I am a faculty in the National Centre for Catalysis Research at the Indian Institute of Technology Madras and had been a faculty in the department of Chemistry at IITM since 1970
Rhodium allenylidenes, which represent a class of ‘flat’ metallabutatrienes, are useful tools for... more Rhodium allenylidenes, which represent a class of ‘flat’ metallabutatrienes, are useful tools for the generation of metal-bound species that are hardly accessible (sometimes not accessible at all) by other synthetic routes. In contrast to various octahedral allenylidene metal complexes, e.g. of Cr 0 , Mn I or Ru II , the square-planar rhodium compounds trans- [RhX(CCCRR′)(PPr i 3 ) 2 ] are attacked by both nucleophiles and electrophiles. Moreover, non-polar substrates such as H 2 or Cl 2 react cleanly with the title complexes to give products in which the allenylidene unit is preserved as part of a newly formed ligand. Attempts to prepare a square-planar cationic metallaheptahexaene, trans-[Rh(CCCRR′) 2 (PP r i 3 ) 2 ] + , unexpectedly led to the formation of two isomeric hexapentaenerhodium(I) complexes of which the isomer having the polyene coordinated in an unsymmetrical fashion is the thermodynamically more stable. C–C coupling reactions also occur on treatment of trans-[RhCl(CCCPh 2 )(PPr i 3 ) 2 ] with vinyl Grignard reagents or phenylacetylene leading to highly unsaturated RhC 5 and RhC 5 P frameworks from which vinylallenes and phosphacumuleneylides are obtained.
Indian journal of chemistry. Sect. A: Inorganic, physical, theoretical & analytical, 2006
The synthesis of tris(2,3-dihydmxynaphthalato)silicatc with different ammonium counter cations ha... more The synthesis of tris(2,3-dihydmxynaphthalato)silicatc with different ammonium counter cations has been achieved both by conventional method and under microwave conditions using tetraelhoxysilane. The compounds have been characterized using elemental analysis, IR, NMR ( 1 H, 13 C and 29 Si), and MALDI-TOF-MS technies. Single crystal X-ray structure of [(n-C 4 H 9 ) 3 NH 2 ][Si(C 10 H 6 O 2 ) 3 ] reveals a distorted octahedral geometry around silicon and only discrete hydrogen bonding interaction between the ion pairs.
The origin of nuclear fission from the point of view of binding energy per nucleon as a function ... more The origin of nuclear fission from the point of view of binding energy per nucleon as a function of the mass number of the atom is brought out. A set of possible nuclear fission reactions is tabulated. The energy distribution in various processes in nuclear fission is outlined. A pictorial representation of nuclear fission is given. Controlled fission and fast breeder reactors are also discussed.
Photocatalytic reduction of carbon dioxide, one of the pathways involved in the carbon dioxide co... more Photocatalytic reduction of carbon dioxide, one of the pathways involved in the carbon dioxide conversion process, has been receiving significant attention from the scientific community in the last four decades. Nevertheless, the mechanism of carbon dioxide reduction is still unclear and the information available is not sufficient for developing it into large scale applications, possibly because of the invariable hurdles associated with the reduction process. The reductive photocatalytic conversion of CO2 involves all the redox reactions occurring at the interface of the semiconductor such as water splitting, hydrogen evolution, oxygen evolution, photo-oxidation reactions and reactions of radical intermediates. The overall product yield is highly dependent on the extent of these competing reactions. Herein, we discuss our perceptions and current status of the interface reactions and their involvement in the fundamental mechanistic aspects of the photocatalytic conversion of CO2.
The technology of carbon dioxide capture is outlined. The possibility of storage of carbon dioxid... more The technology of carbon dioxide capture is outlined. The possibility of storage of carbon dioxide in various media like amines, zeolites, and metal organic frameworks is discussed. Further storage in geological systems, ocean and by mineral carbonation is also considered. The perspectives with regard to carbon dioxide capture and storage are briefly considered.
XRD, EDXA & XPS studies reveal incorporation of N, S & Fe in Sr3Ti2O7 matrix. Doping promotes vis... more XRD, EDXA & XPS studies reveal incorporation of N, S & Fe in Sr3Ti2O7 matrix. Doping promotes visible light activity, Fe is the most effective dopant in reducing band gap and recombination Co-doping N, S & Fe together leads to maximum photo reduction activity.
The search and exploitation of selective new catalytic material based on abundant materials in ea... more The search and exploitation of selective new catalytic material based on abundant materials in earth have been always interesting and also challenging. Hydrotalcites both natural and synthetic ones have been extensively examined in recent times as catalytic-materials for a variety of organic transformations. In all these reactions reported in literature, hydrotalcites have been precursors and active phases mostly resemble the conventional mixed oxides though they exhibit totally different catalytic property in terms of the Turn Over Number (TON) and also selectivity. Some of these catalysts derived from hydrotalcites promote typical base-catalyzed reactions. These systems also exhibit both acid and base sites adjacent to each other and thus responsible for the observed unusual selectivity.
Mesoporous carbon nitrides (MCNs) with large surface areas and tuneable pore diameters are unique... more Mesoporous carbon nitrides (MCNs) with large surface areas and tuneable pore diameters are unique semiconducting materials and exhibit excellent physicochemical properties, which promote their application in diverse fields including photocatalysis, sensing, and energy storage and conversion.
Correction for 'Mesoporous carbon nitrides: synthesis, functionalization, and applications... more Correction for 'Mesoporous carbon nitrides: synthesis, functionalization, and applications' by Kripal S. Lakhi et al., Chem. Soc. Rev., 2017, DOI: .
