Mousa Al-Noaimi

One Step Synthesis of NiO Nanoparticles via Solid-State Thermal Decomposition at Low-Temperature of Novel Aqua(2,9-dimethyl-1,10-phenanthroline)NiCl2 Complex

[NiCl2(C14H12N2)(H2O)] complex has been synthesized from nickel chloride hexahydrate (NiCl2·6H2O) and 2,9-dimethyl-1,10-phenanthroline (dmphen) as N,N-bidentate ligand. The synthesized complex was characterized by elemental analysis, infrared (IR) spectroscopy, ultraviolet-visible (UV-vis) spectroscopy and differential thermal/thermogravimetric analysis (TG/DTA). The complex was further confirmed by single crystal X-ray diffraction (XRD) as triclinic with space group P-1. The desired complex, subjected to thermal decomposition at low temperature of 400 ºC in an open atmosphere, revealed a novel and facile synthesis of pure NiO nanoparticles with uniform spherical particle; the structure of the NiO nanoparticles product was elucidated on the basis of Fourier transform infrared (FT-IR), UV-vis spectroscopy, TG/DTA, XRD, scanning electron microscopy (SEM), energy-dispersive X-ray spectrometry (EDXS) and transmission electron microscopy (TEM).

Trans/cis isomerization of [RuCl2{H2CC(CH2PPh2)2)}(diamine)] complexes: Synthesis, spectral, crystal structure and DFT calculations and catalytic activity in the hydrogenation of α,β-unsaturated ketones

Three complexes of the general formula trans/cis-[Ru((II))(dppme)(N-N)Cl2] {dppme is H2C=C(CH2PPh2)2 and N-N is 1,2-diaminocyclohexane (trans/cis-(1)) and 1-methyl-1,2-diaminopropane (trans-(2)} were obtained by reacting trans-[RuCl2(dppme)2] with an excess amount of corresponding diamine in CH2Cl2 as a solvent. The complexes were characterized by an elemental analysis, IR, (1)H, (13)C and (31)P{1H} NMR, FAB-MS and UV-visible. The trans-(1) (kinetic product) readily isomerizes to the cis-(1) (thermodynamic product) and this process was followed by using (31)P{(1)H} NMR, cyclic voltammetry and UV-vis spectroscopy. The electrochemical studies on complex (1) reveal that the Ru(III)/Ru(II) couples are sensitive to the isomer (trans/cis) formed. The cis-(1) was confirmed by X-ray structure and (31)P{(1)H} NMR. Transfer-hydrogenation reactions for reduction of trans-4-phenyl-3-butene-2-one were conducted using complexes trans/cis-(1) and trans-(2). The electronic spectra of cis/trans-(1) in dichloromethane were calculated with the use of time-dependent DFT methods.

Characterization and biological activities of two copper(II) complexes with dipropylenetriamine and diamine as ligands

Two new mixed-ligand copper(II) complexes, [Cu(dipn)(NN)]Br2(1-2) [dipn=dipropylenetriamine, NN=ethylenediamine (en) (1) and propylenediamine (pn) (2)], have been synthesized. These complexes were characterized by spectroscopic and thermal techniques. Crystal structure for 2 shows a distorted trigonal-bipyramidal geometry around Cu(II) ion with one solvate water molecule. Antimicrobial and antiproliferative assays were conducted to evaluate the biological activities of these complexes. The complexes exhibit a promising antimicrobial effect against an array of microbes at 200μg/mL concentration. The antiproliferative assay shows a high potential of these complexes to target Human keratinocyte cell line with IC50 values of 155 and 152μM. The absorption spectrum of 2 in water was modeled by time-dependent density functional theory (TD-DFT).

