The study of corrosion processes and their inhibition by organic inhibitors is a very active field of research. The presence of nitrogen, oxygen, phosphorous and sulphur in the organic molecules has a major effect on the inhibition efficiency and consequently on the phenomenon of adsorption on some metals surface. A great number of heterocyclic compounds were found to be excellent inhibitors of copper and steel corrosion. The inhibition effect mainly depends on some physicochemical and electronic properties of the organic inhibitor which relate to its functional groups, steric effects, electronic density of donor atoms, and orbital character of donating electrons. DFT Quantum chemical methods have already proven to be very useful in determining the molecular structure as well as elucidating the electronic structure and reactivity. Thus, it has become a common practice to carry out quantum chemical calculations in corrosion inhibition studies.
Handbook of Heterocyclic Corrosion Inhibitors presents a comprehensive overview of corrosion inhibition using heterocyclic compounds. It covers numerous, emerging heterocyclic compound-based industrial corrosion inhibitors that are oriented toward minimizing corrosive damages and prevention methods. Describing the fundamentals of heterocycles, corrosion, and corrosion inhibition, the book considers the potential of different series of N-heterocycles, such as acridine and acridone-based, carbazole-based, imidazole and imidazoline-based, indole and indoline-based, melamine-based, etc. It presents the corrosion inhibition potential of oxygen- and sulfur-based heterocycles compounds. The book also explores issues with corrosion as a result of improper design with descaling, acidification, refinery, and transport processes. The book will be of interest to researchers and graduate students studying corrosion science, heterocyclic chemistry, material science and engineering, energy, chemistry, and colloid science. It will also be a valuable reference for corrosion scientists and R&D engineers working in industrial corrosion and industrial-based corrosion protection systems.
The series Topics in Heterocyclic Chemistry presents critical reviews on present and future trends in the research of heterocyclic compounds. Overall the scope is to cover topics dealing with all areas within heterocyclic chemistry, both experimental and theoretical, of interest to the general heterocyclic chemistry community. The series consists of topic related volumes edited by renowned editors with contributions of experts in the field.
Demonstrates how anyone in math, science, and engineering can master DFT calculations Density functional theory (DFT) is one of the most frequently used computational tools for studying and predicting the properties of isolated molecules, bulk solids, and material interfaces, including surfaces. Although the theoretical underpinnings of DFT are quite complicated, this book demonstrates that the basic concepts underlying the calculations are simple enough to be understood by anyone with a background in chemistry, physics, engineering, or mathematics. The authors show how the widespread availability of powerful DFT codes makes it possible for students and researchers to apply this important computational technique to a broad range of fundamental and applied problems. Density Functional Theory: A Practical Introduction offers a concise, easy-to-follow introduction to the key concepts and practical applications of DFT, focusing on plane-wave DFT. The authors have many years of experience introducing DFT to students from a variety of backgrounds. The book therefore offers several features that have proven to be helpful in enabling students to master the subject, including: Problem sets in each chapter that give readers the opportunity to test their knowledge by performing their own calculations Worked examples that demonstrate how DFT calculations are used to solve real-world problems Further readings listed in each chapter enabling readers to investigate specific topics in greater depth This text is written at a level suitable for individuals from a variety of scientific, mathematical, and engineering backgrounds. No previous experience working with DFT calculations is needed.
Over the past 25 years, the molecular electrostatic potential has become firmly established as an effective guide to molecular interactions. With the recent advances in computational technology, it is currently being applied to a variety of important chemical and biological systems. Its range of applicability has expanded from primarily a focus on sites for electrophilic and nucleophilic attack to now include solvent effects, studies of zeolite, molecular cluster and crystal behavior, and the correlation and prediction of a wide range of macroscopic properties. Moreover, the increasing prominence of density functional theory has raised the molecular electrostatic potential to a new stature on a more fundamental conceptual level. It is rigorously defined in terms of the electron density, and has very interesting topological characteristics since it explicitly reflects opposing contributions from the nuclei and the electrons. This volume opens with a survey chapter by one of the original pioneers of the use of the electrostatic potential in studies of chemical reactivity, Jacopo Tomasi. Though the flow of the succeeding chapters is not stringently defined, the overall trend is that the emphasis changes gradually from methodology to applications. Chapters discussing more theoretical topics are placed near the end. Readers will find the wide variety of topics provided by an international group of authors both convincing and useful.
Enables researchers to fully realize the potential to discover new pharmaceuticals among heterocyclic compounds Integrating heterocyclic chemistry and drug discovery, this innovative text enables readers to understand how and why these two fields go hand in hand in the effective practice of medicinal chemistry. Contributions from international leaders in the field review more than 100 years of findings, explaining their relevance to contemporary drug discovery practice. Moreover, these authors have provided plenty of practical guidance and tips based on their own academic and industrial laboratory experience, helping readers avoid common pitfalls. Heterocyclic Chemistry in Drug Discovery is ideal for readers who want to fully realize the almost limitless potential to discover new and effective pharmaceuticals among heterocyclic compounds, the largest and most varied family of organic compounds. The book features: Several case studies illustrating the role and application of 3, 4, 5, and 6+ heterocyclic ring systems in drug discovery Step-by-step descriptions of synthetic methods and practical techniques Examination of the physical properties for each heterocycle, including NMR data and quantum calculations Detailed explanations of the complexity and intricacies of reactivity and stability for each class of heterocycles Heterocyclic Chemistry in Drug Discovery is recommended as a textbook for organic and medicinal chemistry courses, particularly those emphasizing heterocyclic chemistry. The text also serves as a guide for medicinal and process chemists in the pharmaceutical industry, offering them new insights and new paths to explore for effective drug discovery.
