Summary

Physics advocates research on unifying chemical bonds and recognized parallels on a different (and non-reductive) level, as per the concept of the Great Unification of Forces in Nature. From this perspective, a Physicochemical Grand Unification of Forces would be a worthy project for humankind in order to increase our undertanding of existence and to improve our lives. This entry collection aims to present an account of chemical bonds and interactions in nano- to maco-environments.

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Topic Review
Supramolecular Liquid Crystals
liquid crystal (LC) state, specific orientations and alignments of LC molecules produce outstanding anisotropy in structure and properties, followed by diverse optoelectronic functions.
  • 2.1K
  • 09 Jul 2021
Topic Review
Prebiotic Synthesis of Ribose
Prebiotic reactions describe how biomolecules such as ribose, was synthesized and protected from degradation, nucleobases generated from HCN oligomers and other derivatives including prebiotic RNA (preRNA) were formed at the given circumstances. Prebiotic conditions remained a subject of debate, but a reasonable aspect to consider is that tetrahedral structure shaping biomolecules consisted almost exclusively of elements belonging to the CHNOPS group in the periodic table, where capital letters correspond to the elements of carbon, hydrogen, nitrogen, oxygen, phosphorus and sulfur. Intermediary steps in the formose reaction network contain aldol condensation, aldose-ketose isomerizations, producing C3 - C6 carbohydrates including pentoses. The generation of genetic material could have developed from the formose reaction to ribose and further to non-genetic prebiotic  RNA (preRNA) [1-9]. Consecutive reactions of this pathway are not known. Those known abiotic chemical reactions were selected that could have resulted in preRNA and genetic RNA (genRNA).  Processes generating primitive life on Earth consisted of three successive stages: i) abiotic reactions generating organic molecules, ii) formation of molecular aggregates showing primitive metabolism, iii) development of primitive cells and organisms resembling those that exist today. Only cellular life is known that adapted in every aspect to conditions that exist only on Earth. Here only the 1st stage, the abiotic phase is dealt with. Prebiotic conditions remained subjects of debate ranging from a strong reductive to a strong oxidative climate. Our theory is based on a mildly reductive atmosphere that could have existed at the beginning of life some 4.3 -4.5 billion years ago, much before the Great Oxidation Event that took place much later 2.3 - 2.5 billion years ago. During the abiotic synthesis of organic molecules, ribose was selected as the precursor to life. .
  • 1.9K
  • 15 Jun 2021
Topic Review
Metal Ion Detection by Glutathione
Low cost, sensitive, selective, and rapid methods for heavy metal ion (HMI) detection are of growing demand, and HMI biosensors have great potential in meeting this need due to their timeliness, cost-effectiveness and convenience in operation. The most widely reported peptide probe for HMI detection is glutathione (GSH), especially in case of lead ion (Pb2+) detection. GSH is highly stable, cost-effective, and easy to immobilize on a sensor. 
  • 1.7K
  • 10 Jun 2021
Topic Review
Electrochemical Sensors for Bromate Determination
Potassium bromate (KBrO3), a renowned oxidizing agent, has a huge reputation for being one of the best and least expensive dough-improving substances in the baking industry. As such, its importance in the baking industry cannot be overemphasized. KBrO3 produced the desired result in baking by influencing the physical and chemical properties of macromolecules such as protein and starch often found in the dough. Precisely, the viscosity, extent of gelatinization, swelling characteristics of the dough, and disulfide linkage formation (in gluten proteins) are affected by the use of KBrO3 as an additive in bread baking. Bromate has been found to be a product of water treatment due to bromide ion oxidation that occurs during ozonation.
  • 1.2K
  • 21 Jun 2021
Topic Review
Hydrogen Bond Energy
Hydrogen bonds (HBs) play a crucial role in many physicochemical and biological processes. Theoretical methods can reliably estimate the intermolecular HB energies. Quantifying an intramolecular hydrogen bond (IHB) strength is not as straightforward as the intermolecular one. The main difficulty lies in isolating the X–H···Y interaction present within a molecule than in a dimer or a complex. However, the procedure discussed (viz. molecular tailoring approach) in this article, allows the generation of fragments so that the atoms/functional groups involved in the HB formation are parts of two different fragments. The energies of these fragments are added or substracted, using the inclusion exclusion principle in set theory, to obtained the energy of HB bond.
  • 3.0K
  • 19 May 2021
Topic Review
Azulene Moiety as Electron Reservoir
The nonalternant aromatic azulene, an isomer of alternant naphthalene, differs from the latter in peculiar properties. The large polarization of the π-electron system over the seven and five rings gives to azulene electrophile property a pronounced tendency to donate electrons to an acceptor, substituted at azulene 1 position. This paper presents cases in which azulene transfers electrons to a suitable acceptor as methylium ions, positive charged heteroaromatics and examples of neutral molecules that can accept electrons. 
  • 2.3K
  • 18 May 2021
Topic Review
Silver Nanowire
Detailed AgNW synthesis methods, including template assisted histrorical improvements and modern wet chemical techniques. A detailed analysis of the various pre- and post-treatment methods used to improve the optoelectronic properties of the fabricated Transparent conducting electrode with future outlooks and challanges for practical applicabilty. 
  • 2.5K
  • 05 May 2021
Topic Review
Enantioselective Catalytic C-H Amidations
The crucial role played by compounds bearing amide functions, not only in biological processes but also in several fields of chemistry, life polymers and material sciences, has brought about many significant discoveries and innovative approaches for their chemical synthesis. Within this context, and following the development of C-H functionalization strategies, C-H amidation reactions have only recently emerged as valuable approaches for the construction of amide functions. These methodologies have been successfully used for both C(sp2)- and C(sp3)-H activations and blossoming synthetic applications have appeared in the last two years (2019-2020 timeframe).
  • 1.8K
  • 15 Apr 2021
Topic Review
Nitrogen-Based Alkylating Anticancer Agents
Despite the significant progress in anticancer drug development over recent years, there is a vital need for newer agents with unique, but still effective, mechanisms of action in order to treat the disease, particularly the highly aggressive and drug resistant types. Alkylating agents, in particular nitrogen-based alkylators, are commonly used to treat hematological and solid malignancies; they exert their antineoplastic effects at all phases of the cell cycle and prevent reproduction of tumor cells. Certain alkylating agents have been designed to be more lipophilic, enabling the compound to penetrate the cell and enhance its alkylating activity against tumors. This review details the evolution of currently available alkylating agents and their profiles, with a focus on nitrogen-based alkylating agents, as important anticancer therapy strategies.
  • 1.8K
  • 27 Mar 2021
Topic Review
Gold-based anticancer delivery systems
The structures of these gold derivatives (i.e. gold nanoparticles, gold (I)/(III) complexes and carbene-based gold complexes) were synthesized to evaluate the influence of  increased activity and/or selectivity on their pharmacological effects.
  • 1.4K
  • 06 Apr 2021
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