Catalytic ring-attachment isomerization and dealkylation of diethylbenzenes over halide clusters of group 5 and group 6 transition metals

Kamiguchi, Satoshi

doi:10.1016/j.jcat.2004.01.009

Cited by 27 publications

(3 citation statements)

References 47 publications

(51 reference statements)

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“…(15)) [177] Much literature has appeared on the catalytic ring-attachment isomerization of o-and m-xylenes and the catalytic intermolecular transalkylation (disproportionation) of toluene to produce p-xylene [90,178,179], which is used in its oxidation to form terephthalic acid. Mordenite and ZSM-5 are currently the best catalysts for those catalytic reactions [180][181][182].…”

Section: Methodsmentioning

confidence: 99%

Catalytic Reactions over Halide Cluster Complexes of Group 5–7 Metals

Nagashima

Kamiguchi

Chihara

2014

Metals

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Halide clusters of Group 5-7 metals develop catalytic activity above 150-250 °C, and the activity is retained up to 350-450 °C by taking advantage of their thermal stability, low vapor pressure, and high melting point. Two types of active site function: the solid Brønsted acid site and a coordinatively unsaturated site that catalyzes like the platinum metals do. Various types of catalytic reactions including new reactions and concerted catalyses have been observed over the clusters: hydrogenation, dehydrogenation, hydrogenolysis, isomerization of alkene and alkyne, and alkylation of toluene, amine, phenol, and thiol. Ring-closure reactions to afford quinoline, benzofuran, indene, and heterocyclic common rings are also catalyzed. Beckmann rearrangement, S-acylation of thiol, and dehydrohalogenation are also catalyzed. Although the majority of the reactions proceed over conventional catalysts, closer inspection shows some conspicuous features, particularly in terms of selectivity. Halide cluster catalysts are characterized by some aspects: cluster counter anion is too large to abstract counter cation from the protonated reactants, cluster catalyst is not poisoned by halogen and sulfur atoms. Among others, cluster catalysts are stable at high temperatures up to 350-450 °C. At high temperatures, apparent activation energy decreases, and hence weak acid can be a catalyst without decomposing reactants. OPEN ACCESSMetals 2014, 4 236

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Section: Methodsmentioning

confidence: 99%

Catalytic Reactions over Halide Cluster Complexes of Group 5–7 Metals

Nagashima

Kamiguchi

Chihara

2014

Metals

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“…15,17,18 Molybdenum based nanoclusters consist of octahedral Mo 6 units bearing eight face bridging inner halides and six terminal halides in the apical positions. 19 These apical halides are labile and can be readily exchanged to other ligands to significantly improve the photochemical properties and make them attractive candidates for applications in catalysis, 20,21 radiochemistry, 22 sensors, 23 intercalation chemistry, 24 and solar concentrators. 25 In addition, switching the inner halides from chloride to iodide has also led to improvement in the photoluminescence properties of these nanoclusters.…”

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confidence: 99%

Enhanced Electroluminescence Efficiency in Metal Halide Nanocluster Based Light Emitting Diodes through Apical Halide Exchange

Kuttipillai

Yang

Chen

et al. 2018

ACS Appl. Energy Mater.

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Metal halide nanoclusters represent an attractive class of molecular building blocks for the design of functional materials with superior optical properties that can be utilized in a range of applications. Here, we demonstrate red and near-infrared light emitting diodes with a maximum external quantum efficiency >1%, utilizing phosphorescent octahedral molybdenum iodide nanoclusters. Efficiency improvement in these devices is realized by substituting heavier ligands in the apical nanocluster position that lead to the improvement in photoluminescence and exciton formation efficiencies in the nanoclusters. These results highlight how modulation of nanocluster salts with key terminal ligands has a profound effect on photoluminescence as well as electrical injection.

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“…The table lists the number of routes via a given product Schematic of the reaction route. Sources: 1.1,75 1.2,75 1.3,76 2.1,77 2.2,78 3.1,79 3.2,80 4,81 5. 82 Scheme 2 A set of balanced equations used in the case study.…”

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confidence: 99%