scholarly journals Insights into the Photophysics and Supramolecular Organization of Congo Red in Solution and the Solid State

ChemPhysChem ◽  
2017 ◽  
Vol 18 (5) ◽  
pp. 564-575 ◽  
Author(s):  
Ana L. Costa ◽  
Ana C. Gomes ◽  
Martyn Pillinger ◽  
Isabel S. Gonçalves ◽  
João Pina ◽  
...  
Keyword(s):  
Solid State ◽  
Congo Red ◽  
Supramolecular Organization

scholarly journals Amyloids, Congo red and the apple-green effect

2019 ◽  
Author(s):  
Anna Jagusiak ◽  
Joanna Rybarska ◽  
Leszek Konieczny ◽  
Barbara Piekarska ◽  
Barbara Stopa ◽  
...  
Keyword(s):  
Polyvinyl Alcohol ◽  
Congo Red ◽  
Amyloid Fibril ◽  
Polarized Light ◽  
Electron Delocalization ◽  
Supramolecular Organization ◽  
Spectral Variability ◽  
Spectral Changes ◽  
Strong Capacity ◽  
Nonlinear Increase

This paper attempts to find evidence of the previously proposed opinion that amyloids complex with Congo red molecules which preserve their supramolecular organization. As evidence of the overpowering tendency of Congo red molecules to self-assemble, we present an increasing acidity of molecules that follows increasing concentration of the dye, and a highly notable nonlinear increase in absorbance in the UV band (300–400 nm). This effect is analyzed in a model where the amyloid fibril is simulated by polyvinyl alcohol, providing a scaffold to stabilize a long Congo red micelle. Enormous absorbance in the UV band, coupled with the increasing association capabilities of individual Congo red molecules may cause the absorbance to extend even into the visible band. In addition, the UV and visual absorbance bands shift significantly, depending on conditions, and may either approach or recede from each other, leading to spectral changes which may be observed under polarized light. This commonly observed spectral variability appears to be associated with the strong capacity for electron delocalization in supramolecular Congo red complexed with amyloids.

Supramolecular Organization and Evaporation of Polymeric Tin Trifluoroacetates

2019 ◽  
Author(s):  
Goran Bacic ◽  
Conor D. Rankine ◽  
Jason D. Masuda ◽  
Derek A. Wann ◽  
Sean Barry
Keyword(s):  
Thermal Stability ◽  
Solid State ◽  
Density Functional ◽  
Chemical Vapor ◽  
Atomic Layer ◽  
Building Blocks ◽  
Supramolecular Organization ◽  
Layer Deposition ◽  
Earth Abundant ◽  
Green Potential

<div> <div> <div> <p>Simple tin carboxylates make up a family of important industrial catalysts and precursors for deposition of SnO2 thin films. However, their structures remain disparately characterized, and tin trifluoroacetates have been particularly elusive. Here we report on a combined X-ray diffraction (XRD), gas phase electron diffraction (GED) and density functional theory (DFT) study into the structure and bonding of tin(II) and tin(IV) trifluoroacetates to understand their influence on thermal stability and volatility. Tin(II) bis(trifluoroacetate) (1′) eliminates trifluoroacetic anhydride upon sublimation to form the linear polymeric hexatin(II)-di-μ -oxy-octakis-μ-trifluoroacetate (1F ), which itself sublimes (1 Torr at 191 C) as a 1:1 mixture of 1 and ditin(II)-μ-oxy-bis-μ-trifluoroacetate (1′′). Tin(IV) tetrakis(trifluoroacetate) (2F) is also polymeric in the solid state, but evaporates as a monomer at low temperatures (1 Torr at 84 ◦C). Together they make a family of multifunctional Lewis acidic and basic building blocks for supramolecular organization of clusters and polymers in the solid state. Anomalous trends in the volatility of these trifluoroacetates and their hydrogenated derivatives can be rationalized by consideration of their modes of polymerization with respect to the thermodynamics of evaporation. Both 1F and 2F combine high thermal stability and volatility, and are demonstrated to be complementary, safe, and green potential precursors for chemical vapor deposition (CVD) or atomic layer deposition (ALD) of earth-abundant transparent conducting F-doped SnO2. </p> <div><div><div> <p> </p> </div> </div> </div> </div> </div> </div>

