scispace - formally typeset
Search or ask a question
Author

Salah S. Massoud

Bio: Salah S. Massoud is an academic researcher from University of Louisiana at Lafayette. The author has contributed to research in topics: Square pyramidal molecular geometry & Denticity. The author has an hindex of 32, co-authored 181 publications receiving 3629 citations. Previous affiliations of Salah S. Massoud include Louisiana State University & University of Basel.


Papers
More filters
Journal ArticleDOI
TL;DR: Constantes de stabilite des complexes 1:1, determinees par titrage potentiometrique en solution aqueuse, modes de liaison as discussed by the authors, a.k.a.
Abstract: Constantes de stabilite des complexes 1:1, determinees par titrage potentiometrique en solution aqueuse. Modes de liaison

179 citations

Journal ArticleDOI
TL;DR: Constantes de stabilite des complexes 1:1 formes entre Mg, Ca, Sr, Ba, Mn, Co, Ni, Cu, Zn et Cd divalents et 7-deaza-AMP 2− ou AMP 2−. Structures
Abstract: Constantes de stabilite des complexes 1:1 formes entre Mg, Ca, Sr, Ba, Mn, Co, Ni, Cu, Zn et Cd divalents et 7-deaza-AMP 2− ou AMP 2− . Structures

124 citations

Journal ArticleDOI
TL;DR: In this paper, three dinuclear copper(II) complexes, derived from end-to-end and end-on azido bridging ligands and triamine derivatives, have been synthesized and their crystal structures have been determined by X-ray diffraction methods.
Abstract: Three new dinuclear copper(II) complexes, derived from end-to-end and end-on azido bridging ligands and triamine derivatives, have been synthesized and their crystal structures have been determined by X-ray diffraction methods. These are the dinuclear end-to-end compounds, [Cu2(μ1,3-N3)2(Et3dien)2](ClO4)2 (1) and [Cu2(μ1,3-N3)2(Medpt)2](ClO4)2 (2), and the dinuclear end-on compound [Cu2(μ1,1-N3)2(Medien)2](ClO4)2 (3) (Et3dien is triethyldiethylenetriamine, Medpt is methyldipropylenetriamine and Medien is methyldiethylenetriamine). The [Cu(μ-N3)2Cu]2+ cores are asymmetrical in all 3 compounds. Variable temperature magnetic susceptibility data were collected and fitted to the appropriate equation derived from the Hamiltonian H = −JS1S2. 1 shows unusual ferromagnetic interactions with J = 9 cm−1 through the end-to-end azido bridges while 2 shows an antiferromagnetic interaction through the end-to-end azido bridges with the highest reported absolute magnitude of J = −105 cm−1. The magnetic data of 1 and 2 have been correlated with the Addison parameter, τ, and mainly with the Cu–N3–Cu torsion angle, Δ. 3 shows an unusual antiferromagnetic interaction with J = −16.8 cm−1 through the end-on azido bridges.

102 citations

Journal ArticleDOI
TL;DR: In this paper, the X-ray determination of the structures of tris[(2-pyridyl)methyl]amine compounds was carried out and the results revealed the presence of linkage isomerization.

85 citations


Cited by
More filters
01 Feb 1995
TL;DR: In this paper, the unpolarized absorption and circular dichroism spectra of the fundamental vibrational transitions of the chiral molecule, 4-methyl-2-oxetanone, are calculated ab initio using DFT, MP2, and SCF methodologies and a 5S4P2D/3S2P (TZ2P) basis set.
Abstract: : The unpolarized absorption and circular dichroism spectra of the fundamental vibrational transitions of the chiral molecule, 4-methyl-2-oxetanone, are calculated ab initio. Harmonic force fields are obtained using Density Functional Theory (DFT), MP2, and SCF methodologies and a 5S4P2D/3S2P (TZ2P) basis set. DFT calculations use the Local Spin Density Approximation (LSDA), BLYP, and Becke3LYP (B3LYP) density functionals. Mid-IR spectra predicted using LSDA, BLYP, and B3LYP force fields are of significantly different quality, the B3LYP force field yielding spectra in clearly superior, and overall excellent, agreement with experiment. The MP2 force field yields spectra in slightly worse agreement with experiment than the B3LYP force field. The SCF force field yields spectra in poor agreement with experiment.The basis set dependence of B3LYP force fields is also explored: the 6-31G* and TZ2P basis sets give very similar results while the 3-21G basis set yields spectra in substantially worse agreements with experiment. jg

1,652 citations

Journal ArticleDOI
TL;DR: In this paper, the authors present a review of metal interactions with nucleobases, focusing on the coordination chemistry of metal species with the heterocyclic parts of nucleobase.

404 citations

Journal ArticleDOI
TL;DR: The role of metal ions in ribozymes ternary metal-nucleic acid base-protein complexes metal responsive gene regulation and the zinc metalloregulatory model is studied.
Abstract: Phosphate-metal ion interactions of nucleotides and polynucleotides sugar-metal ion interactions dichotomy of metal ion binding to N1 and N7 of purines general conclusions from sold state studies of nucleotide-metal ion complexes solution studies of nucleotide-metal ion complexes - isomeric equilibria stacking interactions involving nucleotides and metal ion complexes the effect of metal ions on hydrolytic reactions of nucleotides and their phosphoesters metal complexes of sulfur-containing purine derivatives mechanistic insight from kinetic studies on the interaction of model palladium (II) complexes with nucleic acid components platinum (II)-nucleobase interactions - a kinetic approach NMR studies of oligonucleotide-metal ion interactions metal ion interactions with DNA - considerations on structure, stability and effects from metal ion binding electron transfer reactions through the double helix the role of metal ions in ribozymes ternary metal-nucleic acid base-protein complexes metal responsive gene regulation and the zinc metalloregulatory model the role of iron-sulfur proteins in gene regulation current status of structure-activity relationship of platinum anticancer drugs - activation of the trans-geometry cisplatin and derived anticancer drugs - mechanism and current status of DNA binding proteins that bind to and mediate the biological activity of platinum anticancer drug-DNA adducts interactions of metallopharmaceuticals with DNA.

370 citations

Journal Article
TL;DR: In this paper, the authors solved the energy levels which are important in the absorption spectra of the normal complex ions, leaving the crystalline field strength as a parameter, and calculated positions of lines and bands are rather in good agreement with the experimental data in divalent ions [MX 6 ] 2+ (M=Cr, Mn, Fe, Co, Ni), when they adjust the crystallINE field parameter D q suitably.
Abstract: The secular determinants obtained in the previous paper are solved for the energy levels which are important in the absorption spectra of the normal complex ions, leaving the crystalline field strength as a parameter. The values of B and C (Racah's parameters) there needed are determined from the observed spectra of free ions or in some cases by extrapolation. The f -values of the transitions which connect the energy levels calculated are estimated and compared with the observed intensities. The difference of the spectral width among absorption bands and lines is also considered using the energy diagram obtained. Following the assignments determined by the above considerations, the calculated positions of lines and bands are rather in good agreement with the experimental data in divalent ions [MX 6 ] 2+ (M=Cr, Mn, Fe, Co, Ni), when we adjust the crystalline field parameter D q suitably. In trivalent ions [MX 6 ] 3+ (M=Ti, V, Cr, Mn, Fe), it is necessary besides the adjustment of D q to use smaller values ...

363 citations