My research focus revolves around pioneering metal catalysed / Green synthetic methods aimed at synthesizing potentially bioactive heterocyclic compounds. Additionally, I have a keen interest in the photophysical analysis of heterocyclic molecules, exploring their biosensing applications, DFT study and I am also delving into the realm of solution thermodynamics, ion-solvent interaction, solute-solvent interaction, molecular interactions.
EDUCATION
M.Sc, Ph.D in Chemistry
RESEARCH, TEACHING, or OTHER INTERESTS
Chemistry, Organic Chemistry, Physical and Theoretical Chemistry, Spectroscopy
L-histidine solubility studies and thermodynamic behaviour in aqueous solutions of monovalent metal nitrates Sourav Ghosh, Avishek Saha, Jit Chakraborty, Perwez Alam, Sintu Ganai, Puspal Mukherjee, Kalachand Mahali, Sanjay Roy Chemical Thermodynamics and Thermal Analysis, 2026 • Solubility of L-histidine was measured at different temperatures in aqueous sodium nitrate and potassium nitrate salts. • The experimental solubility data were correlated using the van’t Hoff, modified Apelblat, and λh models. • Salting-in/salting-out effects of the electrolytes on the solubility were explained. • Thermodynamic parameters were calculated and explained for the experimental system. • Solvation of L-histidine increases in both NaNO₃ and KNO₃ solutions, with a stronger effect in KNO₃. This article deals with the equilibrium solubility and thermodynamic aspects of L-histidine in water and in aqueous NaNO 3 and KNO 3 solutions. The solubility was evaluated at different temperatures, ranging from 288.15 K to 308.15 K. The solubility data of L-histidine in pure water and aqueous NaNO₃ and KNO₃ solutions were correlated using three thermodynamic models: the van’t Hoff model, the modified Apelblat equation, and the λh equation. The salting-in effect serves as key factor for the variation of solubility in the electrolytic medium. The obtained solubility was used to estimate the thermodynamic behaviour of the solution systems . An analytical gravimetric technique was employed for the determination of solubility of L-histidine in the experimental solution system. In addition, the thermodynamic parameters, including Gibbs free energies, entropies and enthalpies were calculated using least-square method. To ensure the purity of L-histidine from the solvent systems, atomic absorption spectroscopy, IR and XRD studies were performed following standard protocols . Density functional theory (DFT) calculations were performed to support the molecular-level interpretation of ion–solute interactions. Additionally, this analysis elucidates the non-covalent interactions, covering the dissolution and dissolution firmness of amino acid, by considering short-range solute–solvent interactions.
Experimental and thermodynamic correlation of 4-hydroxycoumarin solubility in aqueous-organic solvent systems (DMSO, ACN, DMF) at eight temperatures Sintu Ganai, Bidhan Chandra Mahatha, Avishek Saha, Jit Chakraborty, Puspal Mukherjee, Pratima Mandal, Adel Noubigh, Sanjay Roy Chemical Thermodynamics and Thermal Analysis, 2026 • Equilibrium Solubility of 4-hydroxycoumarin was highest in DMF and lowest in water at all temperatures. • Aqueous–organic solvent mixtures markedly enhanced solubility over pure water. • Experimental solubility data were well correlated using van’t Hoff, Apelblat, and λh models. • Results enable informed solvent selection for efficient extraction and purification of 4-hydroxycoumarin. The solid–liquid equilibrium solubility of 4-hydroxycoumarin (4-HC) was investigated in pure water, pure organic solvents (DMF, ACN, and DMSO), and their aqueous binary mixtures at eight temperatures ranging from 288.15 to 323.15 K under atmospheric pressure. Solubility measurements were performed using a gravimetric method employing a Shimadzu analytical balance, a thermostatic water bath, a shaker, and a vacuum filtration system. The effects of solvent composition and temperature on 4-HC solubility were systematically examined. The results indicate that solubility is strongly influenced by both factors, with significantly enhanced solubility in aqueous–organic mixtures compared to pure water. The van’t Hoff model, the modified Apelblat equation, and the λh model were applied to correlate the experimental data, all showing good agreement with measured values. The resulting insights and model parameters provide useful guidance for optimizing pharmaceutical processes and improving industrial extraction and purification strategies for 4-HC.
Excitation-Dependent Two-State Photoluminescence of Microwave-Synthesized Carbon Dots: Solvent and pH Sensitive Behaviour Puspal Mukherjee, Deblina Mallick, Suranjona Roy, Shovon Chatterjee, Sintu Ganai Chemphyschem, 2026 In this study, carbon dots (C‐dots) were synthesized from resorcinol and trisodium phosphate in ethylene glycol using a microwave‐assisted method. The C‐dots exhibited predominantly green photoluminescence when excited at 460 nm. Their absorption and emission spectra showed strong solvent‐dependent variations, and the quantum yield varied between 45% and 62% depending on the solvent. Both absorption and emission maxima exhibited a noticeable red shift with increasing solvent polarity. Upon varying the excitation wavelength from 300 to 480 nm, two distinct emission bands blue and green emerged. However, no continuous spectral shift was observed in any solvent. Excitation spectra recorded at different emission wavelengths also revealed two well‐defined excitation peaks. The blue emission originates from π → π * transitions within the CC sp 2 domains at the core of the C‐dots, whereas the green emission arises from surface states associated with phenolic –OH and phosphate functional groups. The absence of continuous spectral shift in emission suggests the absence of heterogeneity in CC sp 2 domains in the structure. The pH‐dependent study revealed two emissive states: a dark state at acidic pH due to protonation of surface groups, and a highly emissive state at higher pH due to their deprotonation. Time‐resolved photoluminescence showed specific solvent effects on the emission originating from core and surface of the C‐dots. These findings establish that the green emission is strongly governed by the surface functional groups, while the core‐related blue emission remains distinct.
