Department of Chemistry

Permanent URI for this collectionhttp://localhost:4000/handle/123456789/1924

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Author: search.filters.author.Grover, NitikaStart date: 2020

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    Photocatalyst-free regioselective sulfonamidation of N-(2-hydroxyaryl)amides in visible-light
    (RSC, 2024-09) Grover, Nitika
    In this work, we report a regioselective sulfonamidation of N-(2-hydroxyaryl)amides with iminoiodinanes and iodine in visible light at room temperature. The method does not require a strong oxidant, metal or photocatalyst and enables direct functionalization of a C–H bond to a C–N bond. Mechanistic investigations suggest in situ generation of an N-centered radical from N,N-diiodo-sulfonamide by homolytic N–I bond cleavage followed by its site-specific addition to N-(2-hydroxyaryl)amides to furnish para-sulfonamide derivatives.
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    Investigation of aluminum-based plasmonic devices for sensing applications in the near-infrared region
    (SPIE, 2024-03) Arora, Pankaj; Grover, Nitika
    We present surface plasmon resonance-based sensing devices with Aluminum (Al) as the plasmonic metal in the near-infrared region and analyze the output performances in terms of higher sensitivity and the Figure of Merit (FOM). The optical characteristics of Al-based plasmonic sensors are explored using different interrogation modes (angle and wavelength). Biorecognition elements help to enhance the sensor’s performance, for which 2D nanomaterials are explored for the biofunctionalization of the top surface. In the end, we also present an Al-based plasmonic device that utilizes both prism and nanostructure-based configurations, and the same designed parameters for the device offer high sensitivity and FOM in both angle and wavelength interrogation.
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    Iodine(III)-induced cascade annulation of β-cyanoporphyrins for the efficient synthesis of n-aryliminonaphtho-fused and n-aryl-carboxamide porphyrins
    (Wiley, 2025-12) Grover, Nitika; Kumar, Dalip
    Meso-β fused porphyrins with tunable optoelectronic properties are attractive candidates for applications in light-harvesting, sensing, and catalysis, yet their synthesis often requires harsh conditions or tedious synthetic routes. Herein, a mild, operationally simple, and Cu(OTf)2-catalyzed protocol is reported to access meso-N-aryliminonaphtho-fused and N-arylcarboxamide porphyrins from readily available β-cyanoporphyrins and diaryliodonium salts. Reaction selectivity is controlled by the water content present in the reaction mixture, affording either fused imines or carboxamides in high yields. The protocol tolerates different symmetrical diaryliodonium salts and enables the preparation of free-base, Zn (II), and Cu (II) porphyrin derivatives, all fully characterized by NMR, UV–visible spectroscopy, high resolution mass spectrometry, electrochemistry, and single crystal X-ray diffraction. The π-extended systems exhibit distinct bathochromic shifts (≈42 nm in Soret and ≈80–90 nm in Q-bands) and narrowed highest molecular orbital-lowest unoccupied molecular orbital (HOMO-LUMO) gaps up to 1.54 eV. Electrochemical studies reveal that fused porphyrins exhibited anodically shifted reduction potentials, while Density functional theory calculations attribute the gap reduction to LUMO stabilization and HOMO destabilization induced by fusion. Overall, this strategy provides rapid access to structurally diverse π-extended porphyrins with tailored photophysical and redox properties.
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    I(III)-promoted facile and rapid synthesis of imidazo-azepino-fused porphyrins with enhanced absorption as singlet oxygen generators
    (Wiley, 2026-01) Grover, Nitika
    A facile, high-yielding synthetic protocol has been developed to access azepino-fused porphyrins via iodine(III)-mediated oxidative intramolecular cyclization of β-imidazole or benzimidazole substituted porphyrins. The absorption of the synthesized compounds showed the characteristic features of meso-β-fused porphyrins, with intense Soret bands centered between 440 and 460 nm and two weak bands ranging from 550 to 750 nm (Q-bands) Among the synthesized compounds, the free-base imidazo-azepino-fused porphyrin was found to be an efficient 1O2 producer with a higher singlet oxygen quantum yield (ΦΔ ∼0.78 in DMF) as compared to H2TPP (ΦΔ = 0.64 in DMF). It was observed that the protonated form of 4aH2 exhibits a significant red shift of ∼24 nm in Soret and ∼150 nm in Q-bands. Fitting of the titration data of 4aH2 with TFA yielded an apparent pKa of ∼3.58, demonstrating that imidazole fusion enhances the basicity of the porphyrin system.
