Ru Derivatives Research Articles

Разработка методик анализа таблеток нового вещества с каппа-опиоидной агонистической активностью РУ 1205

Разработана методика фармацевтического анализа таблеток нового каппа-опиоидного агониста, производного имидазобензимидазола, РУ 1205. Изучены основные фармакопейные показатели качества таблеток, проведена оценка содержания посторонних примесей и количественное определение РУ 1205 в таблетках методом ВЭЖХ. Разработана методика определения однородности дозирования с помощью УФ-спектрофотометрии, предложены методики определения подлинности и показателя «Растворение» таблеток РУ 1205.

Nanocomposites: Graphene–Ruthenium(II) Complex Composites for Sensitive ECL Immunosensors (Small 4/2014)

Ru-PTCA/G nanocomposites are synthesized via a one step synthesis procedure under moderate conditions followed by covalent attachment of an amine derivative Ru(II) complex through amide bond formation. As X.-H. Xia and co-workers report on page 706, the product shows good electrochemical activity and ca. 21 times higher luminescence quantum efficiency than the adsorbed Ru(II) complex. A solidstate electrochemiluminescent (ECL) immunosensor is developed based on the Ru-PTCA/G nanocomposites for sensitive detection of α-fetoprotein (AFP). The ECL peak intensity in the presence of AFP is much lower than that in the absence of AFP due to the insulating effect of the formed antigen-antibody complex, which inhibits the electron transfer and the mass transfer of tripropylamine to the surface of the Ru-PTCA/G modified electrode.

Organo Ruthenium–Nickel Dithiolates with Redox-Responsive Nickel Sites

Described is a new family of RuNi dithiolates featuring geometrically flexible Ni centers, which enable both acid–base and redox chemistry, behavior that is characteristic of the hydrogenases. Treatment of Ni(pdt)(dxpe) with (cymene)2Ru2Cl4 affords the salt [(cymene)Ru(Cl)(pdt)Ni(diphos)]Cl (pdt2– = 1,3-propanedithiolate, diphos = dppe = 1,2-bis(diphenylphosphino)ethane ([1Cl]Cl) and diphos = dcpe = 1,2-bis(dicyclohexylphosphino)ethane ([2Cl]Cl)). Cyclic voltammetry revealed that in CH2Cl2 solution [1Cl]Cl reduces irreversibly near −1.6 V vs Fc0/+ followed by the appearance of a reversible 1e– couple assigned to the [1]0/+ couple. Reduction of [1Cl]Cl and [2Cl]Cl with cobaltocene produced the neutral derivatives (cymene)Ru(pdt)Ni(diphos) ([1]0, [2]0). Crystallographic characterization of these compounds revealed short Ru–Ni distance of 2.5539(5) ([1]0) and 2.600(3) Å ([2]0). The 2e– reduction of these chlorides converts the Ni site from square planar to tetrahedral, highlighting the flexibility of the Ni center in these complexes. Variable-temperature NMR studies show that [1]0 and [2]0 are dynamic by virtue of ring flipping in the RuNi(pdt) core. Complexes [1]0 and [2]0 are basic: their conjugate acids, [H1]+ and [H2]+, exhibit pKaPhCN values of 18.94 and 21.65, respectively. Crystallographic characterization of [H1]+ as its aryl borate salt revealed an unsymmetrical Ru–H···Ni interaction and confirmed that the Ni center converted from tetrahedral to square planar, again demonstrating the flexibility of this site.

Preparation and reactivity of germyl complexes of ruthenium and osmium stabilised by cyclopentadienyl, indenyl and tris(pyrazolyl)borate fragments

