Syntheses of (η6-p-cymene)ruthenium(II) piano-stool amine complexes: molecular structure of [(η6-C10H14)RuCl2(H2N-C6H4-p-Cl)]

The dimeric complex [{(η⁶-p-cymene)Ru(μ-Cl)Cl}₂] (1) reacts with S,N-donor Schiff base ligands, para-substituted S-(thiophen-2-ylmethylene)phenylamines in methanol to give mononuclear amine complexes of the type [(η⁶-p-cymene)RuCl₂(NH₂–C₆H₄–p-X)] {X?=?H (2a); X?=?CH₃ (2b); X?=?OCH₃ (2c); X?=?Cl (2d); Br (2e) X?=?NO₂ (2f), respectively} by hydrolysis of the imine group of the ligand after coordination to the metal. The complexes were characterized by analysis and IR and NMR spectroscopy. The molecular structure of [(η⁶-C₁₀H₁₄)RuCl₂(H₂N–C₆H₄–p-Cl)] (2d) was established by a single-crystal X-ray diffraction study.     

Syntheses,spectroscopic and structural studies of indenyl ruthenium complexes incorporating amine and nitrile ligands: molecular structures of [(η5-C9H7) Ru(η2-dppe)(CH3CN)]PF6 and [(η5-C9H7)Ru(η2-dppe)(NH3)]PF6

The reaction of [(η⁵-C₉H₇)Ru(η²-dppe)Cl] (1) with monodentate nitriles, (L) in the presence of NH₄PF₆ afforded the complexes [(η⁵-C₉H₇)Ru(η²-dppe)(L)]PF₆, with L?=?CH₃CN (2a), CH₃CH=CHCN (2b), NCC₆H₄CN (2c), C₆H₅CH₂CN (2d), respectively. However, reaction of 1 with NH₄PF₆ in methanol yielded an amine complex of the type [(η⁵-C₉H₇) Ru(η²-dppe)(NH₃)]PF₆ (3a). The complexes were fully characterized by spectroscopy and analytical data. The molecular structures of the complexes [(η⁵-C₉H₇)Ru(η²-dppe) (CH₃CN)]PF₆ (2a) and [(η⁵-C₉H₇)Ru(η²-dppe)(NH₃)]PF₆ (3a) have been determined by single crystal X-ray analyses.     

Generation of the dichloromethane complex [(η5-C5Me5)Re(NO)(PPh3)(ClCH2Cl]+ BF4−, and its conversion to the oxidative addition product [(η5-C5Me5)Re(NO)(PPh3)(Cl)(CH2Cl)]+ BF4−

Reaction of (η⁵-C₅Me₅)Re(NO)(PPh₃)(CH₃) and HBF₄ · OEt₂ in CH₂Cl₂ at −78°C gives the dichloromethane complex [η⁵-C₅Me₅Re(NO)(PPh₃)(ClCH₂Cl)]⁺ BF₄⁻, which undergoes the title transformation at −35°C. The ReClCH₂Cl carbon is attacked by halide nucleophiles (X⁻) to give XCH₂Cl and the chloride complex (η⁵-C₅Me₅)Re(NO)(PPh₃)(Cl), and exhibits a ¹³C NMR resonance that is coupled to phosphorus (d, ³J(CP) 5.0 Hz) and geminal hydrogens (t, ¹J(CH) 186 Hz).     

Structure and bonding analysis of dimethylgallyl complexes of iron, ruthenium, and osmium [(η5-C5H5)(CO)2M(GaMe2)] and [(η5-C5H5)(Me3P)2M(GaMe2)

