Modulation of the exfoliated graphene work function through cycloaddition of nitrile imines

After the feasibility of the 1,3-dipolar cycloaddition reaction between nitrile imines and exfoliated graphene by density functional theory calculations was proved, very few-layer graphene was effectively functionalized using this procedure. Hydrazones with different electronic properties were used as precursors for the 1,3-dipoles, and microwave irradiation as an energy source enabled the reaction to be performed … Continue reading

Computational Calculations in Microwave-Assisted Organic Synthesis (MAOS). Application to Cycloaddition Reactions.

Computational calculations represent a very useful tool to study separately the ocurrence of thermal and non-thermal effects of microwave irradiation through the determination of the thermodynamic and kinetic parameters of the reaction. In this paper, we approach the computational study of two previously reported cycloaddition reactions. All of the outcomes indicate the presence of a … Continue reading

New review on computational calculations and microwave irradiation

This review, published in Chem. Soc. Rev., provides an overview of the use of Computational Chemistry in MAOS to provide a theoretical understanding of the factors that can be used to explain the improvements in MAOS and how computational calculations can be used as a predictive tool.

Computational Calculations and Thermal Microwave Effects

Computational calculations have been used to elucidate the influence of polarity and activation energy on microwave assited reactions. A systematic classification of reactions according the thermodynamic parameters will help to determine “a priori” the reactions where microwave irradiation will have a positive influence.

2014 in review

The WordPress.com stats helper monkeys prepared a 2014 annual report for this blog. Here’s an excerpt: The concert hall at the Sydney Opera House holds 2,700 people. This blog was viewed about 10,000 times in 2014. If it were a concert at Sydney Opera House, it would take about 4 sold-out performances for that many … Continue reading

Design of Assembled Systems Based on Conjugated Polyphenylene Derivatives and Carbon Nanohorns

Promising materials have been designed and fully characterised by an effective interaction between versatile platforms such as carbon nanohorns (CNHs) and conjugated molecules based on thiophene derivatives. Easy and non-aggressive methods have been described for the synthesis and purification of the final systems. Oligothiophenephenylvinylene (OTP) systems with different geometries and electron density are coupled to … Continue reading

Influence of Polarity and Activation Energy in Microwave-Assisted Organic Synthesis (MAOS).

The aim of this work was to determine the parameters that have a decisive role in microwave-assisted reactions and to develop a model, using computational chemistry, to predict a priori the type of reactions can be improved under microwaves. For this purpose, a computational study has been carried out on a variety of reactions that … Continue reading

The Issue of ‘Molecular Radiators’ in Microwave-Assisted Reactions. Computational Calculations in Ring Closing Metathesis (RCM).

A DFT computational mechanistic study of the ring closing metathesis (RCM) reaction of diallyl ether or N,N-diallyl-p-toluenesulfonamide catalyzed by a second generation Grubbs-type ruthenium carbene complex has been carried out. This study was performed at PCM(CH2Cl2)-B3LYP/6-311+G(2d,p)//B3LYP/SDD theory level. The aim of this work was to shed light on the influence that microwave irradiation has in … Continue reading

Exfoliation of Graphite with Triazine Derivatives under Ball-Milling Conditions: Preparation of Few-Layer Graphene via Selective Noncovalent Interactions

A ball-milling treatment can be employed to exfoliate graphite through interactions with commercially available melamine under solid conditions. This procedure allows the fast production of relatively large quantities of material with a low presence of defects. The milling treatment can be modulated in order to achieve graphene flakes with different sizes. Once prepared, the graphene … Continue reading

DFT-Studies on Cobalt-Catalyzed Cyclotrimerization Reactions. Mechanism and Origin of Reaction Improvement under Microwave Irradiation.

A DFT computational mechanistic study of the [2+2+2] cyclotrimerization of a diyne with benzonitrile, catalyzed by a cobalt complex, has been carried out. Three alternative catalytic cycles have been examined together with the precatalytic step (responsible for the induction period). The favored mechanism takes place via an intramolecular metal-assisted [4+2] cycloaddition. The beneficial role of … Continue reading