scholarly journals Electrochemically Produced Copolymers of Pyrrole and Its Derivatives: A Plentitude of Material Properties Using “Simple” Heterocyclic Co-Monomers

Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 281
Author(s):  
Tomasz Jarosz ◽  
Przemyslaw Ledwon
Keyword(s):  
Biological Activity ◽  
Material Properties ◽  
Building Block ◽  
Conjugated Polymer ◽  
Chemical Structure ◽  
Heterocyclic System ◽  
Repeat Unit ◽  
Polymeric Materials ◽  
Pyrrole Derivatives ◽  
Pyrrole Monomer

Polypyrrole is a classical, well-known conjugated polymer that is produced from a simple heterocyclic system. Numerous pyrrole derivatives exhibit biological activity, and the repeat unit is a common building block present in the chemical structure of many polymeric materials, finding wide application, primarily in optoelectronics and sensing. In this work, we focus on the variety of copolymers and their material properties that can be produced electrochemically, even though all these systems are obtained from mixtures of the “simple” pyrrole monomer and its derivatives with different conjugated and non-conjugated species.

scholarly journals Analysis of the relationship between the predicted biological activity and the chemical structure of S-derivatives of 5-(5-bromofuran-2-yl)-4R-1,2,4-triazole-3-thiols

2021 ◽  
Vol 14 (2) ◽  
pp. 167-172
Author(s):  
O. A. Bigdan
Keyword(s):  
Biological Activity ◽  
Chemical Structure ◽  
Plant Protection ◽  
Hypoxia Inducible Factor ◽  
Polymeric Materials ◽  
Plant Protection Products ◽  
New Drugs ◽  
Antihypoxic Activity ◽  
Oxidation Reactions ◽  
Derivatives Of

1,2,4-Triazole derivatives are actively used as components in the development of new drugs, plant protection products, polymeric materials, anti-corrosion agents and etc. Chemical modeling of substituted 1,2,4-triazoles due to the introduction of different pharmacophores into the structure is very popular among scientists in various fields. Today it is known that some S-derivatives of 5-(5-bromofuran-2-yl)-4R-1,2,4-triazole-3-thiols have antimicrobial activity. The aim of the work is to analyze the relationships between the predicted biological activity and the chemical structure of S-derivatives of 5-(5-bromofuran-2-yl) -4R-1,2,4-triazole-3-thiols. Materials and methods. Virtual screening of compounds was performed using the computer program PASS (Prediction of activity spectra for substances). The results of the forecast were issued in the form of a list of names of probable types of activity with estimates of the probabilities of presence (Pa) and absence of each activity (Pi), which had values from 0 to 1. Results. Analyzing the prediction of biological activity on protein targets from the group of enzymes, we can said that derivatives of 5-(5-bromofuran-2-yl)-4R-1,2,4-triazole-3-thiols were active in the group of oxyreductases (Glutathione reductase, mitochondrial; Cyclooxygenase-2; Hypoxia-inducible factor prolyl hydroxylase 2), which catalyzed oxidation reactions, the transfer of electrons from one molecule (reducer, electron donor) to another (oxidant, electron acceptor). These compounds can demonstrate antioxidant, antihypoxic activity. Conclusions. The conducted forecast of biological activity revealed that derivatives of 5-(5-bromofuran-2-yl)-4R-1,2,4-triazole-3-thiols are the most active and there is a probability to show antitumor, antiviral, antibacterial, diuretic, actoprotective, and antioxidant activity.

Optical and Electrical Properties of Organic Conducting Polymers

2014 ◽  
Vol 8 (1) ◽  
pp. 1457-1463
Author(s):  
Salah Abdulla Hasoon
Keyword(s):  
Electrical Properties ◽  
Conjugated Polymer ◽  
Polymeric Materials ◽  
Quantum Mechanical ◽  
Optical And Electrical Properties ◽  
Electrically Conducting ◽  
Temperature Ranges ◽  
Lithium Tetrafluoroborate ◽  
Absorbance Peak ◽  
Polymerization Method

Novel electrically conducting polymeric materials are prepared in this work. Polythiophene (PT) and poly (3-Methelthiophene) (P3MT) films were prepared by electro-polymerization method using cyclic voltammetry in acetonitrile as a solvent and lithium tetrafluoroborate as the electrolyte on a gold electrode. Electrical properties of P3MT have been examined in different environments using UV-Vis absorption spectroscopy and quantum mechanical ab initio calculations, The observed absorption peaks at 314 and 415 nm, were attributed to the n-π* and π-π* transitions, respectively in the conjugated polymer chain, in contrast, the observed absorbance peak at 649 nm, is responsible for electric conduction. The temperature dependence of the conductivity can be fitted to the Arrhenius and the VTF equations in different temperature ranges.

scholarly journals Chemical Structure and Biological Activity of Humic Substances Define Their Role as Plant Growth Promoters

Molecules ◽  
2021 ◽  
Vol 26 (8) ◽  
pp. 2256
Author(s):  
Serenella Nardi ◽  
Michela Schiavon ◽  
Ornella Francioso
Keyword(s):  
Biological Activity ◽  
Humic Substances ◽  
Chemical Structure ◽  
Molecular Size ◽  
Growth Promoters ◽  
Root Cells ◽  
Sustainable Technologies ◽  
Intracellular Signals ◽  
Key Functional Groups ◽  
Regulatory Functions

