Koordinativ ungesättigte Dirutheniumkomplexe: Synthese und Kristallstrukturen von [Ru2(CO)n(μ‐H)(μ‐PtBu2)(μ‐Ph2PCH2PPh2)] (n = 4; 5) und [Ru2(CO)4(μ‐CH2)(μ‐H)(μ‐PtBu2)(μ‐Ph2PCH2PPh2)]

Coordinatively Unsaturated Diruthenium Complexes: Synthesis and X‐ray Crystal Structures of [Ru₂(CO)_n(μ‐H)(μ‐P^tBu₂)(μ‐Ph₂PCH₂PPh₂)] (n = 4; 5) and [Ru₂(CO)₄(μ‐CH₂)(μ‐H)(μ‐P^tBu₂)(μ‐Ph₂PCH₂PPh₂)] The reaction of [Ru₂(μ‐CO)(CO)₅(μ‐H)(μ‐P^tBu₂)(^tBu₂PH)] ( 2 ) with dppm yields the dinuclear species [Ru₂(μ‐CO)(CO)₄(μ‐H)(μ‐P^tBu₂)(μ‐dppm)] ( 3 ) (dppm = Ph₂PCH₂PPh₂). Under thermal or photolytic conditions 3 loses very easily one carbonyl ligand and affords the corresponding electronically and coordinatively unsaturated complex [Ru₂(CO)₄(μ‐H)(μ‐P^tBu₂)(μ‐dppm)] ( 4 ). 4 is also obtainable by an one‐pot synthesis from [Ru₃(CO)₁₂], an excess of ^tBu₂PH and stoichiometric amounts of dppm via the formation of [Ru₂(CO)₄(μ‐H)(μ‐P^tBu₂)(^tBu₂PH)₂] ( 1 ). 4 exhibits a Ru–Ru double bond which could be confirmed by addition of methylene to the dimetallacyclopropane [Ru₂(CO)₄(μ‐CH₂)(μ‐H)(μ‐P^tBu₂)(μ‐dppm)] ( 5 ). The molecular structures of 3 , 4 and 5 were determined by X‐ray crystal structure analyses.     

Aktivierung von Schwefelkohlenstoff an Trirutheniumclustern: Synthese und Kristallstruktur von [Ru3(CO)5(μ‐H)2(μ‐PCy2)(μ‐Ph2PCH2PPh2){μ‐η2‐PCy2C(S)}(μ3‐S)] und [Ru3(CO)5(CS)(μ‐H)(μ‐PtBu2)(μ‐PCy2)2(μ3‐S)]

Activation of Carbon Disulfide on Triruthenium Clusters: Synthesis and X‐Ray Crystal Structure Analysis of [Ru₃(CO)₅(μ‐H)₂(μ‐PCy₂)(μ‐Ph₂PCH₂PPh₂){μ‐η²‐PCy₂C(S)}(μ₃‐S)] and [Ru₃(CO)₅(CS)(μ‐H)(μ‐P^tBu₂)(μ‐PCy₂)₂(μ₃‐S)] [Ru₃(CO)₆(μ‐H)₂(μ‐PCy₂)₂(μ‐dppm)] ( 1 ) (dppm = Ph₂PCH₂PPh₂) reacts under mild conditions with CS₂ and yields by oxidative decarbonylation and insertion of CS into one phosphido bridge the opened 50 VE‐cluster [Ru₃(CO)₅(μ‐H)₂(μ‐PCy₂)(μ‐dppm){μ‐η²‐PCy₂C(S)}(μ₃‐S)] ( 2 ) with only two M–M bonds. The compound 2 crystallizes in the triclinic space group P 1 with a = 19.093(3), b = 12.2883(12), c = 20.098(3) Å; α = 84.65(3), β = 77.21(3), γ = 81.87(3)° and V = 2790.7(11) ų. The reaction of [Ru₃(CO)₇(μ‐H)(μ‐P^tBu₂)(μ‐PCy₂)₂] ( 3 ) with CS₂ in refluxing toluene affords the 50 VE‐cluster [Ru₃(CO)₅(CS)(μ‐H)(μ‐P^tBu₂)(μ‐PCy₂)₂(μ₃‐S)] ( 4 ). The compound cristallizes in the monoclinic space group P 2₁/a with a = 19.093(3), b = 12.2883(12), c = 20.098(3) Å; β = 104.223(16)° and V = 4570.9(10) ų. Although in the solid state structure one elongated Ru–Ru bond has been found the complex 4 can be considered by means of the ³¹P‐NMR data as an electron‐rich metal cluster.     

