced pressure and the yellow residueextracted with toluene. The toluene extract was evaporatedto afford a yellow microcrystalline solid identified as theneutral h ydr ogensulfide-bridged species [Ru , (p-SH)H ( pSb-CO)(CO),(p-etipdp),] by IR and NMR spectroscopicmeans. Yield: 65%.With lithium acetylide-ethane-1,Zdiamine and lithiumphenylacetylide. A slight excess of Li(C=CH)-NH,C,H,NH,(0.02 g, 0.19 mmol) or Li(C=CPh) (0.02 g, 0.19 mmol) wasadded to a stirred solution of [Ru,(~-H)(~-CO)(CO)~(~-etipdp),]PF, (0.20 g, 0.18 mmol) in acetone (15 cm3) at- 15 "C.The solution turned brown and a yellow crystallinematerial seDarated. This was isolated. washed with cold hexane,clear white. The solvent was removed under reduced pressure toafford a white crystalline material identified spectroscopically,IR and NMR, as the pentacarbonylhydride [Ru,H(CO),(p-etipdp) ,]PF,. Yield: 90%.With sulfur. An excess of sulfur (0.01 g, 0.19 mmol) in toluene(3 cm3) was added to a solution of [RU~(~-H)(~--CO)(CO)~(~-etipdp),]PF, (0.10 g, 0.09 mmol) in acetone (10 cm3) resultingin an immediate change from orange to yellow. The solutionwas stirred for 30 min and the solvent removed under reducedpressure to produce a beige residue which was extracted withCH,Cl,. The CH2Cl, extract was evaporated to give an orangecrystalline solid which was identified as [Ru,(p-SH)(CO),(p-etipdp)2]PF,30 by means of IR and NMR spectroscopy.Yield:75%.CrystallographyCrystal data for the complexes 3,6, 10, 11,13 and 14 are givenin Table 8, together with information on the data collectionsand structure determinations. Data were collected at 295 K on aNonius CAD-4 diffractometer using graphite-monochromatedMo-Ka radiation (h = 0.710 69 A) and a-20 scans. Lorentz-polarisation corrections were applied and as well as absorptioncorrections from empirical cp scans.43 The structures weresolved from Patterson and heavy-atom electron-densitysyntheses and refined by full-matrix least squares on Fusing theprogram SHELX 76.44 The non-hydrogen atoms were assignedanisotropic thermal parameters. Hydrogen atoms were in-cluded in calculated positions and allowed to ride on the atomto which they were attached with a common thermal parameter.The only exceptions were the hydride ligands in 3 and 6 both ofwhich were located in Fourier-difference maps and theirpositions refined with individual isotropic thermal parameters.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. 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