A Showcase of Green Chemistry: Sustainable Synthetic Approach of Zirconium-Based MOF Materials

Zirconium-based metal-organic framework materials (Zr−MOFs) have more practical usage over most conventional benchmark porous materials and even many other MOFs due to the excellent structural stability, rich coordination forms, and various active sites. However, their mass-production and application are restricted by the high-cost raw materials, complex synthesis procedures, harsh reaction conditions, and unexpected environmental impact. Based on the principles of “Green Chemistry”, considerable efforts have been done for breaking through the limitations, and significant progress has been made in the sustainable synthesis of Zr−MOFs over the past decade. In this review, the advancements of green raw materials and green synthesis methods in the synthesis of Zr−MOFs are reviewed, along with the corresponding drawbacks. The challenges and prospects are discussed and outlooked, expecting to provide guidance for the acceleration of the industrialization and commercialization of Zr−MOFs.     

Extraction of humic acid from biological matrix – dry cow dung powder

Abstract

The increased local and global concern, for alarming environmental pollution, offers incentives to explore new green and clean materials and methods for safeguarding the environment. The generation of benign alternate routes for any step in chemical processes, is the need for today and tomorrow. In the present work, humic acid (HA) has been extracted from a green source, “dry cow dung powder”, using simple, cost effective, and eco-friendly methods. HA has been extracted, isolated, and characterized by employing different spectroscopic methods. The process investigated herein imparts a boost to “Green Chemistry”, a promising solution to many global environmental problems.     

氮杂唑合成反应在生物缀合物研究中的应用

介绍了利用1,3-偶极环加成反应合成氮杂三唑和氮杂四唑的设计方法和反应特点, 以及氮杂唑类化合物的合成在生物缀合物研究中的应用.     

Synthesis of seven and higher membered nitrogen containing heterocycles using photochemical irradiation

Photochemical reactions have been applied for the synthesis of complex targets in many examples recently. In many cases, these processes provide access to unique modes of reactivity or offer unrivaled increases in molecular complexity. The key-features of photochemical reactions include increased selectivity, conversion, and yield and are beneficial for industrial and “green” processes. Despite these advantages, however, photochemical reactions in chemical production or R and D processes are rare. Most technical processes are limited to commodity chemicals and have been developed decades ago. The application of photochemical reactions for the synthesis of fine chemicals, natural products, and pharmaceutically active compounds, has become very popular. Photochemical reactions are used for organic synthesis and this review article highlighted the syntheses of heterocycles. Photochemistry is particularly fascinating and afforded an exotic charm due to its unconventional nature. In this review, I have given a clear idea of applicability of photochemical irradiations for the synthesis of a number of seven and higher membered N-heterocycles.     

Liquid crystal chemistry and poetry

This paper comments on a recent article “Revolutionary poetry and liquid crystal chemistry: Herman Gorter, Ada Prins and the interface between literature and science” by Hub Zwart (Foundations of Chemistry, published online: 10 July 2020), in which the author explores the influence of the liquid crystal research of Ada Prins on the epic poem Pan written by her long-time lover Herman Gorter. The present paper reviews the basic science of liquid crystals and explains the connections between the work of Prins and its influence on the poem. Other examples of the use of “liquid crystal” as a literary device are identified from renaissance poetry, and the uses of the metaphor in these poems are analysed from a scientific perspective. From these examples it is suggested that creative concepts from poetry may contain elements of substance that appear in hitherto unrecognised scientific realities.

     

UK chemistry teachers visit Frankfurt

The Royal Society of Chemistry organizes “Study Tours” for chemistry teachers. Normally these tours include visits to industrial plants and, over eight years, many teachers have gained fresh insights into the ways the chemical industry works. Last October a new style of tour was held in Frankfurt — a city with a rich history in producing industrial chemicals. With the great help of Kurt Begitt at GDCh a tour was set up which involved study of the education system (academic and vocational) as well as the more usual study of industrial activity.     

Exploring Green Chemistry,Sustainable Chemistry and innovative business models such as Chemical Leasing in the context of international policy discussions

This article provides an overview on Green Chemistry and Sustainable Chemistry in the context of the 2030 Agenda for Sustainable Development and different policy frameworks such as the EU Circular Economy Action Plan and SAICM, the Strategic Approach of International Chemicals Management. There is an increasing body of evidence suggesting the practicality and applicability of Green Chemistry and Sustainable Chemistry within industrial development policies and international agreements addressing chemicals and waste concerns. To explore the full potential of Green Chemistry and Sustainable Chemistry, the authors come to the conclusion that innovative business models are required to facilitate the engagement of the different players, including industry. While presenting the United Nations Industrial Development Organization (UNIDO)’s experiences and lessons learnt from ten years of work in UNIDO's Global Chemical Leasing Programme, the article also highlights the role that innovative and circular economy business models could play in achieving inclusive and sustainable economic growth. It therefore explores the potential of integrated Chemical Leasing, Green Chemistry and Sustainable Chemistry initiatives at the global level.     

