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J. C. Kuriacose

Bio: J. C. Kuriacose is an academic researcher from Indian Institute of Technology Madras. The author has contributed to research in topic(s): Catalysis & Flash photolysis. The author has an hindex of 9, co-authored 34 publication(s) receiving 248 citation(s).
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Journal ArticleDOI
Abstract: Transfer hydrogenation of ketones to alcohols using iron carbonyls as catalysts in liquid-liquid phase occurs in the presence of phase transfer catalysts (PTC). Based on the percentage yield of the products, the efficiencies of the phase transfer agent, iron carbonyls and the donors are compared. Benzyltriethylammonium chloride and 18-crown-6 are equally effective and better than tricaprylmethylammonium chloride (Aliquat® 336). Among the three iron carbonyls the order of efficiency is Fe3(CO)12 > Fe2(CO)9 > Fe(CO)5. 1-Phenylethanol is a better donor than isopropanol. The relative ease of reducibility of various ketones increases with increasing reduction potential. The stereochemistry of reduction of 4-t-butylcyclohexanone is discussed.

33 citations


Journal ArticleDOI
Abstract: The in situ deposition of Pt and Ir on CdS during the photocatalytic decomposition of aqueous sulfide results in the formation of an effective bifunctional photocatalyst (MS/CdS/M, where MS is Pt or Ir sulfide and M is Pt or Ir) which is more active than CdS and metallized CdS. In situ metallization provides a convenient method for the preparation of metal- and metal-sulfide-deposited CdS. The order of reactivity for the in situ metallization of CdS in the case of the photocatalytic decomposition of aqueous sulfide is Rh > Pt > Ru = Ir > Co ≃ Ni ≃ Fe. Based on the observed results a mechanism for the photocatalytic decomposition of aqueous sulfide is proposed.

31 citations


Journal ArticleDOI
Abstract: Carbonate radicals react with aliphatic amines by a dual mechanism, viz. (i) hydrogen abstraction and (ii) electron transfer. The former is more probable with primary amines. Tertiary amines react via electron transfer. Both mechanisms may operate in secondary amines. Cyclic tertiary amines react with different rates and their relative reactivities are explained on the basis of the concept of Hoffmann's ‘through bond’ interaction.

25 citations


Journal ArticleDOI
K. Vijayasri1, J. Rajaram1, J. C. Kuriacose1Institutions (1)
Abstract: A catalytic amount of RuCl3 in the presence of excess of N-methyl-morpholine N-oxide (NMO) in DMF oxidizes secondary alcohols to ketones. Spectral studies reveal the formation of a Ru(V)-oxo species which is formed in situ on adding N-oxide. The formation of Ru(V) has been established by cyclic voltammetric studies. The mechanism involves the formation of Ru(V)-oxo species in steady state concentrations from Ru(III) and NMO, and this in turn reacts with the substrate in the rate-determining step.

22 citations


Journal ArticleDOI
Abstract: Glucose is transfer hydrogenated by propan-2-ol, butan-2-ol, cyclohexanol, benzyl alcohol, 1-phenylethanol, benzhydrol, 2-methoxyethanol and tetrahydrofurfuryl alcohol in the presence of RuCl2(PPh3)3 at 100 °C and atmospheric pressure. Mixed solvent systems such as dimethylacetamide-water and dioxane-water are utilized for this reaction. The major product from glucose is sorbitol, although glucono-1,5-lactone is invariably formed as a side product from a disproportionation reaction. When 2-methoxyethanol and tetrahydrofurfuryl alcohol are used as hydrogen donors, the catalyst undergoes permanent change to a hydridocarbonyl complex, which catalyzes only disproportionation of glucose. Glucose also acts as a good hydrogen donor when hydrogen acceptors such as cyclohexanone are introduced into the reaction system.

15 citations


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Journal ArticleDOI
Frank E. Osterloh1Institutions (1)
Abstract: Photochemical splitting of water into H2 and O2 using solar energy is a process of great economic and environmental interest. Since the discovery of the first water splitting system based on TiO2 and Pt in 1972 by Fujishima and Honda, over 130 inorganic materials have been discovered as catalysts for this reaction. This review discusses the known inorganic catalysts with a focus on structure–activity relationships.