Preliminary communicationCatalytic olefin hydrogenation with nonacarbonyltris(triphenylphosphine)triruthenium and its derivatives. Crystal structure of [Ru2(CO)5(PPh3)(μ-PPh2)(μ-OCPh)]

The complexes [Ru₃(CO)₇(PPh₂)₂(C₆H₄)] and [Ru₂(CO)₅(PPh₃)(μ-PPh₂)(μ-OCPh)] were obtained by pyrolysis of [Ru₃(CO)₉(PPh₃)₃] and tested as catalysts for the hydrogenation of cyclohexene and 2-cyclohexen-1-one. The structure of [Ru₂(CO)₅(PPh₃)(μ-PPh₂)(μ-OCPh)] was established by a single crystal X-ray diffraction study.     

Koordinativ ungesättigte Dirutheniumkomplexe: Synthese und Kristallstrukturen von [Ru2(CO)4(μ‐H)(μ‐S)(μ‐PtBu2)(μ‐Ph2PCH2PPh2)] und [Ru2(CO)4(μ‐X)(μ‐PtBu2)(μ‐Ph2PCH2PPh2)] (X = Cl,S2CH)

Coordinatively Unsaturated Diruthenium Complexes: Synthesis and X‐Ray Crystal Structures of [Ru₂(CO)₄(μ‐H)(μ‐S)(μ‐P^tBu₂)(μ‐Ph₂PCH₂PPh₂)], [Ru₂(CO)₄(μ‐X)(μ‐P^tBu₂)(μ‐Ph₂PCH₂PPh₂)] (X = Cl, S₂CH) [Ru₂(CO)₄(μ‐H)(μ‐P^tBu₂)(μ‐dppm)] ( 1 ) reacts in benzene with elemental sulfur to the addition product [Ru₂(CO)₄(μ‐H)(μ‐S)(μ‐P^tBu₂)(μ‐dppm)] ( 2 ) (dppm = Ph₂PCH₂PPh₂). 2 is also obtained by reaction of 1 with ethylene sulfide. The reaction of 1 with carbon disulfide yields with insertion of the CS₂ into the Ru₂(μ‐H) bridge the dithioformato complex [Ru₂(CO)₄(μ‐S₂CH)(μ‐P^tBu₂)(μ‐dppm)] ( 3 ). Furthermore, 1 reacts with [NO][BF₄] to the complex salt [Ru₂(CO)₄(μ‐NO)(μ‐H)(μ‐P^tBu₂)(μ‐dppm)][BF₄] ( 4 ), and reaction of 1 with CCl₄ or CHCl₃ affords spontaneously [Ru₂(CO)₄(μ‐Cl)(μ‐P^tBu₂)(μ‐dppm)] ( 5 ) in nearly quantitative yield. The molecular structures of 2 , 3 and 5 were confirmed by crystal structure analyses.     

Diphenylphosphine and diphenylphosphido derivatives of [Ru3(μ-H)(μ3-ampy)(CO)9] (Hampy = 2-amino-6-methylpyridine)

