91837-70-6

Basic information

• Product Name: {Rh2(μ-O2CMe)2{(C6H4)PPh2}{(C6H4)P(C6H5)2}(HO2CMe)2}
• Synonyms: {Rh2(μ-O2CMe)2{(C6H4)PPh2}{(C6H4)P(C6H5)2}(HO2CMe)2}
• CAS NO: 91837-70-6
• Molecular Weight: 966.571
• Mol File: 91837-70-6.mol

Chemical Properties

• CAS DataBase Reference: {Rh2(μ-O2CMe)2{(C6H4)PPh2}{(C6H4)P(C6H5)2}(HO2CMe)2}(CAS DataBase Reference)
• NIST Chemistry Reference: {Rh2(μ-O2CMe)2{(C6H4)PPh2}{(C6H4)P(C6H5)2}(HO2CMe)2}(91837-70-6)
• EPA Substance Registry System: {Rh2(μ-O2CMe)2{(C6H4)PPh2}{(C6H4)P(C6H5)2}(HO2CMe)2}(91837-70-6)

Safety Data

• Hazardous Substances Data: 91837-70-6(Hazardous Substances Data)

Upstream product

• 64-19-7 acetic acid 
• 603-35-0 triphenylphosphine 
• 138459-71-9 Rh₂(O₂CCH₃)3{(C₆H₄)P(C₆H₅)2}(P(C₆H₅)3)(H₂O) 
• 138459-70-8 {Rh2(O2CMe)(μ-O2CMe)2{(C6H4)PPh2}{P(C6H5)3}(HO2CMe)} 

Downstream Products

• 138459-72-0 Rh₂(acetato)2[(C₆H₄)P(C₆H₅)2]2(H₂O)2 
• 125505-48-8 [Rh₂(OCOCH₃)2(P(C₆H₅)3)2((C₆H₄)P(C₆H₅)2)2] 
• 92669-58-4 Rh₂(acetato)2[(C₆H₄)P(C₆H₅)2]2Py₂ 
• 361370-26-5 Rh₂(C₄H₄NO₂)2(C₆H₄P(C₆H₅)2)2 
• 361370-26-5 Rh₂(C₄H₄NO₂)2(C₆H₄P(C₆H₅)2)2 

Relevant articles and documents

Sensitive and selective chromogenic sensing of carbon monoxide via reversible axial CO coordination in binuclear rhodium complexes

The study of probes for CO sensing of a family of binuclear rhodium(II) compounds of general formula [Rh2{(XC6H 3)P(XC6H4)}n(O2CR) 4-n]·L2 containing one or two metalated phosphines (in a head-to-tail arrangement) and different axial ligands has been conducted. Chloroform solutions of these complexes underwent rapid color change, from purple to yellow, when air samples containing CO were bubbled through them. The binuclear rhodium complexes were also adsorbed on silica and used as colorimetric probes for "naked ey" CO detection in the gas phase. When the gray-purple colored silica solids containing the rhodium probes were exposed to air containing increasing concentrations of CO, two colors were observed, in agreement with the formation of two different products. The results are consistent with an axial coordination of the CO molecule in one axial position (pink-orange) or in both (yellow). The crystal structure of 3·(CO) ([Rh2{(C6H4)P(C6H 5)2}2(O2CCF3) 2]·CO) was solved by single X-ray diffraction techniques. In all cases, the binuclear rhodium complexes studied showed a high selective response to CO with a remarkable low detection limit. For instance, compound 5· (CH3CO2H)2 ([Rh2{(m- CH3C6H3)P(m-CH3C6H 4)2}2(O2CCH3) 2]· (CH3CO2H)2) is capable of detection of CO to the "naked ey" at concentrations as low as 0.2 ppm in air. Furthermore, the binding of CO in these rhodium complexes was found to be fully reversible, and release studies of carbon monoxide via thermogravimetric measurements have also been carried out. The importance of the silica support for the maintenance of the CO-displaced L ligands in the vicinity of the probes in a noninnocent manner has been also proved.

