Complexation and metallation of Ph2PCC(CH2)5CCPh2 in triosmium carbonyl clusters

Reaction of Ph₂PCC(CH₂)₅CCPh₂ with Os₃(CO)₁₀(NCMe)₂ affords Os₃(CO)₁₀(μ,η²-(Ph₂P)₂C₉H₁₀) (1) and the double cluster [Os₃(CO)₁₀]₂(μ,η²- (Ph₂P)₂C₉H₁₀)₂ (2), through coordination of the phosphine groups. Thermolysis of 1 in toluene generates Os₃(CO)₇(μ-PPh₂)(μ₃,η⁵-Ph₂PC₉H₁₀) (3) and Os₃(CO)₈(μ-PPh₂)(μ₃,η⁶-Ph₂P(C₉H₁₀)CO) (4). The molecular structures of 1, 3, and 4 have been determined by an X-ray diffraction study. Both 3 and 4 contain a bridging phosphido group and a carbocycle connected to an osmacyclopentadienyl ring, which are apparently derived from C-P bond activation and C-C bond rearrangement of the dpndy ligand governed by the triosmium clusters.     

Synthesis and diphosphine ligand fluxionality in Os3(CO)10(bmi): Kinetic evidence for nondissociative diphosphine isomerization and X-ray crystal structure of 1,1-Os3(CO)10(bmi)

The triosmium cluster 1,2-Os₃(CO)₁₀(MeCN)₂ reacts rapidly with the diphosphine ligand 2,3-bis(diphenylphosphino)-N-p-tolylmaleimide (bmi) at room temperature to give bmi-bridged cluster 1,2-Os₃(CO)₁₀(bmi) (2b) as the major product, along with the chelating isomer 1,1-Os₃(CO)₁₀(bmi) (2c) and the hydride-bridged cluster HOs₃(CO)₉[μ-(PPh₂)CC{PPh(C₆H₄)}C(O)N(tolyl-p)C(O)] (3) as minor by-products. All three cluster compounds have been isolated and fully characterized in solution by IR and NMR spectroscopies (¹H and ³¹P), and X-ray crystallography in the case of 2c. Cluster 2b is unstable and readily isomerizes to 2c in quantitative yield on mild heating. The kinetics for the conversion of 2b → 2c have been measured over the temperature range of 318-348 K in toluene solution, and based on the observed activation parameters a nondissociative isomerization process that proceeds via a transient μ₂-bridged phosphine moiety is presented. Near-UV photolysis of cluster 2c at room temperature affords HOs₃(CO)₉[μ-(PPh₂)CC{PPh(C₆H₄)}C(O)N(tolyl-p)C(O)] (3) with a quantum yield of 0.017. The reactivity of clusters 2b, 2c, and 3 is discussed with respect to related diphosphine-substituted Os₃(CO)₁₀(P-P) clusters prepared by our groups.     

Reaction of the heterometallic cluster Os3Ru(μ-H)2(CO)13 with diphenylphosphine: phosphido-bridged tetrahedral and butterfly clusters

TMNO-activated reaction of the heteronuclear cluster Os₃Ru(μ-H)₂(CO)₁₃ (1) with diphenylphosphine afforded the novel phosphido-bridged clusters Os₃Ru(μ-PPh₂)(μ-H)₃(CO)₁₁ (2), Os₃Ru(μ-PPh₂)₂(μ-H)₂(CO)₁₀ (3), Os₃Ru(μ-PPh₂)₂(μ-H)₄(CO)₉ (4), and Os₃Ru(μ-PPh₂)(μ-H)₃(CO)₁₁(PPh₂H) (5). The formation of 2-5 proceeded via P-H bond cleavage in the adduct Os₃Ru(μ-H)₂(CO)₁₂(PPh₂H) (6). Reaction of 2 with PPh₃ afforded the adduct Os₃Ru(μ-PPh₂)(μ-H)₃(CO)₁₁(PPh₃) (7) and the substituted derivative Os₃Ru(μ-PPh₂)(μ-H)₃(CO)₁₀(PPh₃) (8).     

