Bimetallic cyano-bridged cations: preparation and hydride reduction of [(η5-C5H5)L2Ru(µ-CN)ML′2(η5-C5H5)]PF6[L2,L′2=(PPh3)2,Ph2PCH2CH2PPh2; M = Ru or Fe]. Formation of [Ru(η5-C5H5)(PPh3)H3] and X-ray crystal structure of [(η5-C5H5)(Ph<s

Baird, Gordon J.; Davies, Stephen G.; Moon, Steven D.; Simpson, Stephen J.; Jones, Richard H.

doi:10.1039/dt9850001479

Cited by 46 publications

(5 citation statements)

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“…CD 2 Cl 2 was dried over CaH 2 , degassed by three freeze−pump−thaw cycles, and then purified by vacuum transfer at room temperature. CpRu(dppe)H ( 5a ), CpRu(dppe)D,36a Cp*Ru(dppe)H ( 5c ), CpRu(dppm)H ( 5d ), CpRu(dpbz)H ( 5e ), (Ind)Ru(dppm)H ( 5g ), (Ind)Ru(dppe)H ( 5h ), CpRu(dmpe)H ( 5i ), CpRu(PPh 3 ) 2 H ( 5j ), [Cp*Ru(dppe)(H) 2 ]BF 4 , Cp‘Ru(dppe)Cl, Cp*Ru(dmpe)Cl,1-(1-phenylethylidene)pyrrolidinium tetrafluoroborate ( 6 ), 1-isopropylidenepyrrolidinium tetrafluoroborate ( 12 ), 1-(α- methylcinnamylidene)pyrrolidinium tetrafluoroborate ( 14 ), 1-(1-pyrrolidinyl)-1-phenylethene ( 9 ), α-(diethylamino)styrene ( 25 ), and N -(1-phenylethyl)pyrrolidine ( 8 ) were prepared as described in the literature. Experimental details on eqs 6 and 7 were reported in the Supporting Information of ref .…”

Section: Methodsmentioning

confidence: 99%

Ruthenium-Catalyzed Ionic Hydrogenation of Iminium Cations. Scope and Mechanism

et al. 2005

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Catalysis by CpRu(P-P)H (where P-P is a chelating diphosphine) of the ionic hydrogenation of an iminium cation inolves (1) the transfer of H(-) to form an amine, (2) the coordination of H(2) to the resulting Ru cation, and (3) the transfer of H(+) from the coordinated dihydrogen to the amine formed in (1). With CpRu(dppe)H the principal Ru species during catalysis remains the hydride complex, and H(2) pressure has no effect on either the ee or the turnover frequency. Step (1), H(-) transfer, can be carried out stoichiometrically if the H(2) is replaced by a coordinating solvent. A methyl substituent on the Cp ring decreases the H(-) transfer rate and the turnover frequency slightly. Electron-donating substituents on the phosphine increase the H(-) transfer rate and increase the turnover frequency up to a point: eventually the hydride ligand (i.e., the one in CpRu(dmpe)H) becomes sufficiently basic to deprotonate the iminium cation to the corresponding enamine, and this pre-equilibrium competes with H(-) transfer. Ionic hydrogenation of enamines is possible when a Ru(H(2)) cation (i.e., [CpRu(dppm)(eta(2)-H(2))](+)) is used as the catalyst and the enamine is more basic than the product amine. Ionic hydrogenation of an alpha,beta-unsaturated iminium cation saturates both the C=C and the C=N bonds. A C=N bond is more reactive toward ionic hydrogenation than a C=C one, but in some cases (i.e., CH=CH(2)) the latter may compete with H(2) for a coordination site and decrease the turnover frequency.

