Self-assembly and coverage dependent thermally induced conformational changes of Ni(ii)-meso-tetrakis (4-tert-butylphenyl) benzoporphyrin on Cu(111)

2015 ◽  
Vol 17 (19) ◽  
pp. 13066-13073 ◽  
Author(s):  
Liang Zhang ◽  
Michael Lepper ◽  
Michael Stark ◽  
Dominik Lungerich ◽  
Norbert Jux ◽  
...  
Keyword(s):  
Conformational Changes ◽  
Self Assembly ◽  
Coupling Reaction ◽  
Conformation Change ◽  
Thermally Induced

Irreversible intramolecular conformation change induced by a coverage-dependent dehydrogenative intramolecular aryl–aryl coupling reaction was observed for Ni-TTBPBP on Cu(111).

Self-assembly multi-layer of diazonium resin and its coupling reaction with J-acid and H-acid

2007 ◽  
Vol 72 (3) ◽  
pp. 345-348 ◽  
Author(s):  
Young-A. Son ◽  
Young-Min Park ◽  
Chang-Ju Shin ◽  
Sung-Hoon Kim
Keyword(s):  
Self Assembly ◽  
Coupling Reaction

scholarly journals The effects of Ca2+ and Cd2+ on the secondary and tertiary structure of bovine testis calmodulin. A circular-dichroism study

1986 ◽  
Vol 238 (2) ◽  
pp. 485-490 ◽  
Author(s):  
S R Martin ◽  
P M Bayley
Keyword(s):  
Circular Dichroism ◽  
Conformational Changes ◽  
Metal Ion ◽  
Tertiary Structure ◽  
Thermal Unfolding ◽  
Apparent Effect ◽  
Thermally Induced ◽  
Circular Dichroïsm ◽  
Secondary And Tertiary Structure

Near-u.v. and far-u.v. c.d. spectra of bovine testis calmodulin and its tryptic fragments (TR1C, N-terminal half, residues 1-77, and TR2C, C-terminal half, residues 78-148) were recorded in metal-ion-free buffer and in the presence of saturating concentrations of Ca2+ or Cd2+ under a range of different solvent conditions. The results show the following: if there is any interaction between the N-terminal and C-terminal halves of calmodulin, it has not apparent effect on the secondary or tertiary structure of either half; the conformational changes induced by Ca2+ or Cd2+ are substantially greater in TR2C than they are in TR1C; the presence of Ca2+ or Cd2+ confers considerable stability with respect to urea-induced denaturation, both for the whole molecule and for either of the tryptic fragments; a thermally induced transition occurs in whole calmodulin at temperatures substantially below the temperature of major thermal unfolding, both in the presence and in the absence of added metal ion; the effects of Cd2+ are identical with those of Ca2+ under all conditions studied.

Fabrication of covalently attached conducting multilayer self-assembly film of polyaniline by in situ coupling reaction

2002 ◽  
Vol 128 (3) ◽  
pp. 305-309 ◽  
Author(s):  
Yongjun Zhang ◽  
Ying Guan ◽  
Jin Liu ◽  
Jian Xu ◽  
Weixiao Cao
Keyword(s):  
Self Assembly ◽  
Coupling Reaction

Thermally Induced Self-Assembly and Cyclization of l-Leucyl-l-Leucine in Solid State

2017 ◽  
Vol 121 (36) ◽  
pp. 8603-8610 ◽  
Author(s):  
Marat A. Ziganshin ◽  
Aisylu S. Safiullina ◽  
Alexander V. Gerasimov ◽  
Sufia A. Ziganshina ◽  
Alexander E. Klimovitskii ◽  
...  
Keyword(s):  
Solid State ◽  
Self Assembly ◽  
Thermally Induced

scholarly journals Organic Nanoparticles Based on D-A-D Small Molecule: Self-Assembly, Photophysical Properties, and Synergistic Photodynamic/Photothermal Effects