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.     

Reactions of rhenium and manganese carbonyl complexes with 1,8-bis(diphenylphosphino)naphthalene: Ligand chelation, C-H and C-P bond-cleavage reactions

Reaction of [Re₂(CO)₈(MeCN)₂] with 1,8-bis(diphenylphosphino)naphthalene (dppn) afforded three mono-rhenium complexes fac-[Re(CO)₃(κ¹:η¹-PPh₂C₁₀H₆)(PPh₂H)] (1), fac-[Re(CO)₃{κ¹:κ¹:η¹-(O)PPh₂C₁₀H₆(O)PPh(C₆H₄)}] (2) and fac-[ReCl(CO)₃(κ²-PPh₂C₁₀H₆PPh₂)] (3). Compounds 1-3 are formed by Re-Re bond cleavage and P-C and C-H bond activation of the dppn ligand. Each of these three complexes have three CO groups arranged in facial fashion. Compound 1 contains a chelating cyclometalated diphenylnaphthylphosphine ligand and a terminally coordinated PPh₂H ligand. Compound 2 consists of an orthometalated dppn-dioxide ligand coordinated in a κ¹:κ¹:η¹-fashion via both the oxygen atoms and ortho-carbon atom of one of the phenyl rings. Compound 3 consists of an unchanged chelating dppn ligand and a terminal Cl ligand. Treatment of [Mn₂(CO)₈(MeCN)₂] with a slight excess of dppn in refluxing toluene at 72 °C, gave the previously reported [Mn₂(CO)₈(μ-PPh₂)₂] (4), formed by cleavage of C-P bonds, and the new compound fac-[MnCl(CO)₃(κ²-PPh₂C₁₀H₆PPh₂)] (5), which has an unaltered chelating dppn and a terminal Cl ligand. In sharp contrast, reaction of [Mn₂(CO)₈(MeCN)₂] with slight excess of dppn at room temperature yielded the dimanganese [Mn₂(CO)₉{κ¹-PPh₂(C₁₀H₇)}] (6) in which the diphenylnaphthylphosphine ligand, formed by facile cleavage of one of the P-C bonds, is axially coordinated to one Mn atom. Compound 6 was also obtained from the reaction of [Mn₂(CO)₉(MeCN)] with dppn at room temperature. The XRD structures of complexes 1-3, 5, 6 are reported.     

Activation of 1,3,5-trimethyl-1,3,5-triazacyclohexane by Os3(CO)12 to form amidino [(MeN)2CH] cluster complexes

Reaction of 1,3,5-trimethyl-1,3,5-triazacyclohexane [(MeNCH₂)₃] with Os₃(CO)₁₂ in refluxing toluene results in C-H and C-N bond activation of the (MeNCH₂)₃ ligand to afford three amidino cluster complexes (μ-H)Os₃(CO)₁₀[μ,η²-CH(NMe)₂] (1), (μ-H)Os₃(CO)₉[μ₃,η²-CH(NMe)₂] (2), and Os₂(CO)₆[μ,η²-CH(NMe)₂]₂ (3). The controlled experiments show that thermolysis of 1 yields 2, and heating 2 in the presence of (MeNCH₂)₃ ligand produces 3. The molecular structures of 1 and 3 have been determined by an X-ray diffraction study.     