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Section: Methodsmentioning

confidence: 99%

Ruthenium-Catalyzed Ionic Hydrogenation of Iminium Cations. Scope and Mechanism

et al. 2005

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“…This interest has also caused us to examine the possibility of making the analogous, electron-rich and redox-active C 2 complexes. We noted that the complex [{Cp(Ph 3 P) 2 Ru}(μ-CN){Ru(PPh 3 ) 2 Cp}] + , with redox-active group 8 metal−ligand groups end-capping the CN bridge, had been first successfully prepared and structurally characterized some 20 years ago, with a second structural determination of this cation being reported recently . We chose to use redox-active end-caps similar to those employed earlier, both in the CN chemistry and in our earlier studies of C 4 complexes, i.e., M(dppe)Cp‘ [M = Fe, Ru, Os; Cp‘ = Cp, Cp*], which, in the case of the ruthenium examples, gave complexes exhibiting up to four sequential one-electron oxidations. 21c, However, it should be noted that these groups are bulky enough to result in steric interactions between the phenyl groups of the phosphine ligands that may impede rotation of the metal−ligand moieties about the M−C−C−M axis, leading on one occasion to the isolation of two rotamers of {Ru(PPh 3 ) 2 Cp} 2 (μ-C 4 ) when this complex was crystallized from different solvents 21b.…”

Section: Introductionmentioning

confidence: 99%

Redox-Active Complexes Containing Group 8 Metal Centers Linked by C₂Bridges

et al. 2007

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A series of complexes containing dicarbon ligands bridging redox-active group 8 metal−ligand fragments M(dppe)Cp‘ (M = Fe, Ru, Os; Cp‘ = Cp, Cp*) have been prepared. These complexes give up to four one-electron anodic processes at a platinum electrode, with separations of successive oxidation potentials of ca. 850 mV, giving rise to large comproportionation constants, K C (ca. 1012). Examples of the 36-electron neutral, 35-electron monocationic, and 34-electron dicationic species, together with some related monoprotonated complexes, have been isolated. Structural studies of the 36-, 35-, and 34-electron species derived from the dicarbon complex featuring two Ru(dppe)Cp end-caps (7) show that shortening of the M−C and lengthening of the C−C bonds occur upon oxidation. A complementary spectroelectrochemical investigation has revealed an intense band near 14 300 cm-1 associated with [7]PF6, which is tentatively attributed to a Ru(d)−[Ru(d)/C2(π)]* transition, rather than a genuine IVCT band. These observations have been rationalized using DFT calculations and collectively indicate that the frontier orbitals are delocalized over both group 8 metal centers and the carbon chain.

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“…In general, the IR absorption of bridging CN groups is higher than that of the parent mononuclear CN complexes. [24] Intense sharp absorption bands are also observed (3549 and 3380 cm À1 ), which could indicate the presence of an extensive hydrogen-bond network between water molecules and the nitrogen atoms (OHÀN pta , OHÀ N NCAu ). The 31 P{ 1 H} NMR spectrum of 3 (in D 2 O) shows two singlets at d = À19.21 and À21.82 ppm.…”

