Abdulhakim Ahmed

University of Benghazi · Department of Chemistry

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...

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...

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...

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...

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...

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)

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...

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...

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...

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...

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)...

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...

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...

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...

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/...

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...

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/...

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...

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...

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...

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...

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...

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...

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...

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...

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...

[(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...

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...

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.

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...