Employed Reaction Conditions Research Articles

Alloying Au surface with Pd reduces the intrinsic activity in catalyzing CO oxidation

Various Au-Pd/SiO2 catalysts with a fixed Au loading but different Au:Pd molar ratios were prepared via deposition-precipitation method followed by H2 reduction. The structures were characterized and the catalytic activities in CO oxidation were evaluated. The formation of Au-Pd alloy particles was identified. The Au-Pd alloy particles exhibit enhanced dispersions on SiO2 than Au particles. Charge transfer from Pd to Au within Au-Pd alloy particles. Isolated Pd atoms dominate the surface of Au-Pd alloy particles with large Au:Pd molar ratios while contiguous Pd atoms dominate the surface of Au-Pd alloy particles with small Au:Pd molar ratios. Few synergetic effect of Au-Pd alloy occurs on catalyzing CO oxidation under employed reaction conditions. Alloying Au with Pd reduces the intrinsic activity in catalyzing CO oxidation, and contiguous Pd atoms on the Au-Pd alloy particles are capable of catalyzing CO oxidation while isolated Pd atoms are not. These results advance the fundamental understandings of Au-Pd alloy surfaces in catalyzing CO oxidation.

Solvent-Drop Grinding Method: Efficient Synthesis, DPPH Radical Scavenging and Anti-diabetic Activities of Chalcones, bis-chalcones, Azolines, and bis-azolines

Highly efficient one-pot solvent-free grinding method was reported for synthesis of chalcones 3a-j, 5a,b, 7 and bis-chalcones 9, 11. Cyclodehydration of bis-chalcones 9, 11 and chalcones 3 with hydrazine derivatives under solvent- free grinding method afforded bis-pyrazolines 12a,b, 13a,b and pyrazoline derivatives 14a-g, respectively. In a similar manner, grinding of bis-chalcones 9, 11 and chalcones 3 with hydroxylamine hydrochloride under the employed reaction conditions gave bis-isoxazolines 15, 16 and isoxazoline derivatives 17a-e, respectively. The antioxidant activity of the selected products was studied using 1,1-diphenyl-2-picrylhydrazyl radical (DPPH) assay. Also, the antidiabetic activity of the selected products against normal and alloxan induced diabetic mice was evaluated. Keywords: Anti-diabetic activity, antioxidant activity, bis-isoxazolines, bis-pyrazolines, enones, isoxazolines, pyrazolines, solvent-free grinding.

Green and efficient synthesis of adipic acid from cyclohexene over recyclable H3PW4O24/PEHA/ZrSBA-15 with platelet morphology

Designing a green synthesis system of adipic acid is important to achieve sustainable development of adipic acid-derived industries. A green and efficient synthesis of adipic acid by using one-step oxidative cleavage of cyclohexene over recyclable H3PW4O24/PEHA/ZrSBA-15 is presented in this paper. The synergic effect of Zr-ions modified the acidic framework and auxiliary PEHA molecules toward high dispersion and stabilization of active clusters. These clusters endowed the resulting nanocomposites with unexceptional reusability under employed reaction conditions. Standard characterization techniques, namely, N2 sorption, XRD, FT-IR, TEM, XPS, 1H-NMR, and ICP-AES, were performed to establish the coordinated internal ordered framework of the nanocomposite with platelet morphology. The superiority of layer-by-layer deposition strategy has been proved accordingly. Detailed reaction parameters were screened for the optimization of a catalytic system. Compared with the properties of the catalyst H3PW12O40/PEHA/ZrSBA-15, which is prepared through identical pathways, the properties of the reactive PW4 clusters with strengthened stabilization are favorable. Therefore, excellent catalytic performance of adipic acid yield (∼90.9%) was observed along with efficient recyclability during five reaction cycles.

