Department of Chemical Engineering
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Item Functionalized nitro-piperonal thiosemicarbazone based ruthenium(II)–arene complexes for DNA interaction, anticancer and flow cytometry studies(RSC, 2025-06) Garg, MohitFunctionalized thiosemicarbazones derived from 6-nitro piperonal and their corresponding Ru(II)–(η6-benzene) (RuBNPT, RuBNMT, RuBNCT and RuBNMeT)/(η6-p-cymene) (RuPNPT, RuPNMT, RuPNCT and RuPNMeT) complexes were synthesized and explored for their biological efficacy and anticancer potential. The impact on the complexes’ electronic characteristics, coordination affinity, and bioactivity of the piperonal substitution at the N(4)-position with morpholine (6NMT), pyrrolidine (6NPT), cyclohexyl (6NCT), and N-methyl (6NMeT) groups were investigated. Comprehensive characterization using UV-vis, FT-IR, NMR (1H and 13C), HRMS, and XRD (6NPT and RuPNMT) confirmed the structural integrity of the synthesized compounds. Density functional theory (DFT) calculations revealed insights into electronic and physicochemical properties, while molecular docking studies demonstrated effective binding with the EGFR, suggesting their potential as anticancer agents. DNA and BSA binding studies indicated intercalative and hydrophobic interactions, with RuPNMT exhibiting moderate binding affinity. Cytotoxicity assays, including MTT assay results, indicated the strong activity of the RuPNMT and RuPNPT compounds (RuPNMT and RuPNPT exhibited IC50 values of 10.5 μM and 27.2 μM, respectively, in MDA-MB-231 cells, and 24.6 μM and 58.1 μM in MCF-7 cells). Additionally, apoptosis studies were conducted on these compounds using AO–EB staining and flow cytometry. The presence of heteroatoms and planarity of the N(4)-substituent enhanced the bioactivity of the ligands, while coordination with Ru(II)–arene precursors further amplified their effectiveness. This study underscores the effectiveness of these complexes as promising agents for targeted cancer treatment.Item MXene-mediated internal electric field in WO₃/AgBr nanocomposites for enhanced visible-light-driven peroxymonosulfate activation and dual-mode antibacterial performance(Wiley, 2025-09) Garg, MohitDesigning heterojunctions that enable efficient charge separation without compromising redox potential is key to advancing visible-light-active photocatalysts for water treatment via advanced oxidation processes (AOPs). In this study, a rationally engineered WO3/AgBr/Ti3C2Tx MXene ternary composite is synthesized and comprehensively evaluated for photocatalytic and antibacterial efficacy. Electron paramagnetic resonance and radical scavenging analyses confirmed the light-induced generation of reactive oxygen species (ROS) such as •OH and O2•−. Supported by X-ray photoelectron spectroscopy and density functional theory, an “indirect S-scheme” charge transfer mechanism is proposed, where MXene facilitates selective recombination of low-energy carriers while conserving high-energy electrons and holes for efficient ROS production. The optimized composite exhibited a six-fold improvement in photocatalytic activity over pristine WO3, which further doubled with peroxymonosulfate (PMS), achieving a twelve-fold enhancement overall. Antibacterial studies under dark and light conditions reveal potent dual-mode disinfection, with effective inactivation of Escherichia coli and Staphylococcus aureus. Agarose gel electrophoresis confirmed substantial DNA degradation in PMS-assisted conditions, minimizing the risk of bacterial resuscitation. This multifunctional material, combining efficient charge dynamics, visible-light responsiveness, and strong biocidal action, holds significant promise for integrated pollutant degradation and microbial disinfection in next-generation AOP frameworks.Item Exploration of aldazine Schiff bases as promising bioactive agents: a synergistic approach using DFT, ADME, antibacterial and cytotoxicity analysis(Elsevier, 2026-01) Garg, MohitA straightforward method for synthesizing four new asymmetric Aldazine Schiff base derivatives using aromatic aldehydes and hydrazine precursors was successfully demonstrated under moderate conditions. These compound are designated as follows: 1-((E)-(((E)-2-ethoxy benzylidene) hydrazineylidene) methyl)naphthalene-2-ol (2-EHMN) (L1), 1-((4-ethoxy benzylidene) hydrazineylidene) methyl) naphthalene-2-ol (4-EHMN) (L2), 1-((2‑hydroxy-4-methoxybenzylidene) hydrazineylidene) methyl) naphthalene-2-ol (HMHMN) (L3), and 1-((2‑chloro-6-hydroxyybenzylidene) hydrazineylidene) methyl) naphthalene-2-ol (CHHMN) (L4). The compounds obtained were analyzed via FT-IR, 1H-/13CNMR spectroscopy, HRMS spectrometry techniques, and elemental analysis. Infrared (IR) spectroscopy, UV–Vis spectroscopy, and accurate melting point determination all contribute to the improved study of synthesised compounds. A comprehensive solubility analysis was