Materials ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 502
Author(s):  
Liangliang Yue ◽  
Haolan Li ◽  
Qi Sun ◽  
Xiaogang Luo ◽  
Fengshou Wu ◽  
...  
Keyword(s):  
Self Assembly ◽  
Organic Molecule ◽  
High Efficiency ◽  
Photophysical Properties ◽  
Coupling Reaction ◽  
Ros Generation ◽  
Dead Cell ◽  
Minimal Invasiveness ◽  
Sonogashira Coupling Reaction ◽  
Potential Strategy

Cancer is one of the major diseases threatening human health. Traditional cancer treatments have notable side-effects as they can damage the immune system. Recently, phototherapy, as a potential strategy for clinical cancer therapy, has received wide attention due to its minimal invasiveness and high efficiency. Herein, a small organic molecule (PTA) with a D-A-D structure was prepared via a Sonogashira coupling reaction between the electron-withdrawing dibromo-perylenediimide and electron-donating 4-ethynyl-N,N-diphenylaniline. The amphiphilic organic molecule was then transformed into nanoparticles (PTA-NPs) through the self-assembling method. Upon laser irradiation at 635 nm, PTA-NPs displayed a high photothermal conversion efficiency (PCE = 43%) together with efficient reactive oxygen species (ROS) generation. The fluorescence images also indicated the production of ROS in cancer cells with PTA-NPs. In addition, the biocompatibility and photocytotoxicity of PTA-NPs were evaluated by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and live/dead cell co-staining test. Therefore, the as-prepared organic nanomaterials were demonstrated as promising nanomaterials for cancer phototherapy in the clinic.

scholarly journals A New Heterogeneous Catalyst Obtained via Supramolecular Decoration of Graphene with a Pd2+ Azamacrocyclic Complex

Molecules ◽  
2019 ◽  
Vol 24 (15) ◽  
pp. 2714 ◽  
Author(s):  
Matteo Savastano ◽  
Paloma Arranz-Mascarós ◽  
Maria Paz Clares ◽  
Rafael Cuesta ◽  
Maria Luz Godino-Salido ◽  
...  
Keyword(s):  
Heterogeneous Catalyst ◽  
Self Assembly ◽  
Room Temperature ◽  
Coupling Reaction ◽  
Cross Coupling ◽  
Assembly Process ◽  
Efficient Catalyst ◽  
Mild Conditions ◽  
Cross Coupling Reaction ◽  
Green Procedure

A new G-(H2L)-Pd heterogeneous catalyst has been prepared via a self-assembly process consisting in the spontaneous adsorption, in water at room temperature, of a macrocyclic H2L ligand on graphene (G) (G + H2L = G-(H2L)), followed by decoration of the macrocycle with Pd2+ ions (G-(H2L) + Pd2+ = G-(H2L)-Pd) under the same mild conditions. This supramolecular approach is a sustainable (green) procedure that preserves the special characteristics of graphene and furnishes an efficient catalyst for the Cu-free Sonogashira cross coupling reaction between iodobenzene and phenylacetylene. Indeed, G-(H2L)-Pd shows an excellent conversion (90%) of reactants into diphenylacetylene under mild conditions (50 °C, water, aerobic atmosphere, 14 h). The catalyst proved to be reusable for at least four cycles, although decreasing yields down to 50% were observed.

Circular Dichroism of C-Phycoerythrin: A Conformational Analysis

1980 ◽  
Vol 35 (5-6) ◽  
pp. 367-375 ◽  
Author(s):  
Elisabeth Langer ◽  
Harald Lehner ◽  
Wolfhart Rüdiger ◽  
Barbara Zickendraht-Wendelstadt
Keyword(s):  
Circular Dichroism ◽  
Secondary Structure ◽  
Conformational Changes ◽  
Spectral Region ◽  
Protein Unfolding ◽  
Extensive Study ◽  
Random Coil ◽  
Linear Superposition ◽  
Thermally Induced ◽  
Circular Dichroïsm