Detection of Neutral CO Lost During Ionic Dissociation Using Atmospheric Pressure Thermal Dissociation Mass Spectrometry (APTD-MS)

Elucidation of ion dissociation patterns is particularly important to structural analysis by mass spectrometry (MS). However, typically, only the charged fragments from an ion dissociation event are detected in tandem MS experiments; neutrals are not identified. In recent years, we have developed an atmospheric pressure thermal dissociation (APTD) technique that can be applied to dissociate ions at atmosphere pressure and thus provide one way to characterize neutral fragments. In this paper, we focus on the detection of neutral CO resulting from amino acid and peptide ion dissociation. In the first set of experiments, several protonated amino acids (e.g., + 1 ion of phenylalanine) were found to undergo loss of a neutral (s) of total mass 46?Da, a process leading to iminium ion formation. We successfully detected the neutral species CO by using a CO sensor, UV-Vis and MS analysis following selective CO trapping with a rhodium complex. The capture of CO from dissociation of protonated amino acids supports the assignment of the loss of 46?Da to neutral losses of CO and H2O, rather than loss of formaldehyde or dihydroxycarbene, other possible fragmentation pathways that have been subject of debate for a long time. In a second experiment, we used the APTD method in combination with the CO detection technique, to demonstrate the formation of CO in the conversion of b ions to a ions during peptide ion dissociations. These results showed the potential of APTD in the elucidation of ion dissociation mechanisms, using simple home-built apparatus. [Figure not available: see fulltext.].

Chiral organometallic triangles with Rh-Rh bonds. 2. Compounds prepared from enantiopure cis-Rh2(C6H4PPh 2)2(OAc)2(HOAc)2 and their catalytic potentials

Enantiomers of the orthometalated dirhodium compound cis-Rh 2(C6H4PPh2)2(OAc) 2(HOAc)2 (R-1 and S-1) were prepared from carboxylate exchange reactions of the resolved diasteroiso

Mechanism of the Acid-catalysed Cyclometallation Reaction of Dirhodium(II) Compounds with General Formula (OH2)>

Compounds of general formula (OH2)> 2 (X = H, p-Me, p-Cl, m-Me or m-Cl) have been prepared by photochemical reaction of the corresponding adduct (HO2CMe)> 1.These compounds contain one equatorial phosphine which undergoes a facile cyclometallation reaction, catalysed in the presence of protic acids, to give doubly metallated compounds (HO2CMe)2> 3.The kinetics and mechanism of this cyclometallation have been studied in chloroform and toluene solutions.A mechanism in which protons facilitate loss of one of the acetate groups in the starting compounds is proposed.Preliminary experiments showed that the addition of phosphines enhances the cyclometallation rate.The mechanism is fully concerted with a highly ordered transition state as seen by the very negative activation entropies.The values obtained for the deuterium kinetic isotopic effect indicate that, for the acid-catalysed path, the transition state lies in a more advanced position on the reaction coordinate than for the thermal process.The gap between the isokinetic plots for the acid-catalysed and thermal reactions is ca. 20 kJ mol-1.

Fast ortho-metalation reactions in binuclear dirhodium compounds. Syntheses and molecular structures of a monometalated compound and two doubly metalated compounds with head-to-head configurations

