A Theoretical Approach for Accurate Predictions of the Enthalpies of Formation of Carotenes

Lii, Jenn‐Huei; Liao, Fu-Xing; Hsieh, Hong-Yi; Hu, Ching‐Han

doi:10.1021/jp107973s

Cited by 4 publications

(9 citation statements)

References 47 publications

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“…The CBS-QB3 predictions using atomization scheme were generally more positive than those using the isodesmic scheme (AAD 2.04 kcal/mol), agreeing with previous findings. [50] However, the CBS-QB3 predictions with the isodesmic scheme were in good agreement with both G3 and MM4 results. The only prediction that these methods did not agree upon was the DH f of end group E, which contains a five-membered ring and carbonyl functional groups.…”

Section: Resultssupporting

confidence: 63%

“…[ 50] These additional CCAZ interactions are seven 1,2-, ten 1,3-and one 1,4-interactions, and they were introduced to correct the correlation error in the DFT calculations for the molecules. A computer program was written to evaluate the number of various CCAZ interactions.…”

Section: ;2 Imentioning

confidence: 99%

“…[ 50] All approaches with MPWB1K theory seemed to significantly ease problems related to end group B. The improvement of handling correlation in the MPWB1K theory likely plays an important role here.…”

Section: Ae Ge Ccaz and Mm4 Approachesmentioning

confidence: 99%

“…However, MPWB1K theory seems to do poorer jobs in xanthophylls than in carotenes (RMS 2.67 vs. 1.80 kcal/mol). [50] Enthalphies of formation of xanthophylls DFT calculations were performed on the lowest-energy isomers of the 10 xanthophylls generated using MM4 conformational search. Figure 3 illustrates the structures of four of the xanthophylls.…”

Section: Ae Ge Ccaz and Mm4 Approachesmentioning

confidence: 99%

“…The drawbacks of the AE and GE approaches highlight the need for a better and more efficient way to correct the correlation problem in DFT methods. The theoretical approach proposed in previous research, called the correlation corrected atomization (CCAZ), [50] shows promising results in predicting enthalpies of formation for carotenes. This study extends the application of the CCAZ method, along with DFT theories, to the prediction of enthalpies of formation for xanthophylls.…”

Section: Introductionmentioning

confidence: 99%

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Accurate prediction of the enthalpies of formation for xanthophylls

Lii

Liao

2011

J Comput Chem

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This study investigates the applications of computational approaches in the prediction of enthalpies of formation (ΔH(f)) for C-, H-, and O-containing compounds. Molecular mechanics (MM4) molecular mechanics method, density functional theory (DFT) combined with the atomic equivalent (AE) and group equivalent (GE) schemes, and DFT-based correlation corrected atomization (CCAZ) were used. We emphasized on the application to xanthophylls, C-, H-, and O-containing carotenoids which consist of ∼ 100 atoms and extended π-delocaization systems. Within the training set, MM4 predictions are more accurate than those obtained using AE and GE; however a systematic underestimation was observed in the extended systems. ΔH(f) for the training set molecules predicted by CCAZ combined with DFT are in very good agreement with the G3 results. The average absolute deviations (AADs) of CCAZ combined with B3LYP and MPWB1K are 0.38 and 0.53 kcal/mol compared with the G3 data, and are 0.74 and 0.69 kcal/mol compared with the available experimental data, respectively. Consistency of the CCAZ approach for the selected xanthophylls is revealed by the AAD of 2.68 kcal/mol between B3LYP-CCAZ and MPWB1K-CCAZ.

