A Review on the Synthetic Methods towards Benzothienobenzothiophenes.

Benzothienobenzothiophenes (BTBTs) are a class of heteroacenes for which two distinct isomers have been identified depending on the locations of the fused benzothiophene motifs. Benzothienobenzothiophenes represent a class of heteroacenes demonstrating remarkable electronic properties that make them prominent in the realm of organic semiconductors. The structure of BTBTs, incorporating two sulfur atoms, contributes to their unique electronic characteristics, including narrow bandgaps and effective charge transport pathways. These compounds have gained attention for their high charge carrier mobility, making them desirable candidates for application in organic field-effect transistors (OFETs) and other electronic devices. Researchers have explored various synthetic strategies to design and tailor the properties of BTBT derivatives, leading to advancements in the development of high-performance organic semiconductors. Various synthetic techniques for benzothienobenzothiophenes have been reported in the literature including multistep synthesis, tandem transformations, electrochemical synthesis, and annulations. This review investigates the generality of each synthetic methodology by highlighting its benefits and drawbacks, and it analyses all synthetic approaches described for the creation of the two isomers. For the advantage of the readers, we have delved upon every mechanism of the reactions that are known. Finally, we have also summarized the synthetic methodologies that are used for making benzothienobenzothiophene analogues for material applications.

[2.2]Paracyclophane Derivatives as Building Blocks for Coordination Polymers.

Several new di- and tetracarboxylic [2.2]paracyclophane derivatives were obtained via Suzuki coupling between the appropriately brominated [2.2]paracyclophanes and 4-(methoxycarbonyl)phenylboronic acid. The reaction of one of these products, namely pp-bis(4-carboxyphenyl)[2.2]paracylophane (12), with zinc nitrate afforded a 2D coordination polymer comprising zinc-carboxylate paddlewheel clusters linked together by cyclophane cores. The zinc center is five-coordinated in a square-pyramidal geometry, with a DMF oxygen atom at the apex and four carboxylate oxygen atoms in the base.

Chemistry must respond to the crisis of transgression of planetary boundaries.

Recent assessments alarmingly indicate that many of the world's leading chemicals are transgressing one or more of the nine planetary boundaries, which define safe operating spaces within which humanity can continue to develop and thrive for generations to come. The unfolding crisis cannot be ignored and there is a once-in-a-century opportunity for chemistry - the science of transformation of matter - to make a critical difference to the future of people and planet. How can chemists contribute to meeting these challenges and restore stability and strengthen resilience to the planetary system that humanity needs for its survival? To respond to the wake-up call, three crucial steps are outlined: (1) urgently working to understand the nature of the looming threats, from a chemistry perspective; (2) harnessing the ingenuity and innovation that are central to the practice of chemistry to develop sustainable solutions; and (3) transforming chemistry itself, in education, research and industry, to re-position it as 'chemistry for sustainability' and lead the stewardship of the world's chemical resources. This will require conservation of material stocks in forms that remain available for use, through attention to circularity, as well as strengthening engagement in systems-based approaches to designing chemistry research and processes informed by convergent working with many other disciplines.

A shared future: chemistry's engagement is essential for resilience of people and planet.

Strengthening resilience-elasticity or adaptive capacity-is essential in responding to the wide range of natural hazards and anthropogenic changes humanity faces. Chemistry's roles in resilience are explored for the first time, with its technical capacities set in the wider contexts of cross-disciplinary working and the intersecting worlds of science, society and policy. The roles are framed by chemistry's contributions to the sustainability of people and planet, examined via the human security framework's four material aspects of food, health, economic and environmental security. As the science of transformation of matter, chemistry is deeply involved in these material aspects and in their interfacing with human security's three societal and governance aspects of personal, community and political security. Ultimately, strengthening resilience requires making choices about the present use of resources as a hedge against future hazards and adverse events, with these choices being co-determined by technical capacities and social and political will. It is argued that, to intensify its contributions to resilience, chemistry needs to take action along at least three major lines: (i) taking an integrative approach to the field of 'chemistry and resilience'; (ii) rethinking how the chemical industry operates; and (iii) engaging more with society and policy-makers.

