Redox-triggered reversible modulation of intense near-infrared and visible absorption using a paddlewheel-type diruthenium(III) complex.

A new paddlewheel-type diruthenium complex with 2-amino-3-(trifluoromethyl)pyridine (amtfmp) [Ru2(amtfmp)4Cl2] ([1]), which shows intense and characteristic near-infrared (NIR) and visible absorption, has been developed and structurally characterized by single crystal X-ray diffraction (SCXRD) analyses. This complex exhibits reversible and dramatic NIR and visible electrochromic behavior from deep-blue ([1]) to pink ([1]-) due to the ON-OFF switching of its characteristic ligand-to-metal charge transfer (LMCT) and d-d absorption bands in response to an external voltage or chemical reagent such as decamethylcobaltocene (CoCp*2). The one-electron reduced species of [1], i.

Paddlewheel-type diruthenium(iii,iii) tetrakis(2-aminopyridinate) complexes with NIR absorption features: combined experimental and theoretical study.

The reactions of [Ru(OCCH)Cl] with 2-aminopyridine (Hamp) and 2-amino-4-methylpyridine (Hammp) afforded two novel Ru complexes, [Ru(amp)Cl] (1) and [Ru(ammp)Cl] (2), respectively. Single crystal X-ray diffraction analyses revealed that 1 and 2 adopted typical paddlewheel-type structures, where the Ru units are coordinated with four aminopyridinate ligands with a cis-2:2 arrangement at the equatorial positions and two chloride ligands at the axial positions. The stabilities of 1 and 2 were supported by unrestricted density functional theory (uDFT) calculations.