scholarly journals Novel Quinolizine AIE System: Visualization of Molecular Motion and Elaborate Tailoring for Biological Application

2021 ◽  
Author(s):  
Benzhao He ◽  
Jiachang Huang ◽  
Jianyu Zhang ◽  
Herman H. Y. Sung ◽  
Jacky W. Y. Lam ◽  
...  
Keyword(s):  
Single Molecule ◽  
Molecular Motion ◽  
Molecular Motions ◽  
Ideal Model ◽  
Intramolecular Vibration ◽  
Fluorescence Change ◽  
Intrinsic Roles ◽  
Application Potential ◽  
Vibration Mechanism ◽  
Species Production

Molecular motions are ubiquitous in nature and they immutably play intrinsic roles in all actions. However, exploring appropriate models to decipher molecular motions is an extremely important but very challenging task for researchers. Considering aggregation-induced emission (AIE) luminogens possess their unique merits to visualize molecular motions, it is particularly fascinating to construct new AIE systems as model to study molecular motion. Herein, a novel quinolizine (QLZ) AIE system was constructed based on the restriction intramolecular vibration mechanism. It was demonstrated that QLZ could act as an ideal model to visualize single-molecule motion and macroscopic molecular motion via fluorescence change. Additionally, further elaborate tailoring of this impressive core achieved highly efficient reactive oxygen species production and realized fluorescence imaging-guided photodynamic therapy applications, which confirms the great application potential of this new AIE-active QLZ core. Therefore, this work not only provides an ideal model to visualize molecular motion but also opens a new way for the application of AIEgens.

Non-Markovian Dynamic And Nmr Spectra In Solids

2004 ◽  
Vol 59 (7-8) ◽  
pp. 501-504 ◽  
Author(s):  
M. Olszewski ◽  
N. A. Sergeev ◽  
A.V. Sapiga
Keyword(s):  
Markov Model ◽  
Temperature Dependence ◽  
Absorption Spectra ◽  
Nmr Spectra ◽  
Molecular Motion ◽  
Molecular Motions ◽  
Dichotomic Noise

The influence of non-Markov molecular motions on NMR absorption spectra has been investigated. It has been shown that the simple non-Markov model of water molecular motion with fluctuations driven by dichotomic noise very well explains the observed temperature dependence of NMR spectra in the mineral natrolite. - PACS number: 05.40.+j, 33.25.+k, 76.20.+q

scholarly journals Computational Tool for Ensemble Averaging of Single-Molecule Data

2020 ◽  
Author(s):  
Thomas Blackwell ◽  
W. Tom Stump ◽  
Sarah R. Clippinger ◽  
Michael J. Greenberg
Keyword(s):  
Brownian Motion ◽  
User Interface ◽  
Single Molecule ◽  
Conformational Changes ◽  
Graphical User Interface ◽  
Molecular Motions ◽  
Computational Tool ◽  
Ensemble Averaging ◽  
Mechanochemical Coupling ◽  
Kinetics Of

AbstractMolecular motors couple chemical transitions to conformational changes that perform mechanical work in a wide variety of biological processes. Disruption of this coupling can lead to diseases, and therefore there is a need to accurately measure mechanochemical coupling in motors in both health and disease. Optical tweezers, with nanometer spatial and millisecond temporal resolution, have provided valuable insights into these processes. However, fluctuations due to Brownian motion can make it difficult to precisely resolve these conformational changes. One powerful analysis technique that has improved our ability to accurately measure mechanochemical coupling in motor proteins is ensemble averaging of individual trajectories. Here, we present a user-friendly computational tool, Software for Precise Analysis of Single Molecules (SPASM), for generating ensemble averages of single-molecule data. This tool utilizes several conceptual advances, including optimized procedures for identifying single-molecule interactions and the implementation of a change point algorithm, to more precisely resolve molecular transitions. Using both simulated and experimental data, we demonstrate that these advances allow for accurate determination of the mechanics and kinetics of the myosin working stroke with a smaller set of data. Importantly, we provide our open source MATLAB-based program with a graphical user interface that enables others to readily apply these advances to the analysis of their own data.Statement of SignificanceSingle molecule optical trapping experiments have given unprecedented insights into the mechanisms of molecular machines. Analysis of these experiments is often challenging because Brownian motion-induced fluctuations introduce noise that can obscure molecular motions. A powerful technique for analyzing these noisy traces is ensemble averaging of individual binding interactions, which can uncover information about the mechanics and kinetics of molecular motions that are typically obscured by Brownian motion. Here, we provide an open source, easy-to-use computational tool, SPASM, with a graphical user interface for ensemble averaging of single molecule data. This computational tool utilizes several conceptual advances that significantly improve the accuracy and resolution of ensemble averages, enabling the generation of high-resolution averages from a smaller number of binding interactions.

