Stable neutral radicals based on the polyazaacene skeleton that exhibit high electrochemical amphotericity

Cytotoxic (cis,cis-1,3,5-triaminocyclohexane)ruthenium(II)-diphosphine complexes; evidence for covalent binding and intercalation with DNA

We report cytotoxic ruthenium(ii) complexes of the general formula [RuCl(cis-tach)(diphosphine)]+ (cis-tach = cis-cis-1,3,5-triaminocyclohexane) that have been characterised by 1H, 13C and 31P{1H} NMR spectroscopy, mass spectrometry, X-ray crystallography and elemental analysis. The kinetics of aquation and stability of the active species have been studied, showing that the chlorido ligand is substituted by water at 298 K with first order rate constants of 10-2-10-3 s-1, ideal for potential clinical use as anti-tumour agents. Strong interactions with biologically relevant duplex and quadruplex DNA models correlate with the activity observed with A549, A2780 and 293T cell lines, and the degree of activity was found to be sensitive to the chelating diphosphine ligand. A label-free ptychographic cell imaging technique recorded cell death processes over 4 days. The Ru(ii) cis-tach diphosphine complexes exhibit anti-proliferative effects, in some cases outperforming cisplatin and other cytotoxic ruthenium complexes.

Synthesis and properties of the 3-tert-butyl-7-trifluoromethyl-1,4-dihydro-1-phenyl-1,2,4-benzotriazin-4-yl radical

The novel 3-tert-benzotriazinyl radical carrying the trifluoromethyl group was synthesized and exhibited pure 1D ferromagnetic interaction in the columnar structure.

A new route to the synthesis of near-infrared absorbing pyrazinopyrazine bridged dyes with intramolecular charge transfer character

A simple and versatile procedure was developed for the synthesis of pyrazino[2,3-b]thieno[3,4-e]pyrazine derivatives with intramolecular charge transfer character. The compounds obtained exhibited a narrower band gap compared to those with one pyrazine bridge.