Muhammad Ikram

The enhanced adsorption of sulfur compounds onto mesoporous Ni-AlKIT-6 sorbent, equilibrium and kinetic analysis

High performance nickel supported on mesoporous AlKIT-6 (Si/Al=15, 25, 50, 100) sorbents were prepared by incipient wetness impregnation (IWI) with ultrasonic aid for adsorptive desulfurization of commercial diesel and simulated fuels. The sorbents were characterized by N2 adsorption-desorption, XRD, NH3-TPD, Py-FT-IR, HRTEM, SEM and atomic absorption spectroscopy techniques. The analysis results confirmed that Aluminum atoms entered the framework and 20%Ni-AlKIT-6(15) can still retain three dimensional structure of AlKIT-6(15) and Ni is highly dispersed in the support. The kinetic pseudo second-order model and Langmuir isotherm are shown to exhibits the best fits of experimental data for the adsorption of thiophene (T), benzothiophene (BT) and dibenzothiophene (DBT) over AlKIT-6 and 5-30%Ni-AlKIT-6. Intraparticle diffusion and steric hindrance were the rate controlling step of the adsorption of T and DBT over AlKIT-6(15) and 20%Ni-AlKIT-6(15) as verified through the intraparticle diffusion model. The characterization of regenerated 20%Ni-AlKIT-6(15) revealed that three-dimensional cubic Ia3d symmetric structure was maintained in the sorbent after 6 successive desulfurization-regeneration cycles.

Synthesis, characterization, in vitro antimicrobial, and U2OS tumoricidal activities of different coumarin derivatives.

BackgroundCoumarin and its derivatives are biologically very active. It was found that the enhanced activities are dependent on the coumarin nucleus. Biological significance of these compounds include anti-bacterial, anti-thrombotic and vasodilatory, anti-mutagenic, lipoxygenase and cyclooxygenase inhibition, scavenging of reactive oxygen species, and anti-tumourigenic. Our interest in medicinal chemistry of dicoumarol compounds have been developed by keeping in view the importance of coumarins along with its derivatives in medicinal chemistry. All the synthesized compounds were fully characterized by spectroscopic and analytical techniques and were screened for antimicrobial and U2OS bone cancer activities.Results4-hydroxycoumarin was derivatized by condensing with different aldehydes yielding the dicoumarol and translactonized products. Elemental analyses, ESI(+,−) MS, 1H and 13C{1H}-NMR, infrared spectroscopy and conductance studies were used to characterize the synthesized compounds which revealed the dicoumarol and dichromone structures for the compounds. The compounds were screened against U2OS cancerous cells and pathogenic micro organisms. The compounds with intermolecular H-bonding were found more active revealing a possible relationship among hydrogen bonding, cytotoxicity and antimicrobial activities.ConclusionCoumarin based drugs can be designed for the possible treatment of U2OS leukemia.

Synthesis, crystal structure, DNA binding and molecular docking studies of zinc(II) carboxylates

New zinc(II) carboxylate complexes [Zn(3-F-C6H4CH2COO)2]n (1), [Zn3(3-F-C6H4CH2COO)6(Phen)2] (2) and [Zn3(3-F-C6H4CH2COO)6(bipy)2] (3) were synthesized and characterized by atomic absorption, single crystal structural analysis and IR studies. Complex 1 crystallizes as a coordination polymer constituting a web of μ-η1,η1 carboxylate bridged tetrahedral zinc centers. Complexes 2 and 3 comprise trinuclear zinc centers with two terminal fivefold coordinated slightly distorted square-pyramidal and central sixfold coordinated octahedral zinc centers. The complexes were also assessed for their DNA binding ability by UV/-Vis spectroscopy and their behavior rationalized theoretically by molecular docking studies. A DNA binding study has shown groove binding interactions with the complexes.

Synthesis, Physicochemical, and Biological Studies of Complexes of 2-Aminobenzohydrazine with Co(II), Ni(II), Cu(II), and Zn(II) Chlorides

Coordination complexes of modified hydrazine bearing unit were synthesized with transition metals viz. Cu(II), Co(II), Ni(II), and Zn(II). The ligand amino benzohydrazide (ABH) was synthesized by replacing the methoxy moiety of methyl anthranilate with the nitrogen of the hydrazine hydrate, creating new coordination site. The coordination complexes were made by the reaction of ABH ligand with dehydrated metal chloride in inert environment. The compositions and structures of ligand and coordination complexes were elucidated employing physical measurements such as microanalysis, NMR, IR, UV-visible spectroscopy, magnetic, and conductance measurements. The results revealed the composition as M(ABH)Cl2. All of them exhibited tetrahedral geometry. Thermal studies of these metal complexes reveal the Irving William series trend regarding their stabilities. Antibacterial and antifungal inhibitions were also tested in order to determine the effectiveness of these complexes.