Complexes containing bridging tin- and germanium-substituted metallocarboxylate ligands from the reactions of Ph3SnOH and Ph3GeOH with Os3(CO)12 in the presence of base

The first examples of bridging tin- and germanium-substituted metallocarboxylate ligands have been obtained from the reactions of Ph₃SnOH and Ph₃GeOH with Os₃(CO)₁₂ under basic conditions. Two products: Os₃(CO)₁₀(μ-η²-O=COSnPh₃)(μ-OMe), 1 (18% yield) and Os₃(CO)₁₀(μ-OMe)(μ-OH), 2 (6.9% yield) were obtained from the reaction of Ph₃SnOH with Os₃(CO)₁₂ in the presence of [Bu₄N]OH in methanol solvent. The compound Os₃(CO)₁₀(μ-η²-O=COGePh₃)(μ-OMe), 3 (7.3% yield) was prepared similarly by using Ph₃GeOH in place of Ph₃SnOH. Each of the products 1-3 were characterized structurally by single-crystal X-ray diffraction analysis. Compounds 1 and 3 each contain an μ-η²-O=COMPh₃, M = Sn or Ge ligand bridging a pair of osmium atoms in a triosmium carbonyl cluster complex.     

Ruthenium carbonyl clusters containing PMe2(nap) and derived ligands (nap = 1-naphthyl): generation of naphthalyne derivatives

Bis(dimethylphosphino)naphthalene, 1,8-(PMe₂)₂C₁₀H₆ (dmpn), reacts readily with Ru₃(CO)₁₂ or Ru₃(μ-dppm)(CO)₁₀ with replacement of one of the PMe₂ groups by H to give Ru₃(CO)_12 − n{PMe₂(nap)}_n (n = 1 2, 2 3) or Ru₃(μ-dppm)(CO)₉{PMe₂(nap)} 4; the complex Ru₃(CO)₁₀(dmpn) 1 is obtained only in small amount. Thermolysis of 2 or 4 gives Ru₃(μ-H)₂{μ₃-PMe₂(C₁₀H₅)}(μ-dppm)_n (CO)_8-2n (n = 0 5, 1 6, respectively) containing μ₃-naphthalyne groups.     

Reaction of multifunctional molecule (Ph2P(o-C6H4)CHNCH2CH2)3N with triosmium carbonyl clusters

Reaction of (Ph₂P(o-C₆H₄)CHNCH₂CH₂)₃N with 3 equiv. of Os₃(CO)₁₀(NCMe)₂ at ambient temperature affords the triple cluster [Os₃(CO)₁₀Ph₂P(o-C₆H₄)CHNCH₂CH₂]₃N (1) through coordination of the phosphine and imine groups. Thermolysis of 1 in benzene leads to decarbonylation and C-H/C-N bond activation of the ligand to generate (μ-H)Os₃(CO)₈(μ₃-Ph₂P(o-C₆H₄)CHNCCH₂) (2). The molecular structure of 2 has been determined by an X-ray diffraction study.     

Ruthenium-tin complexes from the reaction of HSnPh3 with Ru3(CO)10(NCMe)2 and their reactions with bis(tri-t-butylphosphine)platinum

The compounds Ru₃(CO)₉(SnPh₃)₂(NCMe)(μ-H)₂ (1), Ru₃(CO)₁₀(SnPh₃)₂(μ-H)₂ (2), Ru(CO)₄(SnPh₃)₂ (3) and Ru(CO)₄(SnPh₃)(H) (4) were obtained from the reaction of Ru₃(CO)₁₀(NCMe)₂ with HSnPh₃ in hexane solvent. Compounds 1, 3 and the new compound Ru₃(CO)₇(SnPh₃)₃(NCMe)₂(μ-H)₃ (5) were obtained from reaction of Ru₃(CO)₁₀(NCMe)₂ with HSnPh₃ in a CH₂Cl₂ and MeCN solvent mixture. Compound 2 and the new compound Ru₃(CO)₉(SnPh₃)₃(μ-H)₃ (6) were obtained from reactions of 1 and 5 with CO, respectively. Compounds 2 and 6 eliminated benzene when heated to yield Ru₃(CO)₁₀(μ-SnPh₂)₂ (7) and Ru₃(CO)₉(μ-SnPh₂)₃ (8) which contain bridging SnPh₂ ligands. Compound 7 was found to react with to yield the adduct, (9) in 59% yield by the addition of groups to two of the Ru-Sn bonds to the bridging SnPh₂ ligands. Fenske-Hall molecular orbital calculations were performed to provide an understanding of the metal-metal bonding in the clusters of 7 and 9. Compounds 1, 2, 5, 6, 7 and 9 were characterized structurally by single crystal X-ray diffraction analysis.     

