Department of Chemistry

Indian Institute of Technology Palakkad&nbsp;(IIT Palakkad or IIT PKD) is a public autonomous&nbsp;engineering&nbsp;and&nbsp;research&nbsp;institute located in&nbsp;Palakkad,&nbsp;Kerala. It was&nbsp;one of the five new&nbsp;IITs&nbsp;proposed in the&nbsp;2014 Union budget of India. The campus was inaugurated on 3 August 2015. The institute has 94 faculty, 978 students, and 63 non-teaching staffs.

IT Palakkad currently offers four-year Bachelor of Technology (B.Tech) and two years MS programmes in 8 different engineering disciplines including&nbsp;Computer Science, Electrical, Mechanical, Civil among others.

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IIT Palakkad

Abstract: We are aiming to develop an electrochemical microcatheter sensor for the detection and real-time continuous monitoring of propofol (PPF), which is an anesthetic drug majorly used during medical treatment. This proposed microcatheter-based sensing strategy meets the challenge of real-time periodic and continuous monitoring of propofol by using d-Ti3C2Tx-rGO-chi-modified carbon paste microcatheter sensor transducer. The sensing methodology relies on voltammetry and chronoamperometry transduction methods. The reusable microcatheter sensor was fabricated by embedding the three electrodes into a few millimeters-wide Teflon tube. The nanocomposite was characterized using advanced analytical instruments such as XRD, FE-SEM, EDX, Raman spectroscopy, and XPS. Further, electrode interfacial properties were characterized with voltammetry and electrochemical impedance spectroscopy. The electroanalytical performance of the modified microcatheter sensor was tested for the detection of PPF in phosphate buffer by using chronoamperometry with a wide linear range of 5 to 110 µM (at an applied potential of 0.3 V vs. Ag/AgCl). The sensor’s practical potency was confirmed in human serum with a dynamic linear range of 10 to 130 µM. The sensor exhibited a good limit of detection values in phosphate buffer (2 µM) and natural human plasma (4 µM). The new sensor displays different dimensions of information while displaying high sensitivity, selectivity, and long-term stability. The outstanding analytical performance of the developed sensor holds considerable promise for the continuous monitoring of propofol, its effective management, and optimization of the doses in the patient's body. Graphical Abstract: [Figure not available: see fulltext.] © 2023, The Author(s), under exclusive licence to Springer-Verlag GmbH Austria, part of Springer Nature.

World University root node

Microchimica Acta

Ti3C2Tx-rGO-chitosan-based microcatheter sensor for real-time continuous monitoring of propofol: toward improved anesthetic management

The design and synthesis of dansyl-appended fluorescent sequence-defined oligomers (SDOs) for the selective detection of toxic Hg2+ ions in water is reported. The system incorporates dithiocarbamate (DTC) to act as the binding unit and hydroxy group at the terminal site to improve water solubility. The sensor exhibited positive solvatochromism. This platform has the advantage of systematically increasing the number of DTC units to improve the sensitivity and in doing so, a 100-fold enhancement in sensitivity was obtained by increasing the number of DTC from one to two. A very low detection limit of 60 pM was achieved with the two DTC system and this platform has scope to improve LOD further. Moreover, visual detection and fabrication of paper strip for easy detection of Hg2+ ions are also possible. The sensor selectively binds to Hg2+ ions even in presence of competitive ions and was applied for detection of Hg2+ contamination in lake and tap water samples. Further, we successfully used our sensor for cell imaging in MCF-7 and HeLa cancer cell lines and detect Hg2+ using fluorescence microscopy. The same system was also capable of removing Hg2+ ions from water with an efficiency &gt; 95%. © 2023 Elsevier B.V.