Re-imagining Priorities for Chemistry: A Central Science for "Freedom from Fear and Want".

Human security, defined as "freedom from want and fear and freedom to live in dignity", provides an overarching concept to address threats to human security dimensions such as health, food, economics, the environment and sustainable development, while placing the individual at the centre of attention. Chemistry is central to addressing these challenges, but surprisingly its role and contributions to human security have hitherto not been explicitly set out. This article situates chemistry in the human security framework, highlighting areas where chemistry knowledge, methods and products are vital. It underscores three complementary facets: 1) chemistry contributes to many dimensions of human security, but needs to do much more in the light of oncoming global challenges; 2) the human security framing illuminates areas where chemistry itself needs to adapt to contribute better, by intensification of current approaches and/or by building or strengthening chemistry tools, skills and competencies; and 3) repositioning as central to human security affords chemistry a powerful opportunity to refresh itself as a science for the benefit of society-and it will need to engage more directly and dynamically at the interface of science, society and policy in order to do so.

An Approach to Paracyclophane-Based Tetrathiafulvalenes: Synthesis and Characterization of a Pseudo-Geminal [2.2]Paracyclophane 1,3-Dithia-2-Thione.

The synthesis of paracyclophane-based tetrathiafulvalene precursors is described in the context of the importance of these compounds in the field of material chemistry. Pseudo-geminal bis(1,3-dithia-2-thione) was synthesized via the corresponding 1,3-dithiol-2-ylium salt. The latter was obtained by a synthetic procedure that involves 4,15-bis(acetyl)[2.2]paracyclophane, a new compound of interest for many researchers.

Realigning science, society and policy in uncertain times.

Against a backdrop of rapidly changing social, economic and geopolitical settings and ideologies, the world is facing a wide range of challenges, including in biodiversity, climate, energy, the environment, food, health and water. These can only be addressed by fully harnessing key capacities that science offers. However, there is a crisis of trust in science which affects some sections of society and some policy-makers, impairing the capacity of science to deliver its essential roles. This damaged relationship between science, society and policy has immense health, economic and social consequences and implications for sustainability of the entire planet. Scientists must strive collectively to re-establish trust by society and politicians where it is damaged, and reinforce conviction of science's central importance in underpinning policy. Science's roles must in turn be acknowledged by policies that sustain innovation and freedom to work without political interference or constraints. A well-functioning and trusting relationship between science, society and policy-makers offers a potent means to thwart and mitigate emergent global challenges.

Blocking the Hype-Hypocrisy-Falsification-Fakery Pathway is Needed to Safeguard Science.

In chemistry and other sciences, hype has become commonplace, compounded by the hypocrisy of those who tolerate or encourage it while disapproving of the consequences. This reduces the credibility and trust upon which all science depends for support. Hype and hypocrisy are but first steps down a slippery slope towards falsification of results and dissemination of fake science. Systemic drivers in the contemporary structure of the science establishment encourage exaggeration and may lure the individual into further steps along the hype-hypocrisy-falsification-fakery continuum. Collective, concerted intervention is required to effectively discourage entry to this dangerous pathway and to restore and protect the probity and reputation of the science system. Chemists must play and active role in this effort.

Fake science and the knowledge crisis: ignorance can be fatal.

Computers, the Internet and social media enable every individual to be a publisher, communicating true or false information instantly and globally. In the 'post-truth' era, deception is commonplace at all levels of contemporary life. Fakery affects science and social information and the two have become highly interactive globally, undermining trust in science and the capacity of individuals and society to make evidence-informed choices, including on life-or-death issues. Ironically, drivers of fake science are embedded in the current science publishing system intended to disseminate evidenced knowledge, in which the intersection of science advancement and reputational and financial rewards for scientists and publishers incentivize gaming and, in the extreme, creation and promotion of falsified results. In the battle for truth, individual scientists, professional associations, academic institutions and funding bodies must act to put their own house in order by promoting ethics and integrity and de-incentivizing the production and publishing of false data and results. They must speak out against false information and fake science in circulation and forcefully contradict public figures who promote it. They must contribute to research that helps understand and counter false information, to education that builds knowledge and skills in assessing information and to strengthening science literacy in society.

