Yazar "Ahmad, Saeed" seçeneğine göre listele

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    Öğe
    A dual-emitting Rhodamine B-encapsulated Zn-based MOF for the selective sensing of Chromium(VI)
    (Pergamon-Elsevier Science Ltd, 2024) Shah, Javed Hussain; Sharif, Shahzad; Sahin, Onur; Shahbaz, Muhammad; Azeem, Waqar; Ahmad, Saeed
    A Rhodamine B-Zn-MOF composite (RhB-Zn-MOF) with dual emission intensity was synthesized through one pot synthesis by in -situ encapsulation of Rhodamine-B dye on a new Zn-MOF metal-organic framework [(Zn (OAc)2(4-BrIPh) (1,10-phenonthroline)(H2O)].H2O, (4-BrIPh = 4-Bromoisophthalic acid). The synthesized encapsulated material was characterized by elemental analysis, FTIR, UV-Visible spectroscopy, TGA, single crystal and powder X-ray diffraction and photoluminescence spectroscopy. The results showed that the synthesized composite, RhB-Zn-MOF could be used as an efficient probe for the selective sensing of Cr(VI) in the presence of Cr(III) as well as other metal ions.
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    Öğe
    Solvothermal synthesis, crystal structure, thermal, magnetic properties and DFT computations of a Ytterbium(III) complex derived from pyridine-2,6-dicarboxylic acid
    (Elsevier, 2022) Sharif, Shahzad; Saeed, Maham; Dege, Necmi; Bano, Rehana; Ahmad, Saeed; Gilani, Mazhar Amjad; Sahin, Onur
    A new ytterbium(III) complex, (DMAH(2))(3)[Yb(Pydc)(3)].4H(2)O (1) {Pydc = Pyridine-2,6-dicarboxylate anion, DMAH(2) = Dimethylammonium} has been prepared under mild solvothermal conditions and character-ized by elemental analysis, IR spectroscopy, thermal analysis and single crystal X-ray diffraction. The DMAH2 molecules in 1 , generated in situ from hydrolysis of N,N-dimethylformamide are responsible to assemble 2D coordination polymer through N-H center dot center dot center dot O and O-H center dot center dot center dot O h ydrogen bonding. Magnetic suscepti-bility measurements indicate that the complex ( 1 ) obeys the Curie Weiss law and the overall magnetic behavior is typical for the presence of weak antiferromagnetic exchange coupling interactions. Theoretical data for geometrical parameters of complex 1 agree well with the experimental data. Large HOMO-LUMO energy gap of 4.33 eV has provided kinetic stability to the complex 1 . NBO analysis reflects that in-tramolecular charge transfer occurred between ligand and metal orbitals with the highest stabilization energy of 1024.04 kcal/mol. The negative electrostatic potential at the nitrogen and dianionic pyridine-2,6-dicarboxylate regions confirms that these are dynamic locations for Yb(III) binding. (c) 2022 Elsevier B.V. All rights reserved.
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    Öğe
    Synthesis, crystal structure and magnetic properties of an octanuclear cerium(III) complex of pyridine-2,6-dicarboxylate
    (Walter De Gruyter Gmbh, 2019) Sharif, Shahzad; Khan, Islam Ullah; Sahin, Onur; Jabeen, Nadia; Ahmad, Saeed; Khan, Bushra
    An octanuclear compound of cerium(III), [Ce-8(Pydc)(10)(HPydc)(4)center dot 22H(2)O]center dot 11H(2)O (1) (Pydc = pyridine-2,6-dicarboxylate anion) was prepared under mild solvothermal conditions and its crystal structure was determined by single-crystal X-ray diffraction. Three kinds of coordination environments are observed, which include: [Ce(Pydc)(3)], [Ce(Pydc)(H2O)(4)(O,O)], and [Ce(H2O)(7) (O,O)]. Each cerium atom in 1 is nine-coordinated but two different geometries are found. The Ce1 and Ce2 atoms exhibit a nearly tricapped trigonal prismatic CeN3O8 geometry, while Ce3 and Ce4 possess CeNO8 and CeO9 coordination polyhedra, which approximate to slightly distorted mono-capped square antiprisms having 12 triangular faces. The Pydc ligands adopt tri-, tetra-, and penta-coordination modes through tridentate chelating and, mu(2) and mu(3)-bridging modes, respectively. The clusters are joined by O-II center dot center dot center dot O hydrogen bonds to generate 3D supramolecular network. Magnetic susceptibility measurements for 1 indicate that the chi(m) values obey the Curie-Weiss law. The overall magnetic behavior is typical for the presence of antiferromagnetic exchange coupling interactions between the cerium(III) ions.