Functionalized lignin-based magnetic adsorbents with tunable structure for the efficient and selective removal of Pb(II) from aqueous solution

A triazine-cored covalent organic polymer (COP) was designed and synthesized via amine linkages under ambient conditions. The novel architecture of the COP was fully characterized via spectroscopic and analytical techniques. The present COP demonstrates a quick, portable and reversible chromogenic response towards noxious HCl vapours.

A reversible chromogenic covalent organic polymer for gas sensing applications

TiO2 nanoparticles immobilized organo-reduced graphene oxide hybrid nanoreactor for catalytic applications

A Pd confined hierarchically conjugated covalent organic polymer for hydrogenation of nitroaromatics: catalysis, kinetics, thermodynamics and mechanism

A triazine based covalent organic polymer (CC-TAPT-COP) was designed and synthesized via nucleophilic substitution reaction between 1,3,5-tris-(p-aminophenyl) triazine and cyanuric chloride under refluxing conditions with bottom-up approach. The structural and morphological properties of CC-TAPT-COP were well characterized by various spectroscopic and analytical techniques. The CC-TAPT-COP appeared as an irregular block morphology (SEM) and possesses remarkable thermal stability. The physical properties such as insolubility, chemical and thermal stability of CC-TAPT-COP provide a sustainable alternative to classical metal-assisted and homogeneous catalysts. In this report, we have explored CC-TAPT-COP as a heterogeneous catalyst for expedient access to the substituted quinazoline, a family of N-containing biopharmaceutical active heterocyclic compounds, at ambient conditions. Moreover, the present work not only supports COPs for their synthesis, but also paves an opportunity for catalytic applications as heterogeneous media.

A new triazine-cored covalent organic polymer for catalytic applications

A novel unsymmetrical covalent organic polymer, COP (1), was designed and characterized using several analytical and spectroscopic techniques. COP (1) was synthesized via the nucleophilic substitution reaction of 2,4,6-trichloro-1,3,5-triazine with p-amino phenol. Subsequently, COP (1) was immobilized with Pd(0) on its exterior and utilized as a heterogeneous catalyst (Pd@1). Pd@1 exhibited excellent catalytic activity and reusability for the Sonogashira C–C cross coupling reaction, and a few new products were synthesized. The confinement of Pd was well supported by the suitable functionalities present on the surface of COP (1). Furthermore, Pd@1 was used for eight consecutive catalytic runs without any considerable loss in its activity and no leaching of the metal NPs was observed.

A Pd NP-confined novel covalent organic polymer for catalytic applications

Herein, we present the first report on the Covalent Organic Polymer (COP) directed non-classical synthesis of an amide bond. An economical route has been chosen for the synthesis of APC-COP using p-aminophenol and cyanuric chloride. APC-COP acts as a smart, valuable and sustainable catalyst for efficient access to the amide bond under mild conditions at room temperature in 30 min. APC-COP exhibits selectivity towards carboxylic acids over esters. The key features of this protocol involve the variety of parameters, viz. wider substrate scope, no use of additive and recyclability, which makes this approach highly desirable in gramscale synthesis. Moreover, we have shown the practical utility of the present method in the catalytic synthesis of paracetamol.

An unsymmetrical covalent organic polymer for catalytic amide synthesis.

The present work describes the preparation of a new covalent organic polymer (COP) and its application as a hetero support for diaryl selenides synthesis. A nitrogen rich COP (CGP) has been synthesized via SNAr reaction of cyanuric chloride with guanidinium hydrochloride. The successful confinement of COP with Ni nanoparticles through post-synthetic transformations (Ni@CGP) provides excellent catalytic activity for the transformation of aryl halides into diaryl selenides using elemental selenium powder. The synthetic transformations are well confirmed using various modern analytical and spectroscopic techniques which reveal high chemical and thermal durability. The N-rich framework of CGP fortifies the confinement of Ni NPs. Ni@CGP provides an efficient approach for diaryl selenides synthesis using a very cheap selenating reagent under water benign solvent conditions (DMSO : H2O) at room temperature with high reusability. Significantly, our work not only contributes the opportunity for developing economical and effective non-noble metal decorated COPs as heterogeneous catalysts, but also delivers an efficient approach to produce industrially important C–Se coupling products.