Tandem α-Arylation/Cyclization of 4-Haloacetoacetates with Arynes: A Metal-Free Approach toward 4-Aryl-3-(2 H)-furanones.

An efficacious, metal-free strategy has been developed for the synthesis of 4-aryl-3-(2 H)-furanones. The reaction proceeds via the nucleophilic addition of an active methylene compound to the aryne followed by ring closing of the adduct. The reaction proceeds under mild conditions, is applicable for gram-scale synthesis of 4-aryl-3-(2 H)-furanones, and is general for a range of substituted arynes and haloacetates.

The Need for Cultural Competence in Science: A Practical Approach to Enhancing Equality, Diversity, and Inclusion.

"The entire field of science needs to enhance its performance with regard to equality, diversity, and inclusion …" Read more in the Editorial by S. A. Matlin, V. W. W. Yam et al.

Convenient diastereoselective synthesis of annulated 3-substituted-(5S*,6S*,Z)-2-(2-(2,4-dinitrophenyl)hydrazono)-5,6-diphenyl-1,3-thiazinan-4-ones.

Racemic 2-(2,4-dinitrophenyl)hydrazono)-5,6-diphenyl-1,3-thiazinan-4-ones and (Z)-N'-(2,4-dinitrophenyl)-2,3-diphenylacrylohydrazide were formed during the diastereoselective reaction between 4-substituted 1-(2,4-dinitrophenyl)thiosemicarbazides and 2,3-diphenylcycloprop-2-enone under refluxing ethanol. The structures of the synthesized compounds were confirmed by single-crystal X-ray analyses.

Living Messages from Chemistry Icons: Legacies with Contemporary Relevance.

Beyond individual scientific virtuosity and creativity that leading figures in chemistry have displayed, they have sometimes conveyed wider messages of significance beyond their own professional specialization. They include insights into broader aspects of science, society or the ways of the world. On the other hand, the words, attitudes and actions of eminent chemists from former times have not always presented good models for others to follow, whether judged by their own contemporary or our present standards. Both positive and negative lessons may convey to us something about humanity in general or the nature of our current predicaments and challenges. In an era when science is more necessary than ever to help meet oncoming global challenges, yet the principles and results of science are irrationally questioned, it is particularly relevant to re-connect with the broad insights and messages that can be derived from examining the thoughts and deeds of chemistry icons from the past.

The Chemical Sciences and Equality, Diversity, and Inclusion.

There has been mounting concern over the absence of gender equality in the sciences in recent years. This has been accompanied by a broadening of the perspective, in order to address issues of equality, diversity and inclusion, relating to a wide range of circumstances in which individuals suffer discrimination. While some progress has been made in some countries, nationally or at the level of institutions, much more needs to be done. The chemical sciences can play a leading role in addressing biases, through 1) becoming a model of good systemic practice in policies, processes, and actions; 2) developing practical skills through training in cultural competence; and 3) promoting a stronger evidence base to uncover both the extent of problems and the degree to which approaches to improve equality, diversity, and inclusion are working.

Existence of Two Fluorescence Bands in all- trans-Polyenes with Six and Seven Double Bonds.

From the analysis of UV/vis absorption, emission, and excitation of emission spectra of all- trans-α,ω-tetra- tert-butylpolyenes with six and seven double-bonds (3,14-di( tert-butyl)-2,2,15,15-tetramethyl-3,5,7,9,11,13-hexadecahexaene (ttbP6), and 3,16-di( tert-butyl)-2,2,17,17-tetramethyl-3,5,7,9,11,13,15-octadecaheptaene (ttbP7)) it is concluded that these hydrocarbons do not exhibit dual S1/S2 fluorescence, as could be inferred from the work of Christensen et al. [ J. Phys. Chem. A 2008 , 112 , 12629 - 12636 ]. The spectral data for ttbP6 and ttbP7 display a unique fluorescence from their S1 states.

