scholarly journals Intramolecular and Intermolecular Contributions to the Barriers for Rotation of Methyl Groups in Crystalline Solids: Electronic Structure Calculations and Solid-State NMR Relaxation Measurements

2011 ◽  
Vol 76 (13) ◽  
pp. 5170-5176 ◽  
Author(s):  
Xianlong Wang ◽  
Peter A. Beckmann ◽  
Clelia W. Mallory ◽  
Arnold L. Rheingold ◽  
Antonio G. DiPasquale ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Solid State ◽  
Solid State Nmr ◽  
Nmr Relaxation ◽  
Electronic Structure Calculations ◽  
Methyl Groups ◽  
Crystalline Solids ◽  
Relaxation Measurements ◽  
Structure Calculations

Investigation of Methyl Reorientations in 1,4-Dimethoxy- 2,6-dimethylbenzene by NMR and Inelastic Neutron Scattering

1979 ◽  
Vol 34 (5) ◽  
pp. 631-645 ◽  
Author(s):  
R. A. Wind ◽  
W. M. M. J. Bovée ◽  
J. C. F. Kupers ◽  
J. Smidt ◽  
Chr. Steenbergen
Keyword(s):  
Solid State ◽  
Neutron Scattering ◽  
Liquid State ◽  
Solid State Nmr ◽  
Inelastic Neutron Scattering ◽  
Nmr Relaxation ◽  
Inelastic Neutron ◽  
Methyl Groups ◽  
Methyl Group ◽  
Nmr Study

Abstract In this paper a solid state NMR relaxation study and inelastic neutron scattering (INS) experiments (the latter in the solid and liquid phase) are reported for a molecule containing methyl groups in different surroundings, namely 1,4-dimethoxy-2,6-dimethylbenzene. The results are compared with each other and with those of a liquid state NMR study reported earlier. It is found that in this way both the shapes and magnitudes of the various hindering potentials can be determined. The result is that the methyl groups 1, 2 and 4 possess a threefold cosine-shaped potential with heights given by 7.7, 9.0 and 15.0 kJ/mol according to the solid state NMR measurements (from the INS study the values 7.5, 7.5 and 16.0 kJ/mol were obtained). For methyl group 6 a mixture of a three-and six-fold symmetry had to be taken into account in order to explain the experiments. Except for methyl group 4 the liquid state NMR results deviate from those obtained with the other two techniques. A possible cause for this discrepancy is discussed. For the molecular structure it is concluded that the reorientations of the methyl groups 1 and 2 are influenced by mutual hindering and that the angle between the plane through the C4-O-C bond and the aromatic plane is small, whereas for the C1-O-C bond this angle is estimated to be about 70°.

scholarly journals Unraveling the complexity of protein backbone dynamics with combined 13C and 15N solid-state NMR relaxation measurements

2015 ◽  
Vol 17 (34) ◽  
pp. 21997-22008 ◽  
Author(s):  
Jonathan M. Lamley ◽  
Matthew J. Lougher ◽  
Hans Juergen Sass ◽  
Marco Rogowski ◽  
Stephan Grzesiek ◽  
...  
Keyword(s):  
Solid State ◽  
Magnetic Fields ◽  
Solid State Nmr ◽  
Nmr Relaxation ◽  
Backbone Dynamics ◽  
Relaxation Rates ◽  
Protein Backbone ◽  
Combined Analysis ◽  
Protein Backbone Dynamics ◽  
Relaxation Measurements

Combined analysis of 13C′ and 15N R1 and R1ρ relaxation rates measured at two magnetic fields leads to improved modeling of backbone dynamics in crystalline protein and provides unique insights into how the same motions contribute differently to relaxation rates in solution and solid state.

High solid-state luminescence in propeller-shaped AIE-active pyridine–ketoiminate–boron complexes

2015 ◽  
Vol 13 (20) ◽  
pp. 5775-5782 ◽  
Author(s):  
Yanping Wu ◽  
Zhenyu Li ◽  
Qingsong Liu ◽  
Xiaoqing Wang ◽  
Hui Yan ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Solid State ◽  
Quantum Yield ◽  
Stokes Shift ◽  
Electronic Structure Calculations ◽  
High Quantum Yield ◽  
X Ray ◽  
Boron Complexes ◽  
Structure Calculations ◽  
State Luminescence

Two pyridine-ketoiminate-based organoboron complexes were demonstrated to possess aggregation-induced emission, large Stokes shift and high quantum yield in the solid-state, which were rationalized through X-ray crystal analysis and electronic structure calculations.

Accurate solid-state band gaps via screened hybrid electronic structure calculations

2008 ◽  
Vol 129 (1) ◽  
pp. 011102 ◽  
Author(s):  
Edward N. Brothers ◽  
Artur F. Izmaylov ◽  
Jacques O. Normand ◽  
Verónica Barone ◽  
Gustavo E. Scuseria
Keyword(s):  
Electronic Structure ◽  
Solid State ◽  
Electronic Structure Calculations ◽  
Band Gaps ◽  
State Band ◽  
Structure Calculations
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