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273 results on '"Bansal, Raj K."'

5. Organic Donor‐Acceptor Complexes As Potential Semiconducting Materials.

Author

Mathur, Chandani, Gupta, Raakhi, and Bansal, Raj K.

Subjects
SEMICONDUCTORS, MALEIC anhydride, POLYCYCLIC aromatic hydrocarbons, VIOLOGENS, TETRACYANOQUINODIMETHANE
Abstract

In this review article, the synthesis, characterization and physico‐chemical properties of the organic donor‐acceptor complexes are highlighted and a special emphasis has been placed on developing them as semiconducting materials. The electron‐rich molecules, i. e., donors have been broadly grouped in three categories, namely polycyclic aromatic hydrocarbons, nitrogen heterocycles and sulphur containing aromatic donors. The reactions of these classes of the donors with the acceptors, namely tetracyanoquinodimethane (TCNQ), tetracyanoethylene (TCNE), tetracyanobenzene (TCNB), benzoquinone, pyromellitic dianhydride and pyromellitic diimides, fullerenes, phenazine, benzothiadiazole, naphthalimide, DMAD, maleic anhydride, viologens and naphthalene diimide are described. The potential applications of the resulting DA complexes for physico‐electronic purposes are also included. The theoretical investigation of many of these products with a view to rationalise their observed physico‐chemical properties is also discussed. [ABSTRACT FROM AUTHOR]

Published
2024
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19. Diels-Alder reaction of phosphaethene with 1,3-dienes: an ab initio study

Author

Wannere, Chaitanya S., Bansal, Raj K., and Schleyer, Paul von Rague

Subjects
Diels-Alder reaction -- Analysis, Density functionals -- Usage, Butadiene -- Physiological aspects, Phosphorus compounds, Biological sciences, Chemistry
Abstract

Research has been conducted on Diels-Alder reactions of phosphaethene with isoprene and 1,3-butadiene. Reaction results have revealed asynchronous transition structures and that the DFT activation energies of these reactions are low.

Published
2002

23. Increased expression of nitric oxide synthase in the myometrium of the pregnant rat uterus

Author

Riemer, R. Kirk, Buscher, Cori, Bansal, Raj K., Black, Stephen M., He, Youping, and Natuzzi, Eileen S.

Subjects
Pregnancy -- Physiological aspects, Nitric oxide -- Physiological aspects, Immunohistochemistry -- Research, Biological sciences
Abstract

The effects of pregnancy and early gestation on the expression of the inducible nitric oxide synthase (iNOS) was analyzed via NOS immunohistochemistry in pregnant rats. Immunohistochemical analysis of iNOS expression in rats indicated the presence of high levels of NOS in the myometrium and decidua of the pregnant rat uterus. Furthermore, pregnancy and early gestation increased the expression of iNOS messenger RNA and proteins compared to the nonpregnant state.

Published
1997

32. A Textbook of Organic Chemistry

Author

Bansal, Raj K. and Bansal, Raj K.

Subjects
Chemistry, Organic
Abstract

This book covers nearly all topics in Organic Chemistry taught upto the B.Sc. level. Topics like resonance, H-bond, hybridization, IUPAC nomenclature, acid-base theory of organic compounds, stereochemistry, structure reactivity relationship and spectroscopy have been introduced early in the book. Subsequent chapters deal with synthetic polymers, aliphatic and aromatic hydrocarbons, alcohols and phenols, ethers, aldehydes, carboxylic acids and their derivatives, amines, carbohydrates, organometallics and terpenes. These topics have been discussed in-depth and in a comprehensive manner. A great deal of attention has been focussed on chemical reactions and their mechanisms. The scope and limitations of the reactions have been stated. Certain topics of general interest namely C.N.G., L.P.G., simple drugs, DNA finger printing, PUFA, trans fatty acids, soaps and detergents, pesticides, industrial alcohols, coal tar, octane number, chromatography, and artificial sweeteners have been highlighted at appropriate places. Also included are approximately 900 in-text and end-of-the-chapter problems, and a set of Multiple Choice Questions (MCQ) at the end of each chapter. A glossary of important terms is also included. This book has been designed as a comprehensive textbook for students upto B.Sc. level. In addition, the book will be immensely useful for those preparing for competitive examinations like I.I.T., AIEEE, medical entrance and others.