Density functional theory calculations have been performed for the dimethylgallyl complexes of iron, ruthenium, and osmium [(η(5)-C(5)H(5))(L)(2)M(GaMe(2)] (M = Fe, Ru, Os; L = CO, PMe(3)) at the DFT/BP86/TZ2P/ZORA level of theory. The calculated geometry of the iron complex [(η(5)-C(5)H(5))(CO)(2)Fe(GaMe(2))] is in excellent agreement with structurally characterized complex [(η(5)-C(5)H(5))(CO)(2)Fe(Ga(t)Bu(2))]. The Pauling bond order of the optimized structures shows that the M-Ga bonds in these complexes are nearly M-Ga single bond. Upon going from M = Fe to M = Os, the calculated M-Ga bond distance increases, while on substitution of the CO ligand by PMe(3), the calculated M-Ga bond distances decrease. The π-bonding component of the total orbital contribution is significantly smaller than that of σ-bonding. Thus, in these complexes the GaX(2) ligand behaves predominantly as a σ-donor. The contributions of the electrostatic interaction terms ΔE(elstat) are significantly smaller in all gallyl complexes than the covalent bonding ΔE(orb) term. The absolute values of the ΔE(Pauli), ΔE(int), and ΔE(elstat) contributions to the M-Ga bonds increases in both sets of complexes via the order Fe < Ru < Os. The Ga-C(CO) and Ga-P bond distances are smaller than the sum of van der Waal radii and, thus, suggest the presence of weak intermolecular Ga-C(CO) and Ga-P interactions.     

Synthesis and structures of the η5-C5H5Cl(CO)2W-η1,η5-(PPh2)C5H4(CO)2Fe-η1,η5-C5H4Mn(CO)3 and MeSi[C5H4(CO)2Fe-η1,η5-C5H4Mn(CO)2PPh3]3 complexes

The metallation of the η⁵-C₅H₅(CO)₂Fe-η¹,η⁵-C₅H₄Mn(CO)₃ complex with BuⁿLi (THF, ?78 °C) followed by the treatment of the lithium derivative with Ph₂PCl afforded the η⁵-Ph₂PC₅H₄(CO)₂Fe-η¹,η⁵-C₅H₄Mn(CO)₃ complex. The reaction of the latter with η⁵-C₅H₅(CO)₃WCl in the presence of Me₃NO produced the trinuclear complex η⁵-C₅H₅Cl(CO)₂W-η¹,η⁵-(Ph₂P)C₅H₄(CO)₂Fe-η¹,η⁵-C₅H₄Mn(CO)₃. The structure of the latter complex was established by IR, UV, and 1H and ³¹P NMR spectroscopy and X-ray diffraction. The reaction of MeSiCl₃ with three equivalents of LiC₅H₄(CO)₂Fe-η¹,η⁵-C₅H₄Mn(CO)₂PPh₃ gave the hexanuclear complex MeSi[C₅H₄(CO)₂Fe-η¹,η⁵-C₅H₄Mn(CO)₂PPh₃]₃.     

New [Ti(η5-C5H5)Cl2(OR)] complexes. Crystal and molecular structure of η5-Cyclopentadienyl(cyclohexoxy)titanium(IV) dichloride

Summary A series of new compounds with molecular formula [Ti(⁵-C₅H₅)Cl₂(OR)] (R=C₆H₁₁ (cyclohexyl,1), CH₂CH(CH₃)₂ (2), CH(C₂H₅)₂ (3), and CH₂C₆H₅ (4)) has been obtained by the reaction of [Ti(⁵-C₅H₅)Cl₃] with the appropriate alcohol. All complexes were characterized by elemental analysis and by IR and¹H NMR spectroscopy. The structure of1 was determined by X-ray diffraction studies; crystal data: triclinic,a=11.334(2),b=13.590(2),c=12.237(2) Å, =113.501(5), =118.182(5), =101.993(6),V=1328.2(4) ų,T=298K, space P1,Z=4, two crystallographically independent molecules in the unit cell. FinalR andR _w values are 0.0583 and 0.0632, respectively. Compound1 exhibits surprisingly short Ti-Cl and Ti-O distances, suggesting strong donation by the chloride and in particular by the alkoxide ligand. The Ti-O-C angle is unusually large.

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Neue [Ti(⁵-C₅H₅)Cl₂(OR)]-Komplexe. Kristall- und Molekülstruktur von ⁵-Cyclopentadienyl(cyclohexoxy)titan(IV) Dichlorid

