Complexes C1 C4 Research Articles

Four mononuclear platinum(II) complexes: synthesis, DNA/BSA binding, DNA cleavage and cytotoxicity.

Four new platinum(II) complexes: PtII L1·H2O (C1, H2 L1=C20H16N2O2), PtII L2Cl2 (C2, L2=C22H16N2O2), PtII L3Cl2·H2O (C3, L3=C20H16N2), PtII L4Cl2·0.4H2O (C4, L4=C18H14N4) have been synthesized and characterized by using various physico-chemical techniques. The binding interaction of the four platinum(II) complexes C1-C4 with calf thymus (CT)-DNA has been investigated by UV-Vis and fluorescence emission spectrometry. The apparent binding constant (K app) values follow the order: C3>C1>C2>C4. In addition, fluorescence spectrometry of bovine serum albumin (BSA) with the four platinum(II) complexes C1-C4 showed that the quenching mechanism might be a static quenching procedure. For C1-C4, the number of binding sites was about one for BSA and the binding constants follow the order: C3 (7.08×105M-1)>C1 (2.82×105M-1)>C2 (0.85×105M-1)>C4 (0.15×105M-1). With the single condition change such as absence of an external agent, the DNA cleavage abilities of C3 exhibit remarkable changes. In addition, the cytotoxicity of C3 in vitro on tumor cells lines (MCF-7, HepG2 and HT29) were examined by MTT and showed better antitumor effects on the tested cells.

Novel cationic dinuclear η3-methallylpalladium complexes containing N,N′-donor bridging ligands: Synthesis, characterization and crystal structure

A series of bifunctional ligands of the type, 1,4-{(2-C5H4N)RC = N}2-C6H4 [R = H (L1), Me (L2)], 1,4-{(2-C5H4N)HCN}2-(C6H4)2 [L3] and 1,4-{(2-C5H4N)HCN}2-C2H4 [L4] were synthesized and fully characterized by IR, 1H NMR and 13C NMR spectroscopy. These ligands react with Pd(dba)2 in the presence of the salt methallyloxytris(dimethylamino)phosphonium hexafluorophosphate [C4H7OP(NMe2)3]+PF6− to give the novel cationic dinuclear η3-methallylpalladium complexes C1C4 in high yields. All new complexes C1C4 have been characterized by CHN analyses, 1H, 13C, 31P NMR and IR spectroscopy. The X-ray crystal structure of complex C1 has been determined.

Part XXIII. Synthesis and characterization of platinum(IV) complexes with O,O′-dialkyl esters of (S,S)-ethylenediamine-N,N′-di-2-(3-methyl)butanoic acid and bromido ligands. Antimicrobial, antibiofilm and antioxidant screening

Four new platinum(IV) complexes C1–C4 of general formula [PtBr4(R2-S,S-eddv)], (R=ethyl, propyl, butyl and pentyl; S,S-eddv=(S,S)--ethylenediamine-N,N′-di-2-(3-methyl)butanoate) have been synthesized and characterized by microanalysis, infrared, 1H and 13C NMR spectroscopy. In vitro antimicrobial activity for these and [PtBr4(R2-S,S-eddp)] complexes (S,S-eddp=(S,S)-ethylenediamine-N,N′-di-2-propanoate) has been investigated. The antibacterial activity was tested against 16 strains of bacteria determining the minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) using microdilution method. In general, platinum(IV) complexes manifested moderate activity against the Gram positive bacteria and low activity against the Gram negative bacteria. The complexes showed weak antioxidative properties tested by two methods (DPPH and reducing power assay).

Stereospecific ligands and their complexes. XX. Synthesis, characterization and antimicrobial activity of palladium(II) complexes with some alkyl esters of ethylenediamine-N,N′-di-S,S-(2,2′-dibenzyl)acetic acid

Four new palladium(II) complexes of general formula [PdCl2(R2-S,S-eddba)] (R=ethyl, n-propyl, n-butyl and n-pentyl; S,S-eddba=ethylenediamine-N,N′-di-S,S-(2,2′-dibenzyl)acetate) have been synthesized and characterized by microanalysis, infrared, 1H and 13C NMR spectroscopy.In vitro antimicrobial activity for ligands L1–L4 general formula R2-S,S-eddba and complexes C1–C4 was investigated.