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confidence: 99%

A Water Soluble Diruthenium–Gold Organometallic Microgel

et al. 2008

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Selection of the combination of metal, ligand set, and spacer groups that are most appropriate to form a coordination complex with a desired function are of paramount importance in supramolecular chemistry. In particular, the establishment of reproducible methods to accomplish controlled selforganization of molecules to form polymers and homo-or heterometallic coordination aggregates is an important field of research.[1] Although important advances have already been made, few metallopolymers, which are one of the most exciting classes of functional materials, are water soluble. An important example of a water-soluble polymer is the polyferrocenylsilane-b-polyaminomethacrylate copolymer described by Manners and co-workers, [2] as part of their ongoing study on metallocene-based polymers.[3] Recent examples also include the water-soluble metallopolymer obtained by reaction of bipyridyl-appended poly(p-phenyleneethynylene) (PPEs) with metal ions in organic and aqueous solution. [4] Other examples of ligands that afford coordination polymers with various topologies and applications are ferrocenyl groups bearing bipyridine (bpy) [5] or carboxylate moieties.[6]A recent example of a non-water-soluble multimetallic polymer is [Sm(, in which the CN ligands bridge the samarium and ruthenium metal centers.[7]The first air-stable water-soluble multimetallic polymer that includes mixed P,N ligands as metal-coordinating spacers has been recently reported by us.[8] This heterobimetallic complex is based on two metal-containing moieties, [CpRu]À , and is bridged by the cagelike water-soluble monodentate phosphine 1,3,5-triaza-7-phosphaadamantane (pta) in an unprecedented P,N coordination mode. More recently, the synthesis of silver coordination polymers containing pta bridging molecules in a tridentate P,N,N' coordination mode [9] has been reported and several examples of pta N coordination have been presented.[10] Therefore the pta molecule could be an excellent ligand from which to obtain water-soluble Ru-Au polymers which could have interesting and useful properties for a variety of applications such as magnetism, [11] nonlinear optics, [12] electrocatalysis, [13] photocatalysis, [14] photovoltaic, [15] template formation of ordered networks, [16] advanced electrode materials, [17] and conjugated coordination polymers.[18]Herein, we describe the first water-soluble, air-stable heterobimetallic polymeric structure based on two metalcontaining moieties [CpRuCNRuCp] + and [Au(CN) 4 ] À , bridged by pta in the P,N coordination mode. Interestingly, this complex display gel-like properties [19] in water, specifically a thermally controlled volume transition. To the best of our knowledge, this is the first example of an coordination polymer network that is sensitive to its environment. The physical and chemical properties of this complex make it a promising material for industrial and biological applications, for example, smart catalysis, drug delivery, or chemical sensing.The first strategy we attempted to obtain a water soluble ...

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Bimetallic cyano-bridged cations: preparation and hydride reduction of [(η⁵-C₅H₅)L₂Ru(µ-CN)ML′₂(η⁵-C₅H₅)]PF₆[L₂,L′₂=(PPh₃)₂,Ph₂PCH₂CH₂PPh₂; M = Ru or Fe]. Formation of [Ru(η⁵-C₅H₅)(PPh₃)H₃] and X-ray crystal structure of [(η⁵-C₅H₅)(Ph

Cited by 46 publications

References 6 publications

Ruthenium-Catalyzed Ionic Hydrogenation of Iminium Cations. Scope and Mechanism

Ruthenium-Catalyzed Ionic Hydrogenation of Iminium Cations. Scope and Mechanism

Redox-Active Complexes Containing Group 8 Metal Centers Linked by C₂Bridges

A Water Soluble Diruthenium–Gold Organometallic Microgel

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Bimetallic cyano-bridged cations: preparation and hydride reduction of [(η5-C5H5)L2Ru(µ-CN)ML′2(η5-C5H5)]PF6[L2,L′2=(PPh3)2,Ph2PCH2CH2PPh2; M = Ru or Fe]. Formation of [Ru(η5-C5H5)(PPh3)H3] and X-ray crystal structure of [(η5-C5H5)(Ph

Cited by 46 publications

References 6 publications

Ruthenium-Catalyzed Ionic Hydrogenation of Iminium Cations. Scope and Mechanism

Ruthenium-Catalyzed Ionic Hydrogenation of Iminium Cations. Scope and Mechanism

Redox-Active Complexes Containing Group 8 Metal Centers Linked by C2Bridges

A Water Soluble Diruthenium–Gold Organometallic Microgel

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Product

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Bimetallic cyano-bridged cations: preparation and hydride reduction of [(η⁵-C₅H₅)L₂Ru(µ-CN)ML′₂(η⁵-C₅H₅)]PF₆[L₂,L′₂=(PPh₃)₂,Ph₂PCH₂CH₂PPh₂; M = Ru or Fe]. Formation of [Ru(η⁵-C₅H₅)(PPh₃)H₃] and X-ray crystal structure of [(η⁵-C₅H₅)(Ph

Redox-Active Complexes Containing Group 8 Metal Centers Linked by C₂Bridges