Sensors and Actuators B: Chemical

Dansyl-appended sequence-defined oligomers for selective ultrasensitive detection of Hg2+ in water, paper strips, living cells and its efficient removal

The aryl ketones, 9-fluorenone (fluor), 9-xanthenone (xanth) and 9,10-anthraquinone (anth), were reacted with β-diketiminato dimagnesium(I) compounds, [{(ArNacnac)Mg}2] (ArNacnac=[HC(MeCNAr)2]−, Ar=mesityl (Mes) or 2,6-diisopropylphenyl (Dip)). This gave stable magnesium ketyl complexes which are monomeric, [(ArNacnac)(DMAP)Mg(fluor⋅)] (Ar=Mes or Dip, DMAP=4-dimethylaminopyridine) and [(MesNacnac)Mg(xanth⋅)(xanth)]; dimeric, [{(MesNacnac)Mg(μ-fluor⋅)}2], or tetrameric, [{(DipNacnac)Mg(μ-anth⋅)}4]. In contrast, di-2-pyridylketone (OCPy2) is doubly reduced with [{(XylNacnac)Mg}2] (Xyl=xylyl) to give a diamagnetic alkoxy/amido complex, [{(XylNacnac)Mg}2(μ-OCPy2)]. These complexes have been characterized by X-ray crystallography and in three cases, EPR spectroscopy. Regioselective C−C hetero-coupling reactions between magnesium ketyls and phenanthroline (phen) have yielded the alkoxy compounds, [(MesNacnac)Mg(OCR2-2-phen)] (OCR2=xanth, OCPh2 or OC(Ph)(2-Me−Ph)). In addition, homo- C−C couplings of the enones, chalcone (chalc) and dibenziylideneactetone (DBA), using magnesium(I) reducing agents, have afforded dimagnesium enolates, [{(ArNacnac)(THF)Mg}2(μ-chalc2)] (Ar=Mes or Xyl) and [{(DipNacnac)(THF)Mg}2(μ-DBA2)]. A pinacol coupling reaction between [{(DipNacnac)Mg}2] and 2-adamantanone (OAd) yielded [{(DipNacnac)(OAd)Mg}2(μ-OAd2)], presumably via a ketyl intermediate. This study further highlights the utility magnesium(I) compounds have as selective reducing agents in organic transformations. © 2023 The Authors. Chemistry - A European Journal published by Wiley-VCH GmbH.

Chemistry–A European Journal

Ketyl Radicals Generated from Magnesium (I) Compounds: Useful Reagents for C‒C Bond Forming Reactions

Functionalized arenes and arenols have diverse applications in chemical synthesis and material chemistry. Selective functionalization of arenols is a topic of prime interest. In particular, direct alkylation of arenols using alcohols is a challenging task. In this report, a ruthenium pincer catalyzed direct α-alkylation of β-naphthol using primary alcohols as alkylating reagents is reported. Notably, aryl and heteroaryl methanols and linear and branched aliphatic alcohols underwent selective alkylation reactions, in which water is the only byproduct. Notably, catalytically derived α-alkyl-β-naphthol products displayed high absorbance, emissive properties and quantum yields (up to 93.2 %). Dearomative bromination on α-alkyl-β-naphthol is demonstrated as a synthetic application. Mechanistic studies indicate that the reaction involves an aldehyde intermediate. DFT studies support this finding and further reveal that a stoichiometric amount of base is required to make the aldol condensation as well as elementary steps required for regeneration of catalytically active species. In situ-generated water molecule from the aldol condensation reaction plays an important role in the regeneration of an active catalyst. © 2023 Wiley-VCH GmbH.

Chemistry - A European Journal

Ruthenium-Catalyzed Selective α-Alkylation of β-Naphthols using Primary Alcohols: Elucidating the Influence of Base and Water

Primary aliphatic amines are crucial and at the very least, millions of tons are required every year. Therefore, significant interest has grown in finding new chemical routes for their synthesis. Additionally, to comply with sustainability requirements, synthetic routes using inexpensive feedstocks are highly prioritized. In this regard, the hydroaminoalkylation (HAA) reaction is highly desirable due to the wide availability and lower price of olefins. Although photoredox catalysis is already known for synthesizing amines, the synthesis of linear aliphatic amines is mostly limited to hydroaminomethylation (HAM) reactions and has never been applied to the synthesis of longer-chain linear aliphatic primary amines. Considering this, the synthesis of functionalized linear aliphatic primary amines is demonstrated by using the decarboxylative radical-polar crossover process, which yielded a wide range of functionalized linear aliphatic amines with excellent yields. The strength of this method is demonstrated by the synthesis of existing drugs and late-stage transformations of complex pharmaceuticals and elaborated with detailed mechanistic studies. © 2024 The Royal Society of Chemistry.