The reactions of [Ru₃(μ-H)(μ-ampy)(CO)₉] (1) (Hampy = 2-amino-6-methylpyridine) with one or two equivalents of PPh₂H lead to the complexes [Ru₃(μ-H)(μ₃-ampy)(CO)₈(PPh₂H)] (2) or [Ru₃(μ-H)(μ₃-ampy)(CO)₇(PPh₂H)₂] (3), in which the PPh₂H ligands are cis to the bridging NH fragment and cis to the hydride. Complex 2 can be transformed in refluxing THF into the phosphido-bridged derivative [Ru₃(μ₃-ampy)(μ-PPh₂)(μ-CO)₂(CO)₆] (4), which contains the PPh₂ ligand spanning one of the two RuRu edges unbridged by the amido moiety, and presents an extremely high ³¹P chemical shift of 386.9 ppm. Under similar conditions, complex 3 gives a mixture of two isomers of [Ru₃(μ-H)(μ₃-ampy)(μ-PPh₂)₂(CO)₆] in a 5:1 ratio; the major product (5) has a plane of symmetry, whereas the minor one (6) is asymmetric.     

Carbonyl substitution chemistry of some trimetallic transition metal cluster complexes with polyfunctional ligands

The trimetallic clusters [Ru₃(CO)₁₀(dppm)], [Ru₃(CO)₁₂] and [RuCo₂(CO)₁₁] react with a number of multifunctional secondary phosphine and tertiary arsine ligands to give products consequent on carbonyl substitution and, in the case of the secondary phosphines, PH activation. The reaction with the unresolved mixed P/S donor, 1-phenylphosphino-2-thio(ethane), HSCH₂CH₂PHPh ( LH₂), gave two products under various conditions which have been characterised by spectroscopic and crystallographic means. These two complexes [Ru₃(μ-dppm)(H)(CO)₇(LH)] and [Ru₃(μ-dppm)(H)(CO)₈(LH)Ru₃(μ-dppm)(CO)₉], show the versatility of the ligand, with it chelating in the former and bridging two Ru₃ units in the latter. The stereogenic centres in the molecules gave rise to complicated spectroscopic data which are consistent with the presence of diastereoisomers. In the case of [Ru₃(CO)₁₂] the reaction with LH₂ gave a poor yield of a tetranuclear butterfly cluster, [Ru₄(CO)₁₀(L)₂], in which two of the ligands bridge opposite hinge wingtip bonds of the cluster. A related ligand, HSCH₂CH₂AsMe(C₆H₄CH₂OMe), reacted with [RuCo₂(CO)₁₁] to give a low yield of the heterobimetallic Ru-Co adduct, [RuCo(CO)₆(SCH₂CH₂AsMe(C₆H₄CH₂OMe))], which appears to be the only one of its type so far structurally characterised.The secondary phosphine, HPMe(C₆H₄(CH₂OMe)) and its oxide HP(O)Me(C₆H₄(CH₂OMe)) also react with the cluster [Ru₃(CO)₁₀(dppm)] to give carbonyl substitution products, [Ru₃(CO)₅(dppm)(μ₂-PMe(C₆H₄CH₂OMe))₄], and [Ru₃H(CO)₇(dppm)(μ₂,η¹-P(O)Me(C₆H₄CH₂OMe))]. The former consists of an open Ru₃ triangle with four phosphide ligands bridging the metal-metal bonds; the latter has the O atom symmetrically bridging one Ru-Ru bond, the P atom being attached to a non-bridged Ru atom.     

Synthesis of new heterometallic complexes by tin-sulfur bond cleavage of pySSnPh3 (pySH = pyridine-2-thiol) at triruthenium and triosmium centres

The ruthenium-tin complex, [Ru₂(CO)₄(SnPh₃)₂(μ-pyS)₂] (1), the main product of the oxidative-addition of pySSnPh₃ to Ru₃(CO)₁₂ in refluxing benzene, is [Ru(CO)₂(pyS)(SnPh₃)] synthon. It reacts with PPh₃ to give [Ru(CO)₂(SnPh₃)(PPh₃)(κ²-pyS)] (2) and further with Ru₃(CO)₁₂ or [Os₃(CO)₁₀(NCMe)₂] to afford the butterfly clusters [MRu₃(CO)₁₂(SnPh₃)(μ₃-pyS)] (3, M=Ru; 4, M=Os). Direct addition of pySSnPh₃ to [Os₃(CO)₁₀(NCMe)₂] at 70 °C gives [Os₃(CO)₉(SnPh₃)(μ₃-pyS)] (5) as the only bimetallic compound, while with unsaturated [Os₃(CO)₈{μ₃-PPh₂CH₂P(Ph)C₆H₄}(μ-H)] the previously reported [Os₃(CO)₈(μ-pyS)(μ-H)(μ-dppm)] (6) and the new bimetallic cluster [Os₃(CO)₇(SnPh₃){μ-Ph₂PCH₂P(Ph)C₆H₄}(μ-pyS)[(μ-H)] (7) are formed at 110 °C. Compounds 1, 2, 4, 5 and 7 have been characterized by X-ray diffraction studies.     