conducted for all synthesized compounds, demonstrating their solubility in dichloromethane (DCM), tetrahydrofuran (THF), and dimethylformamide (DMF). Thermoanalytical studies of all the ligands were also examined and compared. Furthermore, a single-crystal X-ray diffraction (SCXRD) analysis of L1 was conducted using a single-crystal diffractometer, with unit cell calculations and data collection performed using MoKα radiation (λ = 0.7107 Å). Density functional theory (DFT) computations were used to optimise the structures of molecules and assess reactivity, durability, and electronic characteristics of the developed ligands. Molecular docking of L1, L2, and L3 has been done in different proteins, which gives precise results to show the activity for cytotoxicity and antibacterial studies. In silico, the ADME process calculations showed that the synthesised compounds have favourable drug-like features. In vitro antibacterial (L2 and L3) and cytotoxicity (L1) tests were also performed to assess their efficacy as therapeutic agents.Item Computational design of isomeric naphthalenediimide–naphthodithiophene (NDI–NDT) copolymers for organic electronics(ACS, 2025-09) Garg, Mohit; Ghosh, SarbaniThis study presents a comprehensive investigation of conjugated donor–acceptor (D–A) copolymers based on naphthalenediimide (NDI) and two structural isomers of naphthodithiophene (NDT), i.e., linear (L-NDT) and angular (A-NDT), designated as NDI–L-NDT and NDI–A-NDT, respectively. By systematically analyzing their molecular structure, (opto)electronic properties, photovoltaic performance, morphological analysis, and mechanical stability, this study reveals the profound influence of donor isomerism on material properties, relevant to organic electronic applications. In particular, NDI–L-NDT exhibits a lower bandgap attributed to its extended donor π-conjugation and nearly coplanar D–A conformation compared to NDI–A-NDT. NDI–A-NDT demonstrates superior photovoltaic performance due to its higher power conversion efficiency compared to its linear counterpart. Morphological studies based on molecular dynamics simulations reveal that films of both copolymers exhibit similar levels of crystallinity. However, NDI–L-NDT possesses greater thermal stability and mechanical flexibility, capable of withstanding up to 100% strain without cracking, attributed to its dynamic conformational adaptability, making it a promising candidate for flexible electronic applications. This work reveals the potential of structural isomerism in fine-tuning D–A copolymers for multifunctional roles, as donors, acceptors, or single-component materials in next-generation organic electronic devices.Item Magnesium oxide nanoparticles-cellulose acetate based composite beads for lead uptake from contaminated stream: Experimental and DFT based study(Elsevier, 2026-02) Garg, Mohit; Chatterjee, SomakGroundwater, a primary source of drinking water, is becoming increasingly contaminated with toxic heavy metals, particularly lead. The unregulated discharge of industrial effluents into water bodies further exacerbates the problem. Accordingly, an effective system is required to treat these pollutants. Although there are existing solutions with certain challenges, this study aims to develop efficient composite polymeric beads composed of cellulose acetate and magnesium oxide nanoparticles for effective removal of lead from contaminated water. Prepared beads were spherical, synthesized by the phase inversion of polymer solution with the help of a needle-syringe assembly. As-prepared beads were characterized based on its morphological and chemical characteristics, revealing porous texture with considerable crystallinity. Presence of Pbsingle bondO bond in FTIR spectra post lead adsorption highlighted synergy between lead ions and Mgsingle bondOH groups. Uptake mechanism involved the substitution of hydrogen ions by lead ions, resulting in the formation of stable Mgsingle bondOsingle bondPb complexes. This was facilitated by lead's lower electronegativity in contaminated water. Lead uptake by composite beads was governed by monolayer adsorption as evident from isotherm studies. A maximum uptake capacity of 500 mg/g was observed at 298 K, which increased to 600 mg/g at 318 K. Optimum dosage of 1 g/l was identified as ideal for achieving equilibrium conditions. Thermodynamic parameters confirmed that the adsorption process was spontaneous and endothermic in nature. Regeneration studies showed effective reusability up to two cycles, after which the removal capacity reached saturation. Isoelectric point was obtained at a pH value of 9.7. Presence of MgO helped in stabilising lead ions and prevented precipitate formation in alkaline medium, providing a minor reduction in lead removal, as compared to conventional adsorbents. Furthermore, Density functional theory (DFT) based simulation was performed suggesting