Biochemical Evaluation of Copper Compounds Derived from O- and N-/O- Donor Ligands

Compounds [CuII2(benz)4(Hbenz)2] (1) and [CuII(ppa)2(H2O)2]n (2), where benz = benzoate and ppa = 3-pyridinepropionic acid, were synthesized and studied for their 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity and the inhibition of enzymes such as acetylcholinesterase (AChE), butyrylcholinesterase (BChE), lipoxygenase (LOX), urease, chymotrypsin and α-glucosidase. The synthesized compounds were also studied by hemolytic method for their cytotoxicity and found to be low-toxicity substances. For AChE inhibition, compound 2 showed IC50 = 31.22 ± 0.45 μM, as compared to compound 1with IC50 = 36.52 ± 0.44 μM. Both compounds showed comparably low activity against BChE and were also active against urease, but compound 1 exhibited selective anti-urease activity. The anti-α-glucosidase activity of both compounds was comparable with that of standard drug used.

Intercalation of Bi2O3/Bi2S3 nanoparticles into highly expanded MoS2 nanosheets for greatly enhanced gas sensing performance at room temperature

Synthesizing a gas sensor based on heterostructured nanomaterials (NMs) via a controllable morphology by a facile hydrothermal method is an area of frontier research. In the present work, we designed a facile strategy to synthesize a controllable morphology and composition for three component heterojunctions (MoS2-Bi2O3-Bi2S3) NMs using different hydrothermal reaction times. The Bi2S3 easily form as an intermediate phase due to the strong interaction of the Bi2O3 with MoS2 nanosheets (NSs). The as fabricated heterojunctions MB-5 NMs exhibited a sensitive response to NOx gas (Ra/Rg = 10.7 at 50 ppm), with an ultra-fast response time of only 1 s (s) at room temperature (RT) in air. The detection limit was predicted to be as low as 50 ppb. This sensational behaviour of the sensor reveals the outstanding morphological structure and synergistic effect of the MoS2 NSs with Bi2O3 nanoparticles (NPs), which was realized by the flow of electrons across MoS2-Bi2O3-Bi2S3 interfaces through band energy alignment.

The crystal structure of 4-tert-butyl-N′-[(E)-(4-fluoro-3-methoxyphenyl)methylidene]benzohydrazide, C19H21F1N2O2

Abstract C19H21F1N2O2, monoclinic, Cc (no. 9), a = 14.337(3) Å, b = 15.549(3) Å, c = 8.0212(16) Å, β = 103.33(3)°, V = 1740.0(6) Å3, Z = 4, Rgt(F) = 0.0796, wRref(F2) = 0.2192, T = 170 K.

Correction to: Biological Evaluation of Copper Complexes Derived from O- and N-, O-Donor Ligands

The title should read: BIOLOGICAL EVALUATION OF COPPER COMPLEXES DERIVED FROM O- AND N-, O-DONOR LIGANDS

Structure and Magnetic Properties of a New Lattice System of the Heterometallic Decanuclear Ce6Mn4 Aggregate

In this paper, we present a mixed valence f–d Ce6Mn4III compound having formula [Ce6IV Mn4III (μ4-O)4 (μ3-O)4(O2CtBu)12(ea)4(OAc)4]·H2O (1), which is obtained by the reaction of hydrated lanthanide nitrate, pivalic acid, and ethanolamine in MeCN as a solvent. The single crystal X-ray diffraction analysis demonstrates that the central core consists of an octahedron with four triangular pyramids added to four related faces or as an octahedron encapsulated in a tetragon. The fitting of magnetization data using the anisotropic model gives D = 2.13 cm–1 and g = 1.97 (D is the axial zero-field splitting parameter).

Crystal structure of the tri­ethyl­ammonium salt of 3-[(4-hy­droxy-3-meth­oxy­phen­yl)(4-hy­droxy-2-oxo-2H-chromen-3-yl)meth­yl]-2-oxo-2H-chromen-4-olate

3,3′-[(3-Methoxy-4-hydroxyphenyl)methanediyl]bis(4-hydroxy-2H-chromen-2-one), the 4-hydroxy-3-methoxyphenyl-substituted derivative of dicoumarol, was deprotonated by the addition of triethylamine, yielding the respective ammonium salt which was crystallized from a methanol solution. The deprotonated dicoumarol derivative exhibits an intramolecular negative charge-assisted hydrogen bond between the deprotonated and non-deprotonated alcohol functions of the coumarol substituents.