Theoretical Study of the Heterolytic σ Bond Cleavage on the Ge═O Bond of Germanone. An Insight into the Driving Force from Both Electronic and Dynamical Aspects

2017 ◽  
Vol 121 (8) ◽  
pp. 1768-1778 ◽  
Author(s):  
Toshiaki Matsubara ◽  
Tomoyoshi Ito
2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Adeel Y. Abid ◽  
Yuanwei Sun ◽  
Xu Hou ◽  
Congbing Tan ◽  
Xiangli Zhong ◽  
...  

AbstractNontrivial topological structures offer a rich playground in condensed matters and promise alternative device configurations for post-Moore electronics. While recently a number of polar topologies have been discovered in confined ferroelectric PbTiO3 within artificially engineered PbTiO3/SrTiO3 superlattices, little attention was paid to possible topological polar structures in SrTiO3. Here we successfully create previously unrealized polar antivortices within the SrTiO3 of PbTiO3/SrTiO3 superlattices, accomplished by carefully engineering their thicknesses guided by phase-field simulation. Field- and thermal-induced Kosterlitz–Thouless-like topological phase transitions have also been demonstrated, and it was discovered that the driving force for antivortex formation is electrostatic instead of elastic. This work completes an important missing link in polar topologies, expands the reaches of topological structures, and offers insight into searching and manipulating polar textures.


1987 ◽  
Vol 40 (12) ◽  
pp. 1923 ◽  
Author(s):  
ID Rae ◽  
ID Rae ◽  
A Staffa ◽  
A Staffa ◽  
AC Diz ◽  
...  

In order to obtain a deeper insight into the title effect, several compounds with an F atom very close to a C-H of a nearby functional group were synthesized and the relevant couplings measured. The most conspicuous case was that of 8-fluoro-2-hydroxynaphthalene-1-carbaldehyde where a close proximity between the F and H atoms is the result of fluorine-oxygen repulsion and the formation of an intramolecular hydrogen bond between the hydroxyl and carbonyl groups. The experimental four-bond J(F,CHO) coupling is 26.2 Hz. A compound very similar to this one, but without the OH group, was chosen on which to perform a polarization propagator analysis of the through-space (TS) coupling pathways, at the RPA-INDO level. The expression for the TS coupling in terms of the projected polarization propagator and perturbators was numerically analysed. It is found that this coupling is completely dominated by a TS component of the Fermi contact (FC) term, the main features of which are: ( i ) It decays exponentially with the F-H distance; (ii) Its main contribution comes from an electron excitation involving the F lone-pair, the C-H bond of the CHO moiety and its corresponding antibonding orbital;(iii) The π-type lone-pair does not contribute to the TS coupling pathway of the FC term.


Biochemistry ◽  
2000 ◽  
Vol 39 (34) ◽  
pp. 10385-10396 ◽  
Author(s):  
Marc C. Morais ◽  
Wenhai Zhang ◽  
Angela S. Baker ◽  
Guofeng Zhang ◽  
Debra Dunaway-Mariano ◽  
...  

2016 ◽  
Vol 45 (3) ◽  
pp. 1047-1054 ◽  
Author(s):  
Robert Robinson ◽  
Miranda F. Shaw ◽  
Robert Stranger ◽  
Brian F. Yates

The addition of N-heterocyclic carbene (NHC) increases the activity of N2O towards cleavage of both the N–O and N–N bonds.


2017 ◽  
Vol 231 (9) ◽  
Author(s):  
Daniel Nurkowski ◽  
Ahren W. Jasper ◽  
Jethro Akroyd ◽  
Markus Kraft

AbstractIn this work the kinetics of the TiCl


2021 ◽  
Author(s):  
jian Liu ◽  
Melissa Bollmeyer ◽  
Yujeong Kim ◽  
Dengmengfei Xiao ◽  
Samantha N. Macmillan ◽  
...  

Mononuclear Pd(I) species are putative intermediates in Pd-catalyzed reactions, but our knowledge about them is limited due to difficulties in accessing them. Herein, we report the isolation of a Pd(I) amido complex, [(BINAP)Pd(NHArTrip )] (BINAP = 2,2′- bis(diphenylphosphino)-1,1′-binaphthalene, ArTrip = 2,6-bis(2’,4’,6’-triisopropylphenyl)phenyl), from the reaction of (BINAP)PdCl2 with LiNHArTrip. This Pd(I) amido species has been characterized by X-ray crystallography, electron paramagnetic resonance, and multi-edge Pd Xray absorption spectroscopy. Theoretical study revealed that, while the 3-electron-2-center π interaction between Pd and N in the Pd(I) complex imposes severe Pauli repulsion in its Pd–N bond, pronounced attractive inter-ligand dispersion force aids its stabilization. In accord with its electronic features, reactions of homolytic Pd–N bond cleavage and deprotonation of primary amines are observed on the Pd(I) amido complex.


2013 ◽  
Vol 135 (15) ◽  
pp. 5782-5792 ◽  
Author(s):  
Richard F. D’Vries ◽  
Victor A. de la Peña-O’Shea ◽  
Natalia Snejko ◽  
Marta Iglesias ◽  
Enrique Gutiérrez-Puebla ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document