The electronic relaxation of gadolinium complexes used as MRI contrast agents was studied theoretically by following the short time evolution of zero-field-splitting parameters. The statistical analysis of ab initio molecular dynamics trajectories provided a clear separation between static and transient contributions to the zero-field-splitting. For the latter, the correlation time was estimate...

In an effort to obtain synthetic analogues of water-oxidizing complex (WOC) of photosystem II (PS II) of plant photosynthesis, a Schiff base manganese and a cobalt complex, employing Niten, a SALEN type ligand, have been prepared. Cyclic and square wave voltammetric measurements have been performed to assess their redox characteristics. Both complexes undergo several reduction processes in cath...

A selected solid complex of the Schiff base ligand derived from Glutaric anhydride with Cu(II) ion was synthesized and characterized by FT-IR, Electronic, ESR Spectral Analyses, Magnetic susceptibility and Molar Conductance Measurements. The disappearance of ν(O-H) hydroxyl band of the phenolic and the lowering shift of the stretching frequency of the ν(CH=N) azomethine band in the ligand after...

The syntheses and characterization of tetranuclear Ni complexes [(L2)Ni4][C104]4 (3) and [(L2)Ni4(NCS)4] (4) of a 40-membered macrocyclic octaamine-tetrathiophenolate ligand (L2)4are described. Single-crystal X-ray structure analysis of 4 reveals well-separated molecules of the tetranuclear isothiocyanate complex [(L2) N i 4(NCS)4]. The four Ni" centers are arranged in binuclear [N2N i(^2-SR)2N...

Container-molecules are attractive to chemists due to their unique structural characteristics comparable to enzymes and receptors in nature. We report here a family of artificial self-assembled macrocyclic containers that feature induced-fit transformations in response to different anionic guests. Five metal-organic macrocycles with empirical formula of MnL2n (M=Metal; L=Ligand; n=3, 4, 5, 6, 7...

The reaction of [Ag(MeCN)(4)]ClO(4) with N,N,N',N'-tetra(diphenylphosphanylmethyl)ethylenediamine (dppeda) in CH(2)Cl(2)/MeOH afforded an unexpected cationic binuclear complex [Ag(2)(L(1))(2)(η,η-μ-ClO(4))(2)](ClO(4))(2) (L(1) = N,N'-bis(diphenylphosphanylmethyl)-3H-4,5-dihydroimidazole-1-ium) (1). Compound 1 was also prepared in high yield from reactions of [Ag(MeCN)(4)]ClO(4) with N,N'-bis(di...

The title dinuclear complex, [Ag2(CN)3(C9H8N2)2], may be considered as an Ag(II) compound with the corresponding metal site coordinated by two bidentate quinolin-8-amine mol-ecules, one cyanide group and one dicyanidoargentate(I) anion, [Ag(CN)2](-). Since this latter ligand contains an Ag(I) atom, the complex should be a class 1 or class 2 mixed-valence compound, according to the Robin-Day cla...

A water-soluble coordination cage was obtained by reaction of Pd(NO3)2 with a 1,3-di(pyridin-3-yl)benzene ligand featuring short PEG chain. The cavity the metal-organic contains one nitrate anion, which is readily replaced chloride. apparent association constant for chloride binding in buffered aqueous solution Ka=1.8(±0.1)×105 M−1. This value significantly higher than what has been reported ot...

The title compound, [Ag(C(8)H(5)O(4))(C(6)H(5)NO(2))](n), contains one Ag(I) atom, one phthalate ligand and one isonicotinic acid mol-ecule in the asymmetric unit. Each Ag atom is three-coordinated in a T-shaped geometry by two O atoms and one N atom from one phthalate ligand and two isonicotinic acid ligands. The isonicotinic acid ligand bridges two Ag atoms, forming a one-dimensional chain. A...

A new macrocyclic Schiff base complexes were prepared in the presence of lanthanide metal ion[La(III), Ce(III) and Gd(III)] by the reaction of 2,6 – diamino pyridine, benzoyl aceton and metal ion as template effect in the molar ratio of 2: 2: 1 respectively. The lanthanide metal complexes were characterized and investigated by using; 1 HNMR, FTIR, UV/Visible spectroscopy, Elemental analysis (C....