Two modes of C-H bond activation of tris(2-thienyl)phosphine in trinuclear osmium carbonyl clusters

Tris(2-thienyl)phosphine, P(C₄H₃S)₃, reacts with [Os₃(CO)₁₂] at 110 °C to give the phosphine-substituted derivatives [Os₃(CO)₁₁{P(C₄H₃S)₃}] (1), [Os₃(CO)₁₀{P(C₄H₃S)₃}₂] (2) and [Os₃(CO)₉{P(C₄H₃S)₃}₃] (4), as well as the C-H activated product [Os₃(μ-H)(CO)₉{μ-P(C₄H₂S)(C₄H₃S)₂}{P(C₄H₃S)₃}] (3), in which the bridging ligand is equatorially coordinated to two osmium atoms. Thermolysis of 2 in refluxing toluene results in the formation of 3. Compound 1 can also be prepared in high yield from [Os₃(CO)₁₁(NCMe)]. The reaction of [Os₃(μ-H)₂(CO)₁₀] with tris(2-thienyl)phosphine at room temperature afforded [Os₃(μ-H)₂(CO)₉{P(C₄H₃S)₃}] (5) and [Os₃H(μ-H)(CO)₁₀{P(C₄H₃S)₃}] (6), with the ligand coordinated through the phosphorus atom whereas at elevated temperature the cyclometallated compounds [Os₃(μ-H)(CO)₉{μ₃-P(C₄H₂S)(C₄H₃S)₂}] (7) and [Os₃(μ-H)(CO)₈{μ₃-P(C₄H₂S)(C₄H₃S)₂{P(C₄H₃S)₃}] (8) were obtained in addition to 5. Heating 6 in refluxing heptane furnished 5 via loss of one carbonyl ligand. Thermolysis of 1 and 3 in refluxing toluene gives 7 and 8, respectively, in good yields. In 3, the μ-P(C₄H₂S)(C₄H₃S)₂ ligand is coordinated through the phosphorus to one Os atom and through a σ-Os-C bond to the second osmium atom. Compound 7 contains the μ₃-P(C₄H₂S)(C₄H₃S)₂ ligand bound through phosphorus to one Os atom, through a σ-Os-C bond to another and by an η² (π)-interaction to the third osmium atom. Compounds 1, 2 and 4 contain the ligand coordinated exclusively through the phosphorus atom. The crystal and molecular structures of 2, 3, 5, 6 and 7 are reported.     

Reactivity of 2,3-bis(2-pyridyl)pyrazine with [Re2(CO)8(CH3CN)2]: Molecular structures of [Re2(CO)8(C14H10N4)] and [Re2(CO)8(C14H10N4)Re2(CO)8]

The reaction of the labile compound [Re₂(CO)₈(CH₃CN)₂] with 2,3-bis(2-pyridyl)pyrazine in dichloromethane solution at reflux temperature afforded the structural dirhenium isomers [Re₂(CO)₈(C₁₄H₁₀N₄)] (1 and 2), and the complex [Re₂(CO)₈(C₁₄H₁₀N₄)Re₂(CO)₈] (3). In 1, the ligand is σ,σ′-N,N′-coordinated to a Re(CO)₃ fragment through pyridine and pyrazine to form a five-membered chelate ring. A seven-membered ring is obtained for isomer 2 by N-coordination of the 2-pyridyl groups while the pyrazine ring remains uncoordinated. For 2, isomers 2a and 2b are found in a dynamic equilibrium ratio [2a]/[2b]  =  7 in solution, detected by ¹H NMR (−50 °C, CD₃COCD₃), coalescence being observed above room temperature. The ligand in 3 behaves as an 8e-donor bridge bonding two Re(CO)₃ fragments through two (σ,σ′-N,N′) interactions. When the reaction was carried out in refluxing tetrahydrofuran, complex [Re₂(CO)₆(C₁₄H₁₀N₄)₂] (4) was obtained in addition to compounds 1-3. The dinuclear rhenium derivative 4 contains two units of the organic ligand σ,σ′-N,N′-coordinated in a chelate form to each rhenium core. The X-ray crystal structures for 1 and 3 are reported.     