Chemistry of a family of semiquinone monochelates of carbonyl ruthenium(II) generated by reacting quinones with hydridic species

The reactions of [Ru(H)(Cl)(CO)(PPh₃)₃] with 3,5-di-tert-butyl-o-benzoquinone (dbq) and 3,4,5,6-tetrachloro-o-benzoquinone (tcq) have afforded the corresponding semiquinone complexes [Ru^II(dbsq)(Cl)(CO)(PPh₃)₂] and [Ru^II(tcsq)(Cl)(CO)(PPh₃)₂], respectively. The reaction of [Ru(H)₂(CO)(PPh₃)₃] with tcq has furnished [Ru^II(tcsq)(H)(CO)(PPh₃)₂]. Structure determination of [Ru(dbsq)(Cl)(CO)(PPh₃)₂] has revealed that it is a model semiquinonoid chelate with two equal C---O lengths ( 1.291(6) and 1.296(6) Å). The complexes are one-electron paramagnetic (1.85μ_B) and their EPR spectra in fluid media display a triplet structure (g2.00) due to superhyperfine coupling with two trans-³¹P atoms (A_iso17 G). The stretching frequency of the CO ligand increases by 20 cm⁻¹ in going from [Ru(dbsq)(Cl)(CO)(PPh₃)₂] to [Ru(tcsq)(Cl)(CO)(PPh₃)₂] consistent with electron withdrawal by chloro substituents. For the same reason the E_1/2 values of the cyclic voltammetric quinone/semiquinone and semiquinone/catechol couples undergo a shift of 500 mV to higher potentials between [Ru(dbsq)(Cl)(CO)(PPh₃)₂] and [Ru(tcsq)(Cl)(CO)(PPh₃)₂].     

Conversion of allene into μ-dimethylcarbene at a diruthenium centre

Treatment of [Ru₂(CO)(μ-CO) {μ-C(O)C₂Ph₂} (η-C ₅H₅)₂] with allene in toluene at 100°C displaces diphenylacetylene and produces [Ru(CO)(η-C₅H₅)-{η³-C₃H₄Ru(CO)₂(η-C₅H₅)}]; upon protonation a 1-methylvinyl cation [Ru₂(CO)₂(μ-CO){μ-C(Me)CH₂}(η-C₅H₅)₂]⁺ is formed which undergoes nucleophillic attack by hydride to yield the μ-dimethylcarbene complex [Ru₂(CO)₂-(μ-CO)(μ-CMe₂)(η-C₅H₅)₂].     

Propionyl complexes of ruthenium derived from the reaction of ethylene with RuHCl(CO)2(PPh3)2

RuHCl(CO)₂(PPh₃)₂ reacts with ethylene under mild conditions (25 psi, 80°C) to yield a propionyl derivative RuCl(C[O]C₂H₅)(CO)(PPh₃)₂ which is believed to be coordinatively unsaturated. Unlike the acetyl analogue, RuCl[C[O]C₂H₅(CO)-(PPh₃)₂ does not isomerize to RuCl(C₂H₅)(CO)₂(PPh₃)₂ in solution. Under one atmosphere of carbon monoxide, RuCl(C[O]C₂H₅(CO)(PPh₃)₂ exists in equilibrium with two species believed to be RuCl(C[O]C₂H₅)(CO)₂(PPh₃)₂ and [Ru(C[O]C₂H₅)(CO)₃(PPh₃)₂]Cl. RuCl(C[O]C₂H₅)(CO)(PPh₃)₂ reacts with CO/ AgClO₄ to give mer-[Ru(C[O]C₂H₅)(CO)₃(PPh₃)₂]ClO₄, p-tolylisocyanide (RNC) and NaClO₄ to give cis-[Ru(C[O]C₂H₅)(CO)(CNR)₂(PPh₃)₂ClO₄, and hydrochloric acid to yield the hydroxycarbene complex, RuCl₂(CO)(C[OH]C₂H₅)(PPh₃)₂.     

