Do Double Hybrids Provide Accurate Chemical Shifts? A Benchmark Assessment of Density Functional Theory for Proton NMR

Download
Favoritar este trabalho
Como citar esse trabalho?
Detalhes
  • Tipo de apresentação: Apresentação Oral Assíncrona /Asynchronous Oral Communications
  • Eixo temático: Espectroscopia
  • Palavras chaves: density functional methods; proton NMR; structure elucidation; Natural products;

Autoras(es):

  • 1 Department of Chemistry and Physics / La Trobe Institute for Molecular Science / La Trobe University
  • 2 USP - São Carlos
  • 3 Universidade de São Paulo
  • 4 Department of Chemistry and Physics / La Trobe Institute of Molecular Sciences / La Trobe University
  • 5 Institute of Physics / Polish Academy of Sciences

Do Double Hybrids Provide Accurate Chemical Shifts? A Benchmark Assessment of Density Functional Theory for Proton NMR

Júlia Aragon

USP - São Carlos

Resumo

* Chemical shift predictions using DFT methods have been largely applied across the chemical sciences in structure elucidation or even reassignment;
* Only 2 previous publications have evaluated double-hybrid density functionals (DHDFs) for chemical shift predictions leading to mixed results;
* For DHDFs, no previous work has focused on a comprehensive analysis of a popular nuclide e.g., 1H or 13C;
* DHDFs evaluated for 1H NMR calculations showed no benefit over DFs from lower rungs, which represents an exception for the class of DHDFs as they are often recommended for their superior accuracy;
* Findings are supported by an extensive analysis of basis set convergence, geometry effects, use of up 200 individual proton chemical shifts including complex natural products, and so forth.

Questões (1 tópico)

Compartilhe suas ideias ou dúvidas com os autores!

Sabia que o maior estímulo no desenvolvimento científico e cultural é a curiosidade? Deixe seus questionamentos ou sugestões para o autor!

Faça login para interagir

Tem uma dúvida ou sugestão? Compartilhe seu feedback com os autores!

Autor

Marcelo Tavares

Hi Sidney, thanks for the comments. I'm already up so will take the note and Júlia can add later. 

There are certainly other studies benchmarking various density functionals (DFs) for NMR chemical shifts, including more recent ones besides those you mentioned. 

However, very few indeed included double-hybrid DFs (DHDFs, Rung 5) due to unavailability of codes able to handle these calculations. I believe that ours is only the third - other 2 mentioned in Julia's presentation. More importantly, though, ours is the first to show that currently available DHDFs aren't that great, hence, the title of the presentation and our recently published paper. 

Cheers

Autor

Júlia Aragon

Hi prof Sidney, thank you so much for the reading recommendation. But as Marcelo precisely pointed, our goal was to compare the chemical shifts predicted with recently incorporated double hybrids in Orca and the other functionals.