Rh complex encapsulated hexagonal mesoporous silica as an efficient heterogeneous catalyst for the selective hydroformylation of styrene

A rhodium complex encapsulated into the mesopores of hexagonal mesoporous silica [HRh(CO)(PPh3)3-HMS] was investigated for the heterogeneous catalytic hydroformylation of styrene. The catalyst system efficiently catalyzed the hydroformylation of styrene with 100 % conversion, yielding the desired iso-aldehyde selectively. The investigations were performed in detail to study the effects of the amount of catalyst, weight ratio of complex HRh(CO)(PPh3)3–tetraethylorthosilicate, concentration of styrene, pCO, pH2 and temperature on the hydroformylation of styrene. The kinetic performance of the catalyst was favored on increasing the amount of the catalyst, styrene concentration, pH2 and temperature. The rates were decreased on increasing pCO. The determined activation energy (Ea = 32.50 ± 0.8 kJ mol−1) indicated that Ea associated with heterogeneous catalysis is lower than that of the homogeneous catalysis. Under the employed reaction conditions, the iso-aldehyde could be achieved up to 88.90 % with 100 % styrene conversion. The heterogeneous catalyst, HRh(CO)(PPh3)3-HMS was separated and reused effectively up to seven catalytic cycles.

Zirconium phenylphosphonate-anchored methyltrioxorhenium as novel heterogeneous catalyst for epoxidation of cyclohexene

Epoxidation of olefins to epoxides is widely recognized as an important unit process in the manufacture of fine chemicals and intermediates. Developing an environmentally benign heterogeneous catalytic system for olefin epoxidation with high activity and selectivity is still a challenge in this research field. Herein, we report our attempts to synthesize novel zirconium phenylphosphonate-anchored methyltrioxorhenium (MTO/ZrPP) heterogeneous catalysts by a conventional impregnation method and evaluate their catalytic performance for epoxidation of cyclohexene using urea–hydrogen peroxide adduct (UHP) as oxidant without the addition of base ligands. The MTO/ZrPP catalyst samples are characterized by powder X-ray diffraction (XRD), Fourier transform infrared (FT-IR), inductively coupled plasma emission spectrometry (ICP-ES), high resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS), and solid-state 1H magic-angle spinning nuclear magnetic resonance (1H MAS NMR) techniques. Meanwhile, the density functional theory (DFT) calculation is carried out to further understand the structure feature and interactions of the MTO/ZrPP catalyst. It is revealed that MTO is anchored on support surface by the favored hydrogen-bonding interaction between two oxo ligands of MTO and two H atoms from the adjacent phenyls of ZrPP. MTO/ZrPP catalyst displays excellent catalytic activity for cyclohexene epoxidation. Moreover, only cyclohexene oxide production can be obtained under the employed reaction conditions.

One pot synthesis of hollow Cu-doped Ru octahedral nanocages via an in situ generated metastable Cu nanoparticle template.

A facile synthetic strategy was developed for a hollow Ru octahedral nanocage via an in situ generated metastable facet-controlled Cu nanooctahedron. Co-decomposition of Cu and Ru precursors forms a metastable core-shell Cu@Ru nanoparticle, and a subsequent in situ dissolution of the core Cu phase results in a hollow octahedral Cu-doped Ru nanocage. CTAB (cetyltrimethylammonium bromide) was found to effect both the formation and destabilization of the Cu template under the employed reaction conditions, which is the key requirement for one-step synthesis of hollow Cu-doped Ru nanocages. The regioselective, preferential deposition of Ru atoms on the edge and corner of the core template nanoparticle led to a structurally well-defined Cu doped-Ru octahedral nanocage.

Stereocontrolled synthesis of bicyclic sulfamides via Pd-catalyzed alkene carboamination reactions. Control of 1,3-asymmetric induction by manipulating mechanistic pathways.

A new annulation strategy for the synthesis of trans-bicyclic sulfamides is described. The Pd-catalyzed alkene carboamination reactions of 2-allyl and cis-2,5-diallyl pyrrolidinyl sulfamides with aryl and alkenyl triflates afford the fused bicyclic compounds in good yields and with good diastereoselectivity (up to 13:1 dr). Importantly, by employing reaction conditions that favor an anti-aminopalladation mechanism, the relative stereochemistry between the C3 and C4a stereocenters of the products is reversed relative to related Pd-catalyzed carboamination reactions that proceed via syn-aminopalladation.

Tailoring atropisomeric maleimides for stereospecific [2 + 2] photocycloaddition--photochemical and photophysical investigations leading to visible-light photocatalysis.