Acetylene Dithiolate Linking up the [Tp′W(CO)(CN)] Moiety with RuII or PdII

A series of heterodinuclear complexes with acetylene dithiolate (acdt^2?) as the bridging moiety were synthesised by a facile one‐pot procedure that avoided use of the highly elusive acetylene dithiol. Generation of the W–Ru complex [Tp′W(CN)(CO)(C₂S₂)Ru(η⁵‐C₅H₅)(PPh₃)] (Tp’=hydrotris(3,5‐dimethylpyrazolyl)borate) and the W–Pd complexes [Tp′W(CN)(CO)(C₂S₂)Pd(dppe)] and [Tp′W(CO)₂(C₂S₂)Pd(dppe)][PF₆] (dppe=1,2‐bis(diphenylphoshino)ethane), which exhibit a [W(η²‐κ²‐C₂S₂)M] core (M=Ru, Pd), was accomplished by using a transition‐metal‐assisted solvolytical removal of the Me₃Si‐ethyl thiol protecting groups. All intermediate species of the reaction have been fully characterised. The highly coloured W–Ru complex [Tp′W(CN)(CO)(C₂S₂)Ru(η⁵‐C₅H₅)(PPh₃)] shows reversible redox chemistry, as does the prototype complex [Tp′W(CO)₂(C₂S₂)Ru(η⁵‐C₅H₅)(PPh₃)][PF₆]. Single crystal X‐ray diffraction and IR, EPR and UV/Vis spectroscopic studies in conjunction with DFT calculations prove the high electronic delocalisation of states over the acdt^2? linker. Comparative studies revealed a higher donor strength and more pronounced dithiolate character of acdt^2? in [Tp′W(CN)(CO)(C₂S₂)Ru(η⁵‐C₅H₅)(PPh₃)] relative to [Tp′W(CO)₂(C₂S₂)Ru(η⁵‐C₅H₅)(PPh₃)]⁺. In addition, the influence of the overall complex charge on the metric parameters was investigated by single‐crystal X‐ray diffraction studies with the W–Pd complexes [Tp′WL₂(C₂S₂)Pd(dppe)] (L=(CN^?)(CO) or (CO)₂). The central [W(C₂S₂)Pd] units exhibit high structural similarity, which indicates the extensive delocalisation of charge over both metals.     

Activation of Open‐Cage Fullerenes with Ruthenium Carbonyl Clusters

Reactions of the open‐cage fullerene C₆₃NO₂(Py)(Ph)₂ ( 1 ) with [Ru₃(CO)₁₂] produce [Ru₃(CO)₈(μ,η⁵‐C₆₃NO₂(Py)(Ph)₂)] ( 2 ), [Ru₂H(CO)₃(μ,η⁷‐C₆₃N(Py)(Ph)(C₆H₄))] ( 3 ), and [Ru(CO)(Py)₂₍η³‐C₆₃NO₂(Py)(Ph)₂)] ( 4 ), in which the orifice sizes are modified from 12 to 8, 11, and 15‐membered ring, through ruthenium‐mediated C?O and C?C bond activation and formation.     

