GIAO-DFT calculated and experimentally derived complexation-induced chemical shifts of calix[4]arene–solvent inclusion complexesElectronic supplementary information (ESI) available: calculated and observed NMR data and geometrical details for complexes 1–3, 1–4 and 1–5. See http://www.rsc.org/suppdata/p2/b1/b110078p/

Backes, Alexander Christian; Schatz, J.; Siehl, Hans‐Ullrich

doi:10.1039/b110078p

Cited by 15 publications

(4 citation statements)

References 35 publications

(59 reference statements)

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“…These supposed complex conformations are in agreement with calculated MMFF optimizations (Figure 8). The obtained complex induced 1 H shift of the methyl group pointing inside the cavity for the optimized conformation of 0.62 ppm (analogously to a published procedure [29]) also does not differ significantly from the experimental value of 0.66 ppm.…”

Section: Resultssupporting

confidence: 78%

Olefin Metathesis Reaction in Water and in Air Improved by Supramolecular Additives

et al. 2015

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A range of water-immiscible commercially available Grubbs-type precatalysts can be used in ring-closing olefin metathesis reaction in high yields. The synthetic transformation is possible in pure water under ambient conditions. Sulfocalixarenes can help to boost the reactivity of the metathesis reaction by catalyst activation, improved mass transfer, and solubility of reactants in the aqueous reaction media. Additionally, the use of supramolecular additives allows lower catalyst loadings, but still high activity in pure water under aerobic conditions.

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Section: Resultssupporting

confidence: 78%

Olefin Metathesis Reaction in Water and in Air Improved by Supramolecular Additives

et al. 2015

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“…Computational modeling of NMR chemical shifts with quantum chemical models has seen a marked increase in both accuracy and affordability. − Density functional theory (DFT) has been widely applied to predict proton chemical shifts in various chemical systems. MP2 (second-order Møller–Plesset) perturbation theory was also used to understand the nature of noncovalent interactions.…”

Section: Introductionmentioning

confidence: 99%

Theoretical Study on Conformation Dynamics of Three-Station Molecular Shuttle in Different Environments and its Influence on NMR Chemical Shifts and Binding Interactions

Liu

et al. 2014

J. Phys. Chem. A

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Microscopic information on conformational flexibility and macrocycle-thread binding interactions is helpful in rational design of novel multistation molecular shuttles with interesting topology and functions. Molecular dynamics (MD) was applied to simulate conformational changes of thread and macrocycle of a three-station molecular shuttle in different chemical environments (vacuum, CD3CN-CDCl3 solution, and crystal). In contrast with the highly distorted thread conformation in the gas phase and nonpolar CDCl3 solution, the solvated thread in CD3CN-CDCl3 (1:1) mix solvents exhibited a relatively rigid structure. Experimental observations of preferential binding at the protonated dibenzylammonium group (station I) were rationalized by quantum chemical calculations of macrocycle-thread binding energies at three different stations. The orthogonality of site-specific binding interactions at three different stations was also revealed by the nearly constant binding energy obtained at each specific recognition center with the replacement of different neighboring groups and terminal stoppers on the thread. Conformational flexibility has little effect on NMR signals of binding sites, but for some protons that are close to the solvent molecules in the first solvent shell, their chemical shifts are sensitive to the local electrostatic environment caused by nearby solvents. In crystal, π stacking induced evident upfield shifts of NMR signals in comparison with the isolated monomer.

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“…Indeed, such calculations by means of correlated methods (both ab initio and DFT) are abundant in the literature, and no attempt will be made to report on them other than citing a few recent interesting trends, e.g. using computed chemical shifts to probe noncovalent interactions and shielding tensor properties and to determine the structure of naturally occurring molecules . Empirical corrections to calculated shifts were also investigated …”

Section: Introductionmentioning

confidence: 99%

Predicting ¹³C NMR Spectra by DFT Calculations

2003

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C chemical shifts and n J CH coupling constants have been determined both experimentally (by means of J-resolved NMR spectroscopy) and theoretically (by DFT calculations) for a series of organic molecules. With the exception of halogen-bonded carbon nuclei, a good correlation is observed between experimental and calculated data. The magnitude of the most important contributions to the spin-spin coupling constant (Fermi-contact, diamagnetic, and paramagnetic spin-orbit contributions) has been determined. The spinorbit terms are negligible or cancel out ( 1 J CH and 3 J CH ), thus leaving the contact term as the only relevant contribution, but become important for 2 J CH in aromatic (but not in aliphatic) compounds. Relativistic effects on the 13 C chemical shift of carbon bonded to a fairly heavy atom (bromine) have also been investigated. Finally, conformational effects on the long-range n J CH coupling constants has been investigated in a model alkane derivative (n-butyl chloride). The implications to structure prediction and determination by NMR are discussed.

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Cited by 15 publications

References 35 publications

Olefin Metathesis Reaction in Water and in Air Improved by Supramolecular Additives

Olefin Metathesis Reaction in Water and in Air Improved by Supramolecular Additives

Theoretical Study on Conformation Dynamics of Three-Station Molecular Shuttle in Different Environments and its Influence on NMR Chemical Shifts and Binding Interactions

Predicting ¹³C NMR Spectra by DFT Calculations

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Cited by 15 publications

References 35 publications

Olefin Metathesis Reaction in Water and in Air Improved by Supramolecular Additives

Olefin Metathesis Reaction in Water and in Air Improved by Supramolecular Additives

Theoretical Study on Conformation Dynamics of Three-Station Molecular Shuttle in Different Environments and its Influence on NMR Chemical Shifts and Binding Interactions

Predicting 13C NMR Spectra by DFT Calculations

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Predicting ¹³C NMR Spectra by DFT Calculations