Biological activity of bis(pyrazolylpyridine) and terpiridine Os(ii) complexes in the presence of biocompatible ionic liquids

New bis(pyrazolylpyridine) Os(ii) complexes showing possible biological activity with diverse modes of action in the presence of biocompatible ionic liquids as non-toxic cosolvents for sparingly soluble complexes.

"Chemistry-on-the-complex": functional RuII polypyridyl-type sensitizers as divergent building blocks

Ruthenium polypyridyl type complexes are potent photoactive compounds, and have found - among others - a broad range of important applications in the fields of biomedical diagnosis and phototherapy, energy conversion schemes such as dye-sensitized solar cells (DSSCs) and molecular assemblies for tailored photo-initiated processes. In this regard, the linkage of RuII polypyridyl-type complexes with specific functional moieties is highly desirable to enhance their inherent photophysical properties, e.g., with a targeting function to achieve cell selectivity, or with a dye or redox-active subunits for energy- and electron-transfer. However, the classical approach of performing ligand syntheses first and the formation of Ru complexes in the last steps imposes synthetic limitations with regard to tolerating functional groups or moieties as well as requiring lengthy convergent routes. Alternatively, the diversification of Ru complexes after coordination (termed "chemistry-on-the-complex") provides an elegant complementary approach. In addition to the Click chemistry concept, the rapidly developing synthesis and purification methodologies permit the preparation of Ru conjugates via amidation, alkylation and cross-coupling reactions. In this regard, recent developments in chromatography shifted the limits of purification, e.g., by using new commercialized surface-modified silica gels and automated instrumentation. This review provides detailed insights into applying the "chemistry-on-the-complex" concept, which is believed to stimulate the modular preparation of unpreceded molecular assemblies as well as functional materials based on Ru-based building blocks, including combinatorial approaches.

Photochemical property of a Ru(ii) compound based on 3-(2-pyridyl)pyrazole and 2,2′-bipyridine for ablation of cancer cells

Ru(ii) compounds are potential candidates for photodynamic therapy (PDT).

Pyridinium [2,6-bis-(5-phenyl-1H-pyrazol-3-yl-κN)pyridine-κN]tetra-nitrato-κO,O';κO-samarium(III) pyridine monosolvate

In the title compound, (C₅H₆N)[Sm(NO₃)₄(C₂₃H₁₇N₅)]·C₅H₅N, the Sm^III atom is ten-coordinated by the N,N′,N′′-tridentate bis­(pyrazole) ligand and seven O atoms from four nitrate anions (three bidentate and one monodentate). The dihedral angles between the central pyridine ring and adjacent pyrazole rings in the ligand are 1.3 (2) and 3.2 (2)°; the dihedral angles between the pyrazole rings and their pendant phenyl rings are 42.0 (3) and 16.1 (2)°. The conformation of the anionic complex ion is supported by an intra­molecular N—H⋯O hydrogen bond. In the crystal, inversion dimers linked by pairs of N—H⋯O hydrogen bonds occur. The pyridinium cation forms an N—H⋯N hydrogen bond.