New rhodium complexes anchored on silica and modified Y-zeolite as efficient catalysts for hydrogenation of olefins

Sánchez, Félix; Iglesias, Marta; Corma, Avelino; Pino, C. Del

doi:10.1016/0304-5102(91)80132-m

Cited by 35 publications

(16 citation statements)

References 8 publications

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“…252 If the functionalisation of these materials is facilitated by the high concentration of surface silanol groups, the same is not true for zeolites. In fact, Corma et al [253][254][255] reported that the functionalisation of ultrastable Y zeolites with organosilanes (used for anchoring metal complex catalysts) 255 occurs in the mesoporous region. Cauvel et al investigated the functionalisation of a series of Y zeolites with increasing content of mesopores produced by steaming, thus confirming this hypothesis.…”

Section: Hybrid Organic-inorganic Zeolitesmentioning

confidence: 99%

New trends in the synthesis of crystalline microporous materials

Bellussi

Carati

Rizzo

et al. 2013

Catal. Sci. Technol.

110

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Zeolites and related microporous materials form the most important class of microporous solids due to their practical importance in different technological areas. In spite of the extensive research carried out in previous decades, it is surprising to realize that there is still space for innovation in this area, making microporous crystalline solids special among all classes of materials known today. We illustrate here the most recent advances in the field, focusing on the research topics that, in our opinion, are most likely to provide results of practical interest. Three main topics are discussed: (1) the synthesis of new framework topologies, with particular attention to those having extra-large and/or multidimensional pore systems;(2) the modification of the morphological and textural properties of known zeolites, including the discussion on two-dimensional structures and on the synthesis of nanocrystals and of the hierarchical porous structures; (3) the still poorly explored field of silica-based hybrid organic-inorganic porous crystalline materials (hybrid zeolites). For each of these topics, a selection of the most relevant results reported in the literature is provided together with some considerations on the potentialities and future perspectives.

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Section: Hybrid Organic-inorganic Zeolitesmentioning

confidence: 99%

New trends in the synthesis of crystalline microporous materials

Bellussi

Carati

Rizzo

et al. 2013

Catal. Sci. Technol.

110

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“…Rh complexes with the chiral ligand L-prolinamide were prepared by Corma and co-workers and were anchored onto the surface of USY zeolite [61,62]. The heterogenized compounds gave higher ee values than the homogeneous systems; nevertheless, they were less stereoselective than the other Rh complexes eg: [Rh(NBD)(BDPP)] (see paragraph 3.4).…”

Section: Enantioselective Hydrogenations 31 Enantioselective Hydrogmentioning

confidence: 99%

Selective Syntheses on Heterogenized Metal Complexes

Zsigmond

Notheisz

2006

COC

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The preparation and application of heterogenized metal complexes is a relatively new field of research resulting in a new way of catalysis, that we cannot realize either with traditional homogeneous or heterogeneous catalysts. The heterogenized metal complexes can successfully combine the excellent performance (high activity and selectivity) of homogeneous catalysts with the easy separation and recycling of the heterogeneous catalysts. Additionally, in several cases the immobilization of metal complexes leads to enhanced stereo-, chemo-and enantioselectivity, interpreted by a mechanism related to the "confinement concept". This review gives a summary of the different ways of preparation of heterogenized metal complexes on inorganic matrices and shows some applications of such catalysts in synthetic organic chemistry. a) Direct Attachment to the SupportThis can be performed in several different ways: by simple adsorption, ion-pair formation or using an anchoring agent. The easy preparation of these systems is a clear advantage, but their sensitivity to solvent effects is an important drawback.Charges were created on silica via reaction with a silylating agent containing a SO 3 --group. The positively charged Rh(I)-complexes were then ion-exchanged and used in hydrogenations. Leaching could be avoided in toluene and water, but not in methanol [17]. LDHs were used to retain a sulfonated BINAP complex bearing 4 negative charges via

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“…To this end we sought to incorporate well-defined Rh(I) olefin species into 1 due to their potential to carry out solid/gas reactions of commercial interest. Organometallic Rh(I) complexes bearing olefin ligands have been previously isolated on solid supports including alumina, zeolites, − and MOFs . However, their precise structural characterization by SCXRD was not possible because these species lacked long-range order.…”

Section: Introductionmentioning

confidence: 99%

Highly Active Gas Phase Organometallic Catalysis Supported Within Metal–Organic Framework Pores

et al. 2020

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Metal–organic frameworks (MOFs) can act as a platform for the heterogenization of molecular catalysts, providing improved stability, allowing easy catalyst recovery and a route toward structural elucidation of the active catalyst. We have developed a MOF, 1, possessing vacant N,N-chelating sites which are accessible via the porous channels that penetrate the structure. In the present work, cationic rhodium(I) norbornadiene (NBD) and bis(ethylene) (ETH) complexes paired with both noncoordinating and coordinating anions have been incorporated into the N,N-chelation sites of 1 via postsynthetic metalation and facile anion exchange. Exploiting the crystallinity of the host framework, the immobilized Rh(I) complexes were structurally characterized using X-ray crystallography. Ethylene hydrogenation catalysis by 1·[Rh(NBD)]X and 1·[Rh(ETH)2]X (X = Cl and BF4) was studied in the gas phase (2 bar, 46 °C) to reveal that 1·[Rh(ETH)2](BF4) was the most active catalyst (TOF = 64 h–1); the NBD materials and the chloride salt were notably less active. On the basis of these observations, the activity of the Rh(I) bis(ethylene) complexes, 1·[Rh(ETH)2]BF4 and 1·[Rh(ETH)2]Cl, in butene isomerization was also studied using gas-phase NMR spectroscopy. Under one bar of butene at 46 °C, 1·[Rh(ETH)2]BF4 rapidly catalyzes the conversion of 1-butene to 2-butene with a TOF averaging 2000 h–1 over five cycles. Notably, the chloride derivative, 1 [Rh(ETH)2]Cl displays negligible activity in comparison. XPS analysis of the postcatalysis sample, supported by DFT calculations, suggest that the catalytic activity is inhibited by the strong interactions between a Rh(III) allyl hydride intermediate and the chloride anion.

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New rhodium complexes anchored on silica and modified Y-zeolite as efficient catalysts for hydrogenation of olefins

Cited by 35 publications

References 8 publications

New trends in the synthesis of crystalline microporous materials

New trends in the synthesis of crystalline microporous materials

Selective Syntheses on Heterogenized Metal Complexes

Highly Active Gas Phase Organometallic Catalysis Supported Within Metal–Organic Framework Pores

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