Green Chemistry

Selective synthesis of functionalized linear aliphatic primary amines via decarboxylative radical-polar crossover

Herein, we demonstrate the synthesis and characterization of bench stable tri/difluoromethylating reagents and their potential applications in redox neutral hydro tri/difluoromethylation of alkenes enabled by visible light. The new tri/difluoromethylating reagents are obtained on a gram-scale through simply cyclocondensation of commercially available anthranilamide with phenyltrifluoro or difluoromethyl ketone. Preliminary mechanistic studies indicated that a canonical photoredox catalytic cycle is being operative. DFT studies support this and further reveal that deprotonation occurs before radical cleavage. DFT studies also show that the better yield with HCF2 reagent is attributed to the favorable expulsion of the corresponding radical moiety. © 2023 American Chemical Society.

Organic Letters

Photocatalytic Hydro Tri/Difluoromethylation of Alkenes with Bench Stable Tri/Difluoromethylating Reagents

Developing low-cost and reliable sensor systems for the detection of trace amounts of toxic gases is an important area of research. Ammonia (NH3) is a commonly produced industrial chemical and a harmful colorless pungent gas released from various manufacturing and processing industries. Continuous exposure to NH3 vapor causes serious menace to human health, microorganisms, and the ecosystem. Exposure to relatively higher concentrations of NH3 severely affects the respiratory system and leads to kidney failure, nasal erosion ulcers, and gastrointestinal diseases. Excessive accumulation of NH3 in the biosphere can cause various metabolic disruptions. As a consequence of this, therefore, suitable sensing methods for selective detection and quantification of trace amounts of NH3 are of utmost need to protect the environment and living systems. Given this, there have been significant research advances in the preceding years on the development of fluorescence chemosensors for efficient sensing and monitoring of the trace concentration of NH3 both in solution and vapor phases. This review article highlights several fluorescence chemosensors reported until recently for sensing and quantifying NH3 in the vapor phase or ammonium ions (NH4+) in the solution phase. The wide variety of fluorescence chemosensors discussed in this article are systematically gathered according to their structures, functional properties, and fluorescence sensing properties. Finally, the usefulness and existing challenges of using the fluorescence-based sensing method for NH3 detection and the future perspective on this research area have also been highlighted. © 2023 The Royal Society of Chemistry.

Chemical Communications

Recent advances in fluorescence chemosensors for ammonia sensing in the solution and vapor phases

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.

ORGANICS

A Novel Class of Functionally Tuneable Star-Shaped Molecules for Interaction with Multiple Proteins

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. © 2023 by the authors.

Fulltext

International Journal of Molecular Sciences

Superfast Capture of Iodine from Air, Water, and Organic Solvent by Potential Dithiocarbamate-Based Organic Polymer

Herein, we describe the design and synthesis of PyQ, a novel pyrene-quinoline based cell-permeable aggregation-induced emission luminogen (AIEgen) with implications in cellular imaging and antibacterial activity. The synthesised compound was characterised by NMR, HR-MS and IR studies. PyQ exhibited AIE in the DMSO-water mixture and this was confirmed by fluorescence spectroscopic studies. The addition of water to the DMSO solution of PyQ resulted in enhanced fluorescence emission for up to 70% water in DMSO. The SEM and TEM data also confirmed the aggregate formation in addition to DLS, quantum yield and lifetime measurements. The synthesised AIE compound was found to be non-toxic and cell-permeable that could readily label the cytoplasm and plasma membrane. Of note, PyQ exhibited both blue and green emission inside the cell. We further evaluated the antibacterial activity of PyQ aggregates against the model Gram-negative bacteria, Escherichia coli (E. coli) using the standard colony forming unit (CFU) counting assay. The results suggest that the aggregates were potent antibacterial agents and the SEM data clearly showed the disruption of the bacterial membrane. Taken together, this work provides a simple and efficient technique for the development of an AIEgen with antibacterial activity as well as rapid cellular imaging with both blue and green emission. © 2023 Elsevier B.V.