THE MEASUREMENT OF METAL-LIGAND BOND VIBRATIONS IN ACETYLACETONATE COMPLEXES<sup>1</sup>

Dismukes, John P.; Jones, L. H.; Bailar, John C.

doi:10.1021/j100823a021

Cited by 70 publications

(32 citation statements)

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“…In the past, several attempts, for example, directm ethods, [10][11][12] post-synthesis methods, [13][14][15] pH adjusting methods, [16,17] hydrolysis methods, [18] have been made for the synthesis of H-AlSBA-15 by using various inorganic (silicona nd aluminium)p recursors [18,20] but withoutm uch success.I ndeed, one can graft more aluminium by adopting direct methods [10][11][12] and post-synthesis methods, [13][14][15] nonethelesst hese methodsa lways lead to the formation of undesired extraframework aluminium (weak Lewis acidity) and/or non-framework aluminium (strong Lewisa cidity), which also causep ore blockage. [22][23][24][25] Scheme 1d epicts ag eneral synthesis procedure for H-AlSBA-15 by the intrinsic hydrolysis method. Hence,t oo vercome such problems, in this investigation, we have adopted an innovative approachi nw hich the hydrolysis rates of both silicon and aluminium sources are controlled in such way so as to achieve complete condensation of the inorganic species.…”

Section: Introductionmentioning

confidence: 99%

Acid‐Mediated Synthesis of Ordered Mesoporous Aluminosilicates: The Challenge and the Promise

Krishna

Selvam

2017

Chemistry A European J

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A new intrinsic hydrolysis method was employed, for the first-time, to synthesize well-ordered H-AlSBA-15 with trivalent aluminium exclusively in the tetrahedral framework structure of SBA-15. Unlike other methods, which involve incorporation of aluminium ions in both the framework (Brønsted) and non-framework (Lewis) sites of the silicate matrix, the intrinsic hydrolysis method isomorphously substitutes aluminium ions in the tetrahedral network even at high aluminium content. This unique approach relies mainly on the hydrolysis rates of the inorganic (silicon and aluminium) precursors used for the preparation in such a way that the condensation occurs simultaneously so as to overcome the usually encountered difficulties in stabilizing aluminium ions in the silicate matrix. In this way, we could successfully synthesize high quality Brønsted acidic H-AlSBA-15, hitherto not reported. The synthesized materials were systematically characterized by various analytical, spectroscopic, and imaging techniques, including XRD, Brunauer-Emmett-Teller (BET) surface area measurements, TEM, SEM, Si and Al magic angle spinning NMR spectroscopy, X-ray fluorescence (XRF), and NH temperature-programmed desorption (TPD). The characterization results reveal the presence of a highly porous structure (with narrow pores) and tetrahedrally coordinated trivalent aluminium in the silicate matrix with more medium to strong Brønsted acid sites. The resulting high quality catalysts exhibit excellent activity for tert-butylation of phenol with high selectivity towards para-tert-butyl phenol and 2,4-di-tert-butyl phenol.

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Section: Introductionmentioning

confidence: 99%

Acid‐Mediated Synthesis of Ordered Mesoporous Aluminosilicates: The Challenge and the Promise

Krishna

Selvam

2017

Chemistry A European J

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“…Polymeric complexes of chromium acetylacetonate do not usually exist in the solid state [16] and in organic solutions [17], However, DISMUKES et al [18] obtained a polymeric olated chromium(III) acetylacetonate during the course of the IR study of the metal acetylacetonates. Chemical analysis and molecular weight determination in benzene suggested the molecular formula Cr 4 (OH) 6 (acac) e .…”

Section: Discussionmentioning

confidence: 99%

Kinetic Studies of the Chemical Behavior of^{Cr in Organic Solutions of Neutron-Irradiated Trisacetylacetonatochromium (IIΙ)}