Aktivierung von Schwefelkohlenstoff an Trirutheniumclustern: Synthese und Kristallstruktur von [Ru3(CO)4(μ‐PCy2)2(μ‐Ph2PCH2PPh2)(μ3‐S){μ3‐η2‐CSC(S)S}]

Activation of Carbon Disulfide on Triruthenium Clusters: Synthesis and X‐Ray Crystal Structure Analysis of [Ru₃(CO)₄(μ‐PCy₂)₂(μ‐Ph₂PCH₂PPh₂)(μ₃‐S){μ₃‐η²‐CSC(S)S}] [Ru₃(CO)₄(μ‐H)₃(μ‐PCy₂)₃(μ‐dppm)] ( 2 ) (dppm = Ph₂PCH₂PPh₂) reacts with CS₂ at room temperature and yields the open 50 valence electron cluster [Ru₃(CO)₄(μ‐PCy₂)₂(μ‐dppm)(μ₃‐S){μ₃‐η²‐CSC(S)S}] ( 3 ) containing the unusual μ₃‐η²‐C₂S₃ mercaptocarbyne ligand. Compound 3 was characterized by single crystal X‐ray structure analysis.     

Structural Studies of Some Compounds Containing C2 Fragments Attached to Various Metal‐Ligand End‐Groups

The preparation, characterisation and single‐crystal XRD molecular structure determinations of four complexes containing –CC–ML_n end‐groups, namely Ru{C≡CFc′(I)}(dppe)Cp ( 1 ), the vinylidene [Os(=C=CH₂)(PPh₃)₂Cp]PF₆ ( 2 ), trans‐Pt(C≡CC₆H₄‐4‐C≡CPh){C≡CC₆H₄‐4‐C₂Ph[Co₂(μ‐dppm)(CO)₄]}(PPh₃)₂ ( 3 ), and C₆H₄{μ₃‐C₂[AuRu₃(CO)₉(PPh₃)]}₂‐1,4 ( 4 ) are reported. In these compounds a range of –CC– environments is found, extending from the σ‐bonded alkynyl group in 1 to examples where the C₂ unit interacts with either a proton (in vinylidene 2 ), by bridging a dicobalt carbonyl moiety (in 3 ) or the AuRu₃ cluster in 4 . Changes in geometry are rationalised by considering the various bonding modes.     

Koordinativ ungesättigte Dirutheniumkomplexe: Synthese und Kristallstrukturen von [Ru2(CO)3L(μ‐η1 : η2‐C≡CPh)(μ‐PtBu2)(μ‐Ph2PCH2PPh2)] (L = CO,PnBu3)

Coordinatively Unsaturated Diruthenium Complexes: Synthesis and X‐ray Crystal Structures of [Ru₂(CO)₃L(μ‐η¹ : η²‐C≡CPh)(μ‐P^tBu₂)(μ‐Ph₂PCH₂PPh₂)] (L = CO, PⁿBu₃) [Ru₂(CO)₄(μ‐H)(μ‐P^tBu₂)(μ‐dppm)] ( 1 ) reacts with several phosphines (L) in refluxing toluene under substitution of one carbonyl ligand and yields the compounds [Ru₂(CO)₃L(μ‐H)(μ‐P^tBu₂)(μ‐dppm)] (L = PⁿBu₃, 2 a ; L = PCy₂H, 2 b ; L = dppm‐P, 2 c ; dppm = Ph₂PCH₂PPh₂). The reactivity of 1 as well as the activated complexes 2 a – c towards phenylethyne was studied. Thus 1 , 2 a and 2 b , respectively, react with PhC≡CH in refluxing toluene with elimination of dihydrogen to the acetylide‐bridged complexes [Ru₂(CO)₄(μ‐η¹ : η²‐C≡CPh)(μ‐P^tBu₂)(μ‐dppm)] ( 3 ) and [Ru₂(CO)₃L(μ‐η¹ : η²‐C≡CPh)(μ‐P^tBu₂)(μ‐dppm)] ( 4 a and 4 b ). The molecular structures of 3 and 4 a were determined by crystal structure analyses.     