collective indication of consistent trends, with both approaches converging towards the same adsorption behaviour and Pbsingle bondO interaction patterns.Item Illuminating anticancer pathways with pyrene Schiff bases: bridging simulations and experiments(Elsevier, 2026-04) Garg, MohitCytochrome P450 1A1 (CYP1A1) plays a key role in the metabolic activation of carcinogens, making its inhibition a promising chemopreventive strategy. In this study, three pyrene-1-carboxaldehyde-derived Schiff bases, PEBD, APSB, and PyAP were investigated as potential CYP1A1 inhibitors using an integrated computational and experimental approach. Density functional theory (DFT) calculations, molecular docking, molecular dynamics (MD) simulations, and ADME analyses were performed to elucidate their structural features, binding interactions, and drug-likeness. The compounds exhibited strong binding affinities toward CYP1A1, with PEBD showing the highest docking score (–13.89 kcal/mol) and MD binding energy (–41.13 ± 4.07 kcal/mol). Ethidium bromide displacement assays confirmed efficient intercalation into CT-DNA (Kb = 1.54 × 10⁴ M⁻¹ for PEBD). MTT assays revealed that PEBD exerted the strongest cytotoxicity toward breast cancer cell lines MCF-7 (IC₅₀ = 23.9 μM) and MDA-MB-231 (IC₅₀ = 36.7 μM), while remaining non-toxic to normal MCF-10A cells. Overall, these findings highlight PEBD as a promising polycyclic aromatic Schiff base scaffold for the development of CYP1A1-targeted chemopreventive agents against breast cancer.Item Theoretical investigation of electronic and optical properties of ndi-fused-bithiophene (NDI-f-BT) copolymer at different redox states for single-component ambipolar transistors(ACS, 2025-05) Ghosh, Sarbani; Garg, MohitNaphthalene diimide (NDI) copolymerized with thiophene-based donor moieties has the potential to be used as an ambipolar conducting polymer to transport both charge carriers, viz, electrons and holes, at different redox states. The p-type conductivity in these copolymers is not up to the mark compared to the n-type conductivity, and there is scope for improvement by strategically modifying the donor moieties. So, replacing the nonfused thiophene donor moieties with fused thiophene moieties can lead to an increase in the π-conjugation length, which can improve the p-type electronic and optical properties. Here, we have studied the electronic and optical properties of the NDI-fused-bithiophene (NDI-f-BT) donor–acceptor polymer and their evolution at different redox states (up to 200% redox levels) using density functional theory (DFT) and time-dependent density functional theory (TD-DFT). The electron affinity and ionization potential of NDI-f-BT, considering the first redox states, are compared with the experimentally reported lowest unoccupied molecular orbital (LUMO) and highest occupied molecular orbital (HOMO), respectively, measured through electrochemical switching, and they are in good agreement. We note that the TD-DFT calculated optical properties of NDI-f-BT are qualitatively in agreement with the experimental findings and can be used to understand the changes in optical properties during oxidation and reduction. The absorption spectra indicate a red shift up to the 100% redox state, indicating that NDI-f-BT has a good potential to be used in an ambipolar field effect transistor. We also observed the chemical alteration of the donor moieties beyond 100% oxidation level, which leads to an increase in the π-conjugation length to accommodate the bipolaron. This finding indicates that increasing the π-conjugation length can be a strategy to have a balanced p-type conductivity compared to that of the n-type, aiming for ambipolar conductivity of the donor–acceptor copolymer.Item Design & engineering of wood-inspired super-insulating foams(APS, 2023) Garg, MohitBuildings account for 40% of the total U.S. energy consumption. The energy lost through building's walls, roofs and windows is the largest single waste of energy in most buildings. One way to contribute to the building energy efficiency consists in improving their thermal insulation by e.g., developing green and advanced functional materials as insulating panels. With the advent of the Green Economy, the use and valorization of lignocellulosic biomass as a possible alternative of fossil resources is a promising approach for elaborating low cost and high value-added insulation materials. Proper deconstruction or fractionation of cell wall components has indeed been reported to facilitate the development of a wide range of high value materials. The extraction of high aspect ratio cellulose nanomaterials (CNMs) or nanocelluloses, from e.g., wood cell walls, is especially creating a revolution in biobased materials for diverse applications such as packaging, cosmetics, automotive and electronics, owing to their low density, large surface area, and high strength-to-weight