New Calix4pyrrole Derivatives For Ionic And Neutral Guests

The first chapter is a review of fluorescent sensors for explosives detection and ion pair receptors. In the second chapter, two novel pyrene-appended calix[4]pyrroles are reported. Their binding properties to various guests including aromatic explosives and anions are discussed. The third chapter describes the design and synthetic attempts of two calix[4]arene-strapped calix[4]pyrroles to serve as ion pair receptor in order to be selective for potassium salts and sodium salts, respectively

Anion recognition plays a critical role in a range of biological processes, and a variety of receptors and carriers can be found throughout the natural world. Chemists working in the area of supramolecular chemistry have created a range of anion receptors, drawing inspiration from nature as well as their own inventive processes. This book traces the origins of anion recognition chemistry as a unique sub-field in supramolecular chemistry while illustrating the basic approaches currently being used to effect receptor design. The combination of biological overview and summary of current synthetic approaches provides a coverage that is both comprehensive and comprehensible. First, the authors detail the key design motifs that have been used to generate synthetic receptors and which are likely to provide the basis for further developments. They also highlight briefly some of the features that are present in naturally occurring anion recognition and transport systems and summarise the applications of anion recognition chemistry. Providing as it does a detailed review for practitioners in the field and a concise introduction to the topic for newcomers, Anion Receptor Chemistry reflects the current state of the art. Fully referenced and illustrated in colour, it is a welcome addition to the literature.

Comprehensive Supramolecular Chemistry II, Second Edition, Nine Volume Set is a ‘one-stop shop’ that covers supramolecular chemistry, a field that originated from the work of researchers in organic, inorganic and physical chemistry, with some biological influence. The original edition was structured to reflect, in part, the origin of the field. However, in the past two decades, the field has changed a great deal as reflected in this new work that covers the general principles of supramolecular chemistry and molecular recognition, experimental and computational methods in supramolecular chemistry, supramolecular receptors, dynamic supramolecular chemistry, supramolecular engineering, crystallographic (engineered) assemblies, sensors, imaging agents, devices and the latest in nanotechnology. Each section begins with an introduction by an expert in the field, who offers an initial perspective on the development of the field. Each article begins with outlining basic concepts before moving on to more advanced material. Contains content that begins with the basics before moving on to more complex concepts, making it suitable for advanced undergraduates as well as academic researchers Focuses on application of the theory in practice, with particular focus on areas that have gained increasing importance in the 21st century, including nanomedicine, nanotechnology and medicinal chemistry Fully rewritten to make a completely up-to-date reference work that covers all the major advances that have taken place since the First Edition published in 1996

Molecular recognition exploiting non-covalent interactions mediates the structure and function of many critical biological and synthetic molecules. There has thus been continuing and intense efforts in the design and synthesis of supramolecular systems with the capability of recognizing specific chemical species. Among various guest species, Prof. Sessler's group has been focused on the study of artificial anion receptors. Calix[4]pyrrole is a tetrapyrrolic macrocycle that is capable of binding anions via concerted and directional hydrogen bonding. Recently, a tetrathiafulvalene (TTF) functionalized calix[4]pyrrole (TTF-C4P) was synthesized and studied as a receptor for various guest species such as anions, electron deficient guest species, and C60. This dissertation focuses on the recent discovery in supramolecular chemistry of TTF-calix[4]pyrrole derivatives. Chapter 1 provides a brief overview of the historical perspective, redox properties, and uses of TTF derivatives as functional building blocks for supramolecular assemblies, as well as previous findings involving the supramolecular chemistry of TTF-C4P. Chapter 2, as the major focus of this dissertation, describes ion mediated supramolecular and reversible electron transfer processes between TTF-C4P and bisimidazolium salts (BIQ22X−). We discovered that the electron transfer processes between these redox couples could be controlled reversibly by ion binding. Specifically, we found that anion binding to the TTF-C4P receptor promotes the forward ET processes. In contrast, cation complexation to the cavity of TTF-C4P causes the reverse ET processes. Such ion mediated ET processes play an essential role in biological ET systems including photosynthesis and respirations. These reversible ET processes were mapped out by spectroscopic (1H-NMR, UV-Vis NIR titrations, and EPR analysis) and X-ray single crystallographic analyses of both the intermediate and products. Chapter 3 describes the synthesis of aromatic (thiophene and benzene) annulated TTF-calix[4]pyrroles as new and significantly improved receptors for poly-nitroexplosives. The resulting electronic modulations of the parent TTF-pyrrole structure result in significantly enhanced binding affinities for the corresponding TTF-C4Ps toward polynitro-explosives. This is reflected in a high level of positive homotropic allosterism. The degree of the cooperative effect was found to vary depending on the nature of both the receptors and guest species. The origin of the cooperative binding can be explained by conformational locking and an inductive effect of binding the first nitroaromatic guest.