Molecular Motions in (CH3)3XCl, X = Sn and Pb. NMR Investigations and Crystal Structure Study of (CH3)3PbCl and CH3SnBr3

1991 ◽  
Vol 46 (4) ◽  
pp. 337-343 ◽  
Author(s):  
Da Zhang ◽  
Shi-Qi Dou ◽  
Alarich Weiss
Keyword(s):  
Molecular Motion ◽  
Structure Study ◽  
Methyl Groups ◽  
Monoclinic Space Group ◽  
Molecular Motions ◽  
X Ray Diffraction ◽  
Orthorhombic Space Group ◽  
Space Group ◽  
X Ray ◽  
Group D

Abstract The molecular motion in (CH3)3XCl, X = Sn and Pb has been investigated by measurement of the second moment M2(1H) as function of temperature in the range 95 < T,/K<345. The methyl groups in both compounds rotate freely over the whole temperature range studied. In (CH3)3SnCl the C'3-rotation of (CH3)3Sn-group about the Sn CI axis sets in above 273 K. To explain the NMR and INS results, the crystal structures of (CH3)3PbCl and CH3SnBr3 were determined by single X-ray diffraction. (CH3)3PbCl crystallizes in a monoclinic space group C32-C2, a = 1276.7(3) pm, b = 982.3(3) pm, c = 547.0(2) pm, ß = 91.12(1)°; Z = 4, R = 0.035. CH3SnBr3 crystallizes in an orthorhombic space group D162h-Pnma, a = 643.0(3) pm, b= 1005.3(4) pm, c= 1148.0(4) pm; Z = 4, R =0.057

MOLECULAR MOTION IN NANOCHANNELS: SINGLE MOLECULE EVIDENCE AND MULTISCALE SIMULATION

2008 ◽  
Author(s):  
A. P. Netti ◽  
I. De Santo ◽  
M. S. Panemi ◽  
S. Pricl ◽  
Alberto D’Amore ◽  
...  
Keyword(s):  
Single Molecule ◽  
Molecular Motion ◽  
Multiscale Simulation

scholarly journals How Do Molecular Motions Affect Structures and Properties at Molecule and Aggregate Levels?

2021 ◽  
Author(s):  
Deshuang Tu ◽  
Jianyu Zhang ◽  
Yunxiao Zhang ◽  
Herman H.-Y. Sung ◽  
Lijie Liu ◽  
...  
Keyword(s):  
Single Molecule ◽  
Organic Crystals ◽  
Molecular Motions ◽  
Aggregate State ◽  
Reversible Deformation ◽  
Single Molecule Level ◽  
Weak Intermolecular Interactions ◽  
Structures And Properties ◽  
Intramolecular Motions ◽  
Bright Emission

<p>Experimental and theoretical analysis demonstrated that the active intramolecular motions in the excited state of all molecules at single molecule level imparted them with more twisted structural conformations and weak emission. However, owing to the restriction of intramolecular motions in the nano/macro aggregate state, all the molecules assumed less twisted conformations with bright emission. Synergic strong and weak intermolecular interactions allowed their crystals to undergo reversible deformation, which effectively solved the problem of the brittles of organic crystals, meanwhile imparted them with excellent elastic performance. </p>

Student-generated PowerPoint animations: a study of student teachers’ conceptions of molecular motions through their expressed models

2021 ◽  
Author(s):  
Guspatni Guspatni
Keyword(s):  
Student Teachers ◽  
Molecular Motion ◽  
Water Molecules ◽  
Molecular Motions ◽  
Chemistry Student ◽  
Other Information ◽  
Computer Based ◽  
Almost All ◽  
Written Explanations ◽  
Media And Technology