Humic substances (HS) are dominant components of soil organic matter and are recognized as natural, effective growth promoters to be used in sustainable agriculture. In recent years, many efforts have been made to get insights on the relationship between HS chemical structure and their biological activity in plants using combinatory approaches. Relevant results highlight the existence of key functional groups in HS that might trigger positive local and systemic physiological responses via a complex network of hormone-like signaling pathways. The biological activity of HS finely relies on their dosage, origin, molecular size, degree of hydrophobicity and aromaticity, and spatial distribution of hydrophilic and hydrophobic domains. The molecular size of HS also impacts their mode of action in plants, as low molecular size HS can enter the root cells and directly elicit intracellular signals, while high molecular size HS bind to external cell receptors to induce molecular responses. Main targets of HS in plants are nutrient transporters, plasma membrane H+-ATPases, hormone routes, genes/enzymes involved in nitrogen assimilation, cell division, and development. This review aims to give a detailed survey of the mechanisms associated to the growth regulatory functions of HS in view of their use in sustainable technologies.

Strategies and concepts in n-doped conjugated polymer thermoelectrics

2021 ◽  
Vol 9 (9) ◽  
pp. 5149-5163
Author(s):  
Teck Lip Dexter Tam ◽  
Jianwei Xu
Keyword(s):  
Conjugated Polymers ◽  
Conjugated Polymer ◽  
Chemical Structure ◽  
Structure Engineering

In this review, we discuss strategies & concepts in chemical structure engineering for n-type conjugated polymers & n-dopants that have brought about huge improvements in the performance of n-doped conjugated polymer thermoelectrics in recent years.

An expanded isoindigo unit as a new building block for a conjugated polymer leading to high-performance solar cells

2014 ◽  
Vol 2 (15) ◽  
pp. 5427-5433 ◽  
Author(s):  
Shugang Li ◽  
Zhongcheng Yuan ◽  
Jianyu Yuan ◽  
Ping Deng ◽  
Qing Zhang ◽  
...  
Keyword(s):  
Solar Cells ◽  
Solar Cell ◽  
Building Block ◽  
Conjugated Polymer ◽  
High Performance ◽  
Fill Factor ◽  
Solar Cell Device ◽  
Donor Acceptor ◽  
First Time

An expanded isoindigo unit (IBTI) has been incorporated into a donor–acceptor conjugated polymer for the first time. The PCE of the solar cell device based on the new polymer reached 6.41% with a fill factor of 0.71.

Biological Activity of Humic Substances Is Related to Their Chemical Structure

2007 ◽  
Vol 71 (1) ◽  
pp. 75-85 ◽  
Author(s):  
Adele Muscolo ◽  
Maria Sidari ◽  
Emilio Attinà ◽  
Ornella Francioso ◽  
Vitaliano Tugnoli ◽  
...  
Keyword(s):  
Biological Activity ◽  
Humic Substances ◽  
Chemical Structure

Cytokinin activity of some substituted ureas and thioureas

1966 ◽  
Vol 165 (999) ◽  
pp. 245-265 ◽  
Keyword(s):  
Biological Activity ◽  
Active Compound ◽  
Phenyl Ring ◽  
Chemical Structure ◽  
Lower Activity ◽  
Cytokinin Activity ◽  
Hydrogen Atoms ◽  
Detectable Activity ◽  
Low Activity

N , N '-Diphenylurea was shown to have reproducible cytokinin activity . Some 500 ureas, mainly of the N -monosubstituted and N , N '-disubstituted types, were tested an d about one half of these were active. Attempts were made to correlate chemical structure with biological activity. Although there are some exceptions to nearly every generalization it has been possible to formulate some principles. (1) Phenyl urea was the simplest active compound. (2) An HNCONH bridge conferred higher activity than an HNCSNH linkage and any other tested arrangement of the bridge gave inactive com pounds. (3) Compounds in which both amino hydrogen atoms on one or both sides of the bridge were substituted were of low activity or were inactive. (4) Many com pounds of the type R NHCONH 2 in which R = a substituted phenyl ring were tested. Ring substitution generally increased the activity and the highest activity was associated with meta substitution and the lowest with ortho . Compounds with electron-attracting substituents were generally more active than those with electron-donating substituents. Pyridyl compounds were active but com pounds with non-planar rings were inactive. (5) In compounds of the type R NHCONH R ' in which R and R ' were phenyl or substituted phenyl groups the highest activities were usually found in com pounds with one unsubstituted phenyl ring. Those with two substituted phenyl groups generally had lower activity. Some ureas showed detectable activity at 0.1 parts/10 6 . This was about four times less active than kinetin when tested in the tobacco pith assay.

Bacterial Endotoxins: Relationships between Chemical Structure and Biological Activity of the Inner Core-Lipid a Domain

1991 ◽  
pp. 209-217 ◽  
Author(s):  
Ernst Th. Rietschel ◽  
Lore Brade ◽  
Ulrich Schade ◽  
Ulrich Seydel ◽  
Ulrich Zähringer ◽  
...  
Keyword(s):  
Biological Activity ◽  
Chemical Structure ◽  
Lipid A ◽  
Inner Core ◽  
Core Lipid ◽  
Bacterial Endotoxins
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