A Hemilabile NHC-Gold Complex and its Application to the Redox Neutral 1,2-Oxyarylation of Feedstock Alkenes

We describe a Au^I complex of a hemi-labile (C^N) N-heterocyclic carbene ligand that is able to mediate oxidative addition of aryl iodides. Detailed computational and experimental investigations have been undertaken to verify and rationalize the oxidative addition process. Application of this initiation mode has resulted in the first examples of “exogenous oxidant-free” Au^I/Au^III catalyzed 1,2-oxyarylations of ethylene and propylene. These demanding yet powerful processes establish these commodity chemicals as nucleophilic-electrophilic building blocks in catalytic reaction design.     

Groups of Organic Molecules That Operate Collectively

A “chemical system” is defined as an assemblage of molecules that collectively does something interesting or useful. The key word here is “collectively”, a word that implies an interdependency and a group behavior that can be quite different from that of individual molecules. Batteries, computer chips, concrete, mayonnaise, shampoo, paint, liquid crystal displays, composites, and viruses are all examples of commonly encountered systems. A host–guest or “supramolecular” complex, on the other hand, would not be considered a system (as defined here), because only two species are involved. A chemical system is multimolecular, a collection of molecules interlocked in a tangle of dependencies. The review delves into a variety of chemical systems investigated by the author, including micelles, water pools, films, vesicles, and polymers. All of them can be categorized as “self-assembling” or “self-organizing” in the sense that defined structures arise spontaneously owing to noncovalent forces among the component molecules. Such chemical systems are useful for many purposes, including decontamination of environmentally dangerous substances, drug delivery, and separation of organic compounds.     

Configurational rules governing the stereochemical control of chiral initiators in ring-opening polymerizations of heterocyclic monomers

Configuration rules were established for the polymerization of cyclic monomers with chiral initiators. The latter recognize in the monomer an asymmetric carbon of homochiral configuration. The chirality of the initiator is defined by the “local” asymmetry of the ligand and by the overall asymmetry of the particular arrangement of catalytic aggregates. Two types of process called “homosteric” and “antisteric,” which apply to the polymerization of resolvable monomers and achiral monomers of meso structure, are defined. These configurational rules have a general character and are verified in many examples of differently substituted three- or four-membered cyclic monomers (oxiranes, thiiranes, β-lactones). Stereoelective polymerization appears to be an original method for the determination of the absolute configuration of some monomers of unknown chirality.     

Education and training in Analytical Chemistry

Analytical Chemistry is involved in the undergraduate curriculum in the US in many ways. It is one of four required subjects for accreditation of a college or university by the American Chemical Society. However there is much discussion underway in the US about change in the undergraduate training of analytical chemists to more closely reflect the “problem solving” nature of Analytical Chemistry, and to better address the needs of industry. It is suggested that the curriculum should emphasize the fundamentals but also teach applied Analytical Chemistry, the need for teamwork, and the importance of communication skills.     

N′N′N pincer and N′N bidentate(pyrazolylpyridyl) Rh(I) complexes as catalyst precursors for hydroformylation of olefins

Transition Metal Chemistry - The industrial process of hydroformylation or the oxo process has been used for many years in the production of aldehydes from alkenes. Different metals have been used...     

β-cyclodextrin and its silyl derivative inclusion complexes and conjugates with medicine preparation “Ibuprofen” and its synthetic precursors

A possibility of formation of various inclusion complexes and conjugates of β-cyclodextrin and its silyl derivatives with the medicine preparation “Ibuprofen” and its synthetic precursors in dependence of nature of solvent and size of cyclodextrin cavity is demonstrated.     

Process design for integration of extraction,purification and formulation with alternative solvent concepts

Methods of Green Chemistry are in the meantime established in process design for extraction of natural products [1]. Moreover, natural products do have the inherent societal benefit of being a priori bio-degradable and therefore do not cause any additional waste-water and recycling problems in hospitals, cities and municipalities or environmental enrichment [2].Nevertheless, those inherent benefits could be easily compromised if they are not combined with the design and operation of fully integrated processes in manufacturing. One isolated action of Green Chemistry is not sufficient to gain the entrepreneurial balance of economy and ecology with competitive manufacturing, new marketable products, and sustainability. While any process modification could be implemented in substituting simply one existing step, a fully integrated new process needs to be set up to exceed the existing benchmark or best practice and to be transferred into manufacturing.Finding alternative solvents and enhancing mass transfer in extraction need to be integrated. This integration into a complete process from extraction over purification to formulation, considering recycling at all steps, is a complex task which could not be fulfilled on a purely experimental basis. The efforts would be too high and costly. Therefore, the paper reviews the existing status shortly and exemplifies based on a case study, choosing 10-deacetylbaccatin III as a typical example, a theoretical approach in thermodynamics and process modeling, and how they can contribute to an alternative process design. Still, these steps in conceptual process design and basic engineering seem to be the major challenge in industrial acceptance of alternative ideas.The authors have described the transfer into innovative manufacturing concepts already elsewhere [1], [2], [3].     

