Articles
Permanent URI for this collectionhttps://ds.uofallujah.edu.iq/handle/123456789/113
Browse
5 results
Search Results
Item Dioxomolybdenum (VI) and oxomolybdenum (IV) complexes with N, O, and S bidentate ligands, syntheses, spectral characterization, and DFT studies(Journal of Molecular Structure, 2022) Othman I. Alajrawy; Ayad A. AlmhmdiTwo dioxomolybdenum (VI) complexes with the chemical formula [MoO 2 (acac)(HPY)], [MoO 2 (DTO)(HPY)], and oxomolybdenum (IV) complexes [MoO(acac)(HPY)], [MoO(DTO)(HPY)] have been prepared and char- acterized by different spectral techniques such as (FTIR, UV-Vis., Mass, 1 H NMR) spectra, magnetic suscep- tibility, and theoretical studies. The ligands used in this study were acetylacetone, 2-hydrazinopyridine, and dithiooximid. The spectroscopic data and the theoretical calculations suggested distorted octahedral structures for the dioxomolybdenum(VI) complexes. The dioxomolybdenum(VI) complexes were diamag- netic. The oxomolybdenum(IV) complexes are paramagnetic and have distorted square pyramidal struc- tures. Theoretical calculations of the free ligands and the prepared complexes have been done by using DFT calculations using (G 09 W) software. The complexes were very stable and their energies ranged from ( −708.85 to −921.99 a.u.) whereas the free (HPY) and (DTO) ligands were ( −359.06 and −984.54 a.u.), respectively. The prepared complexes are polar (8.11–10.80 Debye) for Mo(VI), and (6.63–13.72 Debye) for Mo(IV). The HOMO orbital energies of the Mo(VI) complexes are ( −0.229, and −0.377 a.u.), respectively whereas for the Mo(IV) complexes are ( −0.192, −0.318 a.u.), respectively while for the (HPY) and (DTO) ligands are ( −0.216, −0.262 a.u.). The LUMO orbitals energies of the Mo(VI) complexes are ( −0.124, and −0.247 a.u.) and for the Mo(IV) are ( −0.093, −0.208 a.u.), respectively.Item NEW OXOMOLYBDENUM(IV) COMPLEXES WITH ADDUCTED MONODENTATE LIGANDS, SPECTROSCOPIC CHARACTERIZATION, DFT CALCULATIONS, BIOLOGICAL AND ANTIOXIDANT ACTIVITY(Chemical Society of Ethiopia and The Authors, 2025) Noor F. Abdalah; Othman I. Alajrawy; Sattar R. MajeedOxomolybdenum(IV) complexes with chemical formula [MoO(ATP)(DIAB)(AMP)] (C1), [MoO(ATP)(DIAB)(Atri)] (C2), [MoO(ATP)(HNQ)(AMP)] (C3) and [MoO(ATP)(HNQ)(Atri)] (C4) have been synthesized and studied using different spectral methods, including atomic absorption, FTIR, UV-Vis., mass spectroscopy, magnetic sensitivity, electrical conductivity, and C.H.N.S. analysis. The ligands were 2 aminothiophenol (ATP), 3,4-diaminobenzoic acid (DIAB), 2-hydroxy-1,4-naphthoquinone (HNQ), 6-amino-2 methylpyridin (AMP), and 3-amino-1,2,4-triazole (Atri). The FTIR spectra confirm (DIAB, AMP, and Atri) were coordinated by amine nitrogen, whereas the (HNQ) ligand was by oxygen, and the (ATP) by nitrogen and sulfur atoms. The υ(S-H) band vanished in comparison to the (ATP) ligand, this demonstrates how Mo(IV) and the sulfur atom. The (HNQ) ligand's oxygen atoms work in tandem with the Mo(IV). Mo(IV) complexes with d2 are paramagnetic. All complexes have been suggested to have an octahedral structure based on computed and experimental evidences. Two Gram-positive and two Gram-negative bacteria were used to test the (ATP) ligand and the produced complexes' activity. The complexes showed an expanded zone of inhibition, indicating that they were more lipophilic than the free (ATP) ligand. Finally, the antioxidant activity of the complexes was tested, and the result showed the following order: Gallic acid ˃ C3 ˃ C2 ˃ C4 ˃ C1 in 60 minItem MWCNT-based material as a gas sensor for H 2 and characterisation(Inorganic Chemistry Communications, 2023) Yasser Naji Ahmed; Mohammed faiad naief; Samar Naser Mohammed; Ahmed Mishaal MohammedIn this study, waste oil was used to produce multi-walled carbon nanotubes (MWCNTs). TEM, FE-SEM and AFM techniques were used to characterise MWCNTs. In addition, the sizes of the synthesised MWCNTs ranged from 28.3 to 49.51 nm. The FTIR technique was used to prove the production of MWCNTCOO. The produced MWCNTCOO were evaluated as gas sensors for H 2 The higher H 2 S and NO 2 ◦ S sensitivity response was recorded at 70 gases at various temperatures and time intervals. C, with a response of 10.6, meanwhile, the greater NO sensitivity response was observed at 190 ◦ C, with a response of 29.9. At 25 ◦ 2 C, the response and recovery times for 100 ppm H 2 ◦ S gas were 18.9 and 96.3 s, respectively, whereas, at 100 C, they were 28.8 and 85.5 s, respectively, thereby demonstrating that the sensor has unique response recovery featuresItem Novel preparation method of fullerene and its ability to detect H2S and NO2 gases(Results in Chemistry, 2023) Mohammed Faiad Naief; Samar Naser Mohammed; Yasser Naji Ahmed; Ahmed Mishaal Mohammed; Sura Naser MohammedIn this study, a new system for fullerene preparation was designed based on the incomplete combustion of liquid asphalt. Transmission electron microscopy, field emission scanning electron microscopy and energy-dispersive X- ray (EDX) techniques were used to characterise fullerene. The sizes of the synthesised fullerene ranged from 48.20 nm to 73 nm. The EDX technique was used to determine the amounts of elements in a component, thereby revealing the formation of fullerene. The produced fullerene was evaluated as a gas sensor for H2S and NO2 gases at various temperatures and time intervals. The sensitivity of the gas sensor decreased with the increased operating temperature reaching 150 ◦C. Then, the sensitivity increased as the temperature increased. The maximum gas sensitivities for NO2 and H2S were 72.86% at 25 ◦C and 75.89% at 200 ◦C, respectively.Item Synthesis and characterisation of MWCNTCOOH and investigation of its potential as gas sensor(journal homepage, 2023) Mohammed Faiad Naief; Samar Naser Mohammed; Yasser Naji Ahmed; Ahmed Mishaal MohammedMonitoring and control of hazardous gases have been a top concern because they lead to serious public health issues, such cardiovascular diseases, respiratory illnesses, central nervous system abnormalities and other ill nesses. These gases are also linked to global warming, which affects the surrounding environment. Therefore, harmful emissions should be limited and neutralised. Traditional gas sensors have slow speed, expensive oper ation, labour and capital intensive and invasive. Scholars need to develop an inexpensive, rapid, efficient, highly sensitive, portable sensors with a low power consumption and a high level of reliability. In this study, multi- walled carbon nanotubes (MWCNTs) were synthesised using plant byproducts. TEM, FE-SEM and AFM were employed to identify MWCNTs. Gas test showed that the sensor had high sensitivity levels of 5.6 and 8.8 and response times as low as 24.3 and 21.6 s for H2 S and NO 2 , respectively.