Reactivity of [Os3(CO)10(NCMe)2] and [Os3(CO)10(μ-Cl)(μ-AuPPh3)] with 4-mercaptopyridine: X-ray structure of [Os3(CO)10(μ-H)(μ-SC5H4N)] and [Os3(CO)10(μ-AuPPh3)(μ-SC5H4N)]

The compound [Os₃(CO)₁₀(μ-Cl)(μ-AuPPh₃)] (2) was prepared from the reaction between [Os₃(CO)₁₀(NCMe)₂] (1) and [AuClPPh₃] under mild conditions. The reaction of 2 with 4-mercaptopyridine (4-pyS) ligand yielded compounds [Os₃(CO)₁₀(μ-H)(μ-SC₅H₄N)] (4), formed by isolobal replacement of the fragment [AuPPh₃]⁺ by H⁺ and [Os₃(CO)₁₀(μ-AuPPh₃)(μ-SC₅H₄N)] (5). [Os₃(CO)₁₀(μ-H)(μ-SC₅H₄N)] (4) was also obtained by substitution of two acetonitrile ligands in the activated cluster 1 by 4-pyS, at room temperature in dichloromethane. Compounds 2-5 were characterized spectroscopically and the molecular structures of 4 and 5 in the solid state were obtained by single crystal X-ray diffraction studies.     

The activation and transformations of acenaphthylene by osmium carbonyl cluster complexes

The reaction of Os₃(CO)₁₀(NCMe)₂ (1) with an excess of acenaphthylene at room temperature provided the complex Os₃(CO)₁₀(μ-H)(μ-η²-C₁₂H₇) (2). Compound 2 contains a σ-π coordinated acenaphthyl ligand bridging an edge of the cluster. Compound 2 was converted to the complex Os₃(CO)₉(μ-H)₂(μ₃-η²-C₁₂H₆) (3) when heated to reflux in a cyclohexane solution. Compound 3 contains a triply bridging acenaphthyne ligand. Compound 3 reacts with acenaphthylene again at 160 °C to yield four new cluster complexes: Os₄(CO)₁₂(μ₄-η²:η²-C₁₂H₆) (4); Os₂(CO)₆(μ-η⁴-C₂₄H₁₂) (5); Os₃(CO)₉(μ-H)(μ₃-η⁴-C₂₄H₁₃) (6); and Os₂(CO)₅(μ-η⁴-C₂₄H₁₂)(η²-C₁₂H₈) (7). All compounds were characterized crystallographically. Compound 4 is a butterfly cluster of four osmium atoms bridged by a single acenaphthyne ligand. Compounds 5 and 7 are dinuclear osmium clusters containing metallacycles formed by the coupling of two equivalents of acenaphthyne. Compound 6 is a triosmium cluster formed by the coupling of an acenaphthyne ligand to an acenapthyl group that is coordinated to the cluster through a combination of σ and π-bonding.     