Abstract An extensive study of the chiroptical properties of C-phycoerythrin and the α-and β-subunits in the spectral region from 700 -200 nm is presented. Based on the VIS-circular dichroism inherently chiral conform ations are proposed for the co­ valently linked chromophores. By means of mean residue ellipticities and the experimental circular dichroism spectra in the region of the n → π* peptide transition the a-helix contents of the apoproteins of the ac-and ß-subunits are estimated to amount to 60% and 40%, respectively. The circular dichroism spectrum of native C-phycoerythrin is congruent with a linear superposition of the α-and β-subspectra, in the whole spectral region studied. Since a-and β-subunits are associated in native C-phycoery-thrin as revealed by sedim entation analysis the interactions between the subunits in the native chromoprotein are not accom panied by substantial conform ational changes. In the temperature range 0°-40°C the thermally induced changes of the chrom ophores in native C-phycoerythrin are not associated with changes of the secondary structure of the apoprotein. Unfolding occurs at 60°-70°C but slowly leads to irreversible denaturation. Protein unfolding starts at 3 M urea. The random coil secondary structure of the apoproteins is reached at 8 M urea. At this concentration the absorbance and the optical activity of the chrom o­ phores are reduced by a factor 3 and 10, respectively. The conformational changes in the peptide with increasing denaturant concentration are not synchronous with those induced in the Chromo­ phore indicating that a m ultistep process is operative during unfolding. The C D results on dena­ turation are supplem ented by absorption and em ission spectroscopy.

scholarly journals Pillararenes Trimer for Self-Assembly

Nanomaterials ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 651 ◽  
Author(s):  
Huacheng Zhang ◽  
Zhaona Liu ◽  
Hui Fu
Keyword(s):  
Self Assembly ◽  
Driving Forces ◽  
Click Reaction ◽  
Noncovalent Interactions ◽  
Coupling Reaction ◽  
Covalent Bonds ◽  
Guest Molecules ◽  
Palladium Catalyzed ◽  
Noncovalent Bonds ◽  
External Stimuli

Pillararenes trimer with particularly designed structural geometry and excellent capacity of recognizing guest molecules is a very efficient and attractive building block for the fabrication of advanced self-assembled materials. Pillararenes trimers could be prepared via both covalent and noncovalent bonds. The classic organic synthesis reactions such as click reaction, palladium-catalyzed coupling reaction, amidation, esterification, and aminolysis are employed to build covalent bonds and integrate three pieces of pillararenes subunits together into the “star-shaped” trimers and linear foldamers. Alternatively, pillararenes trimers could also be assembled in the form of host-guest inclusions and mechanically interlocked molecules via noncovalent interactions, and during those procedures, pillararenes units contribute the cavity for recognizing guest molecules and act as a “wheel” subunit, respectively. By fully utilizing the driving forces such as host-guest interactions, charge transfer, hydrophobic, hydrogen bonding, and C–H…π and π–π stacking interactions, pillararenes trimers-based supramolecular self-assemblies provide a possibility in the construction of multi-dimensional materials such as vesicular and tubular aggregates, layered networks, as well as frameworks. Interestingly, those assembled materials exhibit interesting external stimuli responsiveness to e.g., variable concentrations, changed pH values, different temperature, as well as the addition/removal of competition guests and ions. Thus, they could further be used for diverse applications such as detection, sorption, and separation of significant multi-analytes including metal cations, anions, and amino acids.

Thermally induced cyclization of L ‐isoleucyl‐ L ‐alanine in solid state: Effect of dipeptide structure on reaction temperature and self‐assembly

2019 ◽  
Vol 25 (8) ◽  
Author(s):  
Marat A. Ziganshin ◽  
Radik A. Larionov ◽  
Alexander V. Gerasimov ◽  
Sufia A. Ziganshina ◽  
Alexander E. Klimovitskii ◽  
...  
Keyword(s):  
Solid State ◽  
Reaction Temperature ◽  
Self Assembly ◽  
Thermally Induced ◽  
State Effect

Patterning 2D Organic Crystalline Semiconductors via Thermally Induced Self‐Assembly

2020 ◽  
Vol 6 (9) ◽  
pp. 2000438
Author(s):  
Yiwei Duan ◽  
Jun Qian ◽  
Jianhang Guo ◽  
Sai Jiang ◽  
Chengdong Yang ◽  
...  
Keyword(s):  
Self Assembly ◽  
Thermally Induced
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