Half-sandwich trichlorogermyl complexes Ru(GeCl3)(η5-C5H5)(PPh3)L (1) and Ru(GeCl3)(η5-C9H7)(PPh3)L (2) [L = P(OMe)3 (a), P(OEt)3 (b) and PPh(OEt)2 (c)] were prepared by allowing chloro compounds RuCl(η5-C5H5)(PPh3)L and RuCl(η5-C9H7)(PPh3)L to react with an excess of GeCl2·dioxane in ethanol. Treatment of trichlorogermyl complexes 1 and 2 with LiAlH4 in THF yielded trihydridogermyl derivatives Ru(GeH3)(η5-C5H5)(PPh3)L (3) and Ru(GeH3)(η5-C9H7)(PPh3)L (4). Instead, reaction of trichlorogermyl complexes 1 and 2 with NaBH4 in ethanol afforded triethoxygermyl complexes Ru[Ge(OEt)3](η5-C5H5)(PPh3)L (5) and Ru[Ge(OEt)3](η5-C9H7)(PPh3)L (6). Trichlorogermyl complexes with the tris(pyrazolyl)borate ligand M(GeCl3)(Tp)(PPh3)L [M = Ru (7), Os (10)] were prepared by reacting chloro compounds MCl(Tp)(PPh3)L with an excess of GeCl2·dioxane. Depending on metal centre, nature of phosphite and experimental conditions, the reaction of trichlorogermyl complexes 7 and 10 with LiAlH4 or NaBH4 afforded trihydridogermyl M(GeH3)(Tp)(PPh3)L (8, 12) and triethoxygermyl derivatives M[Ge(OEt)3](Tp)(PPh3)L (9, 11). The complexes were characterised by IR and multinuclear NMR spectroscopy and by X-ray crystal structure determination of 3a.

Preparation and Reactivity of Stannyl Complexes of Ruthenium(II) Stabilized by an Indenyl Ligand

Trichlorostannyl complexes Ru(SnCl3)(η5-C9H7)(PPh3)L (1; L = P(OMe)3, P(OEt)3) were prepared by allowing chloro compounds RuCl(η5-C9H7)(PPh3)L to react with SnCl2·2H2O in ethanol. Treatment of compounds 1 with NaBH4 in ethanol yielded the tin trihydride derivatives Ru(SnH3)(η5-C9H7)(PPh3)L (2). The reaction of trichlorostannyl complexes 1 with MgBrMe in diethyl ether afforded the chlorodimethylstannyl derivatives Ru(SnClMe2)(η5-C9H7)(PPh3)L (3), whereas reaction with Li+C≡CPh– in THF yielded the trialkynylstannyl compounds Ru[Sn(C≡CPh)3](η5-C9H7)(PPh3)L (4). Treatment of the trihydridostannyl complexes 2 with the alkyl propiolate HC≡CCOOR led to the trivinylstannyl derivatives Ru[Sn{C(COOR)═CH2}3](η5-C9H7)(PPh3)L (5, 6; R = Me, Et). However, the reaction of [Ru]–SnH3 (2) with the propargylic alcohol HC≡CCPh2OH yielded the alkene H2C═C(H)CPh2OH and the hydride RuH(η5-C9H7)(PPh3)L (7). Treatment of tin trihydride complexes 2 with H2O led to the trihydroxostannyl derivatives Ru[Sn(OH)3](η5-C9H7)(PPh3)L (8). ...

Hydride Alkenylcarbyne Osmium Complexes versus Cyclopentadienyl Type Half-Sandwich Ruthenium Derivatives

The dihydride complex OsH2Cl2(PiPr3)2 (1) reacts with 2-methyl-1-hexen-3-yne and 2,4-dimethyl-1,3-pentadiene to give the hydride alkenylcarbyne derivatives OsHCl2{≡CC(Me)═CHR}(PiPr3)2 (R = nPr (2), iPr (3)), which have been characterized by X-ray diffraction analysis. DFT calculations (B3PW91) suggest that the enyne is initially hydrogenated to afford a conjugated diene. The latter evolves into the hydride alkenylcarbyne derivative by means of two hydrogen migrations. The first migration is a 1,4-hydrogen shift within the diene (from the terminal CH2 group to the internal double bond) which takes place through the metal center. The second migration is a 1,2-hydrogen shift from the terminal CH2 group to the osmium atom. In contrast to the case for 1, the ruthenium counterpart RuH2Cl2(PiPr3)2 (16) reacts with 2-methyl-1-hexen-3-yne to give a complex mixture of compounds, from which the derivatives Ru(η5-C5HR1R2R3R4)Cl(PiPr3) (17; R1 = C(CH3)═CH2, R2 = Et, R3 = nPr, R4 = Me) and RuCl2{═C(Et)CH═CMe2}(PiPr3)2 (18, traces) are isolated. Both 17 and 18 have been also characterized by X-ray diffraction analysis. DFT calculations (B3PW91) on the formation of 17 suggest that in the ruthenium case the hydrogenation of the enyne leads to an alkenylcarbene intermediate, which reacts with a second enyne molecule to afford the tetrasubstituted cyclopentadienyl group.