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    Emerging devices and materials
    (Springer, 2026-01) Grover, Nitika
    This chapter surveys the fast-moving landscape of emerging devices and materials that are reshaping electronics, photonics, energy, and biomedicine. We begin with the motivations beyond silicon limits and outline advances in flexible and wearable platforms—displays, skin-like sensors, and body-conformal systems—that enable continuous health and environment monitoring. We then profile quantum materials (topological insulators, 2D semiconductors, and quantum dots) alongside next-generation energy technologies, including solid-state batteries, supercapacitors, and perovskite solar cells, highlighting the performance gains and stability/sustainability challenges that steer current research. At the device level, we discuss advanced semiconductors (GaN power devices, silicon photonics, and organic semiconductors) that deliver higher speed, power density, and integration. Bridging biology and electronics, we review biocompatible implants, self-healing materials, and biohybrid systems that promise personalized therapies and regenerative interfaces. Finally, we examine nanotechnology-driven catalysts and medicines, as well as smart and sustainable materials (piezoelectrics, metamaterials, biodegradable polymers) that enable self-powered sensing, wave engineering, and circular-economy pathways. Across these domains, the chapter emphasizes cross-disciplinary design, scalable fabrication, low-toxicity alternatives, and life-cycle thinking as the keys to translating laboratory breakthroughs into human-centered, eco-conscious systems.
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    Nanotechnology in electronic devices
    (Springer, 2026-01) Grover, Nitika
    This chapter synthesizes how nanoscale phenomena—quantum tunneling and confinement, large surface-to-volume ratios, ballistic transport, anisotropic carrier motion in low-symmetry 2D materials, and plasmonics—reshape device physics and enable new electronic–photonic functionalities. It surveys key nanomaterials—graphene/CNTs, quantum dots, TMDs, and metal-oxide nanostructures—and their roles in flexible/wearable platforms, nanosensors, energy systems, and optoelectronics. The chapter then reviews fabrication toolkits spanning top-down lithographies and bottom-up growth (CVD/ALD) that underpin modern nano-integration, followed by device-level advances from FinFETs to gate-all-around FETs that extend electrostatic control past planar scaling. It highlights nanotechnology’s contributions to quantum computing—materials, structures, and coherence considerations for scalable qubits—before assessing energy-efficient nanoelectronics, including low-power memories and architectures, alongside energy harvesting and storage themes. Finally, it connects these threads to optoelectronic devices (e.g., high-bandwidth graphene/TMD photodetectors) and concludes with challenges in stability, manufacturability, and reliable control at atomic dimensions that will steer the next wave of nanoelectronic technologies.
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    Meso-substitution controlled synthesis of bodipy–dpm conjugates: a pathway to tailored photophysical properties
    (2026) Roy, Aniruddha; Arora, Pankaj; Grover, Nitika
    We show that the electronic nature of the meso-aryl substituent in 1,3,5,7-tetramethyl BODIPYs governs the reactivity of the 1,7-methyl (α-methyl) groups toward the Knoevenagel condensation. Reaction of pyrrole-2-aldehyde with electron-deficient 1,3,5,7-tetramethyl-meso-pentafluorophenyl and 1,3,5,7-tetramethyl-meso-4-nitrophenyl BODIPYs yields double condensation at the 1,7-methyl positions to give the corresponding bis(pyrrole) derivatives, whereas the electron-rich meso-tolyl analogue selectively undergoes single condensation at only one of the α-methyl groups under identical conditions. This substituent-dependent divergence extends to reactions with 1,9-diformyl-meso-aryl dipyrromethanes, enabling access to structurally distinct BODIPY–DPM conjugates. Reaction of 1,9-diformyl-DPM with meso-tolyl BODIPY selectively yields acyclic monosubstituted BODIPY–DPM conjugates, whereas the higher reactivity of meso-pentafluorophenyl BODIPY enables condensation between both 1,7-methyl groups and the two aldehyde functionalities of the diformyl-DPM scaffold, affording cyclic, porphyrin-like BODIPY–DPM frameworks. Notably, meso-pentafluorophenyl BODIPYs also undergo nucleophilic aromatic substitution of the para-fluorine atom by piperidine under the condensation conditions, as confirmed unambiguously by single-crystal X-ray diffraction. The resulting BODIPY–DPM and BODIPY–pyrrole conjugates exhibit pronounced bathochromic shifts (90–180 nm relative to parent BODIPYs), deep-red to near-infrared absorption (~670 nm) and emission (~750 nm), enlarged Stokes shifts, and strong intramolecular charge-transfer character. These features translate into efficient heavy-atom-free triplet formation, with singlet-oxygen quantum yields reaching up to 0.45. A representative conjugate (10) exhibits potent photodynamic activity in B16F10 melanoma cells with minimal dark toxicity (IC₅₀ = 0.95 μM). TD-DFT analysis indicates that excited-state twisting reduces ΔEST, thereby facilitating heavy-atom-independent intersystem crossing. Collectively, these results establish a robust molecular design framework for next-generation heavy-atom-free photosensitizers.