Reactivity of [Re2(CO)8(MeCN)2] with thiazoles: Hydrido bridged dirhenium compounds bearing thiazoles in different coordination modes

Reactions of the labile compound [Re₂(CO)₈(MeCN)₂] with thiazole and 4-methylthiazole in refluxing benzene afforded the new compounds [Re₂(CO)₇{μ-2,3-η²-C₃H(R)NS}{η¹-NC₃H₂(4-R)S}(μ-H)] (1, R = H; 2, R = CH₃), [Re₂(CO)₆{μ-2,3-η²-C₃H(R)NS}{η¹-NC₃H₂(4-R)S}₂(μ-H)] (3, R = H; 4, R = CH₃) and fac-[Re(CO)₃(Cl){η¹-NC₃H₂(4-R)S}₂] (5, R = H; 6, R = CH₃). Compounds 1 and 2 contain two rhenium atoms, one bridging thiazolide ligand, coordinated through the C(2) and N atoms and a η¹-thiazole ligand coordinated through the nitrogen atom to the same Re as the thiazolide nitrogen. Compounds 3 and 4 contain a Re₂(CO)₆ group with one bridging thiazolide ligand coordinated through the C(2) and N atoms and two N-coordinated η¹-thiazole ligands, each coordinated to one Re atom. A hydride ligand, formed by oxidative-addition of C(2)-H bond of the ligand, bridges Re-Re bond opposite the thiazolide ligand in compounds 1-4. Compound 5 contains a single rhenium atom with three carbonyl ligands, two N-coordinated η¹-thiazole ligands and a terminal Cl ligand. Treatment of both 1 and 2 with 5 equiv. of thiazole and 4-methylthiazole in the presence of Me₃NO in refluxing benzene afforded 3 and 4, respectively. Further activation of the coordinated η¹-thiazole ligands in 1-4 is, however, unsuccessful and results only nonspecific decomposition. The single-crystal XRD structures of 1-5 are reported.     

Synthesis and characterization of triosmium and triruthenium pyrene clusters

The reaction between 1-pyrenecarboxaldehyde (C₁₆H₉CHO) and the labile triosmium cluster [Os₃(CO)₁₀(CH₃CN)₂] gives rise to the formation of two new compounds by competitive oxidative addition between the aldehydic group and an arene C-H bond, to afford the acyl complex [Os₃(CO)₁₀(μ-H)(μ-COC₁₆H₉)] (1) and the compound [Os₃(CO)₁₀(μ-H) (C₁₆H₈CHO)] (2), respectively. Thermolysis of [Os₃(CO)₁₀(μ-H)(μ-C₁₆H₉CO)] (1) in n-octane affords two new complexes in good yields, [Os₃(CO)₉(μ-H)₂(μ-COC₁₆H₈)] (3) and the pyryne complex [Os₃(CO)₉(μ-H)₂(μ₃-η¹:η¹:η²-C₁₆H₈)] (4).In contrast, when 1-pyrenecarboxaldehyde reacts with [Ru₃(CO)₁₂] only one product is obtained, [Ru₃(CO)₉(μ-H)₂(μ₃-η¹:η¹:η²-C₁₆H₈)] (5), a nonacarbonyl cluster bearing a pyrene ligand. All compounds were characterized by analytical and spectroscopic data, and crystal structures for 1, 2, 4 and 5 were obtained.     

Reactions of the triosmium cluster Os3(μ-H)(μ-OH)(CO)10 with naphthols

Reaction of the cluster Os₃(μ-H)(μ-OH)(CO)₁₀ (1) with 1-naphthol afforded the isomeric clusters 2a and 3a with the formulae Os₃(μ-H)₂(μ₃-1-OC₁₀H₆)(CO)₉. A similar reaction with 2-naphthol, however, gave Os₃(μ-H)(μ-2-OC₁₀H₇)(CO)₁₀, 4b, and the analogue of 2a. These clusters have been structurally characterised to confirm the mode of anchoring of the naphthols.     

