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Developing multifunctional nanomaterials with distinct photochemical properties, such as high quantum yield, improved photostability, and good biocompatibility is critical for a wide range of biomedical applications. Motivated by this, we designed and synthesized a dansyl‐tagged xanthate‐based capping agent (DX) for the synthesis of fluorescent silver nanoparticles (AgNPs). The capping agent DX was characterized by 1H and 13C‐NMR, LC–MS, and FT‐IR. The synthesized DX‐capped fluorescent AgNPs were thoroughly characterized by UV–visible spectroscopy, fluorescence spectroscopy, field emission scanning electron microscope (FE‐SEM), transmission electron microscope (TEM), dynamic light scattering (DLS), and zeta potential. The fluorescent AgNPs showed distinct surface plasmon resonance absorption at λmax = 414 nm, fluorescence at λmax = 498 nm, quantum yield = 0.24, zeta potential = +18.6 mV, average size = 18.2 nm. Furthermore, the biological activity of the fluorescent AgNPs was validated by its interaction with the most abundant protein in the blood, that is, BSA (Bovine serum albumin) and HSA (Human serum albumin) with binding constant of 2.34 × 104 M−1 and 2.14 × 104 M−1 respectively. Interestingly, fluorescence resonance energy transfer (FRET) was observed between the fluorescent AgNPs and BSA/HSA with a FRET efficiency of 77.23% and 56.36%, respectively, indicating strong interaction between fluorescent AgNPs and BSA/HSA. [ABSTRACT FROM AUTHOR]

This review is dedicated to the different varieties of macrocycles synthesis bearing indole units in their architecture by metal-catalyzed strategies. The progress of the new macrocyclization approaches is persisted be a keen area of research. Macrocycles contain a wide variety of molecules, and among those, heteroaryl motifs are valuable constituents that provide an attractive feature to macrocyclic systems. Indole represents one of the privileged pharmacophores against a variety of targets with various biological applications. Among the nitrogen-based heterocycles, indole plays a prominent role in organic synthesis, medicinal chemistry, pharmaceuticals, natural products synthesis, agrochemicals, dye and fragrances, and drug design. These scaffolds are widely distributed in several bioactive natural products and synthetic macrocycles constructed against a specific biochemical target and the most common constituents of naturally occurring molecules. Due to its immense importance, the progress of novel approaches for the synthesis of indole-based scaffolds has increased steadily. The majority of the macrocycles synthesis proceeds through the macrolactamization and macrolactonization, as well as the C–C bond macrocyclization process described by metal-catalyzed ring-closing metathesis (RCM) and coupling reactions. Among macrocyclizations, metal-catalyzed approaches are considered one of the most powerful tools for synthetic chemists in the design of a variety of macrocycles. This review aims to give a comprehensive insight into the synthesis of varieties of macrocycles bearing indole scaffold catalyzed by various transition metals that emerged in the literature over the last two decades. We hope that this review will persuade synthetic chemists to search for novel strategies for the C–C bond macrocyclization by metal-catalyzed protocols. [ABSTRACT FROM AUTHOR]

A novel dansyl-triazole-based fluorescent macrocycle with high Stokes shift and positive solvatochromism was developed. This is an excellent fluorescence sensor for selective detection of nitro-containing antibiotics and other nitro-heteroaromatics. Detection was possible in real samples/paper strips in submicromolar concentration. The interaction of the macrocycle with multiple proteins exhibited its bioactivity. [ABSTRACT FROM AUTHOR]

Molecules with tuneable properties are well known for their applications in the material and bio-medical fields; nevertheless, the structural and functional tunability makes them more significant in diverse applications. Herein, we designed and synthesized a novel class of star-shaped molecules via incorporating two important functional groups, i.e., triazole and dithiocarbamate (DTC). The rationale behind selecting these two key functional groups is their diverse applications, e.g., DTC having applications for therapeutics, pesticides, and vulcanizing agents, and triazole having applications for anti-cancer, fungicides, anti-microbials, inhibitors, etc. The structure of the molecules was strategically designed in such a way that their overall structures are the same (central tertiary-amine and peripheral hydroxy groups), except the key functional group (DTC and triazole) in the respective molecules was different. Following synthesis and characterization, the influence of DTC and triazole groups on their bioactivity was compared via interacting with the most abundant proteins present in the blood, including serum albumin, trypsin, haemoglobin, and ribonuclease. From both the experimental and molecular docking studies, it was confirmed that the triazole molecule has a higher binding affinity towards these proteins as compared to the DTC molecule. In summary, two star-shaped DTC- and triazole-based molecules were synthesized and their bioactivity was compared via binding with blood plasma proteins. [ABSTRACT FROM AUTHOR]

