Khalid Al-Farhan

Crystal structure of triphenylphosphine oxide

The crystal structure of Triphenylphosphine Oxide, C18H15PO, was reinvestigated using Mo-Kα radiation λ=0.71069 Å,μ(Mo-Kα)=1.36 cm−1.Mr=278.1, orthohombic,Pbca,a=29.089(3),b=9.1347(9),c=11.261(1) Å,V=2992.2 Å3,Z=4,Dx=1.235 Mg m−3. The structure was refined by full-matrix least-squares toR=0.040 andRw=0.036 for 1848 unique reflections and 182 variables. Improved bond lengths and angles were obtained; O-P is 1.479(2) Å, weighted means of P-C is 1.803(1) Å, O-P-C is 112.6(1)° and C-P-C is 106.2(1)°.

The synthesis, identification, and X-ray structure of a novel cationic alkynyl silver cluster polymer [Ag3(C2But)2+]n

Abstract The reaction between AgBF4 and [Ag(C2But)]n in 1:2 mol ratio affords the novel cationic polymer [Ag3(C2But)2+]n. The crystal structure has been determined by single-crystal X-ray diffraction study.

Light-stable bis(norharmane)silver(I) compounds: Synthesis, characterization and antiproliferative effects in cancer cells

Four different-anion Ag(I) compounds with the ligand norharmane (9H-Pyrido[3,4-b]indole; Hnor) and having the general formula [Ag(Hnor)2](anion) (anion=ClO4(-), NO3(-) and BF4(-)) [Ag(Hnor)2(MeCN)](PF6) are reported, and studied in detail regarding their coordination mode and in vitro antiproliferative effects. X-ray structural analysis revealed that the complex with the PF6(-) anion has a MeCN solvent molecule weakly coordinated to Ag(I), making the metal coordination T-shaped, while the other compounds present the classical linear Ag(I) coordination. The compounds showed certain cell growth inhibitory effects in two different cancer cell lines, with the perchlorate containing complex being the most toxic and in fact comparable to cisplatin. Notably, the compounds are stable in visible light; and the luminescence in the solid state was found to be extremely weak, whereas in MeOH solution all compounds show a moderate to weak emission band at 375 nm, when excited at 290 nm.

PREPARATION AND CHARACTERIZATION OF NEW In(III), Re(III), AND Re(V) COMPLEXES WITH THENOYLTRIFLUOROACETONE AND SOME BIDENTATE HETEROCYCLIC LIGANDS

ABSTRACT New In(III), Re(III) and Re(V) complexes with the thenoyltrifluoroacetone ligand (HTTA) of the general formulae [In-(TTA)(H2O)4]SO4, [Re(TTA)n(H2O)x]Cl3-n and [ReO(TTA)n-(H2O)x]Cl3-n (where n and x refer to the number of [TTA]− moieties and H2O molecules, respectively) have been prepared and characterized by spectroscopy, thermogravimetry, elemental analyses and X-ray diffraction. The charge densities on the ligand atoms were calculated via CNDO-SCF calculations. The newly prepared complexes. [In(TTA)(H2O)4]SO2 and [ReO(TTA)(H2O)2]CL2 were employed as precursors for the synthesis of the mixed-ligand complexes [In(TTA)(HOCTA)2], [In(TTA)(TZT)2] and [ReO(TTA)(HOTCA)]Cl using R(-)-2-oxothiazolidine 4-carboxylicacid (H2OTCA) and 1H-1,2,4-triazole-3-thiol (H2TZT) as ligands. The synthesized mixed-ligand complexes were characterized by the conventional physical and chemical methods of analysis applied earlier for the characterization of the precursors. The investigated complexes are soluble in water, ethanol and acetonitrile, insoluble in non-polar solvents and could be of potential use for clinical studies. The antibacterial activity of the investigated complexes has been tested and evaluated.

Synthesis, structural chemistry and antimicrobial activity of −(−) borneol derivative

AbstractBorneol is a monoterpene that is a part of traditional Chinese and Japanese medicine. (−) borneol reacted with methanesulfonyl chloride in THF/pyridine to afford the new 1,7,7-trimethylbicyclo[2.2.1]hept-2-yl methane sulfonate derivative in excellent yield. The product is characterized by H1NMR, C13NMR, mass spectroscopy as well as elemental analysis and its structure was identified by X-ray single crystal diffraction. The packing of 1,7,7-trimethylbicyclo[2.2.1]hept-2-yl methanesulfonate exhibits the non-classical C-H···O hydrogen bonding in C(4) and R22(8) chain and ring motifs as structural determinants. This was also confirmed by the analysis of Hirshfeld surfaces. The 1,7,7-trimethylbicyclo[2.2.1]hept-2-yl methane sulfonate antimicrobial activity was tested and compared with its parent (−) borneol against three different pathogens. Particularly, 1,7,7-trimethylbicyclo[2.2.1]hept-2-yl methane sulfonate showed high sensitivity, compared to Chloramphenicol reference material, against Escherichia coli.