Synthesis, characterization and fluorescent properties of 5-(aryliminomethyl)quinaldine-8-ol derivatives and their trinuclear zinc complexes

A series of 5-[1-(arylimino)methyl]quinaldine-8-ol derivatives L1–L5 and their trinuclear zinc(II) complexes (C1–C5) were synthesized. The compounds L1–L5 were fully characterized by the FT-IR spectra, NMR measurement and elemental analysis, meanwhile the zinc complexes C1–C5 were characterized by the FT-IR spectra and elemental analysis as well as the single crystal X-ray diffraction of a representative complex C3, which revealed a trinuclear zinc complex bearing six organic ligands. The fluorescent properties of both organic compounds and the zinc complexes have been carefully investigated by the UV–Vis absorption in various solvents, indicating the significant influences of the solvents and also double exponential decays.

Nickel(II) Complexes with Three-Dimensional Geometry α-Diimine Ligands: Synthesis and Catalytic Activity toward Copolymerization of Norbornene

A series of three-dimensional geometry 9,10-dihydro-9,10-ethanoanthracene-11,12-diimines (L1–L4) and their nickel(II) dibromide complexes (C1–C4) were synthesized and characterized. The nickel complexes C1–C4, with three-dimensional geometry, exhibited very high activities for norbornene (NB) homopolymerization with only B(C6F5)3 as cocatalyst,: for C2 even up to 5.53 × 107 g of polymer/((mol of Ni) h). To investigate the activation of polar monomer, complexes C2 and C3 were selected for copolymerization of NB and 5-norbornene-2-yl acetate (NB-OCOMe) in relatively high activities (1.6–5.8 × 105g of polymer/((mol of Ni) h)) and high molecular weights ((0.2–2.8) × 105 g/mol) as well as narrow molecular weight distributions (MWD < 2 for all polymers) depending on the variation of feed ratios. The reactivity ratios of the NB and NB-OCOMe monomers for C2/B(C6F5)3 system by the Kelen–Tudos method were determined to be rNB-OCOMe = 0.05 and rNB = 6.72, respectively. Moreover, the mechanism of polymerization catal...

Binuclear Pd-methyl complexes of N,N′-{1, n}-alkanediyl-bis(pyridinyl-2-methanimine) ligands (n = 5, 8, 9, 10 and 12): Evaluation as catalysts precursors for phenylacetylene polymerization

A series of bifunctional ligands of the type N,N′-{1, n}-alkanediyl-bis(pyridinyl-2-methanimine) {n = 5, 8, 9, 10, 12}(L1–L5) were synthesized and fully characterized by IR, 1H NMR, and 13C NMR spectroscopy. Binuclear palladium-methylchloride complexes C1–C5 were formed by reacting the ligands with [(COD)Pd(CH3)Cl]. The formed complexes were fully characterized by IR, 1H NMR, 13C NMR, spectroscopy, electrospray ionization mass spectrometry and elemental analysis. The synthesized complexes were evaluated as catalyst precursors for phenylacetylene polymerization after activation with AgBF4, AgBPh4 and NaB(Arf)4 (Sodium tetrakis[(3.5-trifluoromethyl)phenyl]borate) under various reaction conditions (solvent ratio, catalyst type, monomer/catalyst ratio, reaction time and nature of counterion). The cationic palladium-methyl catalyst precursors C1a–C5a were found to be active catalysts for phenylacetylene polymerization. The obtained polyphenylacetylene were analyzed by IR, 1H NMR and 13C NMR spectroscopy and gel permeation chromatography (GPC) and found to be largely cis-transoidal in nature.