gamma-Diimine palladium(II) based complexes mediated polymerization of methyl methacrylate

The synthesis of new palladium(II) complexes of the type [Pd(A-N=C-ph-C=N-A) Cl-2] (4a-e) (A = cyclohexyl (a), 2-isoprpropyl (b), pyrenyl (c), naphthyl (d), and 2,6-diisopropyl (e)) is described. The isolated gamma-diimine ligands and their corresponding palladium(II) complexes were characterized by their physical properties, elemental analysis, H-1 NMR=, C-13 NMR, and infrared spectroscopy. The palladium(II) complexes (4a-e) were employed successfully as catalysts for atom transfer radical polymerization (ATRP) of methyl methacrylate (MMA) in the presence of ethyl-2-bromoisobutyrate (EBIB) as initiator at 90 degrees C. Polymerization with these catalyst systems afforded polymers with low molecular weight distribution (M-w/M-n) and syndio-rich atactic poly (MMA) with relatively higher [rr] diads. (C) 2013 Production and hosting by Elsevier B.V.Peer reviewe

Novel palladium(II) and platinum(II) complexes with a fluoropiperazinyl based ligand exhibiting high cytotoxicity and anticancer activity in vitro

cis-Dichloro-palladium(II) and cis-dichloro-platinum(II) complexes (2, 4) of the general formula [M(N-N)Cl2] (M=Pd(II) and Pt(II), N-N= 1,2-diamino-4-fluoro-5-(4-methyl-1-piperazinyl) benzene, (DFMPB)) and the dicationic palladium(II) complex [Pd(N-N)(CH3CN)2](BF4)2 (3) have been prepared and characterized by elemental analysis, 1H-NMR-, mass spectroscopy, and IR spectroscopy. The cytotoxic effect of these complexes against MDA-231 and MCF-7 human breast cancer cell lines and K562 human leukemia cell line has been studied. The influence was dose dependent and varies with cell type. The palladium(II) complex (2) showed superior cytotoxic effect compared with the corresponding platinum(II) complex and the standard, cisplatin, when tested against all the above cell lines. 2016 Kayed A. Abu-Safieh et al.Scopu

Synthesis, characterization and antibacterial activity studies of new 2‑pyrral‑L‑amino acid Schif base palladium (II) complexes.

Three new 2-pyrral amino acid Schif base palladium (II) complexes were synthesized, characterized and their activity against six bacterial species was investigated. The ligands: Potassium 2-pyrrolidine-L-methioninate (L1), Potassium 2-pyrrolidine-L-histidinate (L2) and Potassium 2-pyrrolidine-L-tryptophanate (L3) were synthesized and reacted with dichloro(1,5- cyclooctadiene)palladium(II) to form new palladium (II) complexes C1, C2 and C3, respectively. 1 NMR, FTIR, UV–Vis,elemental analysis and conductivity measurements were used to characterize the products. The antibacterial activities of the compounds were evaluated against Gram-positive Staphylococcus aureus (S. aureus, ATCC 25923), methicillin-resistant Staphylococcus aureus (MRSA, ATCC 33591), Staphylococcus epidermidis (S. epidermidis, ATCC 12228) and Streptococcus pyogenes (S. pyogenes, ATCC 19615) and, gram-negative Pseudomonas aeruginosa (P. aeruginosa, ATCC 27853) and Klebsiella pneumoniae (K. pneumoniae, ATCC 13883) using the agar well difusion assay and microtitre plate serial dilution method. The palladium complexes were active against the selected bacteria with the imidazole ring containing complex C2 and indole heterocyclic ring containing complex C3 showing the highest activity

Iron and cobalt salicylaldimine complexes as catalysts for epoxide and carbon dioxide coupling: effects of substituents on catalytic activity

The synthesis and characterization of substituted ONNO-donor salen-type Schiff base complexes of general formula [MIII(L)Cl] (L�=�Schiff base ligand, M�=�Fe, Co) is reported. The complexes have been applied as catalysts for the coupling of carbon dioxide and styrene oxide in the presence of tetrabutylammonium bromide as a co-catalyst. The reactions were carried out under relatively low-pressure and solvent-free conditions. The effects of the metal center, ligands, and various substituents on the peripheral sites of the ligand on the coupling reaction were investigated. The catalyst systems were found to be selective for the coupling of CO2 and styrene oxide, resulting in cyclic styrene carbonate. The cobalt(III) complex with no substituents on the ligand showed higher activity (TON�=�1297) than the corresponding iron(III) complex (TON�=�814); however, the iron(III)-based catalysts bearing electron-withdrawing substituents on the salen ligands (NEt3, TON�=�1732) showed the highest catalytic activity under similar reaction conditions. The activity of one of the cobalt(III) complexes toward the coupling of 1-butene oxide, cyclohexene oxide and propylene oxide with CO2 was evaluated, revealing a notable activity for the coupling of 1-butene oxide.Scopu

Novel benzo-15-crown-5 functionalized α-olefin/CO terpolymers for membrane applications

The synthesis of a benzo-15-crown-5 functionalized α-olefin (4′-(undec-10-enylcarboxylate)benzo-15-crown-5, 5) and its terpolymerization with carbon monoxide and various α-olefins are described. A decline of the glass transition temperatures (Tg) of the corresponding terpolymers was observed upon incorporating compound 5 into the polymer main chain. Ion-selective membranes were prepared by encapsulating the benzo-15-crown-5 functionalized α-olefin/CO terpolymers in a microporous polyethylene support. Preliminary ion-transport experiments demonstrate the ability of these novel crown ether substituted polyketones to transport NaClO4 across the membranes. Adjusting the polarity of the polyketones via the length of the olefinic side chain offers a means to control the ion-permeation-rates