Corrole basicity in the excited states: Insights on structure–property relationships

2020 ◽  
Vol 24 (05n07) ◽  
pp. 765-774
Author(s):  
Mikalai M. Kruk ◽  
Dmitry V. Klenitsky ◽  
Lev L. Gladkov ◽  
Wouter Maes
Keyword(s):  
Excited States ◽  
Conformational Changes ◽  
Pyrrole Ring ◽  
Point Of View ◽  
Free Base ◽  
Structure Property ◽  
Substitution Pattern ◽  
Long Wavelength ◽  
Structure Property Relationships ◽  
Fluorescence Measurements

Steady-state fluorescence measurements and quantum-chemical DFT geometry optimizations are applied to extend the structure–property relationships between the free-base corrole macrocycle conformation and its basicity to the lowest excited S[Formula: see text] and T[Formula: see text] states. Direct basicity estimation in the lowest excited S[Formula: see text] state is demonstrated by means of fluorescence quantum yield measurements. The long wavelength T1 tautomer is found to retain its basicity in the S[Formula: see text] state, whereas the short wavelength T2 tautomer shows a noticeable decrease in basicity in the S[Formula: see text] state, which is related to the in-plane tilting of the pyrrole ring to be protonated. The conformational changes upon going from the ground to the lowest excited T[Formula: see text] state and the influence of the meso-aryl substitution pattern on the overall degree of distortions and tilting of the pyrrole ring to be protonated are also discussed from the point of view of macrocycle basicity.

scholarly journals Barbituric Acid Based Fluorogens: Synthesis, Aggregation-Induced Emission, and Protein Fibril Detection

Molecules ◽  
2019 ◽  
Vol 25 (1) ◽  
pp. 32 ◽  
Author(s):  
Siyang Ding ◽  
Bicheng Yao ◽  
Louis Schobben ◽  
Yuning Hong
Keyword(s):  
Barbituric Acid ◽  
Fluorescent Dyes ◽  
Photophysical Properties ◽  
Wavelength Region ◽  
Structure Property ◽  
Aggregation Induced Emission ◽  
Long Wavelength ◽  
Structure Property Relationships ◽  
Potential Applications ◽  
Protein Fibril

Fluorescent dyes, especially those emitting in the long wavelength region, are excellent candidates in the area of bioassay and bioimaging. In this work, we report a series of simple organic fluorescent dyes consisting of electron-donating aniline groups and electron-withdrawing barbituric acid groups. These dyes are very easy to construct while emitting strongly in the red region in their solid state. The photophysical properties of these dyes, such as solvatochromism and aggregation-induced emission, are systematically characterized. Afterward, the structure–property relationships of these barbituric acid based fluorogens are discussed. Finally, we demonstrate their potential applications for protein amyloid fibril detection.

scholarly journals Towards low-energy-light-driven bistable photoswitches: ortho-fluoroaminoazobenzenes

2021 ◽  
Author(s):  
Kim Kuntze ◽  
Jani Viljakka ◽  
Evgenii Titov ◽  
Zafar Ahmed ◽  
Elina Kalenius ◽  
...  
Keyword(s):  
Visible Light ◽  
Excited States ◽  
Quantum Chemical ◽  
Low Energy ◽  
Living Systems ◽  
Structure Property ◽  
Structure Property Relationships ◽  
Thermal Stability Of ◽  
Insight Into ◽  
Cis Isomer

Abstract Thermally stable photoswitches that are driven with low-energy light are rare, yet crucial for extending the applicability of photoresponsive molecules and materials towards, e.g., living systems. Combined ortho-fluorination and -amination couples high visible-light absorptivity of o-aminoazobenzenes with the extraordinary bistability of o-fluoroazobenzenes. Herein, we report a library of easily accessible o-aminofluoroazobenzenes and establish structure–property relationships regarding spectral qualities, visible light isomerization efficiency and thermal stability of the cis-isomer with respect to the degree of o-substitution and choice of amino substituent. We rationalize the experimental results with quantum chemical calculations, revealing the nature of low-lying excited states and providing insight into thermal isomerization. The synthesized azobenzenes absorb at up to 600 nm and their thermal cis-lifetimes range from milliseconds to months. The most unique example can be driven from trans to cis with any wavelength from UV up to 595 nm, while still exhibiting a thermal cis-lifetime of 81 days.

