Statistically representative databases for density functional theoryviadata science

Morgante, Pierpaolo; Peverati, Roberto

doi:10.1039/c9cp03211h

Cited by 31 publications

(32 citation statements)

References 173 publications

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“…This clearly reflects the stabilizing effect of an acyl radical in the transition state of the 1,6-migration. Therefore, based on the expected accuracy of our calculations (~±0.5 kcal/mol), [58][59][60][61][62] we can conclude that the reaction does not proceed through the cyclic structure (9) neither in the triplet nor in the singlet state. Using the same computational strategy, we found that the modification of the substitution pattern on 7-nitroindoline is not as important as initially thought.…”

Section: Figurementioning

confidence: 52%

Unusual Norrish Type I and Type II Nitro-Acyl Migration Transition State in the Photo-Uncaging of 1-Acyl-7-Nitroindolines Revealed by Computations

Morgante¹,

Guruge²,

Ouedraogo³

et al. 2020

Preprint

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The 7-nitroindolinyl family of caging chromophores has received a lot of attention in the past two decades. However, it is not clear if they undergo cyclization or migration upon photo-uncaging to release the active compound. In this study, we performed state-of-the-art density functional theory calculations to fully understand the photo-uncaging mechanism and we compared the probabilities of all plausible pathways. We found that the key transition state in the lowest¬ energy pathway involves an acyl migration. It possesses the characteristics of a combined Norrish Type I and a 1,6-nitro-acyl variation of a Norrish Type II mechanism, which has not been previously reported. We also introduced a new computational procedure that allows the estimation of intersystem crossing rate constants useful to compare the relative quantum yield of substituted cages. This procedure may pave the way for improved cage designs that possess higher quantum yields and more efficient agonist release.

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Section: Figurementioning

confidence: 52%

Unusual Norrish Type I and Type II Nitro-Acyl Migration Transition State in the Photo-Uncaging of 1-Acyl-7-Nitroindolines Revealed by Computations

Morgante¹,

Guruge²,

Ouedraogo³

et al. 2020

Preprint

Self Cite

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“…This reflects the stabilizing effect of an acyl radical in the transition state of the 1,6-migration. The energy difference between the migration and the cyclization pathways is calculated at 1.1 kcal/mol, and since the expected accuracy of our calculations is ±1.0 kcal/mol,50,[65][66][67][68] we can conclude that the two mechanisms are competitive. As such, given the small activation barriers, both mechanisms can co-occur.…”

mentioning

confidence: 51%

Competition Between Cyclization and Unusual Norrish Type I and Type II Nitro-Acyl Migration Pathways in the Photouncaging of 1-Acyl-7-nitroindoline Revealed by Computations

Morgante

Guruge

Ouedraogo

et al. 2020

Preprint

Self Cite

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The 7-nitroindolinyl family of caging chromophores has received much attention in the past two decades. However, its uncaging mechanism is still not clearly understood. In this study, we performed state-of-the-art density functional theory calculations to unravel the photo-uncaging mechanism in its entirety, and we compared the probabilities of all plausible pathways. We found competition between a classical cyclization and acyl migration pathways, and here we explain the electronic and steric reasons behind such competition. The migration mechanism possesses the characteristics of a combined Norrish Type I and a 1,6-nitro-acyl variation of a Norrish Type II mechanism, which is reported here for the first time. We also introduced a computational procedure that allows the estimation of intersystem crossing rate constants useful to compare the relative quantum yield of substituted cages. This procedure may pave the way for improved cage designs that possess higher quantum yields and a more efficient agonist release.

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“…Instead, one may use statistical methods for the partitioning of the full set. Indeed, this approach has been adopted in a recent study, in which a large dataset of ~7000 points is grouped into 16 “clusters.” [ 76 ] In a similar manner, we apply the standard statistical clustering technique for the CUAGAU‐2 dataset. Specifically, the data points are clustered according to the deviations from benchmark values for all assessed methods.…”

Section: Resultsmentioning

confidence: 99%

Assessment and development of DFT with the expanded CUAGAU‐2 set of group‐11 cluster systems

Chan

2020

Int J of Quantum Chemistry

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In the present study, we have compiled the expanded CUAGAU‐2 set of group‐11 (Cu, Ag, Au) cluster systems. It contains species that we find to be more challenging for density functional theory (DFT) methods, which are not represented in the previous set. In the prosses, we have also devised the W1X‐G0 method for cost‐effective calculation of accurate reaction energies for such species; it is comparable to the W1X‐2 composite protocol but with a more sophisticated treatment for core correlation, which is necessary for the group‐11 cluster systems. Our assessment of DFT methods shows the MN15 method to be one of the most accurate for CUAGAU‐2. Nonetheless, the CUAGAU‐2 systems are more challenging for even some of the most advanced DFT methods when compared with main‐group and molecular transition‐metal systems. To facilitate rapid development of functionals with better accuracy and robustness, we have statistically downsized the 123‐point CUAGAU‐2 set to smaller sets with 11 (CUAGAU‐2s) and 41 (CUAGAU‐2m) points. In a brief case study, we have used CUAGAU‐2m and other small test sets to revise the SCAN0 method. The results suggest that reducing %HF in SCAN0 from 25% to 10% (yielding the SCANh method) would lead to an overall better performance, as well as a more uniform accuracy over different properties. This exercise demonstrates the utility of the CUAGAU‐2(s/m) and our previously compiled test sets for the exploration of density functionals.

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Statistically representative databases for density functional theoryviadata science

Abstract: Cluster analysis applied to quantum chemistry: a new broad database of chemical properties with a reasonable computational cost.

Cited by 31 publications

References 173 publications

Unusual Norrish Type I and Type II Nitro-Acyl Migration Transition State in the Photo-Uncaging of 1-Acyl-7-Nitroindolines Revealed by Computations

Unusual Norrish Type I and Type II Nitro-Acyl Migration Transition State in the Photo-Uncaging of 1-Acyl-7-Nitroindolines Revealed by Computations

Competition Between Cyclization and Unusual Norrish Type I and Type II Nitro-Acyl Migration Pathways in the Photouncaging of 1-Acyl-7-nitroindoline Revealed by Computations

Assessment and development of DFT with the expanded CUAGAU‐2 set of group‐11 cluster systems

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