Published
2016

39. Effect of CR1R2/P+R1R2 Exchange on the Degenerate Cope Rearrangement of Barbaralane

Author

Minita Ojha, Maheshwari, Pooja, Gurjar, Asha, and Bansal, Raj K.

Abstract

ABSTARCTTheoretical calculations of the degenerate Cope rearrangement at the DFT (B3LYP/6–31+G*) level reveal that CR1R2/P+R1R2 exchange in barbaralanes results in raising the activation enthalpies by 2.5–4.8 kcal mol−1. Substitution at the 2- and 6-positions by the -C≡N groups brings down the activation enthalpies by 3.5–4.2 kcal mol−1, whereas substitution at these positions by the –CF3 groups raises the activation barriers by ca. 1.8 kcal mol−1. Methylene chloride as solvent does not affect the activation enthalpies. The NICS values and the 1H NMR chemical shifts as well as the bond distances in the transition structures of the Cope rearrangement of 9-substituted barbaralanes and their 9-phospha-analogues confirm their aromatic character. The Natural Bond Orbital (NBO) analysis reveals the existence of conjugative and hyperconjugative interactions in these molecules, which become much stronger in the respective transition structures in the –CN substituted derivatives, but are much weaker in the -CF3 substituted derivatives. Extensive delocalization of 6 electrons resulting from conjugative and hyperconjugative interactions combined with the fast degenerate Cope rearrangement confer bishomoaromatic character on these molecules.

Published
2015
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40. Synthesis of a variety of organophosphorus compounds using 2-phosphaindolizines as precursors.

Author

Sharma, Nivedita and Bansal, Raj K.

Subjects
*ELECTROPHILIC substitution reactions, *DIELS-Alder reaction, *HYDROGEN sulfide, *METAL carbonyls, *ORGANOPHOSPHORUS compounds
Abstract

1,3-Azaphospholo[1,5-a]pyridines named as 2-phosphaindolizines were obtained from [4+1] cyclocondensation and 1,5-electrocyclization methods. These compounds incorporate several reactive functionalities and undergo electrophilic substitution, Diels-Alder reaction and 1,2-addition with hydrogen sulfide and sulfur across the >C=P– functionality and form η1-P coordination compounds with metal carbonyls. Thus, 2-phosphaindolizines could be used as precursors for accessing a variety of organophosphorus compounds. [ABSTRACT FROM AUTHOR]

Published
2019
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42. Diels-Alder reaction with the >C=P– functionality of annelated 1,3-azaphospholes

Author

Maheshwari, Pooja and Bansal, Raj K.

Subjects
regioselectivity, annelated 1,3-azaphospholes, Diels-Alder reaction, stereoselectivity, DFT calculations, annelated 1,4,2-diazaphospholes
Abstract

Department of Chemistry, The IIS University, Jaipur-302 020, Rajasthan, India E-mail : rk.bansal@iisuniv.ac.in Manuscript received 25 January 2014, accepted 15 February 2014 The Diels-Alder reactions of the >C=P– functionality in annelated 1,3-azaphospholes and their diaza-analogues have been reviewed. The article includes experimental and theoretical results accomplished in the author’s (RKB) laboratories.

Published
2014
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46. Pyridinium dichlorophosphinomethylides and 2-phosphaindolizines

Author

Sharma, Anupama, Neelima Gupta, and Bansal, Raj K.

Subjects
2-Phosphaindolizine, pyridinium dichlorophosphinomethylide, 1,5-electrocyclization, 31P NMR
Abstract

Department of Chemistry, University of Rajasthan, Jaipur-302 004, Rajasthan, India E-mail : bansal56@gmail.com Manuscript received 29 December 2010, revised 20 March 2012, accepted 07 June 2012 New 2-phosphaindolizines have been prepared and characterized. The formation of six new pyridinium dichlorophosphinomethylides was detected by 31P NMR spectroscopy. Six pyridinium salts were prepared and characterized spectroscopically.

Published
2013
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