Dicopper(ii) tetrapyridyl complexes incorporated with ancillary ligands for effective water oxidation

Water oxidation catalysis of dicopper(ii) tetrapyridyl complexes under alkaline conditions was improved by diamine ligands.

The effect of alkyl chain tethers on the kinetics and mechanistic behaviour of bifunctional dinuclear platinum(ii) complexes bearing N,N′-dipyridylamine ligands

This study reports on non-classical dinuclear platinum(ii) complexes, with the ability to bind to DNA strands in a different manner from cisplatin and its analogues. This is an effort to design dinuclear Pt(ii) complexes that target DNA and are bifunctional.

[μ-N,N,N′,N′-Tetrakis(pyridin-2-ylmethyl)butane-1,4-diamine]bis[(dimethanol-κO)(perchlorato-κO)copper(II)] bis(perchlorate)

The binuclear cation of the title compound, [Cu2(ClO4)2(C28H32N6)(CH3OH)4](ClO4)2, is located on an inversion centre. The CuIIatom adopts a distorted octahedral coordination geometry due to the Jahn–Teller effect. The equatorial plane consists of one methanol molecule and three N atoms from theN,N,N′,N′-tetrakis(pyridin-2-ylmethyl)butane-1,4-diamine ligand. The Cu—N bond lengths are in the range 1.975 (3)–2.041 (2) Å and the Cu—O bond length is 2.008 (2) Å. The axial coordination sites of the CuIIatom are occupied by the O atoms of one methanol molecule and one perchlorate anion, with Cu—O bond lengths of 2.385 (3) and 2.565 (3) Å, respectively. In the crystal, the cations and the perchlorate anions are connectedviaO—H...O hydrogen bonds. In addition, weak C—H...O interactions stabilize the structure.

Platinum(ii) complexes with hybrid amine-imidazolin-2-imine ligands and their reactivity toward bio-molecules

Two new Pt(ii) complexes with imidazolin-2-imines as ancillary ligands were synthesized and characterized and their reactivity toward bio-molecules was tested.

Palladium(ii) complexes with highly basic imidazolin-2-imines and their reactivity toward small bio-molecules

Pd(ii) complexes with chelating imidazolin-2-imine ligands were synthesized, and the pK_a values and reactivity of these complexes were investigated.

Investigations of the binding of [Pt2(DTBPA)Cl2](II) and [Pt2(TPXA)Cl2](II) to DNA via various cross-linking modes

We have constructed models for a series of platinum-DNA adducts that represent the binding of two agents, [Pt₂(DTBPA)Cl₂](II) and [Pt₂(TPXA)Cl₂](II), to DNA via inter- and intra-strand cross-linking, and carried out molecular dynamics simulations and DNA conformational dynamics calculations. The effects of trans- and cis-configurations of the centers of these di-nuclear platinum agents, and of different bridging linkers, have been investigated on the conformational distortions of platinum-DNA adducts formed via inter- and intra-strand cross-links. The results demonstrate that the DNA conformational distortions for the various platinum-DNA adducts with differing cross-linking modes are greatly influenced by the difference between the platinum-platinum distance for the platinum agent and the platinum-bound N7–N7 distance for the DNA molecule, and by the flexibility of the bridging linkers in the platinum agent. However, the effects of trans/cis-configurations of the platinum-centers on the DNA conformational distortions in the platinum-DNA adducts depend on the inter- and intra-strand cross-linking modes. In addition, we discuss the relevance of DNA base motions, including opening, shift and roll, to the changes in the parameters of the DNA major and minor grooves caused by binding of the platinum agent.

Substitution behaviour of novel dinuclear Pt(II) complexes with bio-relevant nucleophiles

The novel dinuclear Pt(II) complexes [{trans-Pt(NH(3))(2)Cl}(2)(μ-pyrazine)](ClO(4))(2) (Pt1), [{trans-Pt(NH(3))(2)Cl}(2)(μ-4,4'-bipyridyl)](ClO(4))(2)·DMF (Pt2), and [{trans-Pt(NH(3))(2)Cl}(2)(μ-1,2-bis(4-pyridyl)ethane)](ClO(4))(2) (Pt3), were synthesized. Acid-base titrations, and temperature and concentration dependent kinetic measurements of the reactions with biologically relevant ligands such as thiourea (Tu), glutathione (GSH) and guanosine-5'-monophosphate (5'-GMP) were studied at pH 2.5 and 7.2. The reactions were followed under pseudo-first-order conditions by stopped-flow and UV-vis spectrophotometry. (1)H NMR spectroscopy was used to follow the substitution of chloride in the complex [{trans-Pt(NH(3))(2)Cl}(2)(μ-4,4'-bipyridyl)](ClO(4))(2)·DMF by guanosine-5'-monophosphate (5'-GMP) under second-order conditions. The results indicate that the bridging ligand has an influence on the reactivity of the complexes towards nucleophiles. The order of reactivity of the investigated complexes is Pt1 > Pt2 > Pt3.