Towards high-level theoretical studies of large biodiesel molecules: An ONIOM [QCISD(T)/CBS:DFT] study of hydrogen abstraction reactions of CnH2n+1COOCmH2m+1+ H

Lidong Zhang, Peng Zhang

Research output: Journal article publicationJournal articleAcademic researchpeer-review

20 Citations (Scopus)

Abstract

Recent interest in biodiesel combustion urges the need for the theoretical chemical kinetics of large alkyl ester molecules. This is, however, computationally challenging for prevalent high-level electronic structure theory based methods. The hydrogen abstraction reactions of alky esters CnH2n+1COOCmH2m+1(n = 1-5, 9, 15; m = 1, 2) by a hydrogen radical were investigated by a computational technique based on a two-layer ONIOM method, employing a QCISD(T)/CBS method for the high layer and a DFT method for the low layer. The calculated energy barriers and heats of reaction, using the ONIOM method with a minimum of the required chemically active portion, are in very good agreement with those obtained using the widely accepted high-level QCISD(T)/CBS theory because the computational errors were less than 0.1 kcal mol-1for all the tested cases. The ONIOM[QCISD(T)/CBS:DFT] method provides a computationally accurate and affordable approach to the high-level theoretical chemical kinetics of large biodiesel molecules. This journal is
Original languageEnglish
Pages (from-to)200-208
Number of pages9
JournalPhysical Chemistry Chemical Physics
Volume17
Issue number1
DOIs
Publication statusPublished - 7 Jan 2015

ASJC Scopus subject areas

  • Physics and Astronomy(all)
  • Physical and Theoretical Chemistry

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