Aromatization of a Dihydro-3-ruthenaindolizine Complex

The complex RuHCl(η2-H2)(PiPr3)2 (1) reacts with KTp (Tp = hydridotris(pyrazolyl)borate) to give the hydride−dihydrogen derivative RuHTp(η2-H2)(PiPr3) (2), which has been characterized by X-ray diffraction analysis (dH−H = 1.00(3) Å). Treatment of a toluene solution of 2 with 2-vinylpyridine leads to the 1,2-dihydro-3-ruthenaindolizine derivative Ru(CH2CH2−C5H4N)Tp(PiPr3) (3). Complex 3 aromatizes in toluene at 80 °C to afford the 3-ruthenaindolizine complex Ru(CHCH−C5H4N)Tp(PiPr3) (4) by loss of a hydrogen molecule in the absence of any hydrogen acceptor. The aromatic character of 4 is supported by X-ray diffraction analysis, NMR spectroscopy, and DFT calculations.

Enhanced electrochemiluminescence efficiency of Ru(ii) derivative covalently linked carbon nanotubes hybrid

The synthesized derivative Ru(bpy)(3) covalently linked CNTs hybrid shows good electrochemical activity and ca. 17 times higher luminescence quantum efficiency than the adsorbed derivative Ru(bpy)(3). The Ru-CNTs based ECL sensor exhibits high stability toward determination of TPA with a detection limit as low as 8.75 pM.

Reactions of cyano(alkynyl)ethenes with some alkynyl- and diynyl-ruthenium complexes

Reactions of Ru(C CPh)(PPh 3) 2Cp with (NC) 2C CR 1R 2 (R 1 = H, R 2 = C CSiPr i 3 8; R 1 = R 2 = C CPh 9) have given η 3-butadienyl complexes Ru{η 3-C[ C(CN) 2]CPh CR 1R 2}(PPh 3)Cp ( 11, 12), respectively, by formal [2 + 2]-cycloaddition of the alkynyl and alkene, followed by ring-opening of the resulting cyclobutenyl (not detected) and displacement of a PPh 3 ligand. Deprotection (tbaf) of 11 and subsequent reactions with RuCl(dppe)Cp and AuCl(PPh 3) afforded binuclear derivatives Ru{η 3-C[ C(CN) 2]CPh CHC C[ML n ]}(PPh 3)Cp [ML n = Ru(dppe)Cp 19, Au(PPh 3) 20]. Reactions between 8 and Ru(C CC CR)(PP)Cp [PP = (PPh 3) 2, R = Ph, SiMe 3, SiPr i 3; PP = dppe, R = Ph] gave η 1-dienynyl complexes Ru{C CC[ C(CN) 2]CR CH[C C(SiPr i 3)]}(PP)Cp ( 15– 18), respectively, in reactions not involving phosphine ligand displacement. The phthalodinitrile C 6H(C CSiMe 3)(CN) 2(NH 2)(SiMe 3) 10 was obtained serendipitously from (Me 3SiC C) 2CO and CH 2(CN) 2, as shown by an XRD structure determination. The XRD structures of precursor 7 and adducts 11, 12 and 17 are also reported.

Synthesis, Characterization, and Electrochemistry of Diruthenium(III,II) and Monoruthenium(III) Complexes Containing Pyridyl-Substituted 2-Anilinopyridinate Ligands

Reaction of the metal-metal bonded complex Ru(2)(O2CCH3)4Cl with 2-anilino-4-methylpyridine leads to the (3,1) isomer of the diruthenium(III,II) complex Ru2(ap-4-Me)4Cl, 1 while the same reaction with 2-anilino-6-methylpyridine gives the monoruthenium(III) derivative Ru(ap-6-Me)3, 2. Both compounds were examined as to their structural, electrochemical, and UV-visible properties, and the data were then compared to that previously reported for (4,0) Ru2(2-Meap)4Cl and other (3,1) isomers of Ru2(L)4Cl with similar anionic bridging ligands. ESR spectroscopy indicates that the monoruthenium derivative 2 contains low-spin Ru(III), and the presence of a single ruthenium atom is confirmed by an X-ray structure of the compound. The combined electrochemical and UV-vis spectroelectrochemical data indicate that the diruthenium complex 1 is easily converted to its Ru2(4+) and Ru2(6+) forms upon reduction or oxidation by one electron while the monoruthenium derivative 2 also undergoes metal-centered redox processes to give Ru(II) and Ru(IV) complexes under the same solution conditions. The reactivity of 1 with CO and CN- was also examined.