The architecture of molecules plays a significant role in their effective binding with another moiety. Direct comparison of a linear dithiocarbamate and its macrocyclic analogue was carried out, to explore the magnitude of these architectural effects for different biological and material science applications. Linear and macrocyclic compounds with the same functional groups, such as amide, dithiocarbamic ester, naphthyl, and propyl, were designed, synthesized, and compared through their spectral, physicochemical, and thermal properties. Utilizing dithiocarbamates, the compounds were used for the detoxification of water by removal of toxic heavy metals, including Hg2+, Cu2+, Cd2+, Pb2+, Zn2+, and Ni2+ by precipitation. In addition, comparable interactions with various important proteins, such as bovine serum albumin, human serum albumin, haemoglobin, lysozyme, proteinase, ribonuclease, and trypsin, were performed. The observation of better performance for the macrocycle towards protein interaction, and of the linear compound for removal of heavy metals is remarkable, and proves that the compound architecture is important. [ABSTRACT FROM AUTHOR]

Organic polymers are widely explored due to their high stability, scalability, and more facile modification properties. We developed cost-effective dithiocarbamate-based organic polymers synthesized using diamides, carbon disulfide, and diamines to apply for environmental remediation. The sequestration of radioiodine is a serious concern to tackle when dealing with nuclear power for energy requirements. However, many of the current sorbents have the problem of slower adsorption for removing iodine. In this report, we discuss the utilization of an electron-rich dithiocarbamate-based organic polymer for the removal of iodine in a very short time and with high uptake. Our material showed 2.8 g/g uptake of vapor iodine in 1 h, 915.19 mg/g uptake of iodine from cyclohexane within 5 s, 93% removal of saturated iodine from water in 1 min, and 1250 mg/g uptake of triiodide ions from water within 30 s. To the best of our knowledge, the iodine capture was faster than previously observed for any existing material. The material was fully recyclable when applied for up to four cycles. Hence, this dithiocarbamate-based polymer can be a promising system for the fast removal of various forms of iodine and, thus, enhance environmental security. [ABSTRACT FROM AUTHOR]

A modular platform for the synthesis of tunable aza-oxa-based macrocycles was established. Modulations in the backbone and the side-chain functional groups have been rendered to achieve the tunable property. These aza-oxa-based macrocycles can also differ in the number of heteroatoms in the backbone and the ring size of the macrocycles. For the proof of concept, a library of macrocycles was synthesized with various hanging functional groups, different combinations of heteroatoms, and ring sizes in the range of 17–27 atoms and was characterized by NMR and mass spectrometry. In light of the importance of the copper-catalyzed azide-alkyne cycloaddition (CuAAC) reaction and the significance of triazole groups for various applications, we employed the click-reaction-based macrocyclization. The competence of the synthesized macrocycles in various biomedical applications was proven by studying the interactions with the serum albumin proteins; bovine serum albumin and human serum albumin. It was observed that some candidates, based on their hanging functional groups and specific backbone atoms, could interact well with the protein, thus improving the bioactive properties. On the whole, this work is a proof-of-concept to explore the backbone- and side-chain-tunable macrocycle for different properties and applications. [ABSTRACT FROM AUTHOR]

Modification of important physicochemical properties of aqueous surfactant solutions can be achieved by addition of environmentally benign room temperature ionic liquids (ILs). While low aqueous solubility of “hydrophobic” ILs limits the amount of IL that may be added to achieve desired changes in the physicochemical properties, hydrophilic ILs do not have such restrictions associated to them. Alterations in the key physicochemical properties of aqueous solutions of a common nonionic surfactant Triton X-100 (TX100) on addition of up to 30 wt % hydrophilic IL 1-butyl-3-methylimidazolium tetrafluoroborate ([bmim][BF4]) are reported. The presence of micellar aggregates in as high as 30 wt % [bmim][BF4]-added aqueous TX100 solutions is established by dynamic light scattering and fluorescence probe behavior. Increasing the concentration of [bmim][BF4] results in decrease in average micellar size and aggregation number and increase in critical micelle concentration, indicating an overall unfavorable aggregation process. Increase in the dipolarity and the microfluidity of the probe cybotactic region within the palisade layer of the micellar phase upon [bmim][BF4] addition implies increased water penetration and the possibility of TX100-[bmim][BF4] interactions. While the changes in some of the physicochemical properties indicate the role of [bmim][BF4] to be similar to a cosurfactant, the IL acts like a cosolvent as far as changes in other properties are concerned. Effectiveness of IL [bmim][BF4] in modifying physicochemical properties of aqueous TX100 is demonstrated. [ABSTRACT FROM AUTHOR]

