GIAO-DFT study of<sup>13</sup>C NMR chemical shifts of highly pyramidalized alkenes

Vázquez, Santiago

doi:10.1039/b207060j

Cited by 20 publications

(18 citation statements)

References 71 publications

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“…A study by Vazquez also compared measured NMR shift to calculated ones with a comparable DFT method [15] . For the investigated pyramidal alkenes the computed 13 C NMR resonances are in good agreement with experimental data, although an under‐ or overestimation of certain shifts, similar to our work, was found.…”

Section: Resultssupporting

confidence: 85%

Third Time is a Charm – Protonating Tricarboxybenzenes

et al. 2022

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Triprotonation of the three constitution isomers of tricarboxybenzene was accomplished. Furthermore, the preparation of selected mono‐ and dications showed the sequence of protonation steps. The cations were mostly isolated as [SbF6] and [AsF6] species, which were characterized by Raman and NMR spectroscopy as well as X‐ray structure determination. To further elucidate the experimental results, quantum chemical calculations are employed, especially in regard to charge distribution with NPA charges and aromaticity by NICS(0) values. Thermal decomposition of the compounds was investigated in order to explore the possibility of acyl cation formation. The influence of the aromatic system, substitution pattern and anomeric effect concerning the properties of the respective compounds was thus explained.

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Section: Resultssupporting

confidence: 85%

Third Time is a Charm – Protonating Tricarboxybenzenes

et al. 2022

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“…GIAO/DFT (Gauge Including Atomic Orbitals/DFT) approach is extensively used for the calculations of chemical shifts for various types of compounds 32–35. Theoretical calculations of NMR typically benefit from an accurate geometry and large basis set 36.…”

Section: Resultsmentioning

confidence: 99%

Physician ability to assess rheumatoid arthritis disease activity using an electronic medical record–based disease activity calculator

Collier¹,

Grant²,

Estey³

et al. 2009

Arthritis & Rheumatism

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Objective. To assess physicians' concordance with Disease Activity Score in 28 joints (DAS28) categories calculated by an electronic medical record (EMR)-embedded disease activity calculator, as well as attitudes toward this application. Methods. Fifteen rheumatologists used the EMR-embedded disease activity calculator to predict a rheumatoid arthritis (RA) DAS28 disease activity category at the time of each clinical encounter. Results. Physician-predicted DAS28 disease activity categories ranged from high (>5.1, 15% of cohort, 66 of 429 patient visits) to moderate (>3.2-5.1, 21% of cohort, 90 of 429 patient visits) to low (2.6 -3.2, 29% of cohort, 123 of 429 patient visits) to remission (<2.6, 35% of cohort, 150 of 429 patient visits). Overall concordance between calculated DAS28 results and physician-predicted RA disease activity was 64%. Using either the physician-predicted or the calculated DAS28 category as the gold standard, accuracy was greatest for patients in remission (75% and 88% accuracy, respectively) and those with high disease activity (68% and 79% accuracy, respectively), and less for patients with moderate (48% and 62% accuracy, respectively) or low disease activity (62% and 31% accuracy, respectively). Conclusion. Accurate physician prediction of DAS28 remission and high disease activity categories, even without immediate availability of the erythrocyte sedimentation rate or the C-reactive protein level at the time of the visit, may be used to guide quantitatively driven outpatient RA management.

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“…As the pyramidalization angle increases, the HOMO/LUMO energy gap decreases and the C=C double bond elongates. Greater pyramidalization leads to an increase in the heat of hydrogenation and in the olefin strain energy [2,[15][16][17][18].…”

Section: Introductionmentioning

confidence: 99%

Electronic structures of bisnoradamantenyl and bisnoradamantanyl dications and related species

et al. 2013

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The highly pyramidalized molecule bisnoradamantene is extremely reactive toward nucleophiles and dienes. In this work, we studied the electronic structure of bisnoaradamantene, as well as those of its cation and dication, which are previously unreported carbonium ions. According to QTAIM and MO analysis, there is a 3c-2e bonding system in the bisnoradamantenyl cation and a 4c-2e bonding system in the bisnoradamantenyl dication. A topological study indicated that, on going from bisnoradamantene to its dication, π-bond interaction with the bridgehead carbon atom increases. Additional study of the bisnoradamantanyl dication also indicated that it has two multicenter bonding systems. Comparison of the D3BIA and NICS aromaticity indices of these molecules and other derivatives indicates that these indices are well correlated, and analysis of these indices shows that the cationic and dicationic bisnoradamantenyl species are homoaromatic.

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GIAO-DFT study of¹³C NMR chemical shifts of highly pyramidalized alkenes

Cited by 20 publications

References 71 publications

Third Time is a Charm – Protonating Tricarboxybenzenes

Third Time is a Charm – Protonating Tricarboxybenzenes

Physician ability to assess rheumatoid arthritis disease activity using an electronic medical record–based disease activity calculator

Electronic structures of bisnoradamantenyl and bisnoradamantanyl dications and related species

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GIAO-DFT study of13C NMR chemical shifts of highly pyramidalized alkenes

Cited by 20 publications

References 71 publications

Third Time is a Charm – Protonating Tricarboxybenzenes

Third Time is a Charm – Protonating Tricarboxybenzenes

Physician ability to assess rheumatoid arthritis disease activity using an electronic medical record–based disease activity calculator

Electronic structures of bisnoradamantenyl and bisnoradamantanyl dications and related species

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GIAO-DFT study of¹³C NMR chemical shifts of highly pyramidalized alkenes