Enolate‐Phosphane Ligands Providing a Tool for the Selective Substitution of Triphenylphosphane by Carbon Monoxide or Trimethylphosphane in Complex {Ru(Cp)[η2‐P,O‐Ph2PCH2C(tBu)=O](PPh3)}[PF6], and Subsequent Reactivity Towards Terminal Alkynes

AbstractThe deprotonation under basic conditions of the keto‐phosphane ligand in complexes {Ru(Cp)[η1‐P‐Ph2PCH2C(=O)tBu](PPh3)(L)}[PF6] (L = CO or PMe3) that arise from the addition of L to {Ru(Cp)[η2‐P,O‐Ph2PCH2C(tBu)=O](PPh3)}[PF6] generates {Ru+(Cp)[η1‐P‐Ph2PCH=C(tBu)O–](PPh3)(L)} zwitterionic species, as shown by an X‐ray crystal structure determination (L = CO). The removal of the triphenylphosphane ligand is subsequently achieved under thermal activation to afford the neutral derivatives Ru(Cp)[η2‐P,O‐Ph2PCH=C(tBu)O](L). A further protonation step is sufficient to complete the formation of the new complex {Ru(Cp)[η2‐P,O‐Ph2PCH2C(tBu)=O](PMe3)}[PF6], which reacts in methanolat reflux with 1,1‐diphenyl‐2‐propyn‐1‐ol to afford thesix‐membered metallacyclic derivative {Ru(Cp)[η2‐C,P:C(CH=CPh2)OC(tBu)=CH–PPh2](PMe3)}[PF6], as shown by an X‐ray single crystal analysis. The synthesis of related η5‐indenyl ruthenium complexes and of {Ru(Cp)(=C=CH2)[Ph2PCH2C(=O)tBu](PR3)}[PF6] (PR3 = PPh3 or PMe3) vinylidene complexes is also reported. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)

Heterobimetallic Ruthenium‐Cobalt Complexes Containing the Pentamethylcyclopentadienyl or Indenyl Ligand

AbstractThe salt elimination reaction between NaCo(CO)4 and the ruthenium complexes LRu(diphos)Cl and [(Ind)Ru(CO)2Cl] afforded the Ru–Co bimetallic complexes [LRu(μ‐CO)2(μ‐diphos)Co(CO)2] [L = C5Me5 (Cp*), diphos = Ph2P(CH2)nPPh2, 3a: n = 1 , or 3b: n = 2; 3: L = C9H7 (Ind), diphos = Ph2PCH2PPh2 ] and [(Ind)Ru(CO)2Co(CO)4] (3d), respectively, in high yields. However, the same reaction with the monophosphane analogue, [(Ind)Ru(PPh3)2Cl], gave the heterobimetallic complex [(Ind)Ru(PPh3)(CO)(μ‐CO)Co(CO)3] (3e) in fair yield, together with redox‐initiated derivatives Ru(PPh3)2(CO)3 (4e) and [(Ind)Co(CO)(PPh3)] (6e). A similar redox process in the reaction of the dppf analogue, [(Ind)Ru(dppf)Cl] (dppf = 1,1′‐diphenylphosphanylferrocene) gave [Ru(dppf)(CO)3] (4f) and [(Ind)Co(CO)2] (6f), together with a complex salt [(Ind)Ru(dppf)(CO)][Co(CO4)] [5f·Co(CO)4]. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)

Atom transfer radical polymerization of N-(ω′-alkylcarbazolyl)methacrylates via the use of novel heteroleptic Ru(II) polypyridyl initiator

cis-Dichloro-bis(2-(2-pyridyl)-4-carbonylmethylquinoline)ruthenium (II) complex was synthesized and its structure, electrochemical, electronic absorption and emission properties were determined. A derivative Ru(II) complex with radical initiating sites was employed in the atom transfer radical polymerization (ATRP) of functional N-(ω′-alkylcarbazoly)methacrylates to provide linear metallopolymers with the metal chromophores at one termini of the polymer chain. These polymers were characterized by gel permeation chromatography in combination with low-angle laser light-scattering, UV–Vis and emission spectroscopy to verify the covalent attachment of the metal chromophores to the polymer chain. The polymers thermal transitions and thermal stabilities were also investigated by differential scanning calorimetry and thermogravimetric analysis.