Solid-State Supramolecular Organization of Polythiophene Chains Containing Thienothiophene Units

2009 ◽  
Vol 21 (10-11) ◽  
pp. 1193-1198 ◽  
Author(s):  
Patrick Brocorens ◽  
Antoine Van Vooren ◽  
Michael L. Chabinyc ◽  
Michael F. Toney ◽  
Maxim Shkunov ◽  
...  
Keyword(s):  
Solid State ◽  
Supramolecular Organization

scholarly journals The conformation of the Congo-red ligand bound to amyloid fibrils HET-s(218–289): a solid-state NMR study

2017 ◽  
Vol 69 (4) ◽  
pp. 207-213 ◽  
Author(s):  
Chandrakala Gowda ◽  
Giorgia Zandomeneghi ◽  
Herbert Zimmermann ◽  
Anne K. Schütz ◽  
Anja Böckmann ◽  
...  
Keyword(s):  
Solid State ◽  
Congo Red ◽  
Solid State Nmr ◽  
Amyloid Fibrils ◽  
Nmr Study

Photoexcitations in Oligothiophenes: The Role of Conformation Mobility and Intermolecular Interactions.

1999 ◽  
Vol 598 ◽  
Author(s):  
Chiara Botta ◽  
Silvia Destri ◽  
William Porzio ◽  
Gianni Bongiovanni ◽  
Andrea Mura ◽  
...  
Keyword(s):  
Optical Properties ◽  
Solid State ◽  
Intermolecular Interactions ◽  
Photophysical Properties ◽  
Supramolecular Organization ◽  
Relaxation Processes ◽  
Chain Packing ◽  
Backbone Conformation ◽  
Packing Arrangement

ABSTRACTThe optical properties of substituted and unsubstituted oligothiophenes are analysed with respect to their supramolecular organization in the solid state. The spectra typical of the isolated molecules are obtained by reducing the intermolecular interactions by both lateral chain substitution and by inclusion in a host organic crystal. The photophysical properties of the weakly interacting oligothiophenes are strongly influenced by their backbone conformation and conformational mobility. Oligomers included in the channels of a guest crystal show fast torsional relaxation processes during the photoexcitation. Powders of β-substituted oligomers display optical properties dependent on the conformation of their particular chain packing arrangement.

scholarly journals Supramolecular Chirogenesis in Bis-Porphyrin: Crystallographic Structure and CD Spectra for a Complex with a Chiral Guanidine Derivative

Symmetry ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 275
Author(s):  
Irina Osadchuk ◽  
Nele Konrad ◽  
Khai-Nghi Truong ◽  
Kari Rissanen ◽  
Eric Clot ◽  
...  
Keyword(s):  
Solid State ◽  
Computational Simulation ◽  
Spatial Arrangement ◽  
Crystallographic Structure ◽  
Supramolecular Organization ◽  
Cd Spectra ◽  
X Ray Diffraction ◽  
Guest Complex ◽  
X Ray ◽  
Host Guest Complex

The complexation of (3aR,7aR)-N-(3,5-bis(trifluoromethyl)phenyl)octahydro-2H-benzo[d]imidazol-2-imine (BTI), as a guest, to ethane-bridged bis(zinc octaethylporphyrin), bis(ZnOEP), as a host, has been studied by means of ultraviolet-visible (UV-Vis) and circular dichroism (CD) absorption spectroscopies, single crystal X-ray diffraction, and computational simulation. The formation of 1:2 host-guest complex was established by X-ray diffraction and UV-Vis titration studies. Two guest BTI molecules are located at the opposite sides of two porphyrin subunits of bis(ZnOEP) host, which is resting in the anti-conformation. The complexation of BTI molecules proceed via coordination of the imine nitrogens to the zinc ions of each porphyrin subunit of the host. Such supramolecular organization of the complex results in a screw arrangement of the two porphyrin subunits, inducing a strong CD signal in the Soret (B) band region. The corresponding DFT computational studies are in a good agreement with the experimental results and prove the presence of 1:2 host-guest complex as the major component in the solution (97.7%), but its optimized geometry differs from that observed in the solid-state. The UV-Vis and CD spectra simulated by using the solution-state geometry and the TD-DFT/ωB97X-D/cc-pVDZ + SMD (CH2Cl2) level of theory reproduced the experimentally obtained UV-Vis and CD spectra and confirmed the difference between the solid-state and solution structures. Moreover, it was shown that CD spectrum is very sensitive to the spatial arrangement of porphyrin subunits.

