Structure and characterization of platinum(II) and platinum(IV) complexes with protonated nucleobase ligands

Providing evidence for the requirements to achieve supramolecular materials based on metal–nucleobase entities

This article evaluates the strategy to design supramolecular metal–organic frameworks using metal–nucleobase entities as building units.

Preparative separation of the polar part from the rhizomes of Anemarrhena asphodeloides using a hydrophilic C18 stationary phase

The goal of this study was to develop a method that utilized a hydrophilic C18 stationary phase in the preparative high performance liquid chromatography to isolate the polar part from the rhizomes of Anemarrhena asphodeloides. The results showed that an initial mobile phase of pure water for the separation could greatly increase the retention and solubility of the polar compounds at the preparative scale. Introducing polar groups on the surface of the hydrophilic C18 column together with the use of optimized mobile phase compositions improved the column separation selectivity for polar compounds. Eleven previously undescribed compounds in Anemarrhena asphodeloides were obtained, indicating that the method developed in this study would facilitate the purification and separation of the polar part of traditional Chinese medicines.

Multivariant Crystallization of Tetraplatin Precursors from Solutions Containing 1,2-C6H10(NH3)2 2+ and [PtCl6]2– Ions

Seven new phases containing hexachloroplatinate [PtCl6]2− and trans-1,2-dl-diammoniumcyclohexane 1,2-C6H10NH322+ ions were obtained by crystallization from solutions with minor variation of synthesis conditions. The compounds can be applied as precursors for the synthesis of effective anticancer drug tetraplatin ([PtC6H10(NH2)2Cl4]). The phase diversity was achieved by alterations including solvent acidity, crystallization rate, temperature, type of solvent, and the reagents ratio. The compounds were characterized by chemical and thermal analysis, IR, and 1H NMR spectroscopy. Crystal structures of the five compounds were determined by X-ray powder diffraction technique. The phases have ionic structures involving H2O, HCl molecules, or Cl− ions as supplementary species in the lattices. It helps to arrange some frames additionally interconnected by hydrogen bonds between ions and solvent molecules. It was suggested that crystal lattices adapted associated particles presented in solutions. It results in observed variety of the crystal structures. Besides the basic interest the obtained results are important for tetraplatin synthesis control.

Dichlorido(9-methyladenine-κN7)(η5-pentamethylcyclopentadienyl)iridium(III) dichloromethane solvate

In the title complex, [Ir(C₁₀H₁₅)Cl₂(C₆H₇N₅)]·CH₂Cl₂ or [Ir(η⁵-C₅Me₅)Cl₂(9-MeAde-κN⁷)]·CH₂Cl₂ (9-MeAde = 9-methyl­adenine), the coordination geometry of the Ir^III atom approximates to a three-legged piano stool. The 9-methyl­adenine ligand is coordinated in a monodentate fashion to the Ir centre through its N-7 atom. The crystal structure contains centrosymmetric pairs of mol­ecules, inter­acting through two N—H⋯N hydrogen bonds. An intra­molecular N—H⋯Cl hydrogen bond is formed between the H atom of an NH₂ group and a chlorido ligand. Further short intra- and inter­molecular C—H⋯Cl contacts are observed.