Atropisomeric maleimides were synthesized and employed for stereospecific [2 + 2] photocycloaddition. Efficient reaction was observed under direct irradiation, triplet-sensitized UV irradiation, and non-metal catalyzed visible-light irradiation, leading to two regioisomeric (exo/endo) photoproducts with complete chemoselectivity (exclusive [2 + 2] photoproduct). High enantioselectivity (ee > 98%) and diastereoselectivity (dr > 99:1%) were observed under the employed reaction conditions and were largely dependent on the substituent on the maleimide double bond but minimally affected by the substituents on the alkenyl tether. On the basis of detailed photophysical studies, the triplet energies of the maleimides were estimated. The triplet lifetimes appeared to be relatively short at room temperature as a result of fast [2 + 2] photocycloaddition. For the visible-light mediated reaction, triplet energy transfer occurred with a rate constant close to the diffusion-limited value. The mechanism was established by generation of singlet oxygen from the excited maleimides. The high selectivity in the photoproduct upon reaction from the triplet excited state was rationalized on the basis of conformational factors as well as the type of diradical intermediate that was preferred during the photoreaction.

Cycloisomerization of Acetylenic Acids to γ-Alkylidene Lactones using a Palladium(II) Catalyst Supported on Amino-Functionalized Siliceous Mesocellular Foam

Cycloisomerization of various γ-acetylenic acids to their corresponding γ-alkylidene lactones by the use of a heterogeneous Pd(II) catalyst supported on amino-functionalized siliceous mesocellular foam is described. Substrates containing terminal as well as internal alkynes were cyclized in high to excellent yields within 2–24 h under mild reaction conditions. The protocol exhibited high regio- and stereoselectivity, favoring the exo-dig product with high Z selectivity. Moreover, the catalyst displayed excellent stability under the employed reaction conditions, as demonstrated by its good recyclability and low leaching.

An Efficient Synthesis of Benzimidazoles via Palladium-Catalyzed Amine Exchange Reaction from Trialkylamines to o-Phenylenediamine in an Aqueous Medium

Transition metal-catalyzed alkyl group transfer between alkylamines has been known as amine exchange reaction (amine scrambling reaction) and used for the synthesis of unsymmetrical amines and N-heterocycles and the study of the metabolism of amines. During the course of our studies directed towards transition metal-catalyzed C-N bond activation of alkylamines, we developed an alkyl (or alkanol) group transfer from alkylamines (or alkanolamines) to Natom of anilines as well as α-carbon of ketones, which leads to a regioselective α-alkylation of ketones. The former transfer eventually leads to indoles and quinolines under the employed reaction conditions. However, except for our findings, there have been known only a few examples for the synthesis of N-heterocycles using such an amine exchange reaction. It is known that hydropyrimidines, imidazolidines and imidazoles could be formed by palladium-catalyzed intermolecular amine exchange reaction between diamines and alkylamines. Diamines were found to be cyclized to pyrrolidine, piperidine, and azepane via ruthenium-catalyzed intramolecular amine exchange reaction. On the other hand, in connection with this report, Murahashi et al. reported that N-methylbenzylamine reacts with o-phenylenediamine in the presence of Pd/C to give 2-phenylbenzimidazole and 1benzyl-2-phenylbenzimidazole in 37% and 25% yields, respectively. Under these circumstances, the present reaction was disclosed during the course of seeking for a more efficient catalytic system on an intrinsic amine exchange reaction. Herein this report describes an efficient synthesis of benzimidazoles via palladium-catalyzed amine exchange reaction from trialkylamines to o-phenylenediamine in an aqueous medium. To investigate the effect of reaction variants such as solvent, reaction temperature and time, o-phenylenediamine (1) and tributylamine (2a) were chosen as a model reaction. Treatment of equimolar amounts of 1 and 2a in toluene at 110 C for 20 h in the presence of a catalytic amount of 5% Pd/C afforded 2-propylbenzimidazole (3a) in 47% isolated yield with 67% conversion of 1 (run 1). Performing the reaction for a longer reaction time under two-fold molar ratio of 2a to 1 gave no improvement in the yield of 3a (run 2). Higher reaction temperature in toluene was needed for the effective formation of 3a (run 3). However, the reaction carried out under the further addition of H2O resulted in an increased yield of 3a (72%) along with concomitant formation of further N-alkylated benzimidazole 4 (2%) (run 4). In spite of further elaboration for the optimization of reaction conditions (runs 5-7), the best result in terms of the yield of 3a and the selectivity of 3a to 4 is best accomplished under the standard set of condition shown in run 4 of Table 1. Based on reaction conditions of Table 1, various trialkylamines 2 were subjected to the reaction with 1 in order to investigate the reaction scope, and several representative results are summarized in Table 2. An array of trialkylamines (2a-e) having straight alkyl chains reacted with 1 and the corresponding benzimidazoles (3a-e) were obtained in a range of 57-72% yields. Generally, the product yield gradually decreased as the alkyl chain length on 2a-e increases. Thus, in the reaction with 2d and 2e, a longer reaction time was needed for the allowable yield of products. Furthermore, in the case of 2e, three-fold molar ratio of 2e to 1 was necessary for the effective formation of 3e. When the reaction was carried out with two-fold molar ratio of 2e to 1 for 40 h under the employed conditions, 3e was obtained in 31% yield. In the reaction with trialkylamines (2f and 2g) having branched alkyl chains, similar reaction rate and yield were observed with triisoamylamine (2g), whereas higher reaction