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    Engineering dielectric and metallic metasurfaces for sensing applications in the near-infrared region
    (SPIE, 2024) Grover, Nitika; Arora, Pankaj
    Dielectric and metallic metasurfaces are proposed to demonstrate the sensing applications in the near-infrared region under normal incidence light. The geometrical parameters of the proposed metasurfaces are designed using Rigorous coupled analysis under wavelength interrogation, and the results are verified using Comsol Multiphysics software. A layer of 2D nanomaterial (MoS2) is considered to increase the adsorption on the sensing surface. Aluminum-based metallic metasurfaces offer a sensitivity of 1100nm/RIU with a figure of merit of 250 RIU-1. The proposed metasurfaces are further used for the detection of cancer cells in human blood, and a red shift in the wavelength spectra is observed due to the increase in the refractive index.
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    Ultrasensitive surface plasmon resonance-based biosensor for efficient detection of SARS-CoV-2 Virus in the near-infrared region
    (2024) Grover, Nitika; Arora, Pankaj
    This work offers an ultra-sensitive multilayered surface plasmon resonance (SPR)-based biosensor that uses angular interrogation in the near-infrared (NIR) region to detect the novel coronavirus (SARS-CoV-2). The multi-layered biosensor consists of the bimetallic layer (Aluminum (Al) & Gold(Au)), a dielectric layer (MgF2), and an optimized number of 2D nanomaterial (MoS2) layers. The proposed SPR sensor is engineered using the transfer matrix and finite element methods to achieve high sensitivity, the figure of merit (FOM), and detection accuracy. The selection of plasmonic metal and optimization for the different layers have been proved crucial to improving the performance parameter of the proposed sensor. The biosensor configuration (Glass prism/Al/Au/MgF2/MoS2/sensing sample) is observed to exhibit the highest sensitivity of 372°/RIU, FOM of 1690 RIU-1, and detection accuracy of 4.54 degree-1 using the strong binding efficiency of the MoS2 layer and the high dielectric constant of the MgF2 layer. According to the investigation's findings, the proposed SPR-based biosensor exhibits excellent performance in the NIR region, demonstrating accurate real-time detection capabilities that will facilitate its use in field or clinical point-of-care testing applications.
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    TiO2-FG-based plasmonic sensor with enhanced figure of merit for sensing applications: A numerical approach
    (Elsevier, 2025-09) Grover, Nitika; Arora, Pankaj
    A refractive index-based surface plasmon resonance sensor using a multilayer heterostructure in the Kretschmann configuration is proposed for the near-infrared region. In the proposed configuration, aluminum is used as a plasmonic metal, titanium dioxide is used as a dielectric layer, and a fluorinated graphene (FG) layer is used as a 2D nanomaterial to enhance the performance parameters. A thorough comparative study is conducted between popularly used titanium compounds: Titanium dioxide (TiO2) and Titanium disilicide (TiSi2). For the proposed SPR sensor, each layer is engineered and optimized on the grounds of linewidth, detection accuracy (DA), and Figure of Merit (FOM), which are the critical performance parameters. To this end, the geometrical parameters are calculated using the transfer matrix method and analyzed meticulously to find the optimum trade-off points. The proposed sensor is numerically tested efficiently to sense different concentrations of hemoglobin in human blood. For the angle interrogation technique at the wavelength of 1550 nm, the sensor provides an enhanced FOM of 462.8 RIU−1 and a DA of 4 degrees−1. Thus, the proposed design opens a broader window for bio-sensing applications because of the advantages TiO2 and FG layers offer in enhancing the sensing parameters.