Zusammenfassung Durch Umsetzung von [Ti(⁵-C₅H₅)Cl₃] mit dem geeigneten Alkohol wurde eine Reihe von neuen Verbindungen der Formel [Ti(⁵-C₅H₅)(OR)] (R=C₆H₁₁ (cyclohexyl,1), CH₂CH(CH₃)₂ (2), CH(C₂H₅)₂ (3) und CH₂C₆H₅ (4)) erhalten. Alle Komplexe wurden elementaranalytisch sowie IR- und¹H-NMR-spektroskopisch charakterisiert. Die Struktur von1 wurde röntgenographisch bestimmt; Kristalldaten: triklin,a=11.334(2),b=13.590(2),c=12.237(2) Å, =113.501(5), =118.182(5), =101.993(6),V=1328.2(4) ų,T=298K, Raumgruppe P1,Z=4, zwei kristallographisch unabhängige Moleküle in der Elementarzelle; abschließendeR-Werte:R=0.0583 undR _w=0.0632. Verbindung1 zeigt überraschend kurze Ti-Cl- und Ti-O-Abstände; dies deutet auf eine starke -Elektronendonorwirkung des Chlorid- und vor allem des Alkoxidliganden hin. Der Ti-O-C-Bindungswinkel ist ungewöhnlich groß.

     

Stereochemical aspects of the conversion of cyclopentadienylruthenium alkoxycarbene to the corresponding acetylide complexes. Crystal structure of [(η-C5H5)Ru(Ph2PCHMeCHMePPh2)(CCPh)]

Reactions of [(η-C₅H₅)Ru(Diphosphine){C(OCH₃)CH₂C₆H₅}]PF₆ complexes with CH₃MgBr give the corresponding phenylacetylide [(η-C₅-H₅)-Ru(Diphosphine)CCC₆H₅] complexes. A crystal structure determination has been carried out for the product in which the diphosphine is rac-1,2-dimethyl-1,2-ethanediylbis(diphenylphosphine). For the complexes in which the diphosphine is (R)-1,2-propanediylbis(diphenylphosphine), the stereo-chemical outcome of the reaction implies retention of configuration at the metal atom.     

A beneficial kinetic effect of an η(5)-C5Me4H ligand

C-H activation of benzene at 26 °C by (η(5)-C(5)Me(5))W(NO)(CH(2)CMe(3))(η(3)-CH(2)CHCHMe) results after 4 h in the production of five new organometallic complexes, only two of which are isomers of the desired (η(5)-C(5)Me(5))W(NO)(C(6)H(5))(η(3)-CH(2)CHCHMe) compound. In contrast, the identical reaction involving the η(5)-C(5)Me(4)H analogue affords only the phenyl complexes during the first 24 h, thereby facilitating their isolation in good yields. This striking difference in reactivity can be attributed to the lesser steric demands of the η(5)-C(5)Me(4)H ligand that result in its complexes reacting at a significantly slower rate.     

Cyclooctaselenadiazole: synthesis,decomposition pathway,and reaction with (η5-C5H5) Co(L)2 (L = C2H4, PPh3). Crystal and molecular structure of [(η5-C5H5)CO]2(μ2-η3,η2-C8H6Se)

Thermolysis of cyclooctaselenadiazole (2) yields only selenium-containing products. Compound 2 reacts with CpCo sources to give [(η⁵-C₅H₅)CO]₂(μ₂η³,η²-C₈H₆Se), a fluxional compound whose structure has been determined by X-Ray crystallography.     

Molecular structure of ansa-compound (η5-C5H4)CMe2(η5-C9H6)TiCl2

The structure of a new ansa compound, (⁵-C₅H₄)CMe₂(⁵-C₉H₆)TiCl₂ (1), was studied by X-ray analysis:a = 15.00(1),b =15.500(5),c = 13.032(4) Å, = 92.66°(4),V = 3025.1(1) ų, space groupP2₁/.,R = 0.038. The distorted tetrahedral coordination sphere of the Ti atom is formed by two Cl atoms and two -ligands. It was proposed that the angle () between theC-M direction and the line normal to M-Cp can be considered as one of the geometric parameters characteristic of the structure-properties correlation.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 305–308, February, 1995.     

The insertion of cycloheptatriene and cyclohepta-1,3-diene into the RuH bond of RuHCl(PPh3)3 to give Ru(η5-C7H9)Cl(PPh3)2 and Ru(η3-C7H11)Cl(PPh3)2

RuHCl(PPh₃)₃ reacts quantitatively with cycloheptatriene in CH₂Cl₂ at 35°C in 15 min to give Ru(η⁵-C₇H₉)Cl(PPh₃)₂ and PPh₃. The major isomer adopts a conformation with inequivalent phosphorus ligands and no plane of symmetry through the C₇H₉ ligand, but rapid intramolecular scrambling with δG³ = 10.6 kcal mol⁻¹ results in an averaged ¹H, ¹³C, and ³¹P NMR spectrum at room temperature. RuHCl(PPh₃)₃ reacts with cyclohepta-1,3-diene to give initially Ru(η³-C₇H₁₁)Cl(PPh₃)₂, but in a subsequent reaction this is dehydrogenated to give Ru(η⁵-C₇H₉)Cl(PPh₃)₂.     