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Section: Resultssupporting

confidence: 63%

Section: ;2 Imentioning

confidence: 99%

Section: Ae Ge Ccaz and Mm4 Approachesmentioning

confidence: 99%

Section: Ae Ge Ccaz and Mm4 Approachesmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Accurate prediction of the enthalpies of formation for xanthophylls

Lii

Liao

2011

J Comput Chem

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Determination of enthalpies (‘Heats’) of formation

Rogers

Zavitsas

Matsunaga

2012

WIREs Comput Mol Sci

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Determination of enthalpies of formation, now well into its second century, continues to be an active research field. Classical combustion thermochemistry, known by Lavoisier, is carried out with precision in several laboratories, though usually on the microscale, as appropriate to the small quantities of rare or unstable species preparative chemists are able to win and purify. Nonclassical methods such as differential scanning calorimetry and proton emission techniques are practiced. Enthalpy estimation based on additivity has been brought to an improved level of accuracy, and its basis in molecular structure has been examined with the goal of achieving maximum simplicity. Discrepancies between experimental results and additive estimates due to 'special effects' have brought about a considerable amount of causative speculation in the literature. Quantum mechanical methods have enjoyed increased proliferation through new methods of finding enthalpies of formation and other thermochemical and molecular properties such as heat capacity and entropy. Powerful basis set and configuration interaction software is available within the Gaussian c suites of programs. New levels of accuracy, in the kilojoules per mole range, have been achieved by Wn methods, and wider generality is enjoyed by methods based on density functional theory. New tabulation methods have been introduced that use computer error estimation procedures to root out flawed experimental results and increase overall reliability of the data one selects from the compilation. C 2012 John Wiley & Sons, Ltd.in the gaseous state at 298 K, arrive at an enthalpy level that we shall denote H 298 C(g) 6+ + 4H + (g) + 10e − = CH 4 (g)Perhaps more familiar to chemists is the enthalpy of a molecule in the standard state referred to elements also in their standard states. For methane, C(s, gr) + 2 H 2 = CH 4 (g)where (s, gr) indicates the graphitic form of solid carbon. The enthalpy difference between the molecule and its elements, all in the standard states, 6,7 is its enthalpy (frequently called 'heat') of formation f H • . We define the enthalpy of formation of any element in its standard state as zero at all temperatures. This definition works because elements are not converted from one to another in chemical reactions.

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An improved theoretical approach to the empirical corrections of density functional theory

Lii

2011

J Comput Aided Mol Des

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An empirical correction to density functional theory (DFT) has been developed in this study. The approach, called correlation corrected atomization-dispersion (CCAZD), involves short- and long-range terms. Short-range correction consists of bond (1,2-) and angle (1,3-) interactions, which remedies the deficiency of DFT in describing the proto-branching stabilization effects. Long-range correction includes a Buckingham potential function aiming to account for the dispersion interactions. The empirical corrections of DFT were parameterized to reproduce reported ΔH ( f ) values of the training set containing alkane, alcohol and ether molecules. The ΔH ( f ) of the training set molecules predicted by the CCAZD method combined with two different DFT methods, B3LYP and MPWB1K, with a 6-31G* basis set agreed well with the experimental data. For 106 alkane, alcohol and ether compounds, the average absolute deviations (AADs) in ΔH ( f ) were 0.45 and 0.51 kcal/mol for B3LYP- and MPWB1K-CCAZD, respectively. Calculations of isomerization energies, rotational barriers and conformational energies further validated the CCAZD approach. The isomerization energies improved significantly with the CCAZD treatment. The AADs for 22 energies of isomerization reactions were decreased from 3.55 and 2.44 to 0.55 and 0.82 kcal/mol for B3LYP and MPWB1K, respectively. This study also provided predictions of MM4, G3, CBS-QB3 and B2PLYP-D for comparison. The final test of the CCAZD approach on the calculation of the cellobiose analog potential surface also showed promising results. This study demonstrated that DFT calculations with CCAZD empirical corrections achieved very good agreement with reported values for various chemical reactions with a small basis set as 6-31G*.

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A Theoretical Approach for Accurate Predictions of the Enthalpies of Formation of Carotenes

Cited by 4 publications

References 47 publications

Accurate prediction of the enthalpies of formation for xanthophylls

Accurate prediction of the enthalpies of formation for xanthophylls

Determination of enthalpies (‘Heats’) of formation

An improved theoretical approach to the empirical corrections of density functional theory

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