Dithienopyrrole-based Organic Electroactive Materials and Their Photovoltaic Aspects

2020 ◽  
Vol 24 (23) ◽  
pp. 2695-2736
Author(s):  
Renata Rybakiewicz ◽  
Łukasz Skórka ◽  
Roman Gańczarczyk
Keyword(s):  
Molecular Weight ◽  
Building Block ◽  
Pyrrole Ring ◽  
Structure Property ◽  
Practical Application ◽  
Electroactive Materials ◽  
Structure Property Relationships ◽  
High Molecular Weight Species ◽  
Donor Acceptor ◽  
Fused Thiophenes

4H-dithieno[3,2-b:2',3'-d]pyrrole has recently become a useful building block in the synthesis of donor-acceptor molecules with practical application in various organic technologies. The DTP molecule itself consists of a pyrrole ring with two fused thiophenes providing an alternative for the related dithieno[3,2-b:2′,3′-d]thiophene. Most notably, the significance of DTP-based low- and high-molecular weight species has increased in recent years since, upon proper processing, they allow to improve the performance of many fields of organic electronics. This review is a trial of a brief report on recent advances in modern DTP chemistry with examples of their applications, mostly in the area of organic photovoltaics. The scope of this manuscript was to present the structure-property relationships that had been found together with the development of DTP-based materials.

Chemical Design and Structural Chemistry of Lwir Optical Materials

1990 ◽  
Vol 216 ◽  
Author(s):  
C.K. Lowe-Ma ◽  
D.O. Kipp ◽  
T.A. Vanderah
Keyword(s):  
Crystal Structure ◽  
Electronic Configuration ◽  
Structure Type ◽  
Optical Transparency ◽  
Structure Property ◽  
Long Wavelength ◽  
Structure Property Relationships ◽  
New Compounds ◽  
Long Wavelength Infrared

ABSTRACTSome applications for long-wavelength infrared (LWIR) windows require environmental durability and mechanical strength in addition to infrared optical transparency; i.e., the windows must simultaneously serve as optical and as structural ceramics. The requirement of optical transparency at long IR wavelengths eliminates from consideration all ceramics based on oxides and other light-anion compounds, making this a particularly difficult materials problem. The structure-property relationships and chemical rationale used to guide both the screening of known compounds and the synthesis of new compounds likely to possess the desired properties rely on factors such as atomic mass, electronic configuration, coordination number, and crystal structure type.Our research has included the directed synthesis and characterization of a number of ternary indium sulfides as well as ternary calcium yttrium sulfides. Ternary indium sulfides feature both tetrahedral and octahedral coordination of indium. The crystal structure of KInS2 and its relationship to structures observed in other systems such as AIn2S4, A = Ca,Sr,Ba, is described. The crystal structure of CaY2S4 along with studies of yttrium-doped CaS are also described. The AIn2S4 compounds are more fully described in references [1] and [2].

scholarly journals Towards low-energy-light-driven bistable photoswitches: ortho-fluoroaminoazobenzenes

2021 ◽  
Author(s):  
Kim Kuntze ◽  
Jani Viljakka ◽  
Evgenii Titov ◽  
Zafar Ahmed ◽  
Elina Kalenius ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Visible Light ◽  
Excited States ◽  
Quantum Chemical ◽  
Low Energy ◽  
Living Systems ◽  
Structure Property ◽  
Structure Property Relationships ◽  
Thermal Stability Of ◽  
Insight Into

AbstractThermally stable photoswitches that are driven with low-energy light are rare, yet crucial for extending the applicability of photoresponsive molecules and materials towards, e.g., living systems. Combined ortho-fluorination and -amination couples high visible light absorptivity of o-aminoazobenzenes with the extraordinary bistability of o-fluoroazobenzenes. Herein, we report a library of easily accessible o-aminofluoroazobenzenes and establish structure–property relationships regarding spectral qualities, visible light isomerization efficiency and thermal stability of the cis-isomer with respect to the degree of o-substitution and choice of amino substituent. We rationalize the experimental results with quantum chemical calculations, revealing the nature of low-lying excited states and providing insight into thermal isomerization. The synthesized azobenzenes absorb at up to 600 nm and their thermal cis-lifetimes range from milliseconds to months. The most unique example can be driven from trans to cis with any wavelength from UV up to 595 nm, while still exhibiting a thermal cis-lifetime of 81 days. Graphical abstract

scholarly journals Dynamic nature of excited states of donor–acceptor TADF materials for OLEDs: how theory can reveal structure–property relationships

2017 ◽  
Vol 5 (23) ◽  
pp. 5718-5729 ◽  
Author(s):  
Yoann Olivier ◽  
Mónica Moral ◽  
Luca Muccioli ◽  
Juan-Carlos Sancho-García
Keyword(s):  
Excited States ◽  
Theoretical Study ◽  
Light Emission ◽  
Structure Property ◽  
Dynamic Nature ◽  
Structure Property Relationships ◽  
Donor Acceptor ◽  
Torsional Potentials