Potential‐Energy Surfaces,the Born–Oppenheimer Approximations,and the Franck–Condon Principle: Back to the Roots

The concept of a potential‐energy surface (PES) is central to our understanding of spectroscopy, photochemistry, and chemical kinetics. However, the terminology used in connection with the basic approximations is variously, and somewhat confusingly, represented with such phrases as “adiabatic”, “Born–Oppenheimer”, or “Born–Oppenheimer adiabatic” approximation. Concerning the closely relevant and important Franck–Condon principle (FCP), the IUPAC definition differentiates between a classical and quantum mechanical formulation. Consequently, in many publications we find terms such as “Franck–Condon (excited) state”, or a vertical transition to the “Franck–Condon point” with the “Franck–Condon geometry” that relaxes to the excited‐state equilibrium geometry. The Born–Oppenheimer approximation and the “classical” model of the Franck–Condon principle are typical examples of misused terms and lax interpretations of the original theories. In this essay, we revisit the original publications of pioneers of the PES concept and the FCP to help stimulate a lively discussion and clearer thinking around these important concepts.     

Specific Role of Reactor Configurations on the Mass Transfer and Energy Yield: Case of “Batch” and "Circulating” Gliding arc Liquid–Gas Reactors—Part 1: Experimental Study

Plasma Chemistry and Plasma Processing - The mass transfer and energy efficiency in the “batch” and “Circulating” gliding arc configuration reactors for the direct...     

The importance of green chemistry in process research and development

Green Chemistry or Sustainable Chemistry is defined by the Environmental Protection Agency as "the design of chemical products that reduce or eliminate the use of hazardous substances" In recent years there is a greater societal expectation that chemists and chemical engineers should produce greener and more sustainable chemical processes and it is likely that this trend will continue to grow over the next few decades. This tutorial review gives information on solvents and solvent selection, basic environmental metrics collection and three industrial case histories. All three case histories involve enzymatic chemistry. Pregabalin (Lyrica?) is produced using a lipase based resolution and is extremely unusual in that all four manufacturing steps to make pregabalin are performed in water. Sitagliptin (Januvia?) uses a transaminase in the final chemical step. Finally a rosuvastatin (Crestor?) intermediate is produced using a deoxy ribose aldolase (DERA) enzyme in which two carbon-carbon bonds and two chiral centres are formed in the same process step.     

Advances in rapid and effective break-in/conditioning/recovery of automotive PEMFC stacks

Automotive proton exchange membrane fuel cell stacks need to meet manufacturer specified rated beginning-of-life (BOL) performance before being assembled into vehicles and shipped off to customers. The process of “breaking-in” of a freshly assembled stack is often referred to as “conditioning.” It has become an intensely researched area especially in automotive companies, where imminent commercialization of fuel cell electric vehicles (FCEVs) demands a short, energy- and cost-efficient, and practical conditioning protocol. Significant advances in reducing the conditioning time from 1 to 2 days to as low as 4h or less, in some cases without the use of additional inert gases such as nitrogen, and with minimal use of hydrogen, and specialized test stations will be discussed.     

Simulated moving bed technology: old and new

The Simulated Moving Bed (SMB) concept has been applied to the separation of different mixtures as a continuous counter current separation process, avoiding several problems related with solid motion. The aim of this work is to present some relevant examples of SMB separations corresponding to the two major ages in the use of the SMB concept, here named “old” and “new” applications. The “old” applications of SMB technology in the petrochemical industry are still important, with large and highly productive units; and the “new” applications of the second “age” of SMB concept are from the fine chemical, pharmaceutical and biochemistry areas, associated with the demand of high purity products during the last 10 years. Different examples are presented for different ages: a UOP Parex ^® process for the “old”, modelled with the equivalent True Moving Bed (TMB) approach; and a chiral resolution for the “new”, modelled by the real SMB model. Some of the latest developments are also mentioned: the non conventional techniques as the Varicol ^® process, PowerFeed, Modicon, M3C or Enriched Extract-SMB (EE-SMB), MultiFeed (MF), Outlet Streams Swing (OSS) or Pseudo-SMB, involving considerable changes in the SMB concept itself. The use of the last optimization/modelling packages for the development of design techniques, either at the conception stage as well as for performance improvements of existing units is emphasized.     

Radio-green chemistry and nature resourced radiochemistry

The birth of green chemistry in 1990 influenced every branch of sciences including radiochemistry. The development of new radiochemical methods is now dictated by the green chemistry mandates, especially in terms of choosing solvents and reagents. Though there are numbers of environmentally benign reagents and solvents, but sometime atom economy is not fully maintained in the manufacturing process. A newer trend is to use chemicals from natural resources. This new trend in radiochemistry may be termed as “Nature Resourced Radiochemistry”. The development in last two decades in “Radio-green Chemistry” and “Nature Resourced Radiochemistry” has been briefly discussed in the review.