Search

Your search keyword '"Mandal, Swadhin K."' showing total 465 results
Start Over Author "Mandal, Swadhin K."
465 results on '"Mandal, Swadhin K."'

105. Oxygen-bridged hybrid metallocene-nonmetallocene polymetallic catalysts of group 4 metals for bimodal activity in olefin polymerization: synthesis, characterization and theoretical investigation

Author

Mandal, Swadhin K., Gurubasavaraj, Prabhuodeyara M., Roesky, Herbert W., Schwab, Gerald, Stalke, Dietmar, Oswald, Rainer B., and Dolle, Volker

Subjects
Olefins -- Chemical properties, Catalysis -- Research, Organometallic compounds -- Chemical properties, Polymerization -- Research, Chemistry
Abstract

The syntheses of two covalently linked oxygen-bridged hybrid metallocene-nonmetallocene polymetallic catalysts bearing two different catalytically active group 4 metals are discussed. Findings reveal the sterical accessibility of a cation generated on the titanium center for monomer binding.

Published
2007

106. Synthesis, structural characterization, and theoretical investigation of compounds containing an Al-O-M-O-Al (M = Ti, Zr) core

Author

Mandal, Swadhin K., Gurubasavaraj, Prabhuodeyara M., Roesky, Herbert W., Oswald, Rainer B., Ringe, Arne, and Magull, Jorg

Subjects
Aluminum compounds -- Chemical properties, Aluminum compounds -- Electric properties, Titanium compounds -- Chemical properties, Titanium compounds -- Electric properties, Chemistry
Abstract

The synthesis, characterization, and theoretical investigation of a new class of oxide-bridged trimetallic compounds bearing the Al-O-M-O-Al core (M = Ti, Zr) is reported.

Published
2007

107. Synthesis, structural characterization, catalytic properties, and theoretical study of compounds containing an Al-O-M (M=Ti, Hf) core

Author

Gurubasavaraj, Prabhuodeyara M., Mandal, Swadhin K., Roesky, Herbert W., Oswald, Rainer B., Pal, Aritra, and Noltemeyer, Mathias

Subjects
Aluminum compounds -- Chemical properties, Coordination compounds -- Chemical properties, Electron donor-acceptor complexes -- Research, Chemistry
Abstract

The preparation, structural characteristics sand catalytic properties of two kinetically stable heterobimetallic complexes of Al(III) with Ti and Hf are described. Both the complexes bind through an oxygen bridge and the Ti cation center after activation is stabilized by the donor acceptor interaction.

Published
2007

108. Soluble molecular compounds with the Mg-O-Al structural motif: A model approach for the fixation of organometallics on a MgO surface

Author

Nembenna, Sharanappa, Roesky, Herbert W., Mandal, Swadhin K., Oswald, Rainer B., Pal, Aritra, Herbst-Irmer, Regine, Noltemeyer, Mathias, and Schmidt, Hans-Georg

Subjects
Infrared spectroscopy -- Analysis, Magnesium compounds -- Structure, Magnesium compounds -- Optical properties, Stoichiometry -- Analysis, Chemistry
Abstract

A facile route to the molecular compounds with the Mg-O-Al structural motif is reported. The reaction of Mg[[N[(SiMe3).sub.2])].sub2.] with a stoichiometric amount of LAlOH(Me) [L = CH{(CMe)(2.6-i[Pr.sub.2][C.sub.6][H.sub.3]N)}.sub.2] in THFln-hexane at 0 degrees Celsius results in the elimination of HN[[SiMe3].sub.2] and the formation of a heterobimetallic compound in high yield.

Published
2006

109. New family of aminophenalenyl-based neutral radical molecular conductors: Synthesis, structure, and solid state properties

Author

Mandal, Swadhin K., Itkis, Mikhail E., Xiaoliu, Chi, Samanta, Satyabrata, Lidsky, David, Reed, Robert W., Oakley, Richard T., Tham, Fook S., and Haddon, Robert C.

Subjects
Boron -- Properties, Boron -- Chemical properties, Boron -- Structure, Radicals (Chemistry) -- Properties, Radicals (Chemistry) -- Chemical properties, Radicals (Chemistry) -- Structure, Crystals -- Structure, Crystals -- Research, Chemistry
Abstract

The preparation, crystallization, and solid-state characterization of the first members of a new family of spiro-bis-(1,9-diamino-substituted-phenalenuyly)boron neutral radicals are reported. The crystal structures show that the three radicals are monomeric and without close contacts in the crystal lattice.

Published
2005

113. Development of a facile antibody–drug conjugate platform for increased stability and homogeneity

Author

Gupta, Nimish, primary, Kancharla, Johny, additional, Kaushik, Shelly, additional, Ansari, Aasif, additional, Hossain, Samad, additional, Goyal, Ravinder, additional, Pandey, Manoj, additional, Sivaccumar, Jwala, additional, Hussain, Sazid, additional, Sarkar, Arindam, additional, Sengupta, Aniruddha, additional, Mandal, Swadhin K., additional, Roy, Monideepa, additional, and Sengupta, Shiladitya, additional

Published
2017
Full Text
View/download PDF

119. Abnormal-NHC-Supported Nickel Catalysts for Hydroheteroarylation of Vinylarenes

Author

Vijaykumar, Gonela, Jose, Anex, Vardhanapu, Pavan K., P, Sreejyothi, and Mandal, Swadhin K.