A general rhodium-catalyzed cross-coupling reaction of thiols with aryl iodides

The general procedure for the rhodium-catalyzed cross-coupling of thiols with aryl iodides is described. The catalytic system consists of 5mol% of [RhCl(cod)]2 and 10mol% of PPh3 as a ligand. A variety of aryl iodides reacted with thiols, giving aryl thioethers in good to excellent yields. It is important to note that the deactivated aryl iodides such as 4-iodoanisole is worked smoothly to provide the corresponding aryl thioethers in excellent yields. Functional groups such as free-amines, chloro, are all tolerated under the employed reaction conditions.

Simultaneous measurement of X-ray small angle scattering, absorption and reactivity: A continuous flow catalysis reactor

A fixed-bed, continuous flow catalysis reactor is described, in which GISAXS (grazing incidence small angle X-ray scattering)/GIXAS (grazing incidence X-ray absorption spectroscopy) and TPR (temperature-programmed reaction) can be measured simultaneously on samples with low metal coverage. The capabilities offered by this setup are illustrated in the example of the dehydrogenation of cyclohexene, where the size, oxidation state and reactivity of supported cobalt clusters were investigated under ambient pressure conditions. The GIXAS data reveal an evolution of the oxidation state of the catalytic particles with temperature. Simultaneously recorded GISAXS data show stable clusters, without any indication of sintering under employed reaction conditions.

Synthesis of Uniform TiO<SUB>2</SUB> Nanoparticles with Egg Albumen Proteins as Novel Biotemplate

A novel bio-templated route was reported for the fabrication of uniform and well dispersed TiO, nanoparticles using denatured egg albumen (EA) proteins network as template. Anatase TiO2 nanoparticles of ca. 9 nm with narrow size distribution were obtained under employed reaction conditions, as proved by the XRD and TEM results. The as-prepared TiO2 nanoparticles were further characterized by means of XPS, FTIR, TG-DTA and UV-Vis. Based on the characterization results, a possible process of heat-induced denatured protein network as template matrix to fabricate TiO2 nanoparticles was carefully proposed. The method with egg albumen as bio-template provides us a cheap, green and repeatable route for the fabrication of nanoparticles under mild conditions.

Tailored Growth of In(OH)3Shell on Functionalized Polystyrene Beads

Fabrication of organic-inorganic composite particles with tailored size, shape, and morphology has been attracting great attention from researchers because of their fascinating properties and applications in a variety of potential fields. In this study, we report on the fabrication of PS-In(OH)(3) (polystyrene-indium hydroxide) composite particles by hydrolyzing the In(OC(3)H(7))(3) (indium isopropoxide) salt in the presence of beta-diketone functionalized PS colloidal particles. A systematic investigation of the employed reaction conditions allowed us to tune the morphology, size, and In(OH)(3) content of the PS-In(OH)(3) composite particles. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) results illustrate that variation in the employed concentration of the In(OC(3)H(7))(3) salt in reaction media can effectively tune the morphology of resulting composite particles between "core-shell" and "raspberry-like". X-ray diffraction (XRD) analysis confirms the phase purity of In(OH)(3) nanoparticles precipitated on the surface of PS beads. Colloidal stability of the composite particles has been found to be reduced with increasing the deposited amount of In(OH)(3) nanoparticles. Thermogravimetric analysis (TGA) suggests a continuous increase in the deposited amount of In(OH)(3) nanoparticles with increasing concentration of In(OC(3)H(7))(3) salt in reaction media. The resulting PS-In(OH)(3) composite particles are envisioned to be used in a myriad of potential applications including fabrication of optoelectronic devices, absorption/separation supporting material, catalysts, and hydrophobic surfaces.

