Abdulhakim Ahmed

Abdulhakim Ahmed
University of Benghazi · Department of Chemistry

PhD
small metal clusters properties using DFT model & the adsorption of gas (NO, CO, H2S ...etc) on small metal clusters

About

33
Publications
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90
Citations
Citations since 2016
9 Research Items
28 Citations
201620172018201920202021202202468
201620172018201920202021202202468
201620172018201920202021202202468
201620172018201920202021202202468
Introduction

Publications

Publications (33)
Article
The interconversion between different isomers of copper clusters has been investigated using density functional theory. Seven distinct transition states have been located for the isomerization of the Cu3, Cu4, Cu5, Cu6 and Cu7 clusters. The chemisorption of nitric oxide on copper clusters has been studied and the approach of nitric oxide to produce...
Article
Full-text available
Structure and relative stability of Pdn clusters for n=1-6 were investigated using density functional methods at the B3PW91 level of theory. The structures of the optimized Palladium clusters were investigated and the results are compared with the available experimental values. Stability of the clusters was determined from their relative energy val...
Article
Full-text available
The adsorption of nitric oxide molecule on small palladium clusters (Pdn;n=1-6) has been investigated by the density functional theory. The orientations of nitric oxide to get a nitrosyl (-NO) and Isonitrosyl (-ON) ligands were implemented. The most stable palladium clusters have been used as adsorbate. The resulting nitrosyl and Isonitrosyl pallad...
Article
Full-text available
The structures and nonlinear optical properties (NLO) of 5-thioxo-1,4-thiazaolidin-3-one(Rhodanine) and 5-thioxo-1,4,2-thiazasilolidin-3-one (silarhodanine) tautomers were studied in gas phase and in solutions using the B3LYP density functional theory and composite CBS-QB3 method. The global minimum at the B3LYP/6-31++G(d,p) and CBS-QB3 levels of t...
Article
Full-text available
Two pairs of complexes, [Mn(CO)3(benzene)]⁺/[Mn(CO)3(naphthalene)]⁺ and [Cr(CO)3(tropylium)]⁺/[Cr(CO)3(benzotropylium)]⁺, have been used as a platform to establish the extent to which the well-known ‘indenyl effect’ translates into other bicyclic ligand systems. Density functional theory (DFT) suggests that the ‘naphthalene effect’ is minimal, the...
Presentation
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Talk during the Quantum Day held in wed.21-3-2018. Particle wave Duality (the History) the final slide is related to (Stupid questions vs smart answers)
Article
Two pairs of complexes, [Mn(CO)3(benzene)]+/[Mn(CO)3(naphthalene)]+ and [Cr(CO)3(tropylium)]+/[Cr(CO)3(benzotropylium)]+, have been used as a platform to establish the extent to which the well-known ‘indenyl effect’ translates into other bicyclic ligand systems. Density functional theory (DFT) suggests that the ‘naphthalene effect’ is minimal, the...
Article
Full-text available
The electronic structure and reactivity of hydroxyaminogermanone conformers were studied in the gas phase by density functional theory. Seven minimum structures (1-7) and six transition states (TSs) were located. The global isomeric structure was 2 at the B3LYP/6-311++G (d,p) level of theory. The natural bond orbital (NBO) analysis reveals that the...
Article
Full-text available
The Z/E iminol forms of formohydroxamic acids (HX(OH)NHOH where X=C, Si, Ge, Sn and Pb) have been investigated in the gas phase using B3LYP density functional theory at B3LYP/6-31++G(d,p) level of theory.The barrier to the rotation of Z to the more stable isomer E is significant in C, Si and Ge structures, whereas in Sn and Pb the Ztautomer is more...
Article
The structure and reactivity of hydroxyaminosilanethione conformers were studied in the gas phase using density functional theory. Eight local minima were located, including two featuring pentacoordinate silicon atoms (2Z, S2) and one with a nitrososilanethiol structure (4Z). The global minimum at the B3LYP/6-31++G(dp)//B3LYP/6-31G(d) levels of the...
Article
