Crystal polymorphism and crystalline-state photochromism of a rhodium dithionite complex with n-methoxypropyl moieties

CrystEngComm ◽  
2022 ◽  
Author(s):  
Yuu Kajiwara ◽  
Hidetaka Nakai
Keyword(s):  
Crystalline State ◽  
Dinuclear Complex ◽  
Crystal Polymorphism ◽  
Polymorphic Crystals

A rhodium dinuclear complex having n-methoxypropyltetramethylcyclopentadienyl (CpMPro = η5-C5Me4n-C3H6OCH3) and photoresponsive dithionite (μ-O2SSO2) ligands, [(CpMProRh)2(μ-CH2)2(μ-O2SSO2] (1MPro), was found to form two polymorphic crystals (a previously reported brock-like α-crystal and a...

Crystal Polymorphism of 1-Butyl-3-methylimidazolium Hexafluorophosphate: Phase Diagram, Structure, and Dynamics

2019 ◽  
Vol 72 (2) ◽  
pp. 11 ◽  
Author(s):  
Takatsugu Endo ◽  
Kozo Fujii ◽  
Keiko Nishikawa
Keyword(s):  
Phase Diagram ◽  
Thermal Hysteresis ◽  
Current Status ◽  
Ion Structure ◽  
Crystal Polymorphism ◽  
Structure And Dynamics ◽  
X Ray Scattering ◽  
Polymorphic Crystals ◽  
Temperature And Pressure ◽  
Calorimetric Studies

The ionic liquid (IL), 1-butyl-3-methylimidazolium hexafluorophosphate ([C4mim]PF6), is one of the most representative ILs. Despite its relatively simple ion structure and popularity, [C4mim]PF6 shows complex and confusing thermal phase behaviours, which stem from crystal polymorphism associated with cation conformational change and large thermal hysteresis. To the best of our knowledge, [C4mim]PF6 is the most investigated IL in terms of phase diagram, whereas full understanding has not yet been achieved due to its complexity. Here we review the current status of understanding of the phase diagram and structure/dynamics of each crystalline phase. Presently, depending on temperature and pressure, five structurally different polymorphic crystals have been reported as α, β, γ, δ, and δ’ in addition to some unspecified phases implied by calorimetric studies. Particularly for the α, β and γ phases, the structure and dynamics are well investigated by Raman, NMR, and X-ray scattering techniques.

Unusual motion of n-methoxypropyl moiety observed in the photochromic crystals of an organorhodium dithionite complex with n-methoxypropyltetramethylcyclopentadienyl ligands

2021 ◽  
Author(s):  
Yuu Kajiwara ◽  
Seiya Miyata ◽  
Hidetaka Nakai
Keyword(s):  
Single Crystal ◽  
Conformational Change ◽  
Crystalline State ◽  
Dinuclear Complex ◽  
X Ray Diffraction ◽  
X Ray

Crystalline-state photochromism of a new organorhodium dinuclear complex having n-methoxypropyltetramethylcyclopentadienyl (η-C5Me4n-C3H6OCH3) and photoresponsive dithionite (μ-O2SSO2) ligands was investigated directly by performing single crystal X-ray diffraction experiments; reversible conformational change of...

Imaging modulated reflections from a semi-crystalline state of profilin:actin crystals

2004 ◽  
Vol 37 (2) ◽  
pp. 327-330 ◽  
Author(s):  
J. J. Lovelace ◽  
K. Narayan ◽  
J. K. Chik ◽  
H. D. Bellamy ◽  
E. H. Snell ◽  
...  
Keyword(s):  
Image Processing ◽  
Data Collection ◽  
Small Molecule ◽  
Structure Determination ◽  
Preliminary Data ◽  
Crystalline State ◽  
Biological Significance ◽  
Protein Crystals ◽  
Terra Incognita ◽  
Polymorphic Crystals

Modulated protein crystals remainterra incognitafor most crystallographers. While small-molecule crystallographers have successfully wrestled with and conquered this type of structure determination, to date no modulated macromolecular structures have been reported. Profilin:β-actin in a modulated semi-crystalline state presents a challenge of sufficient biological significance to motivate the development of methods for the accurate collection of data on the complex diffraction pattern and, ultimately, the solution of its structure. In the present work, fine φ-sliced data collection was used to resolve the closely spaced satellite reflections from these polymorphic crystals. Image-processing methods were used to visualize these data for comparison with the original precession data. These preliminary data demonstrate the feasibility of using fine φ-slicing to collect accurately the intensities and positions of the main and satellite reflections from these modulated protein crystals.