Abstract

Herein we report the hydroheteroarylation of vinylarenes with benzoxazole in the presence of a free abnormal N-heterocyclic carbene and Ni(COD)2, resulting in 1,1-diarylethane products exclusively. In an attempt to understand the mechanism of this catalytic reaction, two abnormal-NHC (aNHC)-coordinated Ni(II) cyclooctenyl complexes were isolated and their solid-state structures were determined by X-ray crystallographic studies. These Ni(II) cyclooctenyl complexes act as active catalyst precursors to generate in situ aNHC-Ni(0) species, which undergo oxidative addition with heteroarene to form Ni(II) hydride intermediates.

Published
2024
Full Text
View/download PDF

131. Metal-Free Reduction of CO2 to Methoxyborane under Ambient Conditions through Borondiformate Formation.

Author

Sau, Samaresh Chandra, Bhattacharjee, Rameswar, Vardhanapu, Pavan K., Vijaykumar, Gonela, Datta, Ayan, and Mandal, Swadhin K.

Subjects
CARBENES, HOMOGENEOUS catalysis, CHEMICAL reduction, CARBON dioxide, BORON
Abstract

An abnormal N-heterocyclic carbene (aNHC) based homogeneous catalyst has been used for the reduction of carbon dioxide to methoxyborane in the presence of a range of hydroboranes under ambient conditions and resulted in the highest turnover number of 6000. A catalytically active reaction intermediate, [aNHC-H⋅9BBN(OCOH)2] was structurally characterized and authenticated by NMR spectroscopy. A detailed mechanistic cycle of this catalytic process via borondiformate formation has been proposed from tandem experimental and computational experiments. [ABSTRACT FROM AUTHOR]

Published
2016
Full Text
View/download PDF

144. Abnormal N-Heterocyclic-Carbene-Mediated Fixation of CO2 and N2O, and the Activation of Tetrahydro­furan and Tetrahydrothiophene under Ambient Conditions.

Author

Thakur, Arunabha, Vardhanapu, Pavan K., Vijaykumar, Gonela, Kumar Hota, Pradip, and Mandal, Swadhin K.

Subjects
CARBON dioxide, NITROUS oxide, CARBENES, ACTIVATION (Chemistry), FURANS, THIOPHENES
Abstract

A strong σ-donor abnormal N-heterocyclic carbene ( aNHC), 1,3-bis(2,6-diisopropylphenyl)-2,4-diphenylimidazol-5-ylidene ( L1), reacted with B(C6F5)3 in the presence of CO2 and N2O to form the adducts [ aNHC ·CO2 ·B(C6F5)3] ( 1) and [ aNHC ·N2O ·B(C6F5)3] ( 2), respectively, in high yields at room temperature within a very short period of time. Furthermore, this aNHC/B(C6F5)3 reagent system was found to be very efficient for the ring-opening of tetrahydrofuran (thf) and tetrahydrothiophene (tht), affording 3 and 4, respectively, within 5-10 min at room temperature in good yields. Interestingly, this aNHC forms the air-stable Lewis acid/base adduct [ aNHC ·B(C6F5)3] ( 5) with B(C6F5)3 in the absence of any suitable substrate upon keeping this mixture in solution. DFT calculations showed that the Lewis acid/base adduct 5 is energetically less stable than compounds 1- 4, and this may be the driving force for the formation of compounds 1- 4 in the presence of small molecules such as CO2, N2O, thf and tht. All the new compounds were characterized spectroscopically (1H, 13C, 19F and 11B NMR, IR spectroscopy) in solution and the solid-state structures were unambiguously established by single-crystal X-ray diffraction analysis. [ABSTRACT FROM AUTHOR]

Published
2016
Full Text
View/download PDF

146. Dehydration of Amides by Redox‐Active Phenalenyl Based Mn‐Catalyst.

Author

Chakraborty, Soumi, Biswas, Amit, and Mandal, Swadhin K.

Subjects
*DEHYDRATION, *AMIDES, *RADICALS (Chemistry), *NITRILES, *CATALYSTS
Abstract

A redox‐active phenalenyl ligand coordinated Mn(III)‐complex can be reduced chemically to generate an active catalyst containing a ligand‐centered radical. This chemically reduced Mn‐catalyst shows excellent catalytic reactivity for silylative dehydration of a wide range of primary amides (including late‐stage diversification of various bio‐active molecules) to synthesize nitriles using an inert and inexpensive silane, polymethylhydrosiloxane (PMHS), under mild conditions. Control experiments suggest a radical pathway for the present catalytic reaction, initiated by the ligand‐centered radical. [ABSTRACT FROM AUTHOR]

Published
2023
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results