Heterotrimetallic Ru(II)/Pd(II)/Ru(II) complexes: Synthesis, crystalstructure, spectral characterization, DFT calculation and antimicrobial study

New ruthenium(II) mononuclear complexes of the type [RuCl2(PPh3)2(η(2)-triamine)] (2) [RuCl(PPh3)2(η(3)-triamine)]Cl (5) (triemine=N(1)-(2-aminoethyl)-1,2-ethanediamine) have been synthesized by reacting [RuCl2(PPh3)3] (1) with one mole equivalent of N(1)-(2-aminoethyl)-1,2-ethanediamine in dichloromethane. Reaction of (2) with half-equivalent of (PhCN)2PdCl2 or Pd(OAc)2 in dichloromethane as a solvent afforded two novel heterotrimetallic Ru(II)-Pd(II)-Ru(II) complexes, [Ru(II)Cl2(PPh3)2(triamine)]2[Pd(II)X2](X=Cl, OAc) (3 and 4), bearing bioactive ligand. The progress of the undertaken reactions was monitored by (31)P{1H} NMR and FTIR. Crystal structure of complex 2 was confirmed by X-ray diffraction. The absorption spectrum of 2 in dichloromethane was modeled by time-dependent density functional theory (TD-DFT). The in vitro antimicrobial studies of complex 2-5 against an array of microorganisms (bacteria and fungi) were conducted. Complexes 3 and 4 exhibit high dual antibacterial and antifungal activity inhibiting microorganisms possibly via hydrolytic pathway which further evidenced by electrochemical analyses. The complexes 3 and 4 show a high inhibitory activity at 200 μg/ml concentration, suggesting that complexes 3 and 4 are two efficient catalytic inhibitor of microorganisms and further, they should be tested against cancer strains.

Heterocyclic thiocarboxylato complexes of iron: synthesis, characterization, electrochemistry, and reactions

Heterocyclic-thiocarboxylato complexes of iron, CpFe(CO)2SCO-het (het = 2-C4H3O, 2-C4H3S, CH2-2-C4H3S), have been synthesized via the reaction of iron sulfides, (μ-S x )[CpFe(CO)2]2 (x = 3, 4), with heterocyclic acid chlorides het-COCl. Photolytic substitutions of these complexes CpFe(CO)2SCO-het with triphenylphosphine, triethylphosphite, triphenylarsine, and triphenylantimony [ER3 (E = P, R = Ph, OC2H5; E = As, Sb, R = Ph)] exclusively gave the monosubstituted complexes CpFe(CO)(ER3)SCO-het in good yields. The new complexes have been characterized by elemental analysis, UV-Vis, IR, 1H, and 31P NMR spectroscopies and by cyclic voltammetry for a representative family (1, 4a–d). The solid state structures of CpFe(CO)2SCO(2-C4H3S) (2), CpFe(CO)(PPh3)SCO(2-C4H3S) (5a), CpFe(CO)(AsPh3)SCO(2-C4H3S) (5b), and CpFe(CO)(SbPh3)SCO(2-C4H3S) (5c) were determined by X-ray crystal structure analysis.

PRETREATMENT EFFECTS ON THE CATALYTIC ACTIVITY OF JORDANIAN BENTONITE

De-tert-butylation of 2-tert-butylphenol was carried out over thermally-treated and acid-treated Jordanian bentonite clay samples. This reaction was found to follow first-order kinetics for all clay samples with different pretreatment procedures. The apparent rate constant, k, was also determined, and found to depend on the pretreatment. Thermal pretreatment at temperatures up to 250°C has an enhancing effect on surface acid sites. The total surface acidity (Ho <4.8) and the concentration of strong acid sites peaked at 250°C. Also, as a result, the maximum catalyst activity was obtained with samples treated at this temperature. Acid pretreatment with 0.10 M HCl, 1.0 M H2SO4 or 1.0 M H3PO4, followed by thermal treatment at 250°C produced the best enhancement effect on the surface acidity and catalytic activity.

