Rhodium carbonyl cluster chemistry under high pressure of carbon monoxide and hydrogen. 3. Synthesis, characterization, and reactivity of HRh(CO)4

Vidal, José Luis Martı́nez; Walker, W. E.

doi:10.1021/ic50215a049

Cited by 75 publications

(19 citation statements)

References 11 publications

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“…Chini and Martinengo made numerous unsuccessful attempts to protonate [HRh(CO) 4 ] − 17. Finally, Vidal and Walker reported the treatment of [Rh 4 (CO) 12 ] with 1300 bar of hydrogen and carbon monoxide and the in situ observation of an infrared spectrum with bands at 2008 (w), 2039 (vs), and 2070 (m) cm −1 , which they assigned to [HRh(CO) 4 ], although four bands should be observed in the mid‐infrared region 18. It is important to note that the primary laboratories or groups involved with in situ spectroscopic studies of rhodium carbonyl chemistry and catalysis, namely Whyman at ICI, Pino and Bor in Zürich, and Markó at Veszprém,19 never reported a successful attempt.…”

Section: Methodsmentioning

confidence: 99%

Rhodium Tetracarbonyl Hydride: The Elusive Metal Carbonyl Hydride

Widjaja

Chew

et al. 2002

Angew. Chem. Int. Ed.

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One of the missing links in the chemistry of rhodium is the spectroscopic identification of the simple, unmodified rhodium carbonyl hydride [HRh(CO) 4 ]. Pure-component spectra of this compound and its deuterium analogue, [DRh(CO) 4 ], were obtained by investigating solutions of [Rh 4 (CO) 12 ] in n-hexane upon exposure to varying partial pressures of H 2 /CO and D 2 /CO. The in situ high-pressure FTIR spectra were measured and subjected to band-target entropy minimization (BTEM), an advanced signal-processing technique (SVD single-value decomposition). For more information see the following pages. Figure 4. The reconstructed pure-component spectra of the organometallic carbonyl hydrides: a) [HCo(CO) 4 ], b) [HRh(CO) 4 ], c) [DRh(CO) 4 ].OC Rh CO CO H OC Rh CO CO D CO CO Scheme 1. Schematic representation of the trigonal-bipyramidal structures of [HRh(CO) 4 ] and [DRh(CO) 4 ].

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Section: Methodsmentioning

confidence: 99%

Rhodium Tetracarbonyl Hydride: The Elusive Metal Carbonyl Hydride

Widjaja

Chew

et al. 2002

Angew. Chem. Int. Ed.

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“…These results suggest that the catalytically active species is the same for the lower L/ Rh molar ratios but may change at the high L/Rh ratio. It seems likely that the active catalyst in each reaction is a Rh(I) complex of the phosphite ligand, 1, rather than HRh(CO) 4 [35,36] because no hydrogenation of the alkene is observed at any of the L/Rh ratios [37][38][39]. The iso:n ratios are consistent with those expected for styrene, which has preference for the iso aldehyde [40], and are lower than those observed with Chiraphite Ò under the same reaction conditions (iso:n 91:9) [8].…”

Section: Hydroformylation Of Styrene Using Ligandmentioning

confidence: 99%

Synthesis, characterization and coordination chemistry of a new phosphite–ether ligand: The effects of alkali metal salts and the ligand/Rh molar ratio on the catalytic activity and regioselectivity of a Rh(I) complex of this ligand in the hydroformylation of styrene

Kaisare¹,

Owens²,

Valente³

et al. 2010

Journal of Organometallic Chemistry

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“…However, the systematic geometry optimizations resulted in only one energy-minimum structure 1, shown in Figure 2 4 ] Vidal and Walker proposed that the rhodium complex should have a C 3v symmetric structure. [52] Jonas and Thiel could also establish the C 3v form of [HRh(CO) 4 ] as an energy minimum. [53] Using various theoretical methods (HF, MP2, BP86) and two different basis sets, they found geometries very similar to the one shown in Figure 2.…”

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confidence: 99%

[HRh(CO)4]-Catalyzed Hydrogenation of Co: A Systematic Ab Initio Quantum-Chemical Investigation of the Reaction Mechanism

Pidun

Frenking

1998

Chem. Eur. J.

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The mechanism of the [HRh(CO) 4 ]-catalyzed hydrogenation of carbon monoxide has been studied with the help of ab initio quantumchemical calculations at the MP2 level of theory. A quasirelativistic effective core potential was used at rhodium in combination with valence basis sets of double-zeta quality with additional polarization functions. A systematic and unbiased approach has been followed: In the first part of the investigation, for each intermediate of the postulated catalytic mechanism all stable conformations were determined and characterized as minima on the potential energy surface by calculation of the energy Hessian. In the geometry optimizations all theoretically reasonable structures were taken into account (up to 32 starting structures per intermediate) and not just those which fit well into the proposed mechanism. In the second part of the work, the calculated energyminimum structures were integrated into the catalytic mechanism and the transition states for the individual reaction steps were determined and characterized by calculation of the intrinsic reaction coordinate (IRC) connecting them with the corresponding energyminimum structures. In spite of this unbiased approach, a rather simple and very smooth reaction profile for the catalytic mechanism is found, without thermodynamic traps or insurmountable barriers. The first step of the catalysis, the formation of the formyl complex [(HCO)Rh(CO) 3 ] from the starting catalyst [HRh(CO) 4 ], is the rate-determining step of the whole reaction and thus responsible for the requirement of high temperature and pressure. The details of the calculated mechanism help to understand a number of experimental observations and answer several questions discussed in the literature. Furthermore, the presented results might serve as a basis for a rational improvement of the catalyst systems currently in use.

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Rhodium carbonyl cluster chemistry under high pressure of carbon monoxide and hydrogen. 3. Synthesis, characterization, and reactivity of HRh(CO)4

Cited by 75 publications

References 11 publications

Rhodium Tetracarbonyl Hydride: The Elusive Metal Carbonyl Hydride

Rhodium Tetracarbonyl Hydride: The Elusive Metal Carbonyl Hydride

Synthesis, characterization and coordination chemistry of a new phosphite–ether ligand: The effects of alkali metal salts and the ligand/Rh molar ratio on the catalytic activity and regioselectivity of a Rh(I) complex of this ligand in the hydroformylation of styrene

[HRh(CO)4]-Catalyzed Hydrogenation of Co: A Systematic Ab Initio Quantum-Chemical Investigation of the Reaction Mechanism

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