Self-Assembly Optical Components

2003 ◽  
Vol 771 ◽  
Author(s):  
Pavel I. Lazarev ◽  
Michael V. Paukshto ◽  
Elena N. Sidorenko
Keyword(s):  
Optical Properties ◽  
Self Assembly ◽  
Crystalline State ◽  
Liquid Crystalline ◽  
Film Deposition ◽  
X Ray Diffraction ◽  
Optical Components ◽  
Crystal Film ◽  
Solid Film ◽  
Thin Crystal

AbstractWe report a new method of Thin Crystal Film deposition. In the present paper we describe the method of crystallization, structure, and optical properties of Bisbenzimidazo[2,1-a:1',2',b']anthra[2,1,9-def:6,5,10-d'e'f']-diisoquinoline-6,9-dion (mixture with cis-isomer) (abbreviated DBI PTCA) sulfonation product. The Thin Crystal Film has a thickness of 200-1000 nm, with anisotropic optical properties such as refraction and absorption indices. X-ray diffraction data evidences a lyotropic liquid crystalline state in liquid phase and crystalline state in solid film. Anisotropic optical properties of the film make it useful in optical devices, e.g. liquid crystal displays.

Azobenzene Crystal Polymorphism Enables Tuneable Photoinduced Deformation, Mechanical Behaviors and Photoluminescent Properties

2021 ◽  
Author(s):  
Yunhui Hao ◽  
Lei Gao ◽  
Xiunan Zhang ◽  
Rongli Wei ◽  
Ting Wang ◽  
...  
Keyword(s):  
Smart Materials ◽  
Molecular Crystals ◽  
Stimuli Responsive ◽  
Mechanical Behaviors ◽  
Crystal Polymorphism

Stimuli-responsive molecular crystals are fascinating for their potential as adaptive smart materials. However, achieving one crystal that could respond to multiple stimuli and perform multiple functionalities simultaneously is still challenging....

scholarly journals Nanocrystal-Loaded Micelles for the Enhanced In Vivo Circulation of Docetaxel

Molecules ◽  
2021 ◽  
Vol 26 (15) ◽  
pp. 4481
Author(s):  
Meng Cheng ◽  
Qiaoming Liu ◽  
Tiantian Gan ◽  
Yuanying Fang ◽  
Pengfei Yue ◽  
...  
Keyword(s):  
Thin Film ◽  
Retention Time ◽  
Blood Circulation ◽  
Crystalline State ◽  
Circulation System ◽  
Particle Sizes ◽  
High Pressure Homogenization ◽  
Rapid Dissolution ◽  
Efficient Route

Prolonging in vivo circulation has proved to be an efficient route for enhancing the therapeutic effect of rapidly metabolized drugs. In this study, we aimed to construct a nanocrystal-loaded micelles delivery system to enhance the blood circulation of docetaxel (DOC). We employed high-pressure homogenization to prepare docetaxel nanocrystals (DOC(Nc)), and then produced docetaxel nanocrystal-loaded micelles (DOC(Nc)@mPEG-PLA) by a thin-film hydration method. The particle sizes of optimized DOC(Nc), docetaxel micelles (DOC@mPEG-PLA), and DOC(Nc)@mPEG-PLA were 168.4, 36.3, and 72.5 nm, respectively. The crystallinity of docetaxel was decreased after transforming it into nanocrystals, and the crystalline state of docetaxel in micelles was amorphous. The constructed DOC(Nc)@mPEG-PLA showed good stability as its particle size showed no significant change in 7 days. Despite their rapid dissolution, docetaxel nanocrystals exhibited higher bioavailability. The micelles prolonged the retention time of docetaxel in the circulation system of rats, and DOC(Nc)@mPEG-PLA exhibited the highest retention time and bioavailability. These results reveal that constructing nanocrystal-loaded micelles may be a promising way to enhance the in vivo circulation and bioavailability of rapidly metabolized drugs such as docetaxel.

scholarly journals Selective Ion Exchange in Supramolecular Channels in the Crystalline State

2019 ◽  
Vol 58 (13) ◽  
pp. 4169-4172 ◽  
Author(s):  
Katsuya Ichihashi ◽  
Daisuke Konno ◽  
Kseniya Yu. Maryunina ◽  
Katsuya Inoue ◽  
Kazuhiro Toyoda ◽  
...  
Keyword(s):  
Ion Exchange ◽  
Crystalline State
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