The direct deprotonation of the η5-pyrrolyl ligand in (η5-C4H4N)(Ph3P)2ReH2

Treatment of (η⁵-C₄H₄N)(Ph₃P)₂ReH₂ (C₄H₄N = pyrrolyl) with n-BuLi at −78°C leads to regioselective (α-position) ring deprotonation. Reaction of the deprotonated product with RI (R = Me, n-Bu) gives (η⁵-2-RC₄H₃N)(Ph₃P)₂ReH₂ in high yield.     

[2 + 2] Photodimerization of the acenaphthylene ruthenium complex [(C5Me4CH2OMe)Ru(η6-C12H8)]+

The [2 + 2] photodimerization of the complex [(C₅Me₄CH₂OMe)Ru(η⁶-C₁₂H₈)]⁺ under visible-light irradiation leads to a mixture of the head-to-head heptacyclene products [(μ-η⁶: η⁶-C₂₄H₁₆)Ru₂(C₅Me₄CH₂OMe)₂]²⁺ (syn- and anti-) with the predominant formation of the syn-isomer; the structures of both isomers were established by X-ray diffraction analysis.     

Bis(diphenylphosphino)methylamine as chelate ligand in pentamethylcyclopentadienylrhodium(III) and iridium(III) complexes.: Crystal structure of [(η5-C5Me5)RhCl{η2-P,P′-(PPh2)2NMe}]BF4

Reactions of the dimers [{(η⁵-C₅Me₅)MCl(μ-Cl)}₂] (M=Rh, Ir) with the ligand NMe(PPh₂)₂ in 1:2 molar ratio afford the mononuclear cationic complexes [(η⁵-C₅Me₅)MCl{η²-P,P′-(Ph₂P)₂NMe}]Cl (M=Rh 1, Ir 2). Similar iodide complexes, [(η⁵-C₅Me₅)MCl{η²-P,P′-(Ph₂P)₂NMe}]I (M=Rh 3, Ir 4), can be prepared by N-functionalization of co-ordinated dppa ligand in complexes [(η⁵-C₅Me₅)MCl{η²-P,P′-(Ph₂P)₂NH}]BF₄. The tetrafluoroborate derivatives, [(η⁵-C₅Me₅)MCl{η²-P,P′-(Ph₂P)₂NMe}]BF₄ (M=Rh 5, Ir 6) are prepared by reaction of complexes 1–4 with AgBF₄ in acetone. All the compounds described are characterised by microanalysis, IR and NMR (¹H, ³¹P{¹H}) spectroscopy. The crystal structure of complex 5 is determined by X-ray diffraction methods. The complex exhibits a pseudo-octahedral molecular structure with a C₅Me₅ group occupying three co-ordination positions and a bidentate chelate P,P′-bonded ligand and a chloride atom completing the co-ordination sphere.     

Synthesis and the fluxional behavior of the 30-electron cationic iron-molybdenum triple-decker complex with a central pentaphospholyl ligand, [(η-C7H7)Mo(μ-η:η-P5)Fe(η-C5Me5)]BF4

The reaction of [(η-C₇H₇)Mo(MeCN)₃)]BF₄ with (η-C₅Me₅)Fe(η-P₅) afforded the new 30-electron triple-decker complex [(η-C₇H₇)Mo(μ-η:η-P₅)Fe(η-C₅Me₅)]BF₄. Studies of the temperature dependence of the¹H NMR spectra demonstrated that the resulting compound contains a fluxional cyclohepatrienyl ligand. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1374–1376, July, 1999.     