The book presents the current status of corrosion inhibitor technology. A special focus is placed on various types of green corrosion inhibitors and their applications. Keywords: Green Corrosion Inhibitors, Sustainable Corrosion Inhibitors, Green Organic Inhibitors, Inhibitors from Biomass and Natural Sources, Polysaccharide, Applications for Concrete, Coatings, Copper and Copper Alloys, Corrosion Control in Conventional and Monolithic Metals.
Advances in Heterocyclic Chemistry is the definitive series in the field - one of great importance to organic chemists, polymer chemists, and many biological scientists. Because biology and organic chemistry increasingly intersect, the associated nomenclature also is being used more frequently in explanations. Written by established authorities in the field from around the world, this comprehensive review combines descriptive synthetic chemistry and mechanistic insight to yield an understanding of how chemistry drives the preparation and useful properties of heterocyclic compounds. Considered the definitive serial in the field of heterocyclic chemistry Serves as the go-to reference for organic chemists, polymer chemists and many biological scientists Provides the latest comprehensive reviews written by established authorities in the field Combines descriptive synthetic chemistry and mechanistic insight to enhance understanding of how chemistry drives the preparation and useful properties of heterocyclic compounds
Chapter 1 introduces the tools employed in this dissertation and provides some insight into the author's perspectives on science. In chapter 2, the absorption and fluorescence properties of cyclic azacyanine (CAC) derivatives were examined in water, acetonitrile, n-butyronitrile, methanol, ethanol, DMSO, DMF and dichloromethane. The presence of electron donating or withdrawing groups on the CAC affects the spectroscopic properties of the parent system. The general solvent relaxation displayed by azacyanine derivatives is in accordance with Lippert-Mataga's prediction but exception is noted in the case of protic solvent due to specific hydrogen bonding interactions. Fluorescence lifetime decay studies indicate a relaxation time in the nanosecond timescale with mono exponential decay; the fluorescence lifetime values are in the same range as those found earlier1 for another class of CAC. It is also observed that electron-donating substituents markedly increase the excited state lifetime; whereas electron-withdrawing groups marginally decrease the excited state lifetime compared to the parent compound. The absorption spectrum of 2.2, which contains two electron-withdrawing groups (2,8-dichloro), exhibits a red shift of 20 nm relative to that of the parent system (2.1). Quantum chemical computations were used to explore the origins of the reactivity and spectroscopic properties of CACs 2.1, 2.2, 2.3 and 2.4; the results of these calculations are consistent with a model in which regioselectivity results from differences in mechanistic steps occurring after initial attack by hydroxide on the CAC. In chapter 3, quantum chemical calculations coupled to experiments were used to predict covalent hydration propensities of biologically-relevant [alpha]-ketoamides. Experimentally determined hydration equilibrium constants for related ketones and aldehydes were compared to computationally determined values to develop a method for predicting hydration equilibrium constants. This method was used on six newly synthesized [alpha]-ketoamides to experimentally verify computational predictions. A correlation between calculation and experiment was observed and applied to models of several pertinent APIs. Our results indicate that the keto form is favored for practically all [alpha]-ketoamides in biological environs. Myeloperoxidase (MPO) produces hypohalous acids as a key component of the innate immune response; however, release of these acids extracellularly results in inflammatory cell and tissue damage. In chapter 4, the two-step, one-pot Davis-Beirut reaction was used to synthesize a library of 2H-indazoles and 1H-indazolones as putative inhibitors of MPO. A structure-activity relationship study was undertaken wherein compounds were evaluated utilizing taurine-chloramine and MPO-mediated H2O2 consumption assays. Docking studies as well as toxicophore and Lipinski analyses were performed. Fourteen compounds were found to be potent inhibitors with IC50 values 1 [mu]M, suggesting these compounds could be considered as potential modulators of pro-oxidative tissue injury pertubated by the inflammatory MPO:H2O2:HOCl/ HOBr system. In chapter 5, an applied computational chemistry laboratory exercise is described in which students utilize modern quantum chemical calculations of chemical shifts to assign the structure of a recently isolated natural product. A pre/post assessment was used to measure student learning gains and verify that students demonstrated proficiency of key learning objectives. Pseudolaric acid (PXA) is a diterpenoid which is of particular interest to the chemical and biological communities as it has shown antifungal and antifertility properties, has displayed cytotoxic activity against multi-drug resistant cell lines, and has displayed selective inhibition of human leukemia cell lines. Chapter 6 reports the isolation and structural assignment of an all carbon diterpene intermediate along the pathway towards PXA (D4 or 'Sibongilene') using various 1-dimensional and 2-dimensional (1D and 2D) nuclear magnetic resonance (NMR) techniques, which are then supported by thorough and rigorous computational NMR to determine which of 48 possible constitutional and stereoisomers was isolated. The proposed structural connectivity was supported by these NMR calculations and classical transition state theory was used to suggest a possible mechanism by which this complicated natural product is formed. In chapter 7, reductive heterocycle-heterocycle (heterocycle --heterocycle; H-H) transformations that give 4-aminoquinolines, 3-acylindoles, and quinolin-4(1H)-ones from 2-nitrophenyl substituted isoxazoles are reported. When this methodology is applied to 3,5-, 4,5-, and 3,4-bis-(2-nitrophenyl)isoxazoles, chemoselective heterocyclization gives quinolin-4(1H)-ones, and 4-aminoquinolines, exclusively. In chapter 8, a heterocycle-to-heterocycle strategy is presented for the preparation of highly fluorescent and solvatochromic dibenzonaphthyridinones (DBNs) via methodology that leads to the formation of a tertiary, spiro-fused carbon center. A linear correlation between the results of photophysical experiments and time dependent density functional theory calculations was observed for the [lambda][subscript max] of excitation for DBNs with varying electronic character.
