Molecular Dynamics of Regioregular Poly(3-hexylthiophene) Investigated by NMR Relaxation and an Interpretation of Temperature Dependent Optical Absorption

2010 ◽  
Vol 114 (3) ◽  
pp. 1241-1248 ◽  
Author(s):  
Koji Yazawa ◽  
Yoshio Inoue ◽  
Tadashi Shimizu ◽  
Masataka Tansho ◽  
Naoki Asakawa
CrystEngComm ◽  
2016 ◽  
Vol 18 (38) ◽  
pp. 7297-7304 ◽  
Author(s):  
Linjun Wang ◽  
David Beljonne

We report on a first-principle theoretical investigation of the optical absorption and emission spectra of poly(3-hexylthiophene) (P3HT) aggregates by means of a multiscale all-atom hybrid approach, which combines molecular dynamics simulations, quantum-chemical calculations, and solving of a Frenkel–Holstein model.


2019 ◽  
Author(s):  
Allison Edwards ◽  
Abdolreza Javidialesaadi ◽  
Katie Weigandt ◽  
George Stan ◽  
Charles Eads

We study molecular arrangements and dynamics in alkyl ethoxylate nonionic surfactant micelles by combining high field (600 and 700 MHz) NMR relaxation measurements with large-scale atomistic molecular dynamics simulations. For spherical micelles, but not for cylindrical micelles, cross relaxation rates are positive only for surfactant alkyl tail atoms connected to the hydrophilic head group. All cross relaxation rates are negative for cylindrical micelles. This effect is reproducible either by changing composition (ratios of the nonionic surfactants) or changing temperature of a single surfactant in order to change the micelle shape. We validate the micelle shape by SANS and use the results as a guide for our simulations. We calculate parameters that determine relaxation rates directly from simulated trajectories, without introducing specific functional forms. Results indicate that relative motions of nearby atoms are liquid-like, in agreement with 13C T1 measurements, though constrained by micelle morphology. Relative motions of distant atoms have slower components because the relative changes in distances and angles are smaller when the moving atoms are further apart. The slow, long-range motions appear to be responsible for the predominantly negative cross relaxation rates observed in NOESY spectra. The densities of atoms from positions 1 and 2 in the boundary region are lower in spherical micelles compared to cylindrical micelles. Correspondingly, motions in this region are less constrained by micelle morphology in the spherical compared to the cylindrical cases. The two effects of morphology lead to the unusual occurrence of positive cross relaxation involving positions 1 and 2 for spheres.


2020 ◽  
Vol 27 (12) ◽  
pp. 122704
Author(s):  
Yuzhi Zhang ◽  
Chang Gao ◽  
Qianrui Liu ◽  
Linfeng Zhang ◽  
Han Wang ◽  
...  

ACS Omega ◽  
2021 ◽  
Author(s):  
Khagendra Baral ◽  
Saro San ◽  
Ridwan Sakidja ◽  
Adrien Couet ◽  
Kumar Sridharan ◽  
...  

Author(s):  
Mahendera Kumar Meena ◽  
Durgesh Kumar ◽  
Kamlesh Kumari ◽  
Nagendra Kumar Kaushik ◽  
Rammapa Venkatesh Kumar ◽  
...  

2022 ◽  
Vol 13 (1) ◽  
Author(s):  
Albert A. Smith ◽  
Alexander Vogel ◽  
Oskar Engberg ◽  
Peter W. Hildebrand ◽  
Daniel Huster

AbstractBiomolecular function is based on a complex hierarchy of molecular motions. While biophysical methods can reveal details of specific motions, a concept for the comprehensive description of molecular dynamics over a wide range of correlation times has been unattainable. Here, we report an approach to construct the dynamic landscape of biomolecules, which describes the aggregate influence of multiple motions acting on various timescales and on multiple positions in the molecule. To this end, we use 13C NMR relaxation and molecular dynamics simulation data for the characterization of fully hydrated palmitoyl-oleoyl-phosphatidylcholine bilayers. We combine dynamics detector methodology with a new frame analysis of motion that yields site-specific amplitudes of motion, separated both by type and timescale of motion. In this study, we show that this separation allows the detailed description of the dynamic landscape, which yields vast differences in motional amplitudes and correlation times depending on molecular position.


Sign in / Sign up

Export Citation Format

Share Document