Subject:
All Disciplines Arts & Humanities Biology & Life Sciences Business & Economics Chemistry & Materials Science Computer Science & Mathematics Engineering Environmental & Earth Sciences Medicine & Pharmacology Physical Sciences Public Health & Healthcare Social Sciences
Sort:
Hottest Latest Alphabetical (A-Z) Alphabetical (Z-A)
Type:
All Topic Review Biography
Topic Review
Phosphorus fire retardants for polystyrene
Polystyrene, despite its high flammability, is widely used as a thermal insulation material for buildings, for food packaging, in electrical and automotive industries, etc. A number of modification routes have been explored to improve the fire retardance and boost the thermal stability of commercially important styrene-based polymeric products. The earlier strategies mostly involved the use of halogenated fire retardants. Nowadays, these compounds are considered to be persistent pollutants that are hazardous to public and environmental health. Many well-known halogen-based fire retardants, regardless of their chemical structures and modes of action, have been withdrawn from built environments in the European Union, USA, and Canada. This had triggered a growing research interest in, and an industrial demand for, halogen-free alternatives, which not only will reduce the flammability but also address toxicity and bioaccumulation issues. Among the possible options, phosphorus-containing compounds have received greater attention due to their excellent fire-retarding efficiencies and environmentally friendly attributes. Numerous reports were also published on reactive and additive modifications of polystyrene in different forms, particularly in the last decade; hence, the current article aims to provide a critical review of these publications. The authors mainly intend to focus on the chemistries of phosphorous compounds, with the P atom being in different chemical environments, used either as reactive, or additive, fire retardants in styrene-based materials. The chemical pathways and possible mechanisms behind the fire retardance are discussed in this review.
  • 1.6K
  • 26 Aug 2020
Topic Review
Synthesis of β-Lactams
Stereoselective synthesis of cis and trans β-lactams under diverse conditions is performed.  Numerous conditions are used for this study. The formation of β-lactam depends on the conditions of the experiments, structures of the imines and acid chlorides, order of addition of the reagents, reaction temperature, and solvents. A few mathematical graphs are plotted to explain the results.   
  • 1.5K
  • 25 Nov 2020
Topic Review
The Molecular Electron Density Theory
The Molecular Electron Density Theory (MEDT) was proposed in 2016 as a  contemporary reactivity model in Organic Chemistry against the Frontier Molecular Orbital (FMO) theory.
  • 1.5K
  • 22 Oct 2020
Topic Review
Multicomponent Bargellini Reaction
The multicomponent reaction between phenol, chloroform and acetone is known as Bargellini reaction. In this  article we collected and discussed all the Bargellini and Bargellini-like reactions carried out over the years. The main goal is that this knowledge-sharing will help chemists to properly use this transformation and imagine novel reactivities based on it.
  • 1.5K
  • 08 Mar 2021
Topic Review
Catalytic Synthesis of Glycerol Carbonate
Glycerol carbonate (GC) belongs to the family of organic carbonates that are regarded as very typical “green chemistry” products for their unique advantages in many fields, such as high boiling point solvents, pharmaceutical intermediates, and material intermediates.
  • 1.5K
  • 10 Feb 2022
Topic Review
Betulinic Acid
Betulinic acid (BA, 3β-hydroxy-lup-20(29)-en-28-oic acid) is a pentacyclic triterpene acid present predominantly in Betula ssp. (Betulaceae) and is also widely spread in many species belonging to different plant families. BA presents a wide spectrum of remarkable pharmacological properties, such as cytotoxic, anti-HIV, anti-inflammatory, antidiabetic and antimicrobial activities, including antiprotozoal effects.
  • 1.5K
  • 24 May 2021
Topic Review Peer Reviewed
Tautomerism of β-Diketones and β-Thioxoketones
The present overview concentrates on recent developments of tautomerism of β-diketones and β-thioxoketones, both in solution and in the solid state. In particular, the latter has been a matter of debate and unresolved problems. Measurements of 13C, 17O, and 2H chemical shifts have been used. Deuterium isotope effects on chemical shifts are proposed as a tool in the study of this problem. Photoconversion of β-diketones and β-thioxoketones are discussed in detail, and the incorporation of β-diketones into molecules with fluorescent properties is assessed. Finally, docking studies of β-diketones are scrutinized with an emphasis on correct tautomeric structures and knowledge about barriers to interconversion of tautomers.
  • 1.4K
  • 10 Mar 2023
Topic Review
Alcohol
In chemistry, alcohol is an organic compound that carries at least one hydroxyl functional group (−OH) bound to a saturated carbon atom. The term alcohol originally referred to the primary alcohol ethanol (ethyl alcohol), which is used as a drug and is the main alcohol present in alcoholic drinks. An important class of alcohols, of which methanol and ethanol are the simplest members, includes all compounds for which the general formula is CnH2n+1OH. Simple monoalcohols that are the subject of this article include primary (RCH2OH), secondary (R2CHOH) and tertiary (R3COH) alcohols. The suffix -ol appears in the IUPAC chemical name of all substances where the hydroxyl group is the functional group with the highest priority. When a higher priority group is present in the compound, the prefix hydroxy- is used in its IUPAC name. The suffix -ol in non-IUPAC names (such as paracetamol or cholesterol) also typically indicates that the substance is an alcohol. However, many substances that contain hydroxyl functional groups (particularly sugars, such as glucose and sucrose) have names which include neither the suffix -ol, nor the prefix hydroxy-.
  • 1.4K
  • 27 Oct 2022
Topic Review
Production Methods of Peptides
Peptides are organic polymers composed of 2–50 amino acids linked to each other by means of covalent amide (=peptide) bonds. The composition, length and sequence of the amino acid chain have a dramatic influence on the activity of the peptide itself, for example in the human body. Peptides are called bioactive if they have a beneficial impact on body functions, on biological processes and, as a consequence, on health. The main production methods to obtain peptides are enzymatic hydrolysis, microbial fermentation, recombinant approach and, especially, chemical synthesis. 
  • 1.4K
  • 01 Sep 2021
Topic Review
Molecular Iodine-Catalyzed Reactions
Department of Mathematics and Natural Sciences, College of Sciences and Human Studies, Deanship of Research, Prince Mohammad Bin Fahd University, Al Khobar 31952, KSA; Email: bimalbanik10@gmail.com; bbanik@pmu.edu.sa In continuation of our research on the synthesis of diverse organic molecules, we report here molecular iodine-catalyzed diverse synthetic processes. These methods are efficient and produce products in high yield. The success of molecular iodine-catalyzed reactions depends on the release of hydroiodic acid in the reaction media.
  • 1.3K
  • 01 Jun 2020
  • Page
  • of
  • 30
Featured Entry Collections
>>

Featured Books

>>
Encyclopedia of Social Sciences
Encyclopedia of COVID-19
Encyclopedia of Fungi
Encyclopedia of Digital Society, Industry 5.0 and Smart City
Feedback