Synthesis,Structures, and Reactivities of Pincer‐Type Ruthenium Complexes Bearing Two Proton‐Responsive Pyrazole Arms

A new metal–ligand bifunctional, pincer‐type ruthenium complex [RuCl( L1‐H2 )(PPh₃)₂]Cl ( 1 ; L1‐H2 =2,6‐bis(5‐tert‐butyl‐1H‐pyrazol‐3‐yl)pyridine) featuring two proton‐delivering pyrazole arms has been synthesized. Complex 1 , derived from [RuCl₂(PPh₃)₃] with L1‐H2 , underwent reversible deprotonation with potassium carbonate to afford the pyrazolato–pyrazole complex [RuCl(L1‐H)(PPh₃)₂] ( 2 ). Further deprotonation of 1 and 2 with potassium hexamethyldisilazide in methanol resulted in the formation of the bis(pyrazolato) complex [Ru(L1)(MeOH)(PPh₃)₂] ( 3 ). Complex 3 smoothly reacted with dioxygen and dinitrogen to give the side‐on peroxo complex [Ru(L1)(O₂)(PPh₃)₂] ( 4 ) and end‐on dinitrogen complex [Ru(L1)(N₂)(PPh₃)₂] ( 5 ), respectively. On the other hand, the reaction of [RuCl₂(PPh₃)₃] with less hindered 2,6‐di(1H‐pyrazol‐3‐yl)pyridine ( L3‐H2 ) led to the formation of the dinuclear complex [{RuCl₂(PPh₃)₂}₂(μ₂‐ L3‐H2 )₂] ( 6 ), in which the pyrazole‐based ligand adopted a tautomeric form different from L1‐H2 in 1 and the central pyridine remained uncoordinated. The detailed structures of 1 , 2 , 3 , 3.MeOH , 4 , 5 , 6 were determined by X‐ray crystallography.     

A dinuclear triple bonded RuRu compound: preparation and crystal structure of μ,μ′-1,2-phenylenediimine-(N,N′)-dicarbonylbis(triphenylphosphine)diruthenium(RuRu) (I)

Reaction of [Ru{1,2-C₆H₄(NH)₂}(PPh₃)₃] (1) with CO in toluene at room temperature afforsa as one of the products the dinuclear complex syn-[Ru₂{μ-1,2-C₆H₄(NH)₂}(CO)₂(PPh₃)₂] (2). The crystal structure of 2 reveals it to be an unsaturated bimetallic species, with two Ru(CO)(PPh₃) moieties bridged by an 8e⁻ donor η²-diimine ligand in a tetrahedral-like fashion and involving a triple RuRu bond.     

Corrigendum

Reactions of NaMn(CO)₃ with RuCl₂(PMe₃)₄, RuCl₂(dppm)₂ and RuCl₂(PPh₃)₃ lead either to an ionic species [Ru₂Cl₃(PMe₃)₆]+[Mn(CO)₅]^? or to metal—metal bonded RuMn compounds such as RuMn(μ-CO)₂(CO)₃(μ-dppm)₂ Cl, and, quite unexpectedly, to the μ-phosphido complex RuMn(μ-PPh₂)(CO)₆(PPh₃)₂ via a hydride intermediate.     

Synthesis and characterisation of saturated and unsaturated triruthenium clusters containing electronically symmetrical and asymmetrical alkynes