Synthesis and characterization of Ru2(DMBA)4X2 (X = CN, N3, N(CN)2, I): controlling structural, redox, and magnetic properties with axial ligands.

Metathesis reactions between Ru(2)(DMBA)(4)Cl(2) (DMBA = N,N'-dimethylbenzamidinate) and MX (M = Na and K) yielded bis-adduct derivatives Ru(2)(DMBA)(4)X(2) (X = CN (1), N(3) (2), N(CN)(2) (3)). Metathesis reactions between Ru(2)(DMBA)(4)(NO(3))(2) and KI resulted in Ru(2)(DMBA)(4)I(2) (4). Compound 1 is diamagnetic, while compounds 2-4 are paramagnetic (S = 1). Both compounds 1 and 2 undergo two reversible one-electron processes, an oxidation and a reduction, while compound 3 features a quasireversible reduction. Single-crystal X-ray diffraction studies revealed that the Ru-Ru bond lengths are 2.4508(9), 2.3166(7), 2.304[1], and 2.328(1) A for compounds 1-4, respectively. Structural and electrochemical data clearly indicate that the axial ligands impart a significant influence on the electronic structures of diruthenium species.

Further studies of tetrakis( N, N′-dialkylbenzamidinato)diruthenium(III) chloro and alkynyl compounds: molecular engineering of metallayne monomers

Three diruthenium(III) compounds Ru 2( L) 4Cl 2, where L is mMeODMBA ( N, N′-dimethyl-3-methoxybenzamidinate, 1a), DiMeODMBA ( N, N′-dimethyl-3,5-dimethoxy benzamidinate, 1b), or DEBA ( N, N′-diethylbenzamidinate, 1c), were prepared from the reactions between Ru 2(OAc) 4Cl and respective H L under reflux conditions. Metathesis reactions between 1 and LiC 2Y resulted in bis-alkynyl derivatives Ru 2( L) 4(C 2Y) 2 [Y=Ph ( 2), SiMe 3 ( 3), Si i Pr 3 ( 4) and C 2SiMe 3 ( 5)]. The parent compounds 1 are paramagnetic ( S=1), while bis-alkynyl derivatives 2– 5 are diamagnetic and display well-solved 1H- and 13C-NMR spectra. Molecular structures of compounds 1b, 1c, 2c, 3c and 4b were established through single crystal X-ray diffraction studies, which revealed RuRu bond lengths of ca. 2.32 Å for parent compounds 1 and 2.45 Å for bis-alkynyl derivatives. Cyclic voltammograms of all compounds feature three one-electron couples: an oxidation and two reductions, while the reversibility of observed couples depends on the nature of axial ligands.

The kinetic instability of σ-bound aryloxide in coordinatively unsaturated or labile complexes of ruthenium

Reaction of RuCl 2(PPh 3) 3 ( 1) or RuHCl(PPh 3) 3 ( 2) with KOAr (Ar=4- tBuC 6H 4) in non-alcohol solvents affords π-aryloxide derivatives Ru(η 5-ArO)( o-C 6H 4PPh 2)(PPh 3) ( 3a) or RuH(η 5-ArO)(PPh 3) 2 ( 6a), respectively. The phenoxide analogues 3b and 6b are obtained on use of KOPh or TlOPh. Treatment of 1 with 1 equiv. KOAr in the presence of isopropanol liberates the phenol and acetone, affording clean 2 in quantitative yields. In 3:1 methanol–CH 2Cl 2, RuHCl(CO)(PPh 3) 3 ( 4) is also formed in small amounts. Reaction of 1 with 2 KOAr in 20% MeOH–CH 2Cl 2 affords a mixture of 6a and RuH 2(CO)(PPh 3) 3 ( 5). In the corresponding reaction of 2 with 1 KOAr, σ–π isomerization of the σ-aryloxide ligand dominates, affording 6a·MeOH as the principal product. Treatment of 6a with ethereal HCl gives [RuH(η 6-ArOH)(PPh 3) 2]Cl ( 7a); the corresponding reaction of 6b yields RuCl(η 5-PhO)(PPh 3) 2 ( 8b). The crystal structures of 3a, 3b, 4, 5, 7a, and 8b are reported.