A comparative study of the reactivity of unsaturated triosmium clusters [Os3(CO)8{μ3-Ph2PCH2P(Ph)C6H4}(μ-H)] and [Os3(CO)9{μ3-η-C7H3(2-Me)NS}(μ-H)] with BuNC

Treatment of unsaturated [Os₃(CO)₈{μ₃-Ph₂PCH₂P(Ph)C₆H₄}(μ-H)] (2) with ^tBuNC at room temperature gives [Os₃(CO)₈(CNBu^t)){μ₃-Ph₂PCH₂P(Ph)C₆H₄}(μ-H)] (3) which on thermolysis in refluxing toluene furnishes [Os₃(CO)₇(CNBu^t){μ₃-Ph₂PCHP(Ph)C₆H₄}(μ-H)₂] (4). Reaction of the labile complex [Os₃(CO)₉(μ-dppm)(NCMe)] (5) with ^tBuNC at room temperature affords the substitution product [Os₃(CO)₉(μ-dppm)(CNBu^t)] (6). Thermolysis of 6 in refluxing toluene gives 4. On the other hand, the reaction of unsaturated [Os₃(CO)₉{μ₃-η²-C₇H₃(2-Me)NS}(μ-H)] (7) with ^tBuNC yields the addition product [Os₃(CO)₉(CNBu^t){μ-η²-C₇H₃(2-Me)NS}(μ-H)] (8) which on decarbonylation in refluxing toluene gives unsaturated [Os₃(CO)₈(CNBu^t){μ₃-η²-C₇H₃(2-Me)NS}(μ-H)] (9). Compound 9 reacts with PPh₃ at room temperature to give the adduct [Os₃(CO)₈(PPh₃)(CNBu^t){μ-η²-C₇H₃(2-Me)NS(μ-H)] (10). Compound 8 exists as two isomers in solution whereas 10 occurs in four isomeric forms. The molecular structures of 3, 6, 8, and 10 have been determined by X-ray diffraction studies.     

Reactivity of a functionalized trisamido ligand with Zr(NMe2)4 and GaMe3

NMR study of the reactivity of multifunctional ligand cis,cis-C₆H₉(NHCH₂C₆H₄-o-PPh₂)₃ (1) with GaMe₃ and Zr(NMe₂)₄ was carried out, yielding [cis,cis-(κ^N-NHCH₂C₆H₄-o-PPh₂)(κ^N-NCH₂C₆H₄-o-PPh₂)₂C₆H₉]GaMe (2) and [cis,cis-(NCH₂C₆H₄-o-PPh₂)₃C₆H₉]Ga₂Me₃ (3), and [cis,cis-(NCH₂C₆H₄-o-PPh₂)₃C₆H₉]Zr(NMe₂) (4), respectively. The spectral properties of 2 and 3 are very similar to that observed for the equivalent aluminum species already reported, but form at a much slower rate which allows for the observation of a GaMe₃⋅1 adduct. Species 4 undergoes coordination/displacement of one of the phosphine arms, which was observed using both NMR spectroscopy and DFT analyses.     

Reaction of tri(2-furyl)phosphine with triosmium clusters: C-H and P-C activation to afford furyne and phosphinidene ligands

Addition of tri(2-furyl)phosphine, PFu₃, to [Os₃(CO)₁₀(μ-H)₂] at room temperature gives [HOs₃(CO)₁₀(PFu₃)(μ-H)] (1), while in refluxing toluene the same reactants afford [Os₃(CO)₉{μ₃-PFu₂(C₄H₂O)}(μ-H)] (2) resulting from orthometallatation of a furyl ring. Reaction of PFu₃ with [Os₃(CO)_10−n(NCMe)_n] (n = 0, 1, 2) affords the substituted clusters [Os₃(CO)_12−n(PFu₃)_n] (n = 1-3) (3-5), the phosphine ligands occupying equatorial position in all cases. Heating [Os₃(CO)₁₁(PFu₃)] (3) in refluxing octane gives [Os₃(CO)₉(μ₃-PFu)(μ₃-η²-C₄H₂O)] (6) which results from both carbon-hydrogen and carbon-phosphorus bond activation and contains both μ₃-η²-furyne and furylphosphinidene ligands. All new clusters have been characterized by spectroscopic methods together with single crystal X-ray diffraction for 2, 3 and 6.