1,874 citations


Journal ArticleDOI
TL;DR: Past and present developments in hydrogenolysis reactions are highlighted, with special emphasis on the direct utilization of cellulosic feedstocks, to bridge currently available technologies and future biomass-based refinery concepts.
Abstract: In view of the diminishing oil resources and the ongoing climate change, the use of efficient and environmentally benign technologies for the utilization of renewable resources has become indispensible. Therein, hydrogenolysis reactions offer a promising possibility for future biorefinery concepts. These reactions result in the cleavage of C-C and C-O bonds by hydrogen and allow direct access to valuable platform chemicals already integrated in today's value chains. Thus, hydrogenolysis bears the potential to bridge currently available technologies and future biomass-based refinery concepts. This Review highlights past and present developments in this field, with special emphasis on the direct utilization of cellulosic feedstocks.

645 citations


Journal ArticleDOI
Abstract: Although the use of CO as a reductant had been in the past confined to few reactions, its use in organic synthesis, especially in the reductive carbonylation of nitro aromatics and the oxidative carbonylation of aromatic amines, has increased dramatically. Since the discovery of CO-induced reduction of nitro groups, there has been a wide spread increase of interest in the application and mechanistic understanding of this reaction. In a major review published in 1988 it was noted, that in practice no studies of the mechanism of N-carbonylation of aromatic nitro compounds with alcohols leading to carbamates have been carried out. This review clearly shows a major change since that publication. Indeed, metal-catalyzed reductive carbonylation of nitro aromatics using CO as reducing agent has been in the past 10 years the subject of intense investigation both in academia and in the chemical industry. Several articles and reviews have covered the subject up to the late 1980s. The authors will concentrate on more recent literature, but sometimes older data will be used to establish an understanding of these reactions. 127 refs.

557 citations


Journal ArticleDOI
TL;DR: A framework for this hypothesis is provided and the potential sources and properties of these radicals that are likely to become increasingly recognized as important mediators of biological processes are discussed.
Abstract: Nitrogen dioxide and carbonate radical anion have received sporadic attention thus far from biological investigators. However, accumulating data on the biochemical reactions of nitric oxide and its derived oxidants suggest that these radicals may play a role in various pathophysiological processes. These potential roles are also indicated by recent studies on the high efficiency of urate and nitroxides in protecting cells and whole animals against the injury associated with conditions of excessive nitric oxide production. The high protective effects of these antioxidants are incompletely defined at the mechanistic level but some of them can be explained by their efficiency in scavenging peroxynitrite-derived radicals, particularly nitrogen dioxide and carbonate radical anion. In this review, we provide a framework for this hypothesis and discuss the potential sources and properties of these radicals that are likely to become increasingly recognized as important mediators of biological processes.

449 citations


Journal ArticleDOI
Kasper Wenderich1, Guido Mul1Institutions (1)
TL;DR: For a variety of metals and semiconductors, an attempt is made to generalize observations in the literature on the effect of process conditions applied during photodeposition on (i) particle size distributions, (ii) oxidation states of the metals obtained, and (iii) consequences for photocatalytic activities.
Abstract: In this review, for a variety of metals and semiconductors, an attempt is made to generalize observations in the literature on the effect of process conditions applied during photodeposition on (i) particle size distributions, (ii) oxidation states of the metals obtained, and (iii) consequences for photocatalytic activities. Process parameters include presence or absence of (organic) sacrificial agents, applied pH, presence or absence of an air/inert atmosphere, metal precursor type and concentration, and temperature. Most intensively reviewed are studies concerning (i) TiO2; (ii) ZnO, focusing on Ag deposition; (iii) WO3, with a strong emphasis on the photodeposition of Pt; and (iv) CdS, again with a focus on deposition of Pt. Furthermore, a detailed overview is given of achievements in structure-directed photodeposition, which could ultimately be employed to obtain highly effective photocatalytic materials. Finally, we provide suggestions for improvements in description of the photodeposition methods applied when included in scientific papers.

446 citations


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Performance
Metrics

Author's H-index: 9

No. of papers from the Author in previous years
YearPapers
19951
19932
19921
19911
19903
19895