Full-text available
The global isomeric structure in the gas phase and with water-assisted in solution is predicated at B3LYP/6-31++G** // B3LYP/6-31G* levels of theory. The free energies, enthalpies of solvation and equilibrium constants are calculated at the same level of theory. Eight local minima structures (S1-S8) and nine hydrated structures (S1.H 2 O-S8.H 2 O)...
Article
Full-text available
The proton transfer processes have generated eight minimum structures of the silarhodanine molecule. These structures were studied in the gas phase by a high level theory complete basis set (CBS-Q). All the structure are heterocyclic compounds except S2 structure. The global isomeric structure was S5 at the CBS-Q levels of theory. The acyclic struc...
Article
The tautomerizm of (hydroxphosphino)silanethione molecule 1 were investigated by density function theory calculations. The potential energy surface, the global isomeric structures and the transition states of intramolecular proton transfer were calculated at B3LYP/6-31G(d) level of theory. The energy was further studied by a single point calculatio...
Article
Full-text available
The Silathioformohydroxamic acid conformers were studied in the gas phase by a high level density functional theory. The global isomeric structure was S2 at the CBS-Q levels of theory. The stability order for the conformers were 1E>1Z>4Z>2Z>2E>3Z>S1. Thirteen anions and seven cations of various conformers have been studied. The protonation and depr...
Article
Full-text available
A quantum chemistry calculation has been applied in order to investigate the intramolecular proton transfer process in thioformohydroxamic in gas phase and in water. The global isomeric structures, the transfer potential surfaces, the harmonic frequency and transition states geometries of intramolecular proton transfer were calculated at the B3LYP/...
Article
Full-text available
The molecular structure of 1,2-diphosphinoethane conformers have been studied in the gas phase. The ab initio Hartree-Fock with 6-31G* basis set and the Moller-Plesset second-order MP2/6-311G* were applied. Twelve conformers have been located on the potential energy surface. The Geometries, the total electronic energy, HOMO, LUMO, HOMO-LUMO gap, 1...
Article
Full-text available
A quantum chemistry calculation has been applied in order to investigate the intramolecular proton transfer process in thioformohydroxamic in gas phase and in water. The global isomeric structures, the transfer potential surfaces, the harmonic frequency and transition states geometries of intramolecular proton transfer were calculated at the B3LYP/...
Article
Full-text available
THE ABSTRACT Organic ligands of octano, N-methyl, N-phenyl, N-(p-chloro phenyl) octanohydroximic acids were prepared. The interaction of such ligands with La(III), Co(IV), Th(IV), ZrO(II) and UO2(II) ions under pH control in (1:1), (1:2) and (1:3) Molar ratios (M:L) led to the formation of solid complexes which gave analytical data suggested the (1...
Article
Full-text available
Schiff bases are highly important in industrial and biological fields. The present study has been carried out to investigate the geometrical structure of complexes with M(II) and M(III) ions. The complexes were prepared by condensation of acetyl acetone with benzidine (L), P–phenylene diamine (L1), P-toluidine (L2), and aniline (L3) using different...
Article
Full-text available
Neutral tetradentate N2O2 type complexes of vanadium(IV) have been synthesized using a Schiff base formed by the condensation of o-aminobenzoicacid, o-aminophenol. Benzidin and 1,4-phenylenediamine with Benzil, saliasldehyde, and 2-methlycyclo-pentane-1,3-dione in alcohol medium. All the complexes were characterized on the basis of their micro anal...
Article
Full-text available
The syntheses of some NI(II), Co(II) and Cu(II) Schiff base complexes have been reported. The Schiff base llgands H2L1 (C 40H32N2O2), H2L 3 (C32H28N2O2) and H 2L3 (C22H26N2O 2) under were prepared by the condensation of amines namely benzidine and 1,4-phenylenediamine with benzoin, benzoylacetone and acetylacetone. A fourth ligand H2L4 (C34H28N 2O2...