Considerable efforts have been made to develop the supramolecular systems being capable of selectively binding and recognizing specific chemical species. Within this context, particular has been put towards nuclear waste remediation, environmental chemistry, and biology. Calix[4]pyrroles are non-conjugated tetrapyrrolic macrocycles capable of binding anions and neutral substrates via concerted and directional hydrogen bonding. Moreover, functionalization of the calix[4]pyrrole meso position allows the incorporation of additional binding sites for both cations and anions. Due to the ease of preparation and functionalization, elaborated calix[4]pyrroles have been employed as various anion and ion pair receptors as well as potential extractants for species present in high-level liquid waste (HLLW) and transporters for biological important ions in connection with therapeutic aims. These studies reported herein are primarily focused on the discovery in meso-substituted calix[4]pyrrole-functionalized extended molecular systems and applications for environmental concerns. Chapter 1 provides a brief overview regarding the historical perspective and inherent properties of calix[4]pyrroles, as well as outlines recent contributions for capturing, extracting and sequestering chemical species with environmental concerns. Chapter 2 describes the extraction of the sulfate anion via bipyrrole-strapped calix[4]pyrroles. Through these studies, we have discovered such cryptand-like receptors could extract the highly hydrophilic sulfate anion into an organic solvent from aqueous solutions when A336Cl was used as a coextractant. Chapter 3 depicts a novel meso-functionalized calix[4]pyrrole-based three dimensional networked molecular cage. Interestingly, upon treatment of fluoride, the resultant framework could be disassembled, which serves to release the inner molecules. Moreover, multiple lone pairs and hydrogen bonding donors provided by the calix[4]pyrrole building units allow for a highly selective adsorption for CO2 over other gaseous guest, such as N2, O2, H2 and CH4. Chapter 4 describes two novel calix[4]pyrrole-based uranyl complex cages, cage-1 and -2. The transformation from a tripodal cage (cage-1) to a tetrapodal system (cage-2) was achieved by a sunlight induced photochemical oxidation or via simple addition of hydrogen peroxide. Chapter 5 details the synthetic procedures and characterizations of all compounds used in these studies.

Contributions featuring the chemistry and applications of a family of macrocyclic compounds collectively known as 'calixarenes' are presented in this edited volume. The arsenal of structures based on calixarenes provides tools which are effective in numerous areas of supramolecular chemistry. The Editors have compiled a timely volume which contains up to date, high calibre contributions from a large number of international authors. A broad perspective on the progress and future of calixarene chemistry is presented. Aimed at students and researchers active in Supramolecular Chemistry.

Molecular Toxinology has been consolidated as a scientific area focused on the intertwined description of several aspects of animal toxins. In an inquiring biotechnological world, animal toxins appear as an invaluable source for the discovery of therapeutic polypeptides. Animal toxins rely on specific chemical interactions with their partner molecule to exert their biological actions. The comprehension of how molecules interact and recognize their target is essential for the rational exploration of bioactive polypeptides as therapeutics. Investigation on the mechanism of molecular interaction and recognition offers a window of opportunity for the pharmaceutical industry and clinical medicine. Thus, this book brings examples of two interconnected themes - molecular recognition and toxinology concerning to the integration between analytical procedures and biomedical applications.

Brett M. Rambo ∙ Eric S. Silver ∙ Christopher W. Bielawski ∙ Jonathan L. Sessler Covalent Polymers Containing Discrete Heterocyclic Anion Receptors Philip A. Gale ∙ Chang-Hee Lee Calix[n]pyrroles as Anion and Ion-Pair Complexants Wim Dehaen Calix[n]phyrins: Synthesis and Anion Recognition Hiromitsu Maeda Acyclic Oligopyrrolic Anion Receptors Jeffery T. Davis Anion Binding and Transport by Prodigiosin and Its Analogs Hemraj Juwarker ∙ Jae-min Suk ∙ Kyu-Sung Jeong Indoles and Related Heterocycles Pavel Anzenbacher Jr. Pyrrole-Based Anion Sensors, Part I: Colorimetric Sensors Pavel Anzenbacher Jr. Pyrrole-Based Anion Sensors, Part II: Fluorescence, Luminescence, and Electrochemical Sensors Ermitas Alcalde ∙ Immaculada Dinarès ∙ Neus Mesquida Imidazolium-Based Receptors Nathan L. Kilah ∙ Paul D. Beer Pyridine and Pyridinium-Based Anion Receptors Kevin P. McDonald ∙ Yuran Hua ∙ Amar H. Flood 1,2,3-Triazoles and the Expanding Utility of Charge Neutral CHlllAnion Interactions

This volume will capture transformational changes in both the chemistry and engineering side of solvent extraction, creating new directions and deepening our understanding of the structure and dynamics of liquid-liquid systems from the molecular- to nano- to meso- to bulk-scale. Reviews will cover advances in microfluidics, new tools for understanding the structure and dynamics of the liquid-liquid interface, ionic liquids in liquid-liquid extraction, molecular dynamics to visualize interactions in the solvent phase, liquid-liquid electrochemistry to interrogate the energetics of interfacial transport and complexation, design of new extractants, and the streamlining of process applications.

From the Publisher: "Kenan Malik shows that race is not a biological reality-but also why it is so useful in scientific and medical research. He claims that it is not through scientific research into human differences but through our obsession with identity and diversity that dangerous ideas about race are once more catching fire. Blaming the preservation of racial ideas on the liberal antiracist movement with its emphasis on human difference over human commonalities, Malik shows how antiracists have, in recent years, become increasingly hostile to both scientific ideas and freedom of thought." Blending politics, history, science, and philosophy, Malik explores the science of skull measurement and the politics of the Holocaust; diabetes rates among Hispanics and the fate of the Elgin Marbles; the genetics of altruism and the struggle for Aboriginal rights; the successes of Human Genome Project and the failures of multiculturalism. Confronting issues such as the link between race and intelligence, the promotion of race-specific drugs, the fashion for genealogy, and why scientific research into controversial areas should not be constrained, Malik proves that the debate about race is back-and shows us how to deal with it.