Facile η5-η3 hapticity interconversion in pentamethylcyclopentadienyl ruthenium(II) complexes containing a phenylmethallyl ("open indenyl") ligand

The indenyl effect has been introduced to pentadienyl ("open cyclopentadienyl") chemistry by preparation of the phenylmethallyl ("open indenyl") ligand oInd(Me). The reaction of its potassium salt K(oInd(Me)) with [(η(5)-C(5)Me(5))RuCl](4) afforded the sandwich complex [(η(5)-C(5)Me(5))Ru(η(5)-oInd(Me))] (1), which, upon treatment with PMe(3), CO, and 2,6-dimethylphenyl isocyanide (CN-o-Xy), easily underwent η(5)-η(3) hapticity interconversion and formed the complexes [(η(5)-C(5)Me(5))Ru(η(3)-oInd(Me))(L)] (2, L = PMe(3); 3, L = CO; 4, L = CN-o-Xy). In these complexes, the η(3)-bound phenylmethallyl ligand adopts an anti-conformation with regard to the relative positions of the phenyl and methyl substituents. For the PMe(3) complex anti-2, slow conversion to the syn-isomer was observed, and this equilibrium reaction was monitored by NMR spectroscopy at 50 °C to determine a first order rate constant of k(323 K) = 6.57 × 10(-6) (± 0.02 × 10(-6)) s(-1) and an activation barrier of ΔG° = 26.8 kcal mol(-1). DFT calculations afforded a stabilization of syn-2 and syn-3 by ΔG(298) = -1.54 and -1.74 kcal mol(-1) over the respective anti-isomer.     

Some reactions of [(η6-C6Me6)Ru(η6-[2.2]paracyclophane)]-[BF4]2 with nucleophiles

Single addition of the nucleophiles X⁻ (X = H, CN, OH) to the less sterically hindered ring in [(η⁶-C₆Me₆)Ru(η⁶-C₁₆H₁₆)][BF₄]₂ (1) proceeds smoothly to produce, as the sole product, [(exo-η⁵-C₆Me₆X)Ru(η⁶-C₁₆H₁₆)][BF₄]. Use of Na[BD₄] in place of Na[BH₄] gives the expected shift in ν(C-H_exo) in the infrared spectrum.     

The asymmetric sythesis of (-)-actinonin using the iron chiral auxiliary [(η5-C5H5)Fe(CO)(PPh3)]

The asymmetric synthesis of the α-pentyl succinate fragment of (-)-Actinonin is achieved using the chiral iron acetyl S-(+)-[(η⁵-C₅H₅)Fe(CO)(PPh₃)COCH₃] and subsequently converted to (-)-Actinonin in an overall yield of 41%.     

Water-soluble arene ruthenium complexes containing pyridinethiolato ligands: Synthesis,molecular structure,redox properties and anticancer activity of the cations [(η6-arene)Ru(p-SC5H4NH)3]2+

The cationic complexes [(η⁶-arene)Ru(SC₅H₄NH)₃]²⁺, arene being C₆H₆ (1), MeC₆H₅ (2), p-ⁱPrC₆H₄Me (3) or C₆Me₆ (4), have been synthesised from the reaction of 4-pyridinethiol with the corresponding precursor (η⁶-arene)₂Ru₂(μ₂-Cl)₂Cl₂ and isolated as the chloride salts. The single-crystal X-ray structure of [4](PF₆)₂ reveals three 4-pyridinethiol moieties coordinated to the ruthenium centre through the sulphur atom, with the hydrogen atom transferred from the sulphur to the nitrogen atom. The electrochemical study of 1–4 shows a clear correlation between the Ru(II)/Ru(III) redox potentials and the number of alkyl substituents at the arene ligand (E°′ (Ru^II/III): 1 > 2 > 3 > 4), whereas the cytotoxicity towards A2780 ovarian cancer cells follows the series 4 > 1 > 3 > 2, the hexamethylbenzene derivative 4 being the most cytotoxic one. The corresponding reaction of the ortho-isomer, 2-pyridinethiol, with (η⁶-C₆Me₆)₂Ru₂(μ₂-Cl)₂Cl₂ does not lead to the expected 2-pyridinethiolato analogue, but yields the neutral complex (η⁶-C₆Me₆)Ru(η²-SC₅H₄N)(η¹-SC₅H₄N) (5). The analogous complex (η⁶-C₆Me₆)Ru(η²-SC₉H₆N)-(η¹-SC₉H₆N) (6) is obtained from the similar reaction with 2-quinolinethiol.