Yazar "Munawar, Khurram Shahzad" seçeneğine göre listele

Listeleniyor 1 - 3 / 3
  • [ X ]
    Öğe
    Pyridine-2,6-Dicarboxylic Acid As a Facile and Highly Selective Turn-Off Fluorimetric Chemosensor for Detection of Cu (II) Ions in Aqueous Media
    (Springer/Plenum Publishers, 2024) Shah, Javed Hussain; Sharif, Shahzad; Shahbaz, Muhammad; Riaz, Bilal; Shahzad, Sundas; Sahin, Onur; Munawar, Khurram Shahzad
    Copper metal is third most abundant trace element in human body. Determination of Cu (II) ions is a burning topic in field of environment protection and food safety because of its significant impact on ecosystem. In this study, 2,6-pyridine dicarboxylic acid (PDA) has been explored as turn-off florescent probe for florescent detection of Cu (II) ions. This sensor showed highly selective complexing ability towards Cu (II) ions. Addition of aqueous solution of Cu (II) ions remarkably quenched the fluorescence intensity of PDA while, on contrary, there was no any prominent fluorescence quenching interference on addition of various metal ions. The binding mode of PDA and Cu (II) ions was determined as stoichiometry of 1:1 and it was further confirmed by single crystal XRD analysis. Mechanisms of static and dynamic quenching were confirmed by stern-volmer plot. Limit of detection (LOD) and limit of quantification (LOQ) for Cu (II) ions was calculated as 3.6 mu M and 1.23 mu M respectively, which is far below the acceptable value (31.5 mu M) according to the World Health Organization. The use of the sensor for detection of Cu (II) ions in real samples in aqueous media was also performed.
  • [ X ]
    Öğe
    Redox active cobalt based bi-linker metal organic frameworks derived from 5-sulfoisopthalic acid and 4,4-bipyridine for supercapacitor
    (Pergamon-Elsevier Science Ltd, 2025) Shah, Javed Hussain; Shahbaz, Muhammad; Sharif, Shahzad; Ullah, Ghulam; Shahzad, Sundas; Munawar, Khurram Shahzad; Sahin, Onur
    In this research study, we have synthesized, characterized and extensively compared the electrochemical characteristics of two materials derived from 5-sulphoisophtalic acid, 4,4-bipyridine and cobalt metal using sonochemical method. Cobalt-bipyridine complex with 5-SIP in lattice structure (RG-41) showed predominant capacitive behavior whereas Co-SIP-Bpy MOF (RG-42) exhibited significant pseudocapacitive attributes due to the presence of coordination linkage responsible for the electron transfer. Due to the effective electrochemical properties of RG-42, we implemented it practically by fabricating a hybrid device with outstanding electrochemical features, demonstrating impressive 92 % cyclic stability with energy density and power density of 51.41 Wh/kg and 800 W/kg at 1 A/g, respectively. Dunn's method was employed to obtain capacitive-diffusive contributions for both half-electrochemical cells as well as hybrid device. These results underscored the potential of RG-42 as a competitive electrode material for future energy storage applications.
  • [ X ]
    Öğe
    Synthesis, crystal structure, supramolecular assembly inspection via hirshfeld surface analysis and computational investigation of the pyrimethamine-based salts
    (Elsevier, 2025) Tahir, Muhammad Nawaz; Malik, Abida Naseem; Ashfaq, Muhammad; Munawar, Khurram Shahzad; Rashid, Zahid; Imran, Muhammad
    In current research work, two salts abbreviated as 5DECA and 2DECA derived from pyrimethamine and aceclofenac are synthesized by using a simple method of reflux in methanol. The crystal structures of salts are investigated by the single-crystal X-ray diffraction (SC-XRD) technique. The supramolecular architecture of both compounds contained N-H & ctdot;O, N-H & ctdot;N, C-H & ctdot;O, off-set it & ctdot;it stacking, and C-O & ctdot;it interactions. The difference in supramolecular architecture is that in 5DECA, O-H & ctdot;O and C-H & ctdot;it interactions are present, whereas in 2DECA, N-H & ctdot;Cl, C-H & ctdot;Cl, and C-Cl & ctdot;it interactions are present. The presence of water molecule in 5DECA is the main reason for the difference between the supramolecular architecture of compounds. The intermolecular interactions in terms of interatomic contacts are probed by Hirshfeld surface analysis (HSA). Void analysis is performed to understand the mechanical response of crystals. Computational studies, conducted at the DFT/ B3LYP//ma-def2-SVP level of theory, confirmed that the supramolecular assemblies in these systems are governed by it-it and N-H & ctdot;O interactions. These calculations also determined several key factors, comprising structural features, molecular electrostatic potential (MEP), the HOMO-LUMO energy gap (Delta E), and Infrared spectroscopic absorption peaks.