Student-generated drawings are known to be effective in building and revealing students’ conceptions of chemistry. Some chemistry concepts, moreover, include changes and processes that cannot be merely represented by static drawings. Computer-based animations are needed to represent the dynamics. In this study, 25 chemistry student teachers, who had studied the concept of molecular motions and had taken the course of Chemistry Instructional Media and Technology, were assigned to make expressed models of water molecules’ motions in the form of animations with PowerPoint, the most familiar program and installed on students’ computers. Students were also assigned to give written explanations of the three molecular motions. Within one month, both tasks were due simultaneously. Students’ expressed models were analysed based on Custom Animation features used for the animations, while students’ written explanations were analysed based on the typology of the sentences. It was found that all students appeared to hold correct conceptions of translation; many students appeared to hold correct conceptions of rotation; and almost all students appeared to hold misconceptions of vibration. There was no substantial difference between PowerPoint Animations and written explanations in revealing students’ conceptions of molecular motions. However, there were several inconsistencies of students’ conceptions that occurred in both tasks. For example, several students who incorrectly explained rotation as circular movements displayed a spinning of the particle on its own axis in the animation. Students’ expressed models in PowerPoint Animations provided other information unrevealed in their written explanations. These pieces of information included types of molecular motion in different phases, simultaneous motions, and deflections of molecules after collisions. The analysis of students’ expressed models in PowerPoint Animations can be an effective approach to reveal students’ conceptions of molecular dynamics if accompanied by adequate tutorials on the animation program, clear instructions, and guidance to get learning resources.

scholarly journals How Do Molecular Motions Affect Structures and Properties at Molecule and Aggregate Levels?

2021 ◽  
Author(s):  
Deshuang Tu ◽  
Jianyu Zhang ◽  
Yunxiao Zhang ◽  
Herman H.-Y. Sung ◽  
Lijie Liu ◽  
...  
Keyword(s):  
Single Molecule ◽  
Organic Crystals ◽  
Molecular Motions ◽  
Aggregate State ◽  
Reversible Deformation ◽  
Single Molecule Level ◽  
Weak Intermolecular Interactions ◽  
Structures And Properties ◽  
Intramolecular Motions ◽  
Bright Emission

<p>Experimental and theoretical analysis demonstrated that the active intramolecular motions in the excited state of all molecules at single molecule level imparted them with more twisted structural conformations and weak emission. However, owing to the restriction of intramolecular motions in the nano/macro aggregate state, all the molecules assumed less twisted conformations with bright emission. Synergic strong and weak intermolecular interactions allowed their crystals to undergo reversible deformation, which effectively solved the problem of the brittles of organic crystals, meanwhile imparted them with excellent elastic performance. </p>

scholarly journals Visualizing Solid-State Molecular Motion by a Common Structural Determination Technique

2019 ◽  
Author(s):  
Jun Zhang ◽  
Haoke Zhang ◽  
Junkai Liu ◽  
Jacky W. Y. Lam ◽  
Ben Zhong Tang
Keyword(s):  
Solid State ◽  
Molecular Motion ◽  
Testing Temperature ◽  
Vital Role ◽  
Structural Determination ◽  
Molecular Motions ◽  
X Ray Diffraction ◽  
Phenyl Rings ◽  
Common Technique ◽  
Intramolecular Motions

Solid-state molecular motion plays a vital role in many advanced technologies. However, visualization of these processes is still challenging due to the limitation of characterization method. In this work, a common structural determination technique, single-crystal X-ray diffraction, is applied to “see” the static and dynamic molecular motions in tetraphenylethylene (TPE) which exhibits aggregation-induce emission (AIE) effect. Five kinds of motions, stretching, torsion, twisting, rocking, and wagging are observed and analyzed. As the static molecular motions, the middle double bond in TPE becomes short and twisted and the peripheral phenyl rings as a whole tend to be more twisted with the raising of testing temperature (150 to 298 K). Meanwhile, dynamic motions of phenyl-rings rocking and wagging are found to be more and more vigorous along with the increase of temperature. This work provides a platform for visualizing solid-state molecular motion based on a common technique. It also affords direct evidence for the AIE mechanism of restriction of intramolecular motions.

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