Omori

Shiokawa

1972

Radiochimica Acta

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The reformation reaction of the recoil 51 Cr atoms in the organic solution of the neutron-irradiated trisacetylacetonatochromium(III) was investigated in detail by means of a combination of the solvent extraction and ion-exchange methods, and it was compared with the thermal annealing reaction in the solid phase. The reformation curves of the parent complex in the organic phase are very similar to the annealing isotherms in the solid phase. On the basis of kinetic analysis of the reformation reaction in the organic phase, the existence of polymeric acetylacetonate complexes in the solid phase is suggested. ZusammenfassungDie Rückbildungsreaktion der Rückstoß-51 Cr-Atome in der organischen Lösung von mit Neutronen bestrahltem Triacetylacetonatchrom(III) wurde im Detail mit Hilfe einer Kombination aus Lösungsmittelextraktion und Ionenaustausch untersucht und mit der thermischen Ausheilungsreaktion in der festen Phase verglichen. Die Rückbildungskurven des Ausgangskomplexes in der organischen Phase sind den Ausheilungsisothermen in der festen Phase sehr ähnlich. Auf der Grundlage der kinetischen Analyse der Rückbildungsreaktion in der organischen Phase wird das Vorhandensein von polymeren Acetylacetonatkomplexen in der festen Phase vermutet. RésuméOn a examiné en détail la réaction de recombinaison des atomes de recul de "Cr en solution organique de triacétyl-acétonato-chrome(III) soumise à l'irradiation neutronique. La méthode utilisée combinait l'extraction par solvant et l'échange d'ions. La réaction a été comparée à la réaction thermique de recuit en phase solide. Les courbes de recombinaison du complexe initial en phase organique ressemblent beaucoup aux isothermes de recuit de la phase solide. L'analyse cinétique de la réaction de recombinaison en phase organique permet de proposer l'existence en phase solide de complexes polymères d'acétylacétonate.

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“…In our earlier study [9], bands were observed at 1,571 and 1,526 cm -1 for Ir(acac) x species on alumina, and at 1,557 and 1,526 cm -1 for Ir(acac) x on silica. On alumina, Al(acac) x species were detected at 1,585-1,597 and 1,535 cm -1 [9,17], and bands of pure Ir(acac) 3 at 1,549 and 1,522 cm -1 [9]. No surface species were observed after Hacac treatment of silica.…”

Section: Characterization Of Supported Ir(acac)mentioning

confidence: 94%

“…The number of metal and carbon atoms per nm 2 was calculated from support surface areas and the average elemental contents. The decrease in relative mass of the support after metal deposition is taken into account as described by Puurunen [17]. The acac-toiridium ratios were calculated assuming that all detected carbon is in the form of acac ligands.…”

Section: Catalyst Preparationmentioning

confidence: 99%

“…Associative adsorption of Ir(acac) 3 cannot yet be ruled out as being responsible, at least partly, for the high number of ligands on the surface. The pretreatment of the support affects the number of OH groups on the surface and thereby the potential reaction sites [7,17]. However, the increase of pretreatment temperature from 300 to 500°C is apparently not enough to affect the iridium loading.…”

Section: Ir(acac) 3 Depositionmentioning

confidence: 99%

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Beta Zeolite-Supported Iridium Catalysts by Gas Phase Deposition

et al. 2009

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In this study, H-beta zeolite-supported iridium catalysts were prepared by atomic layer deposition (ALD) and characterized as such and after different activation treatments. A reference catalyst was prepared by wet impregnation. The samples were tested in decalin ring opening reaction. ALD samples were clearly more active and selective in decalin ring opening compared to impregnated sample. The differences observed in characteristics and activities between ALD samples and impregnated sample are discussed.

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THE MEASUREMENT OF METAL-LIGAND BOND VIBRATIONS IN ACETYLACETONATE COMPLEXES¹

Cited by 70 publications

References 0 publications

Acid‐Mediated Synthesis of Ordered Mesoporous Aluminosilicates: The Challenge and the Promise

Acid‐Mediated Synthesis of Ordered Mesoporous Aluminosilicates: The Challenge and the Promise

Kinetic Studies of the Chemical Behavior of^{Cr in Organic Solutions of Neutron-Irradiated Trisacetylacetonatochromium (IIΙ)}

Beta Zeolite-Supported Iridium Catalysts by Gas Phase Deposition

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THE MEASUREMENT OF METAL-LIGAND BOND VIBRATIONS IN ACETYLACETONATE COMPLEXES1

Cited by 70 publications

References 0 publications

Acid‐Mediated Synthesis of Ordered Mesoporous Aluminosilicates: The Challenge and the Promise

Acid‐Mediated Synthesis of Ordered Mesoporous Aluminosilicates: The Challenge and the Promise

Kinetic Studies of the Chemical Behavior ofCr in Organic Solutions of Neutron-Irradiated Trisacetylacetonatochromium (IIΙ)

Beta Zeolite-Supported Iridium Catalysts by Gas Phase Deposition

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THE MEASUREMENT OF METAL-LIGAND BOND VIBRATIONS IN ACETYLACETONATE COMPLEXES¹

Kinetic Studies of the Chemical Behavior of^{Cr in Organic Solutions of Neutron-Irradiated Trisacetylacetonatochromium (IIΙ)}