scholarly journals Computational insights into the Multi-Diels-Alder reactions of neutral C60 and its Li+ encapsulated analogue: A DFT study

2021 ◽  
Author(s):  
Tamalika Ash ◽  
Soumadip Banerjee ◽  
Tanay Debnath ◽  
Abhijit Das
Keyword(s):  
Density Functional ◽  
Positive Impact ◽  
Cycloaddition Reaction ◽  
Diels Alder ◽  
Functional Theory ◽  
Long Run ◽  
Encounter Complex ◽  
Adjacent Position ◽  
High Degree ◽  
Derivatives Of

Diels-Alder cycloaddition reaction is helpful to produce covalent derivatives of fullerene with desirable electronic and physical properties. In the present venture, we have computationally investigated the reactivity of neutral C and its Li encapsulated derivative towards Multi-Diels-Alder (MDA) reaction with 1,3-butadiene, employing density functional theory (DFT). The computational reports available to date illustrate the functionalization of fullerene surfaces of neutral and encapsulated C (Ca and Sm) with two butadiene molecules. In this article, we aim to investigate whether more than two butadiene molecules can be attached to the fullerene surface or not. To do so, we have shown that the MDA reaction initiates with the formation of an encounter complex between the mono-functionalized fullerene product and the second butadiene molecule. In this context, two different approaches, namely ‘Direct’ and ‘Alternative’ have been considered based on the attachment of the second butadiene, i.e., whether it is attached to the opposite or adjacent position of the first functionalization, which eventually produces the same final product. We have explored the MDA reactions by considering a total of four diene molecules that can be embedded successfully on the fullerene surface, with each reaction step having a high degree of exothermicity, thus making the overall reaction thermodynamically facile. In harmony with the mono- and bis-cycloaddition reactions, for MDA reaction also, the positive impact of Li encapsulation for enhancing the reactivity of fullerene surface towards butadiene attachment is evident from our study. On-the-fly calculations also suggest the bond preference for [6, 6] connectivity than its [6, 5] counterpart, to be the suitable dienophile, just like the mono- and bis-functionalization reported earlier. Overall, the present study will foresee an extensive idea about the detailed mechanism of the MDA reaction on neutral C and Li@C that could encourage the scientists to perform the aforementioned reaction for other fullerene derivatives in the long run.

scholarly journals Alloying effect on the order–disorder transformation in tetragonal FeNi

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Li-Yun Tian ◽  
Oliver Gutfleisch ◽  
Olle Eriksson ◽  
Levente Vitos
Keyword(s):  
Transition Temperature ◽  
High Performance ◽  
Density Functional ◽  
Permanent Magnets ◽  
Positive Impact ◽  
Design Strategies ◽  
Alloying Effect ◽  
Functional Theory ◽  
Disorder Transition ◽  
Disorder Transition Temperature

AbstractTetragonal ($${\hbox{L1}}_{0}$$ L1 0 ) FeNi is a promising material for high-performance rare-earth-free permanent magnets. Pure tetragonal FeNi is very difficult to synthesize due to its low chemical order–disorder transition temperature ($$\approx {593}$$ ≈ 593  K), and thus one must consider alternative non-equilibrium processing routes and alloy design strategies that make the formation of tetragonal FeNi feasible. In this paper, we investigate by density functional theory as implemented in the exact muffin-tin orbitals method whether alloying FeNi with a suitable element can have a positive impact on the phase formation and ordering properties while largely maintaining its attractive intrinsic magnetic properties. We find that small amount of non-magnetic (Al and Ti) or magnetic (Cr and Co) elements increase the order–disorder transition temperature. Adding Mo to the Co-doped system further enhances the ordering temperature while the Curie temperature is decreased only by a few degrees. Our results show that alloying is a viable route to stabilizing the ordered tetragonal phase of FeNi.

scholarly journals DFT Studies of Graphene-Functionalised Derivatives of Capecitabine

2017 ◽  
Vol 72 (12) ◽  
pp. 1131-1138 ◽  
Author(s):  
Mehdi Aramideh ◽  
Mahmoud Mirzaei ◽  
Ghadamali Khodarahmi ◽  
Oğuz Gülseren
Keyword(s):  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Atomic Scale ◽  
Phase System ◽  
Molecular Models ◽  
Functional Theory ◽  
Atomic Properties ◽  
Scale Properties ◽  
Derivatives Of

AbstractCancer is one of the major problems for so many people around the world; therefore, dedicating efforts to explore efficient therapeutic methodologies is very important for researchers of life sciences. In this case, nanostructures are expected to be carriers of medicinal compounds for targeted drug design and delivery purposes. Within this work, the graphene (Gr)-functionalised derivatives of capecitabine (CAP), as a representative anticancer, have been studied based on density functional theory calculations. Two different sizes of Gr molecular models have been used for the functionalisation of CAP counterparts, CAP-Gr3 and CAP-Gr5, to explore the effects of Gr-functionalisation on the original properties of CAP. All singular and functionalised molecular models have been optimised and the molecular and atomic scale properties have been evaluated for the optimised structures. Higher formation favourability has been obtained for CAP-Gr5 in comparison with CAP-Gr3 and better structural stability has been obtained in the water-solvated system than the isolated gas-phase system for all models. The CAP-Gr5 model could play a better role of electron transferring in comparison with the CAP-Gr3 model. As a concluding remark, the molecular properties of CAP changed from singular to functionalised models whereas the atomic properties remained almost unchanged, which is expected for a carrier not to use significant perturbations to the original properties of the carried counterpart.