Article
Density functional theory reveals multiple pathways for intramolecular hydride transfer in the cyclopentadienyl and indenyl species (eta(5)-C5H5)Fe(CO)(3)H and (eta(5)-C9H7)Fe(CO)(3)H. The ability of the indenyl ligand to undergo facile eta(5)- to eta(3)-'ring slippage' stabilises the isomer where the hydride is bonded directly to the metal, which...
Article
Full-text available
The ligand and its complexes of Cr(III), Fe(III), Co(II), Ni(II), Cu(II) and Zn(II) were investigated in terms of synthesis, elemental analysis, molar conductivity, thermal analysis, infrared spectra and magnetic susceptibility measurements. The ligand: 4-[4’-(3-Hydroxy-1-ethyl-but-2-enylideneamino)-biphenyl-4-ylimino]-pent-2- en-ol (C22H24N2O2) ha...
Conference Paper
Full-text available
The transformation of few isomeric tautomers of thioformohydroxamic (TFH), thioacetohydroxamic (TAH) and thiobenzohydroxamic (TBH) acids via intramolecular hydrogen transfer were investigated by density functional calculations. The global isomeric structures, the transfer potential surfaces, the harmonic frequency and transition states geometries o...
Article
Full-text available
The Schiff base ligands and their complexes of divalent metals of Ni(II), Co(II) and Cu(II) were investigated in terms of synthesis, elemental analysis, molar conductivity, thermal analysis, infrared spectra, ultraviolet-visible and magnetic susceptibility measurements. The ligands have been synthesized by condensation of benzoylacetone and ethylen...
Conference Paper
Full-text available
First principle quantum chemical calculations at the HF level of theory, using the 3-21G and 3-21G* split-valence basis sets have been used to investigate the molecular geometry and electronic properties of Bis(phosphino)methane (H2PCH2PH2) (BMP) conformers. Phosphine (PH3) (AP) and methyl phosphine (CH3PH2) (MP)are also investigated for a comparis...
Article
[(η5-Indenyl)Fe(CO)3]BF4 (I) undergoes facile monocarbonyl substitution at room temperature in acetone by monophosphines, monophosphites and MPh3 (M =1cr; As, Sb, Bi) ligands (L) to form [(η5-Indenyl)Fe(CO)2L]BF4. Ditertiary phosphines, PPh2(CH2)n PPh2 (n = 1, 2, 4, 6, 8) and both the arsines, AsPh2(CH2)2AsPh2 and AsMe2 (CH2)5AsMe2 react similarly...
Article
Full-text available
The Fourier transform infrared and Raman spectra of the cations [η5-C9H7Fe(CO)n dppa]+ (n = 1, 2; dppa=bisdiphenylphosphinoalkane, where alkane=methane, ethane, butane, hexane and octane) and [{η5-C9H7Fe(CO)2}2-μ-dppa]2+ indicate that the alkyl chain lengths have effects on the structures of the bidentate cations resulting in increased back-donatio...
Article
Full-text available
Spectroscopic evidence is presented for the formation at low temperatures of the η3-indenyl intermediate [(η3-C9H7)Fe(CO3H], prior to formation of t by reduction of the tricarbonylironindenyl cation with sodium cyanoborohydride in acetone.
Article
Full-text available
Four binuclear dichloro-bridged copper(II) complexes have been prepared and physically characterized. The characterization was involved the elemental analysis, molar conductivity, thermal analysis, infrared spectra and magnetic susceptibility measurements. The ligands have been synthesized by the condensation of acetylacetone (C5H8O2) and p-phenyle...

Questions

Questions (3)
Question
I am using Gaussian09 and I am looking for an answer for the following: What is the best DFT Functionals for high multiplicity metal cluster?
Question
I got a problem when doing optimization using SCF=RESTART. The message I received is saying: ERROR IN INPUT DENSITY. Can any one help me?
Question
I am doing NMR calculations for iron complex.

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Projects

Projects (3)
Project
The aim of the present work is to investigate the adsorption of nitric oxide on small copper clusters (Cun n=1-7) using density functional theory, in particular, structural properties, and electronic structures, charge transfer, different potentials, binding energies and the stretching frequency.
Project
Indenyl effect