scholarly journals DNP-supported solid-state NMR studies of 13C,15N,29Si-enriched biosilica of Cyclotella cryptica and Thalassiosira pseudonana

2021 ◽  
Vol 1 (1) ◽  
Author(s):  
Helena Leona Ehren ◽  
Felicitas Kolbe ◽  
Alessandra Lucini Paioni ◽  
Eike Brunner ◽  
Marc Baldus
Keyword(s):  
Solid State ◽  
Solid State Nmr ◽  
Nuclear Polarization ◽  
Thalassiosira Pseudonana ◽  
Supramolecular Organization ◽  
Structural Elements ◽  
Nmr Studies ◽  
Amine Nitrogen ◽  
Nmr Signals ◽  
Cyclotella Cryptica

AbstractSolid-state NMR spectroscopy represents a powerful method for the investigation of diatom biosilica but detailed studies regarding its chemical composition and structural organization can be prohibited by insufficient spectroscopic sensitivity. Here, we used two-dimensional (2D) Dynamic Nuclear Polarization (DNP)-supported solid-state NMR experiments to obtain information about the molecular composition and supramolecular organization of proteins and carbohydrates in 13C,15N,29Si-labeled biosilica of C. cryptica. As a reference, we conducted DNP experiments on isotope-labeled biosilica of T. pseudonana. DNP-enhancement factors for different NMR signals, and thus, for different organic compounds, provide information about the supramolecular architecture of the biosilica. In addition, DNP-supported heteronuclear nitrogen-carbon correlation experiments allowed us to prove the presence of different structural elements of long chain polyamines (LCPAs) and revealed the occurrence of amine-nitrogen moieties exhibiting a correlation with carbonyl carbons that may indicate cross-linking of LCPAs to proteins as previously seen in studies on proteins extracted from other diatoms.

scholarly journals DNP-Supported Solid-State NMR Studies of 13C,15N,29Si-Enriched Biosilica of Cyclotella Cryptica and Thalassiosira Pseudonana

2020 ◽  
Author(s):  
Helena Ehren ◽  
Felicitas Kolbe ◽  
Alesandra Lucini Paioni ◽  
Eike Brunner ◽  
Marc Baldus
Keyword(s):  
Solid State ◽  
Solid State Nmr ◽  
Nuclear Polarization ◽  
Thalassiosira Pseudonana ◽  
Supramolecular Organization ◽  
Powerful Method ◽  
Nmr Studies ◽  
Amine Nitrogen ◽  
Nmr Signals ◽  
Cyclotella Cryptica

Abstract Solid-state NMR spectroscopy represents a powerful method for the investigation of diatom biosilica but detailed studies regarding its chemical composition and structural organization can be prohibited by insufficient spectroscopic sensitivity. Here, we used two-dimensional (2D) Dynamic Nuclear Polarization (DNP)-supported solid-state NMR experiments to obtain information about the molecular composition and supramolecular organization of proteins and carbohydrates in13C,15N,29Si-labeled biosilica of C. cryptica. As a reference, we conducted DNP experiments on isotope-labeled biosilica of T. pseudonana. DNP-enhancement factors for different NMR signals, and thus, for different organic compounds, provide information about the supramolecular architecture of the biosilica. In addition, DNP-supported heteronuclear nitrogen-carbon correlation experiments allowed us to prove the presence of different LCPAs (long chain polyamines) and revealed the occurrence of amine-nitrogen moieties exhibiting a correlation with carbonyl carbons that may indicate cross-linking of LCPAs to proteins as previously seen in studies on proteins extracted from other diatoms.

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