C−N and C−C Coupling Reactions: Preparation of New N-Heterocyclic Ruthenium Derivatives

Three novel types of complexes containing heterocyclic ligands are prepared by condensation of the allenylidene ligand of [Ru(η5-C5H5)(CCCPh2)(CO)(PiPr3)]BF4 (1) with propargylamines. Complex 1 reacts with propargylamine to give initially [Ru(η5-C5H5){C(CHCPh2)NHCH2C⋮CH}(CO)(PiPr3)]BF4 (2). Treatment of 2 with KOH in methanol affords the bicyclic derivative Ru(η5-C5H5){4-methylidene-6,6-diphenyl-2-azabicyclo[3.1.0]hex-2-en-1-yl}(CO)(PiPr3) (3). The formation of 3 takes place via the intermediate Ru(η5-C5H5){C(CHCPh2)NCH2C⋮CH}(CO)(PiPr3) (4), which is isolated when the deprotonation of 2 is carried out in tetrahydrofuran as solvent. In contrast to propargylamine, the addition of 1,1-diethylpropargylamine to 1 leads to the dihydropyridiniumyl derivative [Ru(η5-C5H5){2,2-diethyl-5-diphenylidene-2,5-dihydropyridinium-6-yl)(CO)(PiPr3)]BF4 (5) in a one-pot synthesis. Complex 1 also reacts with N-methylpropargylamine. The reaction affords [Ru(η5-C5H5){C(CHCPh2)N(CH3)CH2C⋮CH}(CO)(PiPr3)]BF4 (6). Treatment of 6 with sodium methoxide, at −78 °C, gives a 1:1 mixture of the dihydronaphthopyrrolyl diastereomers (RRuSC,SRuRC)-[Ru(η5-C5H5){9-phenyl-4,4a-dihydronaphtho[2,3-c]-1-pyrrolyl})(CO)(PiPr3) (7a) and (RRuRC,SRuSC)-[Ru(η5-C5H5){9-phenyl-4,4a-dihydronaphtho[2,3-c]-1-pyrrolyl})(CO)(PiPr3) (7b). Complexes 3 and 5 and the enantiomeric mixture 7a have been characterized by X-ray diffraction analysis.

Tetrakis(N,N'-dimethylbenzamidinato)diruthenium(III) compounds bearing axial chloro and alkynyl ligands: a new family of redox rich diruthenium compounds.

Novel diruthenium(III) compound Ru(2)(DMBA)(4)Cl(2) (1, DMBA = N,N'-dimethylbenzamidinate) was obtained via refluxing Ru(2)(OAc)(4)Cl with dimethylbenzamidine in the presence of LiCl and Et(3)N under ambient atmosphere. Metathesis reactions between 1 and MC(2)Y (M = Li and Na) yielded bis-alkynyl derivatives Ru(2)(DMBA)(4)(C(2)Y)(2) (Y = SiMe(3) (2a), H (2b), Ph (2c), and C(2)SiMe(3) (3a)), and further desilylation of 3a using K(2)CO(3) resulted in Ru(2)(DMBA)(4)(C(4)H)(2) (3b). Compound 1 is paramagnetic (S = 1), while compounds 2 and 3 are diamagnetic. The single-crystal X-ray diffraction study revealed that the Ru-Ru distances are 2.3224(7), 2.4501(6), and 2.4559(6) A for 1, 2a, and 3b, respectively. A strong Ru-C sigma-bond in alkynyl adducts was implied by the short Ru-C distances in 2a (1.955(4) A) and 3b (1.952[5] A). All the compounds undergo three one-electron redox processes, an oxidation and two reductions, and the reversibility of redox couples depends on the nature of axial ligands.

Bis(keto-phosphane) and Bis(enolato-phosphane) Ruthenium Complexes − Synthesis and X-ray Structure Determination of RuCl(NO)[η2-(P,O)-Ph2PCH=C(tBu)O