Rhodium allenylidenes, which represent a class of ‘flat’ metallabutatrienes, are useful tools for... more Rhodium allenylidenes, which represent a class of ‘flat’ metallabutatrienes, are useful tools for the generation of metal-bound species that are hardly accessible (sometimes not accessible at all) by other synthetic routes. In contrast to various octahedral allenylidene metal complexes, e.g. of Cr 0 , Mn I or Ru II , the square-planar rhodium compounds trans- [RhX(CCCRR′)(PPr i 3 ) 2 ] are attacked by both nucleophiles and electrophiles. Moreover, non-polar substrates such as H 2 or Cl 2 react cleanly with the title complexes to give products in which the allenylidene unit is preserved as part of a newly formed ligand. Attempts to prepare a square-planar cationic metallaheptahexaene, trans-[Rh(CCCRR′) 2 (PP r i 3 ) 2 ] + , unexpectedly led to the formation of two isomeric hexapentaenerhodium(I) complexes of which the isomer having the polyene coordinated in an unsymmetrical fashion is the thermodynamically more stable. C–C coupling reactions also occur on treatment of trans-[RhCl(CCCPh 2 )(PPr i 3 ) 2 ] with vinyl Grignard reagents or phenylacetylene leading to highly unsaturated RhC 5 and RhC 5 P frameworks from which vinylallenes and phosphacumuleneylides are obtained.
Indian journal of chemistry. Sect. A: Inorganic, physical, theoretical & analytical, 2006
The synthesis of tris(2,3-dihydmxynaphthalato)silicatc with different ammonium counter cations ha... more The synthesis of tris(2,3-dihydmxynaphthalato)silicatc with different ammonium counter cations has been achieved both by conventional method and under microwave conditions using tetraelhoxysilane. The compounds have been characterized using elemental analysis, IR, NMR ( 1 H, 13 C and 29 Si), and MALDI-TOF-MS technies. Single crystal X-ray structure of [(n-C 4 H 9 ) 3 NH 2 ][Si(C 10 H 6 O 2 ) 3 ] reveals a distorted octahedral geometry around silicon and only discrete hydrogen bonding interaction between the ion pairs.
The origin of nuclear fission from the point of view of binding energy per nucleon as a function ... more The origin of nuclear fission from the point of view of binding energy per nucleon as a function of the mass number of the atom is brought out. A set of possible nuclear fission reactions is tabulated. The energy distribution in various processes in nuclear fission is outlined. A pictorial representation of nuclear fission is given. Controlled fission and fast breeder reactors are also discussed.
Photocatalytic reduction of carbon dioxide, one of the pathways involved in the carbon dioxide co... more Photocatalytic reduction of carbon dioxide, one of the pathways involved in the carbon dioxide conversion process, has been receiving significant attention from the scientific community in the last four decades. Nevertheless, the mechanism of carbon dioxide reduction is still unclear and the information available is not sufficient for developing it into large scale applications, possibly because of the invariable hurdles associated with the reduction process. The reductive photocatalytic conversion of CO2 involves all the redox reactions occurring at the interface of the semiconductor such as water splitting, hydrogen evolution, oxygen evolution, photo-oxidation reactions and reactions of radical intermediates. The overall product yield is highly dependent on the extent of these competing reactions. Herein, we discuss our perceptions and current status of the interface reactions and their involvement in the fundamental mechanistic aspects of the photocatalytic conversion of CO2.
The technology of carbon dioxide capture is outlined. The possibility of storage of carbon dioxid... more The technology of carbon dioxide capture is outlined. The possibility of storage of carbon dioxide in various media like amines, zeolites, and metal organic frameworks is discussed. Further storage in geological systems, ocean and by mineral carbonation is also considered. The perspectives with regard to carbon dioxide capture and storage are briefly considered.
XRD, EDXA & XPS studies reveal incorporation of N, S & Fe in Sr3Ti2O7 matrix. Doping promotes vis... more XRD, EDXA & XPS studies reveal incorporation of N, S & Fe in Sr3Ti2O7 matrix. Doping promotes visible light activity, Fe is the most effective dopant in reducing band gap and recombination Co-doping N, S & Fe together leads to maximum photo reduction activity.
The search and exploitation of selective new catalytic material based on abundant materials in ea... more The search and exploitation of selective new catalytic material based on abundant materials in earth have been always interesting and also challenging. Hydrotalcites both natural and synthetic ones have been extensively examined in recent times as catalytic-materials for a variety of organic transformations. In all these reactions reported in literature, hydrotalcites have been precursors and active phases mostly resemble the conventional mixed oxides though they exhibit totally different catalytic property in terms of the Turn Over Number (TON) and also selectivity. Some of these catalysts derived from hydrotalcites promote typical base-catalyzed reactions. These systems also exhibit both acid and base sites adjacent to each other and thus responsible for the observed unusual selectivity.
Mesoporous carbon nitrides (MCNs) with large surface areas and tuneable pore diameters are unique... more Mesoporous carbon nitrides (MCNs) with large surface areas and tuneable pore diameters are unique semiconducting materials and exhibit excellent physicochemical properties, which promote their application in diverse fields including photocatalysis, sensing, and energy storage and conversion.
Correction for 'Mesoporous carbon nitrides: synthesis, functionalization, and applications... more Correction for 'Mesoporous carbon nitrides: synthesis, functionalization, and applications' by Kripal S. Lakhi et al., Chem. Soc. Rev., 2017, DOI: .
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