Influence of Noncovalent Interactions on the Solubility of l-Histidine in the Presence of Aqueous Potassium Halides at Diverse Temperatures Sourav Ghosh, Avishek Saha, Jit Chakraborty, Sintu Ganai, Puspal Mukherjee, Kalachand Mahali, Adel Noubigh, Sanjay Roy Journal of Chemical and Engineering Data, 2025 The study presents the solubility and thermodynamic properties of l -histidine in the presence of potassium halides, mainly in KBr and KI, in an aqueous medium. The experiments were conducted at six equidistant temperatures from 288.15 to 313.15 K. The analytical gravimetric method was applied to measure solubility. The solubility depends on the salting-in or salting-out effects of the electrolytes present. Positive values for the Setchenow constant signify the solubility enhancement of l -histidine in an electrolytic solution in comparison to pure aqueous solution. The solubility values were utilized to obtain thermodynamic insights into electrolytic solutions. The thermodynamic properties depend on the intermolecular interactions and noncovalent processes that exist among the molecules and ions present in the solvent system. The solubility of l -histidine is higher in aqueous KI than that in aqueous KBr under experimental conditions. The transfer Gibbs energy signifies the effective solvent–solute interaction under the electrolytic environment. Then again, values for transfer entropy magnify the solvent–solvent interaction in an electrolytic atmosphere. The study emphasizes the variation in the thermochemical behavior of l -histidine in the experimental environment and hence will strengthen the understanding of the behavior of the experimental amino acid for its increased use in industrial purposes.
Can Synergistic Solvation Increase Polarity Beyond Water? An Intriguing Case Study of Aqueous Binary Mixtures of 1,2-Dimethoxyethane, 2-Methoxyethanol, and Ethylene Glycol Puspal Mukherjee, Sanchaita Das, Deblina Mallick, Sanjay Roy, Sintu Ganai Journal of Physical Chemistry B, 2025 In this study, the synergistic behavior of aqueous binary mixtures of 1,2-dimethoxyethane (DME), 2-methoxyethanol (2ME), and ethylene glycol (EG) was investigated using three solvatochromic dyes: coumarin 461 (C461), 4-aminophthalimide (4AP), and para-nitroaniline (pNA) through steady-state UV-visible spectroscopy and fluorescence emission spectroscopy. The absorption maxima of the dyes exhibited extensive bathochromic shifts with varying solvent mixture compositions. In the water-rich region of the mixtures, the absorption maxima displayed significantly larger bathochromic shifts compared with those in pure water. A clear case of synergistic solvation was observed, indicating that the polarity of mixtures exceeds that of pure water. The synergistic effect was pronounced in the water-DME and water-2ME mixtures, while it was weaker in the water-EG mixture. This "hyper-polarity" was analyzed from the molar transition energy variation using a generalized Bosch solvation model. In the water-DME and water-2ME mixtures, the equilibrium constant for synergistic solvation was significantly greater than that for preferential solvation, whereas in the water-EG mixture, the values were comparable. This behavior stemmed from the intermolecular hydrogen bonding between water and cosolvents. The mole fraction of synergistic solvation suggested microheterogeneity around the solute within the mixtures. Notably, the variation in emission maxima of the probes showed no synergistic behavior, implying that solvent reorientation in the excited state disrupts the synergistic effect. IR spectroscopy was also employed to investigate the hydrogen-bonded structures in the binary mixtures. Analytical modeling of -OH and -CH stretching frequency was established, and it revealed that the formation of water-DME and water-2ME hydrogen-bonded aggregates is responsible for the observed synergistic "hyper-polarity" effect.
Design and Development of Magnetically Retrievable Nanohybrid Catalyst for the Green Synthesis of Paracetamol Pranay Biswas, Gahul Amin, Sintu Ganai, Puspal Mukherjee, Debasree Bose, Rajib Sarkar Current Green Chemistry, 2025 Paracetamol is one of the most prescribed drugs, which requires a global production of over 200,000 tons/year. The production of paracetamol at the industrial level still relies on multistep methodologies utilizing stoichiometric amounts of oxidizing and reducing agents and corrosive reagents, which demands a sustainable protocol for the synthesis of paracetamol. In this article, we aimed to develop a magnetically retrievable nanohybrid catalyst for the synthesis of paracetamol under mild and green reaction conditions for up to five cycles. Fe3O4 nanoparticles were synthesized and Pd(0) particles were embedded into the nanoparticle so that it could be used as a magnetically retrievable catalyst. This hybrid catalyst was successfully utilized in the synthesis of paracetamol in a one-pot reaction with high yield and efficacy within a short time, demonstrating that the nanohybrid catalyst offers advantages in the synthesis of drug leads for industrial purposes.