ratio. I will present our latest research on heat transport of fully bio-based foams and their thermal response as a function of relative humidity. The deconstruction of wood cell wall into cellulose nanofibers (CNFs) lays the foundation for the production of high-performance bio-based foams. I will discuss two engineering approaches to manufacture super-insulating foams: 1- the influence of chemical surface modification of CNFs on heat transfer of subsequent foams, and 2- the nature-inspired assembly of unmodified CNFs with another wood-biopolymer namely lignin, for enhanced performance. This presentation aims to share an insight on the potential of wood-based foams as thermal insulation materials, but also to inspire scientists, researchers, and future generations to exploit the biomass beyond traditional end-use products, such as for the engineering and manufacturing of sustainable advanced functional materials for energy transfer, storage, or conversion.Item Unraveling the anticancer efficacy and biomolecular properties of ru(ii)-arene complexes of pyrene-based thiosemicarbazone ligands: a comprehensive in silico/in vitro exploration(ACS, 2024-01) Garg, MohitWe report the successful synthesis and comprehensive characterization of novel Ru(II)-arene complexes incorporating pyrene-based thiosemicarbazone (TSC) ligands. Utilizing a suite of advanced spectroscopic techniques including ultraviolet–visible (UV–visible), Fourier transform infrared (FT-IR), 1H NMR, 13C NMR, and high-resolution mass spectrometry (HRMS), the intricate structural and electronic nuances of these complexes were elucidated. X-ray crystallographic data unequivocally affirmed the ligands’ preferential coordination through the thionyl sulfur and imine nitrogen moieties with the Ru(II) ion. Rigorous density functional theory (DFT) computations reveal these complexes as exemplary electron donors, concomitantly hinting at their significant bioactive potential. Notably, molecular docking and molecular dynamic simulation studies suggest that they are potential SND1 protein inhibitors, which are essential proteins in the functioning of cancer cells. Furthermore, they have a strong affinity for binding to CT-DNA and bovine serum albumin (BSA), indicating DNA intercalation and a strong protein-binding ability. Intriguingly, the Ru-arene TSC complexes unveiled potent cytotoxic activity against an array of cancerous cell lines─most notably MDA-MB-231 (IC50 = 10.2 ± 0.02 μM), A549 (IC50 = 25.7 ± 0.07 μM), and HeLa (IC50 = 20.7 ± 0.05 μM) for RuP2P emerging as a standout agent.Item Copper-mediated cyclization of thiosemicarbazones leading to 1,3,4-thiadiazoles: Structural elucidation, DFT calculations, in vitro biological evaluation and in silico evaluation studies(Elsevier, 2024-05) Garg, MohitCancer's global impact necessitates innovative and less toxic treatments. Thiosemicarbazones (TSCs), adaptable metal chelators, offer such potential. In this study, we have synthesized N (4)-substituted heterocyclic TSCs from syringaldehyde (TSL1, TSL2), and also report the unexpected copper-mediated cyclization of the TSCs to form thiadiazoles (TSL3, TSL4), expanding research avenues. This work includes extensive characterization and studies such as DNA/protein binding, molecular docking, and theoretical analyses to demonstrate the potential of the as-prepared TSCs and thiadiazoles against different cancer cells. The DFT results depict that the thiadiazoles exhibit greater structural stability and reduced reactivity compared to the corresponding TSCs. The docking results suggest superior EGFR inhibition for TSL3 with a binding constant value of − 6.99 Kcal/mol. According to molecular dynamics studies, the TSL3-EGFR complex exhibits a lower average RMSD (1.39 nm) as compared to the TSL1-EGFR complex (3.29 nm) suggesting that both the thiadiazole and thiosemicarbazone examined here can be good inhibitors of EGFR protein, also that TSL3 can inhibit EGFR better than TSL1. ADME analysis indicates drug-likeness and oral availability of the thiadiazole-based drugs. The DNA binding experiment through absorption and emission spectroscopy discovered that TSL3 is more active towards DNA which is quantitatively calculated with a Kb value of 4.74 × 106 M−1, Kq value of 4.04 × 104 M−1and Kapp value of 5 × 106 M−1. Furthermore, the BSA binding studies carried out with fluorescence spectroscopy showed that TSL3 shows better binding capacity (1.64 × 105 M−1) with BSA protein. All the compounds show significant cytotoxicity against A459-lung, MCF-7-breast, and HepG2-liver cancer cell lines; TSL3 exhibits the best cytotoxicity, albeit less effective than cisplatin. Thiadiazoles demonstrate greater cytotoxicity than the TSCs. Overall, the promise of TSCs and thiadiazoles in cancer research is highlighted by this study. Furthermore, it unveils unexpected copper-mediated cyclization of the TSCs to thiadiazoles.