rac-(E,E)-N,N′-Bis(2-chloro­benzyl­idene)cyclo­hexane-1,2-di­amine

In the title racemic Schiff base ligand, C20H20Cl2N2, which was prepared by the condensation of 2-chlorobenzaldehyde and cyclohexane-1,2-diamine, the cyclohexane ring adopts a chair conformation and the dihedral angle between the aromatic rings of the 2-chlorophenyl substituent groups is 62.52 (8)°. In the structure, there are two short intramolecular methine C—H⋯Cl interactions [C⋯Cl = 3.066 (2) and 3.076 (3) Å], and in the crystal there are also weak intermolecular aromatic C—H⋯Cl [3.464 (3), 3.553 (3) and 3.600 (3) Å] and Cl⋯Cl [3.557 (3) and 3.891 (3) Å] contacts.

Synthesis and Characterization of CpFe(CO)(EPh3)SeSO2R (E═P, As, Sb)

Photolytic substitution reactions of the iron selenosulfonate complexes CpFe(CO) 2 SeSO 2 R with EPh 3 produces the monosubstituted complexes CpFe(CO)(EPh 3 )SeSO 2 R [E = P (a), As (b), Sb (c); R = C 6 H 5 (1), 4-CH 3 C 6 H4 (2), 4-CH3OC 6 H 4 (3)] in good yields. Complexes 1–3 were characterized by spectroscopic techniques and elemental analysis.

Selective Hydrogenation of Cinnamaldehyde Catalyzed by Ruthenium (II) Complexes Based on Azoimine Ligands

In this work, four Ru (II) complexes based on azoimine ligands were tested with respect to their catalytic behavior in the liquid phase hydrogenation of cinnamaldehyde. The introduction of a thiophenyl substitution in the azoimine ligand was found to enhance significantly the catalytic activity and selectivity of the Ru complex. The catalytic behavior of the most active complex in this work was studied with respect to the effect of the co-catalyst KOH, the Ru complex and the cinnamaldehyde (CALD) concentrations as well as with respect to the effect of the reaction temperature. KOH is needed to transform the Ru complex into a reactive form and the higher the KOH concentration in the system, the higher is the efficiency of the catalytic system. The order of this activation process with respect to KOH and with respect to the Ru complex was found to be one in both cases. With a CALD-to-Ru ratio of 84:1 at T=86 o C, pH2=4 bar and [KOH]= 5.82×10 -3 M, a complete conversion could be accomplished in only 90 minutes with selectivity to cinnamyl alcohol approaching 95%. Increasing the initial concentration of cinnamaldehyde has, under the reaction conditions investigated in this work, a negative effect on the rate of hydrogenation with an order decreasing with increased concentration from -1 to -3. Based on our results, an outer-sphere mechanism is ruled out to operate in this system.

Design, Synthesis, Characterization of Novel Ruthenium(II) Catalysts: Highly Efficient and Selective Hydrogenation of Cinnamaldehyde to (E)-3-Phenylprop-2-en-1-ol

In this contribution, two novel supported and non-supported ruthenium(II) complexes of type [RuCl2(dppme)(NN)] where [dppme is H2C=C(CH2PPh2)2 and NN is N1-(3-(trimethoxysilyl)propyl)ethane-1,2-diamine] were prepared. The NN co-ligand caused release of one of the dppme ligands from [RuCl2(dppme)2] precursor to yield complex 1. The process of substitution of dppme by NN was monitored by 31P{1H}-NMR. Taking advantage of the presence of trimethoxysilane group in the backbone of complex 1, polysiloxane xerogel counterpart, X1, was prepared via sol-gel immobilization using tetraethoxysilane as cross-linker. Both complexes 1 and X1 have been characterized via elemental analysis, CV and a number of spectroscopic techniques including FT-IR, 1H-, 13C-, and 31P-NMR, and mass spectrometry. Importantly, carbonyl selective hydrogenation was successfully accomplished under mild conditions using complex 1 as a homogenous catalyst and X1 as a heterogeneous catalyst, respectively.