scholarly journals Asymmetric Bis-PNP Pincer Complexes of Zirconium and Hafnium - a Measure of Hemilability

2020 ◽  
Author(s):  
Celia Idelson ◽  
Leah Webster ◽  
Tobias Krämer ◽  
Mark Chadwick
Keyword(s):  
Nmr Spectroscopy ◽  
Dft Calculations ◽  
Energy Barrier ◽  
Pincer Complexes ◽  
Pincer Ligands ◽  
Direct Contrast ◽  
Vt Nmr

Asymmetrically-bound pyrrollide-based bis-PNP pincer complexes of zirconium and hafnium<br>have been formed. The [κ2-PNPPh][κ3-PNPPh]MCl2 species are in direct contrast to previous<br>zirconium PNP pincer complexes. The pincer ligands are fluxional in their binding and the<br>energy barrier for exchange has been approximated using VT-NMR spectroscopy and the<br>result validated by DFT calculations.

scholarly journals Asymmetric Bis-PNP Pincer Complexes of Zirconium and Hafnium - a Measure of Hemilability

2020 ◽  
Author(s):  
Celia Idelson ◽  
Leah Webster ◽  
Tobias Krämer ◽  
Mark Chadwick
Keyword(s):  
Nmr Spectroscopy ◽  
Dft Calculations ◽  
Energy Barrier ◽  
Pincer Complexes ◽  
Pincer Ligands ◽  
Direct Contrast ◽  
Vt Nmr

Asymmetrically-bound pyrrollide-based bis-PNP pincer complexes of zirconium and hafnium<br>have been formed. The [κ2-PNPPh][κ3-PNPPh]MCl2 species are in direct contrast to previous<br>zirconium PNP pincer complexes. The pincer ligands are fluxional in their binding and the<br>energy barrier for exchange has been approximated using VT-NMR spectroscopy and the<br>result validated by DFT calculations.

scholarly journals The Activating Effect of Strong Acid for Pd-Catalyzed Directed C–H Activation by Concerted Metalation-Deprotonation Mechanism

Molecules ◽  
2021 ◽  
Vol 26 (13) ◽  
pp. 4083
Author(s):  
Heming Jiang ◽  
Tian-Yu Sun
Keyword(s):  
Activation Energy ◽  
Dft Calculations ◽  
Energy Barrier ◽  
Computational Study ◽  
Strong Acid ◽  
Activation Energy Barrier ◽  
Pd Catalysts ◽  
Acid Ligand ◽  
Strong Acids

A computational study on the origin of the activating effect for Pd-catalyzed directed C–H activation by the concerted metalation-deprotonation (CMD) mechanism is conducted. DFT calculations indicate that strong acids can make Pd catalysts coordinate with directing groups (DGs) of the substrates more strongly and lower the C–H activation energy barrier. For the CMD mechanism, the electrophilicity of the Pd center and the basicity of the corresponding acid ligand for deprotonating the C–H bond are vital to the overall C–H activation energy barrier. Furthermore, this rule might disclose the role of some additives for C–H activation.

scholarly journals Synthesis, characterization and modeling of self-assembled porphyrin nanorods

2019 ◽  
Vol 23 (11n12) ◽  
pp. 1346-1354 ◽  
Author(s):  
Danielle Laurencin ◽  
Pascal G. Yot ◽  
Christel Gervais ◽  
Yannick Guari ◽  
Sébastien Clément ◽  
...  
Keyword(s):  
Solid State ◽  
Nmr Spectroscopy ◽  
Dft Calculations ◽  
Powder Diffraction ◽  
Solid State Nmr ◽  
Molecular Level ◽  
Ion Association ◽  
Free Base ◽  
X Ray ◽  
Solid State Nmr Spectroscopy

Porphyrin nanorods were prepared by ion-association between free-base meso 5,10,15,20-tetrakis-(4-[Formula: see text]-methylpyridinium)porphyrin cations and tetraphenylborate anions. The nanorods have variable lengths (up to a few micrometers long) and diameters ([Formula: see text]50–500 nm). Their structure at the molecular level was elucidated by combining multinuclear solid state NMR spectroscopy, synchrotron X-ray powder diffraction and DFT calculations.

Fries Rearrangement of Aryl Formates:  A Mechanistic Study by Means of1H,2H, and11B NMR Spectroscopy and DFT Calculations

2006 ◽  
Vol 71 (25) ◽  
pp. 9331-9340 ◽  
Author(s):  
Alessandro Bagno ◽  
Willi Kantlehner ◽  
Ralf Kress ◽  
Giacomo Saielli ◽  
Edmont Stoyanov
Keyword(s):  
Nmr Spectroscopy ◽  
Dft Calculations ◽  
Mechanistic Study ◽  
Fries Rearrangement

scholarly journals Combining solid-state NMR spectroscopy with first-principles calculations – a guide to NMR crystallography

2016 ◽  
Vol 52 (45) ◽  
pp. 7186-7204 ◽  
Author(s):  
Sharon E. Ashbrook ◽  
David McKay
Keyword(s):  
Solid State ◽  
Nmr Spectroscopy ◽  
Dft Calculations ◽  
First Principles ◽  
Solid State Nmr ◽  
Nmr Spectra ◽  
First Principles Calculations ◽  
Recent Developments ◽  
Future Potential ◽  
Nmr Crystallography

DFT calculations are an important tool in assigning and interpreting NMR spectra of solids: we discuss recent developments and their future potential in the context of NMR crystallography.

Structure of 1-methyl-2-oxo-pyrido[2,1b][3,4]dihydropyrimidinium bromide studied by X-ray diffraction, FTIR and NMR spectroscopy and DFT calculations

2007 ◽  
Vol 843 (1-3) ◽  
pp. 107-115 ◽  
Author(s):  
M. Szafran ◽  
I. Kowalczyk ◽  
E. Bartoszak-Adamska ◽  
M. Jaskólski ◽  
B. Nowak-Wydra
Keyword(s):  
Nmr Spectroscopy ◽  
Dft Calculations ◽  
X Ray Diffraction ◽  
X Ray

Structures of Nonheme Oxoiron(IV) Complexes from X-ray Crystallography, NMR Spectroscopy, and DFT Calculations

2005 ◽  
Vol 44 (24) ◽  
pp. 3690-3694 ◽  
Author(s):  
Eric J. Klinker ◽  
József Kaizer ◽  
William W. Brennessel ◽  
Nathaniel L. Woodrum ◽  
Christopher J. Cramer ◽  
...  
Keyword(s):  
Nmr Spectroscopy ◽  
Dft Calculations ◽  
X Ray ◽  
X Ray Crystallography
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