The importance of sequence-defined polymers is evident in highly developed biological systems. As such, their synthetic de novo production with similar macromolecular diversity, efficiency, and speed has been the focus of considerable research. In this brief review, the rationale behind the new synthesis of sequence-defined oligothioetheramides (oligoTEAs) will be placed in context with the accepted methods of peptide and peptoid synthesis, where all methods notably utilize chemical orthogonality in their design. Along with the conceptual design, we will discuss the assembly of oligoTEAs by highlighting the solution-phase kinetics of each orthogonal reaction, the liquid-phase fluorous purification methodology, a proof-of-principle synthesis, and the assembly of a full-length oligomer. Overall, the success of oligoTEAs stems from the rapid orthogonal chemical reactions at each end of the unique N-allyl-N-acrylamide monomer. OligoTEAs seek to contribute and advance the field of sequence-defined polymers by providing additional structural diversity to fundamentally study sequence-structure-function relationships for both material science and biological applications. 1 Introduction 2 Supported Synthesis via Orthogonal Chemistries 3 Conceptual Design of OligoTEA Assembly 4 Proof-of-Principle 5 Synthesis and Characterization of OligoTEAs 6 Conclusion [ABSTRACT FROM AUTHOR]

Biological systems have long recognized the importance of macromolecular diversity and have evolved efficient processes for the rapid synthesis of sequence-defined biopolymers. However, achieving sequence control via synthetic methods has proven to be a difficult challenge. Herein we describe efforts to circumvent this difficulty via the use of orthogonal allyl acrylamide building blocks and a liquid-phase fluorous support for the de novo design and synthesis of sequence-specific polymers. We demonstrate proof-of-concept via synthesis and characterization of two sequence-isomeric 10-mer polymers. 1H NMR and LCMS were used to confirm their chemical structure while tandem MS was used to confirm sequence identity. Further validation of this methodology was provided via the successful synthesis of a sequence-specific 16-mer polymer incorporating nine different monomers. This strategy thus shows promise as an efficient approach for the assembly of sequence-specific functional polymers. [ABSTRACT FROM AUTHOR]

Supramolecular photoinduced electron transfer dynamics between coumarin 153 (C153) and 4,4′-dimethyl viologen dichloride (MV2+) across the molecular barrier of a host molecule, octa acid (OA), has been investigated with femtosecond time resolution. The ultrafast electron transfer from C153 to MV2+ followed excitation with 150 fs laser pulses at a wavelength of 390 nm despite the fact that C153 was incarcerated within an OA2 capsule. As a result, the photoexcited coumarin did not show any of the typical relaxation dynamics that is usually observed in free solution. Instead, the excited electron was transferred across the molecular wall of the capsuleplex within 20 ps. Likewise, the lifetime of the charge transfer state was short (724 ps), and electron back-transfer reestablished the ground state of the system within 1 ns, showing strong electronic coupling among the excited electron donor, host, and acceptor. When the donor was encapsulated into the host molecule, the electron transfer process showed significantly accelerated dynamics and essentially no solvent relaxation compared with that in free solution. The study was also extended to N-methylpyridinium iodide as the acceptor with similar results. [ABSTRACT FROM AUTHOR]

A new design strategy is described for chloride ion sensors based on suppression of excited state intramolecular proton transfer in squaramides as a fluorescence “turn on” mechanism. [ABSTRACT FROM AUTHOR]

The use of supramolecular architectures to control the spatially dependent spin exchange (spin communication) between two covalently linked radical centers (biradical) has been explored. Cucurbit[8]uril, through supramolecular steric effect, completely suppresses spin exchange between two adjacent radical centers in a biradical. [ABSTRACT FROM AUTHOR]