[2.2]Paracyclophane-Bis(triazole) Systems: Synthesis and Photochemical Behavior.

Mono-, pseudo-gem, and pseudo-para ethynylcyclophanes and bis(azides) have been employed as addition partners in CuAAC reactions to design and build complex extended molecular scaffolds. The reactivity of the resulting triazoles was investigated under photochemical conditions. A variety of newly substituted [2.2]paracyclophanes were identified; deazotization of pseudo-gem and pseudo-para adducts provided indolophane derivatives. An intramolecular stabilization effect was observed in the case of pseudo-gem derivatives. A photochemical rearrangement from a pseudo-para adduct to a pseudo-ortho product was identified.

The Ethical and Social Dimensions of Chemistry: Reflections, Considerations, and Clarifications.

"Ethics in Chemistry" is a huge topic with various viewpoints and arguments on what it actually is and what compliance to ethical guidelines and participation in ethical discourse imply, covering principles of science and research ethics, profession ethics, and technology ethics. Overview and clarity are lost easily. The authors-members of the recently formed EuCheMS working party "Ethics in Chemistry"-present an attempt to collect and sort the ethically relevant aspects and challenges that chemists see themselves confronted with. Based on this list, strategies for ethical action are outlined. On the one hand, there are those issues that are a matter of compliance to existing guidelines and standards. On the other hand, there are those conflicts that arise at the intersection of science, technology and society and that need engaged chemists participating in the larger discourse for sustainability. This Editorial attempts to point out why this is important and what chemists can do in particular.

The Chemical Sciences and Health: Strengthening Synergies at a Vital Interface.

The indispensable contributions to health made by the chemical sciences have become increasingly constrained by three systemic factors. These involve fragmentations: in the way that the chemicals sciences are structured, practiced, and inter-related to aspects of health; in the combination of public and private efforts delivering medicinal products; and in the regulatory systems which oversee health-related issues across health, food, and the environment. Interlinked systemic reforms are advocated, involving (1) recontextualization of the chemistry/health interface through creating a recognized field of "the chemical sciences and health"; (2) determined and comprehensive efforts, by countries wishing to retain or strengthen their pharmaceutical development capacities, to reinforce their education, research, and innovation eco-systems; and (3) adoption of an integrated approach to the regulation of pharmaceuticals, food, and the environment.

The influence of halogen substituents on the biological properties of sulfur-containing flavonoids.

A series of halogen-substituted tricyclic flavonoids containing a 1,3-dithiol-2-ylium moiety has been synthesized from the corresponding 3-dithiocarbamic flavanones. The influence of halogen substituents on the antibacterial properties of the tricyclic flavonoids has been investigated against Staphylococcus aureus and Escherichia coli. On going from fluorine to iodine, these compounds exhibit good to excellent inhibitory properties against both Gram-positive and Gram-negative pathogens. These results suggest that size is the main factor for the change in potency rather than polarity/electronics.

Antibacterial structure-activity relationship studies of several tricyclic sulfur-containing flavonoids.

A structure-activity relationship study concerning the antibacterial properties of several halogen-substituted tricyclic sulfur-containing flavonoids has been performed. The compounds have been synthesized by cyclocondensation of the corresponding 3-dithiocarbamic flavanones under acidic conditions. The influence of different halogen substituents on the antibacterial properties has been tested against Staphylococcus aureus and Escherichia coli. Amongst the N,N-dialkylamino-substituted flavonoids, those having an N,N-diethylamino moiety exhibited good to excellent antimicrobial properties against both pathogens. Fluorine-substituted flavonoids were found to be less active than those bearing other halogen atoms.