Preparation of nitrones and studies of their intramolecular 1,3-dipolar cycloaddition reactions

1513-1518Nitrones are prepared from different 2-allyloxy-1-benz­aldehydes and intramolecular 1,3-dipolar cycloaddition reaction of these nitrones have been studied in different solvents at their boiling points

<span style="font-size:12.0pt; mso-bidi-font-size:14.0pt;mso-fareast-font-family:"Times New Roman";mso-ansi-language: EN-GB;mso-fareast-language:EN-US;mso-bidi-language:AR-SA;font-weight:normal; mso-bidi-font-weight:bold" lang="EN-GB">Studies of intramolecular nitrone-alkene cyclo­addition reaction: Regio- and diastereo­selective synthesis of chlorinated isoxazolidines</span>

146-152A number of stable nitrones have been prepared. The intramolecular cycloaddition reaction of these nitrones in boiling xylene leading to regio- and diastereoselective formation of chlorinated isoxazolidines in 81-93% yields have been reported

Flexoelectric studies on mixtures of compounds made of rodlike and bent-core molecules

We report measurements of the temperature variations of the flexoelastic ratio (e<SUB>1</SUB>-e<SUB>3</SUB>)/K of octadecyl cyanobiphenyl and a mixture of this compound with another one with bent-core (BC) molecules, using hybrid aligned nematic cells. Addition of 5 mol% of the BC compound doubles the flexoelastic ratio, implying that the BC compound has ~ 20 times larger value compared to that of the compound with calamitic molecules. Mixtures with &gt;11 mol% of the BC compound exhibit only a homeotropic alignment. We develop a simple model to account for this result which arises because of a large positive self-energy due to flexoelectric polarization

Electrochemical conversion of CO2 to fuel by MXenes (M2C): A first principles study

Herein we have made a comprehensive analysis for the conversion of CO2 to fuel (CH4) on two dimensional MXenes (M=Mo, Hf) of the type M2C. Evaluation of parameters like Mulliken charge, adsorption energy, bond angle and bond distance demonstrated that activation is more pronounced with Hf2C compared to Mo2C due to transfer of higher electron density to CO2 in the former than in the latter case. CO2 adsorbed M2C realizes large shift of valance and conduction band vis-a-vis free M2C, leading to substantial charge transfer from MXenes. The enhanced activation of CO2 over Hf2C has been confirmed from the increased splitting of π and π* energy level of CO2 for Hf2C compared to Mo2C. The dense electron localization contour maps further explained the ease of electron transfer to CO2 involving Hf2C. Analysis of Gibbs free energy for successive steps for the conversion of CO2 to CH4 revealed that fuel conversion is more feasible with Hf2C over Mo2C