scholarly journals Aqueous Diels–Alder reactions for thermochemical storage and heat transfer fluids identified using density functional theory

2020 ◽  
Vol 41 (24) ◽  
pp. 2137-2150
Author(s):  
Evan Walter Clark Spotte‐Smith ◽  
Peiyuan Yu ◽  
Samuel M. Blau ◽  
Ravi S. Prasher ◽  
Anubhav Jain
Keyword(s):  
Heat Transfer ◽  
Density Functional Theory ◽  
Density Functional ◽  
Diels Alder ◽  
Functional Theory ◽  
Heat Transfer Fluids

scholarly journals DFT Visualization and Experimental Evidence of BHT-Mg-Catalyzed Copolymerization of Lactides, Lactones and Ethylene Phosphates

Polymers ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 1641 ◽  
Author(s):  
Ilya Nifant’ev ◽  
Andrey Shlyakhtin ◽  
Maxim Kosarev ◽  
Dmitry Gavrilov ◽  
Stanislav Karchevsky ◽  
...  
Keyword(s):  
Ring Opening ◽  
Density Functional ◽  
Point Of View ◽  
Basis Set ◽  
Random Copolymers ◽  
Key Factors ◽  
Functional Theory ◽  
Cyclic Esters ◽  
Dft Modeling ◽  
Derivatives Of

Catalytic ring-opening polymerization (ROP) of cyclic esters (lactides, lactones) and cyclic ethylene phosphates is an effective way to process materials with regulated hydrophilicity and controlled biodegradability. Random copolymers of cyclic monomers of different chemical nature are highly attractive due to their high variability of characteristics. Aryloxy-alkoxy complexes of non-toxic metals such as derivatives of 2,6-di-tert-butyl-4-methylphenoxy magnesium (BHT-Mg) complexes are effective coordination catalysts for homopolymerization of all types of traditional ROP monomers. In the present paper, we report the results of density functional theory (DFT) modeling of BHT-Mg-catalyzed copolymerization for lactone/lactide, lactone/ethylene phosphate and lactide/ethylene phosphate mixtures. ε-Caprolactone (ε-CL), l-lactide (l-LA) and methyl ethylene phosphate (MeOEP) were used as examples of monomers in DFT simulations by the Gaussian-09 program package with the B3PW91/DGTZVP basis set. Both binuclear and mononuclear reaction mechanistic concepts have been applied for the calculations of the reaction profiles. The results of calculations predict the possibility of the formation of random copolymers based on l-LA/MeOEP, and substantial hindrance of copolymerization for ε-CL/l-LA and ε-CL/MeOEP pairs. From the mechanistic point of view, the formation of highly stable five-membered chelate by the products of l-LA ring-opening and high donor properties of phosphates are the key factors that rule the reactions. The results of DFT modeling have been confirmed by copolymerization experiments.

scholarly journals Silver-catalysed azide–alkyne cycloaddition (AgAAC): assessing the mechanism by density functional theory calculations

2016 ◽  
Vol 3 (9) ◽  
pp. 160090 ◽  
Author(s):  
Biswadip Banerji ◽  
K. Chandrasekhar ◽  
Sunil Kumar Killi ◽  
Sumit Kumar Pramanik ◽  
Pal Uttam ◽  
...  
Keyword(s):  
Density Functional ◽  
Click Reaction ◽  
Cycloaddition Reaction ◽  
Triazole Ring ◽  
Density Functional Theory Calculations ◽  
Dipolar Cycloaddition ◽  
Reaction Conditions ◽  
Functional Theory ◽  
Click Reactions ◽  
Counter Ions

‘Click reactions’ are the copper catalysed dipolar cycloaddition reaction of azides and alkynes to incorporate nitrogens into a cyclic hydrocarbon scaffold forming a triazole ring. Owing to its efficiency and versatility, this reaction and the products, triazole-containing heterocycles, have immense importance in medicinal chemistry. Copper is the only known catalyst to carry out this reaction, the mechanism of which remains unclear. We report here that the ‘click reactions’ can also be catalysed by silver halides in non-aqueous medium. It constitutes an alternative to the well-known CuAAC click reaction. The yield of the reaction varies on the type of counter ion present in the silver salt. This reaction exhibits significant features, such as high regioselectivity, mild reaction conditions, easy availability of substrates and reasonably good yields. In this communication, the findings of a new catalyst along with the effect of solvent and counter ions will help to decipher the still obscure mechanism of this important reaction.

Sign in / Sign up

Export Citation Format

Share Document