The multi-step reactions for the synthesis of C 8 aldehydes and alcohol from propene in a single pot using an eco-friendly multi-functional catalyst system: Kinetic performance for parametric optimization

Kinetics of multi-step reactions including hydroformylation, aldol condensation and hydrogenation was carried out in a single pot for optimization of the reaction parameters for the synthesis of C 8 aldehydes and alcohol from propene using an eco-friendly multi-functional heterogeneous catalyst system [HF/HT] where [HF] = rhodium complex, HRh(CO)(PPh 3) 3 and [HT] = hydrotalcite, Mg 1− x Al x (OH 2) x+ (CO 3 2−) x/ n · mH 2O. The catalyst [HF/HT] was synthesized by impregnation of [HF] onto the surface of [HT]. In the typical catalytic experiments conducted in a 100 mL high pressure reactor under the employed reaction conditions: propene = 10 atm, CO = 5 atm, H 2 = 15 atm, [HF/HT] = 700 mg, HT/HF ratio = 7, Mg/Al molar ratio of [HT] = 3.5, aldol temperature = 250 °C, reaction time = 12 h, agitation speed = 1000 rpm, and in 50 mL toluene as a solvent, 68.4 × 10 −3 M of 2-ethylhexanol with 18% selectivity was achieved. The rates of reactions were determined by analyzing the amounts of products formed at different time using gas chromatography. Kinetics of the various reactions were performed in detail by investigating the effect of reaction parameters such as Mg/Al molar ratio of [HT] at aldol temperature 150 and 250 °C, amount of [HT] and [HF] complex, aldol temperature, partial pressure of CO and H 2 on the rates of formation of products namely, 2-ethylhexanol, 2-ethylhexanal, 2-ethylhexenal, butanals and butanols. The rates of reactions were found to be influenced by all these studied parameters. On increasing these parameters, the rates of formation of the products and their further conversions in single pot were favored.

Single-Step Method for the Isolation and Surface Functionalization of Cellulosic Nanowhiskers

Surface modification of cellulosic nanowhiskers (CNW) is of great interest, especially to facilitate their use as polymer reinforcements. Generally, alteration of the surface chemistry is performed using multiple reaction steps. In contrast, this study demonstrates that the needed hydrolysis of amorphous cellulose chains can be performed simultaneously with the esterification of accessible hydroxyl groups to produce surface functionalized CNW in a single step. The reaction is carried out in an acid mixture composed of hydrochloric and an organic acid (acetic and butyric are both demonstrated). Resulting CNW are of similar dimensions compared to those obtained by hydrochloric acid hydrolysis alone; sizes are verified by multiangle laser-light scattering and transmission electron microscopy. However, narrower diameter polydispersity indices indicate that surface groups aid the individualization of the nanowhiskers (Px = 2.5 and 2.1 for acetic and butyric acid, Px = 3.0 for hydrochloric acid). More than half of the hydroxyl groups located on the CNW surface are substituted under the employed reaction conditions as determined by quantitative Fourier-transform infrared-spectroscopy. The resulting surface modified CNW are dispersible in ethyl acetate and toluene indicating increased hydrophobicity and thus are presumably more compatible with hydrophobic polymers when used as a reinforcing phase.

Selective oxidation of methane by molecular oxygen catalyzed by a bridged binuclear ruthenium complex at moderate pressures and ambient temperature

The oxidation of methane by molecular oxygen was found to be efficiently catalyzed by a binuclear bridged ruthenium complex, bis-(μ-acetato)(μ-oxo) bis-salen ruthenium (III), [L 2 Ru 2 (μ-O)(μ-CH 3COO) 2] 1 (L = Hsalen), in which methanol was observed to be formed selectively with small formation of formaldehyde at moderate total pressure 10–15 atm and at 30 °C in a 1:1 (v/v) mixture of acetone–water solvent. In typical experiments conducted in a pressure reactor of 100 ml capacity at 30 °C and 15 atm pressure, 27 × 10 −3 M methanol and 2.4 × 10 −3 M formaldehyde were found to be formed with 5 × 10 −4 M catalyst. The employed partial pressures of methane and molecular oxygen in these catalytic experiments were at 10 and 5 atm, respectively. Complex 1 was synthesized, characterized and evaluated for catalytic oxidation of methane in detail as a function of total pressure, CH 4:O 2 pressure ratio, concentration of the catalyst and the pressures of methane and molecular oxygen in which oxidation proved to be favorably effected by these parameters. The rates of the oxidation of methane to methanol were linearly increased on increasing the concentrations of the catalyst, methane and molecular oxygen under employed reaction conditions showing first order dependence kinetics in each concentration parameter. Based on the kinetics and experimental results, a non-radical, ionic mechanism is suggested for the oxidation of methane to methanol.