The reactions of Rh2(O2CCH3)4(MeOH)2 and triphenylphosphine, in 1:4, 1:2, and 1:1 molar ratios, have been spectroscopically studied using different reaction conditions. Very reactive intermediate products, Rh2(O2CCH3)3[(C6H 4)PPh2](HO2CCH3)2 (1(HO2CCH3)2) and Rh2(O2CCH3)3[(C6H 4)PPh2][PPh3](HO2CCH3) (2(HO2CCH3)) have been isolated. The structure of 1(HO2CCH3)2 has been determined by X-ray diffraction. Crystal data: space group P1, a = 9.807 (6) ?, b = 19.822 (10) ?, c = 8.476 (5) ?, α = 80.10 (2)°, β = 111.02 (2)°, γ = 93.67 (2)°, Z = 2, 3374 reflections, R = 0.0289. 1(HO2CCH3)2 readily reacts with an excess of triphenylphosphine at room temperature to form the already reported doubly metalated compound Rh2(O2CCH3)2[(C6H 4)PPh2]2(PPh3)2 (3(PPh3)2) with a head-to-tail structure. However under thermal conditions 1(HO2CCH3)2 reacts with excess of triphenylphosphine giving in addition to 3(PPh3)2, Rh2(O2CCH3)2[(C6H 4)PPh2]2(PPh3)(HO 2CCH3) (4-(PPh3,HO2CCH3)), a doubly metalated compound with the orthometalated ligands in a head-to-head configuration. The structure of the closely related bis(acetic acid) adduct Rh2(O2CCH3)2[(C6H 4)PPh2]2(HO2CCH3) 2 (4(HO2CCH3)2) has been determined by X-ray diffraction. Crystal data: space group C2/c, a = 23.443 (9) ?, b = 19.868 (8) ?, c = 20.158 (9) ?, β = 106.60 (2)°, Z = 8, 4873 reflections, R = 0.0451. The same mixture of compounds is formed from the reaction of Rh2(O2CCH3)4(MeOH)2 and a 4-mol excess of PPh3 in refluxing acetic acid. Para-substituted triarylphosphines P(p-XC6H4)3 (X = CH3, Cl) behave in a similar way, yielding a mixture of compounds with head-to-tail and head-to-head configurations. The structure of the compound Rh2(O2CCH3)2[(ClC6H 3)P(p-ClC6H4)2]2(HO 2CCH3)2 (8(HO2CCH3)2), having a head-to-head configuration, has been determined by X-ray diffraction. Crystal data: space group C2/c, a = 36.063 (9) ?, b = 16.558 (6) ?, c = 23.531 (8) ?, β = 125.34 (2)°, Z = 8, 4316 reflections, R = 0.0525. Two different reaction pathways are proposed to justify this chemical behavior.

Structural and electrochemical characterization of the novel ortho-metalated dirhodium(II) compounds Rh2(O2CCH3)2[(C6H 5)2P(C6H4)]2·2L

The complex Rh2(O2CCH3)2[(C6H 5)2P(C6H4)] 2·2CH3CO2H, 1, was obtained by reaction of Rh2-(O2CCH3)4·2MeOH with triphenylphosphine in acetic acid. The purple crystals belong to the monoclinic system, space group C2/c with unit cell dimensions of a = 10.111 (3) A?, b = 19.653 (10) A?, c = 21.033 (8) A?, β = 97.63 (3)°, V = 4142 (3) A?3, and Z = 4. The molecule consists of a dirhodium unit bridged by two cisoid acetate ligands and by triphenylphosphine ligands in which orthometalation has occurred at one of the phenyl rings on each phosphine, with a molecule of acetic acid in each axial site. The electrochemical reactivity of this novel dirhodium(II) compound was investigated in three organic solvents in the presence of potential donor ligands, such as pyridine, p-dithiane, and PMe2Ph. In each experiment a one-electron oxidation was observed at potentials between +0.25 and +1.04 V vs. Ag-AgCl. In addition, two ill-defined reductions were observed at potentials in excess of -0.60 V. The pyridine adduct Rh2(O2CCH3)2[(C6-H 5)2P(C6H4)] 2·2C5H5N, 2, was prepared independently and was shown, by X-ray crystallography, to contain the same general arrangement of ligands. It too forms monoclinic crystals in space group C2/c with unit cell dimensions a = 24.289 (4) A?, b = 10.391 (3) A?, c = 23.056 (5) A?, β = 131.85 (2)°, V = 4334 (2) A?3 and Z = 4. Both compounds are unusual in that the Rh-Rh distances, 2.508 (1) A? in 1 and 2.556 (2) A? in 2, are significantly greater than those reported for any of the dirhodium tetracarboxylates Rh2(O2CR)4·2L. Rh2(O2CR)4·2L.