A slow reaction consisting of a cleavage of one Ru−Cl bond occurred when a mixture of RuCl2[Ph2PCH2C(tBu)=O]2 (1) and [NH4][PF6] was dissolved in methanol as shown by a subsequent reaction with carbon monoxide affording the stable cationic derivative {RuCl(CO)[Ph2PCH2C(tBu)=O]2}[PF6] (2). By contrast, the straightforward reaction of 1 with carbon monoxide yielded RuCl2(CO)[Ph2PCH2C(tBu)=O][Ph2PCH2C(=O)tBu] (3) which contains unreactive Ru−Cl bonds. The isomerization of 2, which is induced under sun light exposure, is the preliminary step to the selective formation of the all-cis bis(enolato-phosphane) derivative (ccc)Ru(CO)2[η2-(P,O)-Ph2PCH=C(tBu)O]2 (9). The isomeric bis(enolato-phosphane) derivative (cct)-Ru(CO)2[η2-(P,O)-Ph2PCH=C(tBu)O]2 (10), with trans phosphorus and cis carbonyl ligands, respectively, was selectively obtained under mild basic conditions, starting from (cct)-RuCl2(CO)2[Ph2PCH2C(=O)tBu]2 (4), which results from the reaction of 3 with carbon monoxide under thermal activation. Through an oxidative addition process, the reaction of 1 with [NO][BF4] yielded {RuCl2(NO)[Ph2PCH2C(tBu)=O][Ph2PCH2C(=O)tBu]}[BF4] (13) with trans phosphorus and trans chloride ligands, respectively. Simple deprotonation of 13 generated the enolato-phosphane RuIV complex RuCl2(NO)[Ph2PCH=C(tBu)O][Ph2PCH2C(=O)tBu] (14) which retains the same geometry. Under basic conditions, the bis(enolato-phosphane) derivative RuCl(NO)[η2-(P,O)-Ph2PCH=C(tBu)O]2 (15) was obtained. The formation of 15 surprisingly showed a trans to cis rearrangement of the two phosphorus coordinating atoms, as further confirmed by an X-ray structure determination.

The Allenylidene Complex [Ru(η5-C5H5)(CCCPh2)(CO)(PiPr3)]BF4 as a Precursor of Novel Pyrido[1,2-a]pyrimidinyl and 1,3-Thiazinyl Complexes

The allenylidene complex [Ru(η5-C5H5)(CCCPh2)(CO)(PiPr3)]BF4 (1) reacts with 2-aminopyridine to give a mixture of the complexes [Ru(η5-C5H5){2,2-diphenyl-2H-pyridinium[1,2-a]pyrimidin-4-yl}(CO)(PiPr3)]BF4 (2) and (3). The molar ratio of the isomers in the mixture depends on the reaction temperature. At temperatures lower than −30 °C, isomer 2 is the main reaction product, while at 0 °C an inverse relationship is observed. The structure of 2 has been determined by an X-ray investigation, revealing a Ru−C(bicycle) distance of 2.08(1) Å. Treatment of 2 with sodium methoxide results in the deprotonation of the NH group of the heterocycle to give the pyrido[1,2-a]pyrimidinyl derivative Ru(η5-C5H5){2,2-diphenyl-2H-pyrido[1,2-a]pyrimidin-4-yl}(CO)(PiPr3) (4), which has been also characterized by an X-ray diffraction analysis. In this case, the study reveals a Ru−C(bicycle) distance of 2.097(5) Å. The deprotonation of 2 is reversible. Thus, the addition of HBF4·OEt2 to dichloromethane solutions of 4 regenerates 2. Similarly, the treatment of 4 with methyl trifluoromethanesulfonate affords [Ru(η5-C5H5){1-methyl-2,2-diphenyl-2H-pyridinium[1,2-a]pyrimidin-4-yl}(CO)(PiPr3)]CF3SO3 (5). Complex 1 also reacts with thioisonicotinamide. The reaction yields [Ru(η5-C5H5){4,4-diphenyl-2-(p-pyridinyl)-4H-1,3-thiazinium-6−yl}(CO)(PiPr3)]BF4 (6), which in the presence of sodium methoxide affords Ru(η5-C5H5){4,4-diphenyl-2-(p-pyridinyl)-4H-1,3-thiazin-6-yl}(CO)(PiPr3) (7). The structure of 7 has been determined by an X-ray investigation, revealing a Ru−C(cycle) distance of 2.067(4) Å. The deprotonation of 6 is also reversible. Thus, the addition of HBF4·OEt2 to dichloromethane solutions of 7 regenerates 6. Similarly, treatment of 7 with methyl trifluoromethanesulfonate gives [Ru(η5-C5H5){3-methyl-4,4-diphenyl-2-(p-pyridinyl)-4H-1,3-thiazinium-6-yl}(CO)(PiPr3)]CF3SO3 (8).