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

Palladium(II) complexes incorporating phenylazo arylmethine ancillary ligands: Synthesis, spectral and antitumor activity

A series of azoimine palladium(II) complexes of the general type cis-[PdCl2L] (1–6) {L = PhNNC(COMe)NC6H4X, where X = H (L1), CH3 (L2), Cl (L3), Br (L4), naphthyl (L5) and OMe (L6)} have been prepared by the reaction of cis-[PdCl2(NCPh)2] and the ligands (L) in acetone at room temperature. These complexes have been characterized by spectroscopic (IR-, UV–Vis and NMR) and electrochemical techniques. In addition, their biological activity has been studied via MTT test and by detecting the inhibition of clonal growth in three tumor cell lines, namely T47D human ductal breast carcinoma, MTLn3 murine mammary adenocarcinoma and RAW 264.7 murine leukemic monocyte macrophage. All of the tested palladium(II) complexes showed a noticeable antitumor activity. Complexes 4 and 5 showed a higher cytotoxic activity against human T47D breast tumor cell line than cisplatin, while comparable activity was observed against murine mammary MTLn3 adenocarcinoma cell line

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