In a theoretical study, we characterized the nature of the key excited states involved in the TADF process of donor–acceptor compounds and showed that light emission is enhanced by dynamic fluctuations of the donor–acceptor torsion resulting from flat torsional potentials.

scholarly journals Impact of Substitution Pattern and Chain Length on the Thermotropic Properties of Alkoxy-Substituted Triphenyl-Tristriazolotriazines

Molecules ◽  
2020 ◽  
Vol 25 (23) ◽  
pp. 5761
Author(s):  
Thorsten Rieth ◽  
Natalie Tober ◽  
Daniel Limbach ◽  
Tobias Haspel ◽  
Marcel Sperner ◽  
...  
Keyword(s):  
Liquid Crystalline ◽  
Structure Property ◽  
Substitution Pattern ◽  
Polarized Optical Microscopy ◽  
X Ray ◽  
Alkyl Chains ◽  
Structure Property Relationships ◽  
X Ray Scattering ◽  
Linear Chains ◽  
Thermotropic Properties

Tristriazolotriazines (TTTs) with a threefold alkoxyphenyl substitution were prepared and studied by DSC, polarized optical microscopy (POM) and X-ray scattering. Six pentyloxy chains are sufficient to induce liquid-crystalline behavior in these star-shaped compounds. Thermotropic properties of TTTs with varying substitution patterns and a periphery of linear chains of different lengths, branching in the chain and swallow-tails, are compared. Generally, these disks display broad and stable thermotropic mesophases, with the tangential TTT being superior to the radial isomer. The structure–property relationships of the number of alkyl chains, their position, length and structure were studied.

Structure-property relationships of PE/PP sandwiched films

1987 ◽  
Vol 45 ◽  
pp. 454-455
Author(s):  
J. Petermann ◽  
G. Broza ◽  
U. Rieck ◽  
A. Jaballah ◽  
A. Kawaguchi
Keyword(s):  
Mechanical Tests ◽  
Polymer Materials ◽  
Ionic Crystals ◽  
Structure Property ◽  
Polymer Systems ◽  
Structure Property Relationships ◽  
Oriented Films ◽  
Materials Used ◽  
Polymer Laminates ◽  
Heated Glass

Oriented overgrowth of polymer materials onto ionic crystals is well known and recently it was demonstrated that this epitaxial crystallisation can also occur in polymer/polymer systems, under certain conditions. The morphologies and the resulting physical properties of such systems will be presented, especially the influence of epitaxial interfaces on the adhesion of polymer laminates and the mechanical properties of epitaxially crystallized sandwiched layers.Materials used were polyethylene, PE, Lupolen 6021 DX (HDPE) and 1810 D (LDPE) from BASF AG; polypropylene, PP, (PPN) provided by Höchst AG and polybutene-1, PB-1, Vestolen BT from Chemische Werke Hüls. Thin oriented films were prepared according to the method of Petermann and Gohil, by winding up two different polymer films from two separately heated glass-plates simultaneously with the help of a motor driven cylinder. One double layer was used for TEM investigations, while about 1000 sandwiched layers were taken for mechanical tests.

Approaches for TEM imaging of cavitation in toughened nylon

1989 ◽  
Vol 47 ◽  
pp. 352-353
Author(s):  
Barbara A. Wood
Keyword(s):  
Morphological Characteristics ◽  
Structure Property ◽  
Polymer Systems ◽  
Selective Staining ◽  
Structure Property Relationships ◽  
Rubber Toughened ◽  
Shear Yield ◽  
Controversial Topic ◽  
Selection Of ◽  
Diamond Knife

A controversial topic in the study of structure-property relationships of toughened polymer systems is the internal cavitation of toughener particles resulting from damage on impact or tensile deformation.Detailed observations of the influence of morphological characteristics such as particle size distribution on deformation mechanisms such as shear yield and cavitation could provide valuable guidance for selection of processing conditions, but TEM observation of damaged zones presents some experimental difficulties.Previously published TEM images of impact fractured toughened nylon show holes but contrast between matrix and toughener is lacking; other systems investigated have clearly shown cavitated impact modifier particles. In rubber toughened nylon, the physical characteristics of cavitated material differ from undamaged material to the extent that sectioning of heavily damaged regions by cryoultramicrotomy with a diamond knife results in sections of greater than optimum thickness (Figure 1). The detailed morphology is obscured despite selective staining of the rubber phase using the ruthenium trichloride route to ruthenium tetroxide.

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