The synthesis and characterisation of μ₃-η²-alkynyl triruthenium clusters, [Ru₃(μ₃-η²-R¹-4-C₆H₄CCR²)(μ-dppm)(μ-CO)(CO)₇] (1, saturated), [Ru₃(μ₃-η²-R¹-4-C₆H₄CCR²)(μ-dppm)(CO)₇] (2, unsaturated) and [Ru₃(μ₃-η²-R¹-4-C₆H₄CCR²)(μ-dppm)(PPh₃)(CO)₇] (3, saturated) containing symmetrical and asymmetrical alkynes in which R¹ and R² are electron donor or electron withdrawing groups in the para position of the aromatic ring(s) or R² is ferrocenyl, are reported. Clusters 1 were obtained from the reactions of [PPN][Ru₃(μ-Cl)(CO)₁₀] with R¹-4-C₆H₄CCR² and dppm. Clusters 1 were successfully decarbonylated to give unsturated clusters 2, with the exception of the FcCCC₆H₄-4-NO₂ containing cluster, which is stable. Novel adducts 3 were obtained in high yields by addition of PPh₃ to unsaturated clusters 2. Clusters 1-3 were characterised by analytical and spectroscopic data, and structures were proposed on the basis of systematic ³¹P NMR studies and correlations with X-ray structural data of related compounds available in the literature. Saturated compounds 1 contain a CO and a dppm ligands bridging the same edge, which is also parallel to the μ₃-η²-alkyne, as opposed to the structure previously proposed for the PhCCPh and other derivatives, and established by X-ray crystallography for the PhCCCCPh cluster derivative, in which the dppm ligand bridges a different edge. Unsaturated compounds 2 exhibit the same structure established for the PhCCPh derivative in the solid state, with the alkyne bonded in the μ₃-η²-mode perpendicular to the Ru₂ edge supported by the dppm ligand. Because the dppm phosphorus chemical shifts were sensitive to the alkyne electronic asymmetry, it was possible to show that clusters containing electronically asymmetrical alkynes exist in two inseparable isomeric forms, which differ with respect to the alkyne orientation. Similarly to their osmium analogues, saturated compounds 3 exist as inseparable mixtures of isomers that differ with respect to the position of the bridging CO and dppm ligands, and in the cases of asymmetrical alkyne derivatives, also with respect to the orientation of the alkyne. This work has established, therefore, that μ-CO and dppm ligand positions respective to the μ₃-η²-alkyne in saturated clusters 1 and 3 are sensitive both to the nature of the coordinated alkyne and to the presence of a PPh₃ in place of a CO ligand on the metal frame.     

[Fe2(μsb‐CO)(CO)3(NO)(μ‐PtBu2)(μ‐Ph2PCH2PPh2)]: Synthese,Kristallstruktur und Koordinationsisomerie

[Fe₂(μ_sb‐CO)(CO)₃(NO)(μ‐P^tBu₂)(μ‐Ph₂PCH₂PPh₂)]: Synthesis, X‐ray Crystal Structure and Isomerization Na[Fe₂(μ‐CO)(CO)₆(μ‐P^tBu₂)] ( 1 ) reacts with [NO][BF₄] at —60 °C in THF to the nitrosyl complex [Fe₂(CO)₆(NO)(μ‐P^tBu₂)] ( 2 ). The subsequent reaction of 2 with phosphanes (L) under mild conditions affords the complexes [Fe₂(CO)₅(NO)L(μ‐P^tBu₂)], L = PPh₃, ( 3a ); η‐dppm (dppm = Ph₂PCH₂PPh₂), ( 3b ). In this case the phosphane substitutes one carbonyl ligand at the iron tetracarbonyl fragment in 2 , which was confirmed by the X‐ray crystal structure analysis of 3a . In solution 3b loses one CO ligand very easily to give dppm as bridging ligand on the Fe‐Fe bond. The thus formed compound [Fe₂(CO)₄(NO)(μ‐P^tBu₂)(μ‐dppm)] ( 4 ) occurs in solution in different solvents and over a wide temperature range as a mixture of the two isomers [Fe₂(μ_sb‐CO)(CO)₃(NO)(μ‐P^tBu₂)(μ‐dppm)] ( 4a ) and [Fe₂(CO)₄(μ‐NO)(μ‐P^tBu₂)(μ‐dppm)] ( 4b ). 4a was unambiguously characterized by single‐crystal X‐ray structure analysis while 4b was confirmed both by NMR investigations in solution as well as by means of DFT calculations. Furthermore, the spontaneous reaction of [Fe₂(CO)₄(μ‐H)(μ‐P^tBu₂)(μ‐dppm)] ( 5 ) with NO at —60 °C in toluene yields a complicated mixture of products containing [Fe₂(μ‐CO)(CO)₄(μ‐H)(μ‐P^tBu₂)(μ‐dppm)] ( 6 ) as main product beside the isomers 4a and 4b occuring in very low yields.