Ni nanoparticle-confined covalent organic polymer directed diaryl-selenides synthesis

The first quarter of the 21st century has remarkably been characterized by a multitude of challenges confronting human society as a whole in terms of several outbreaks of infectious viral diseases, such as the 2003 severe acute respiratory syndrome (SARS), China; the 2009 influenza H1N1, Mexico; the 2012 Middle East respiratory syndrome (MERS), Saudi Arabia; and the ongoing coronavirus disease 19 (COVID-19), China. COVID-19, caused by SARS-CoV-2, reportedly broke out in December 2019, Wuhan, the capital of China's Hubei province, and continues unabated, leading to considerable devastation and death worldwide. The most common target organ of SARS-CoV-2 is the lungs, especially the bronchial and alveolar epithelial cells, culminating in acute respiratory distress syndrome (ARDS) in severe patients. Nevertheless, other tissues and organs are also known to be critically affected following infection, thereby complicating the overall aetiology and prognosis. Excluding H1N1, the SARS-CoV (also referred as SARS-CoV-1), MERS, and SARS-CoV-2 are collectively referred to as coronaviruses, and taxonomically placed under the realm Riboviria, order Nidovirales, suborder Cornidovirineae, family Coronaviridae, subfamily Orthocoronavirinae, genus Betacoronavirus, and subgenus Sarbecovirus. As of 23 September 2021, the ongoing SARS-CoV-2 pandemic has globally resulted in around 229 million and 4.7 million reported infections and deaths, respectively, apart from causing huge psychosomatic debilitation, academic loss, and deep economic recession. Such an unprecedented pandemic has compelled researchers, especially epidemiologists and immunologists, to search for SARS-CoV-2-associated potential immunogenic molecules to develop a vaccine as an immediate prophylactic measure. Amongst multiple structural and non-structural proteins, the homotrimeric spike (S) glycoprotein has been empirically found as the most suitable candidate for vaccine development owing to its immense immunogenic potential, which makes it capable of eliciting both humoral and cell-mediated immune responses. As a consequence, it has become possible to design appropriate, safe, and effective vaccines, apart from related therapeutic agents, to reduce both morbidity and mortality. As of 23 September 2021, four vaccines, namely, Comirnaty, COVID-19 vaccine Janssen, Spikevax, and Vaxzevria, have received the European Medicines Agency's (EMA) approval, and around thirty are under the phase three clinical trial with emergency authorization by the vaccine-developing country-specific National Regulatory Authority (NRA). In addition, 100-150 vaccines are under various phases of pre-clinical and clinical trials. The mainstay of global vaccination is to introduce herd immunity, which would protect the majority of the population, including immunocompromised individuals, from infection and disease. Here, we primarily discuss category-wise vaccine development, their respective advantages and disadvantages, associated efficiency and potential safety aspects, antigenicity of SARS-CoV-2 structural proteins and immune responses to them along with the emergence of SARS-CoV-2 VOC, and the urgent need of achieving herd immunity to contain the pandemic.

Deepika Yadav

Papers

A Pd confined hierarchically conjugated covalent organic polymer for hydrogenation of nitroaromatics: catalysis, kinetics, thermodynamics and mechanism

A Pd NP-confined novel covalent organic polymer for catalytic applications

An unsymmetrical covalent organic polymer for catalytic amide synthesis.

Ni nanoparticle-confined covalent organic polymer directed diaryl-selenides synthesis

Insights into COVID-19 Vaccine Development Based on Immunogenic Structural Proteins of SARS-CoV-2, Host Immune Responses, and Herd Immunity