Concise and Diversity-Oriented Synthesis of Ligand Arm-Functionalized Azoamides

Azoamides, previously established as bioactive intracellular GSH-depleting agents, were decorated with a terminal alkyne moiety to 4 and then were transformed, by copper(I)-catalyzed azide-alkyne cycloaddition (CuAAC), into different ligand-arm functionalized azoamides 6. Azides 5 having ligand-arms amenable for binding to platinum(II) were selected for this study. Because, for the fragile azoamides 4, the typically employed reaction conditions for CuAAC failed, several alternative solvents and copper catalysts were tested. Excellent results were obtained with copper(II) sulfate pentahydrate/metallic copper and especially with heterogeneous catalysts, such as copper-in-charcoal, cupric oxide, and cuprous oxide. The heterogeneous catalysts were employed to obtain the desired products in almost quantitative yields by a simple three-step "stir-filter-evaporate" protocol with no or negligible contamination with copper impurities. This is of particular importance because compounds 6 have been designed for coordination.

Convenient Conditions for the Enantioselective Synthesis of α‐Methyl‐α‐amino Acids with the Use of Cinchona Ammonium Salts as Phase‐Transfer Organocatalysts

AbstractThe enantioselective α‐alkylation of 2‐naphthalenecarbaldehyde aldimine alanine tert‐butyl ester is carried out by using N‐anthracenylmethyl ammonium salts from the simple and unmodified cinchonidine and cinchonine alkaloids as phase‐transfer organocatalysts, which affords (S)‐ and (R)‐enantioenriched α‐methyl‐α‐amino acid (AMAA) derivatives in 71–98 % yield and 79–96 % ee. The employed reaction conditions, rubidium hydroxide as base and toluene/chloroform as solvent at –20 °C, allows higher enantioselectivities to be obtained than those previously obtained by using other Cinchona alkaloid‐derived ammonium salts, even with a lower catalyst loading (5 mol‐%). (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)

Reaction of HRu3(CO)10(μ-COMe) with bma: NMR and X-ray structural evidence for the formation of the Ph2PH-substituted cluster HRu3(CO)8(Ph2PH)[μ-PPh2C=CC(O)OC(O)

Me3NO activation of the methylidyne-bridged cluster HRu3(CO)10(μ-COMe) (1) in the presence of the unsaturated diphosphine ligand 2,3-bis(diphenylphosphino)maleic anhydride (bma) furnishes the bma-substituted cluster HRu3(CO)8(bma)(μ-COMe) (2) and the diphenylphosphine-substituted cluster HRu3(CO)8(Ph2PH)[μ-PPh2C=CC(O)OC(O)] (3) as the major and minor products, respectively. The 1H and 31P NMR data indicate that the bma ligand in cluster 2 is chelated to one of the ruthenium atoms that is bridged by the hydride and methylidyne ligands. Cluster 3 has been fully characterized in solution by IR and NMR spectroscopies, and the solid-state structure determined by X-ray crystallography. 3 crystallizes in the monoclinic space P21, a = 12.1467(7) Å, b = 19.284(1) Å, c = 16.867(1) Å, β = 109.639(6)°, V = 3721.0(4) Å3, Z = 4, and dcalcd = 1.774 g cm−3; R = 0.0325, R w = 0.0383 for 3518 reflections with I > 3σ(I). The X-ray data confirm that one of the P–C(maleic anhydride) bonds of the bma ligand has been cleaved and that cluster 3 contains Ph2PH and μ-PPh2C=CC(O)OC(O) ligands, the latter which functions as a face-capping ligand to all three ruthenium atoms. Control experiments indicate that cluster 2 does not function as a precursor to cluster 3 under the employed reaction conditions.