Insights into the strong in-vitro anticancer effects for bis(triphenylphosphane)iminium compounds having perchlorate, tetrafluoridoborate and bis(chlorido)argentate anions

Three new compounds containing the bis(triphenylphosphane)iminium cation (PPN(+)) with ClO4(-), BF4(-) and [AgCl2](-) as counter anions have been synthesized and structurally characterized. The two derivatives with ClO4(-) and BF4(-) were found to be isostructural by single crystal X-ray diffraction. Interestingly, the three compounds show extremely potent antiproliferative effects against the human cancer cell line SKOV3. To gain insights into the possible mechanisms of biological action, several intracellular targets have been considered. Thus, DNA binding has been evaluated, as well as the effects of the compounds on the mitochondrial function. Furthermore, the compounds have been tested as possible inhibitors of the seleno-enzyme thioredoxin reductase.

Heteroleptic Copper(I) Complexes of “Scorpionate” Bis-pyrazolyl Carboxylate Ligand with Auxiliary Phosphine as Potential Anticancer Agents: An Insight into Cytotoxic Mode

New copper(I) complexes [CuCl(PPh3)(L)] (1: L = LA = 4-carboxyphenyl)bis(3,5-dimethylpyrazolyl)methane; (2: L = LB = 3-carboxyphenyl)bis(3,5-dimethylpyrazolyl)methane) were prepared and characterised by elemental analysis and various spectroscopic techniques such as FT-IR, NMR, UV–Vis, and ESI-MS. The molecular structures of complexes 1 and 2 were analyzed by theoretical B3LYP/DFT method. Furthermore, in vitro DNA binding studies were carried out to check the ability of complexes 1 and 2 to interact with native calf thymus DNA (CT-DNA) using absorption titration, fluorescence quenching and circular dichroism, which is indicative of more avid binding of the complex 1. Moreover, DNA mobility assay was also conducted to study the concentration-dependent cleavage pattern of pBR322 DNA by complex 1, and the role of ROS species to have a mechanistic insight on the cleavage pattern, which ascertained substantial roles by both hydrolytic and oxidative pathways. Additionally, we analyzed the potential of the interaction of complex 1 with DNA and enzyme (Topo I and II) with the aid of molecular modeling. Furthermore, cytotoxic activity of complex 1 was tested against HepG2 cancer cell lines. Thus, the potential of the complex 1 is promising though further in vivo investigations may be required before subjecting it to clinical trials.

N'-(Di-2-pyridylmethyl-ene)benzo-hydrazide.

In the title Schiff base, C18H14N4O, the amido –NH– unit is connected to one of the two pyridyl N atoms at an N(—H)⋯N distance of 2.624 (2) Å. The molecular packing features an intermolecular C—H⋯N R 2 2(6) hydrogen-bonding ring motif.

Quinazoline, pyrazolo[1,5-c]quinazoline and spiro quinazoline dimers from the reaction of 2-aminoacetophenone hydrazones with triphosgene

The reaction of hydrazones of 2-aminoacetophenone with triphosgene in dichloromethane or benzene in the presence of triethylamine gave quinazolines, pyrazolo[1,5-c]quinazoline and spiro quinazoline dimers. The latter compounds are being reported for the first time. In addition, a 4,4-disubstituted quinazoline derivative is prepared and its x-ray crystal structure is reported.

Copper Disordered Hexakis(phenylethynyl)pentaargentate(I) Cluster

The X-ray single-crystal structure determination of an anionic cluster, [Ag 4.46 Cu 0.54 (C 8 H 5 ) 6 ], with bis(triphenylphosphine)iminium counterions, [N(C 18 H 15 P) 2 ], prepared from the reaction of [Cu(C=CPh) 2 ] ― and [{Ag(C=CPh)} n ] in a 1 :4 mole ratio, revealed a trigonal bipyramidal arrangement of Ag 5 with positional disorder, with copper substituting silver in some equatorial positions making the ratio of metal atoms 8.3Ag :1Cu. Each equatorial metal atom is bonded to the alkynyl ligands in an almost linear fashion. Ag atoms in apical positions are asymmetrically π bonded, with varying degrees of strength, to three alkyne ligands each.