Influence of polystyrenesulfonate on electron transfer quenching of ruthenium trisbipyridine luminescence by viologens: non-covalent assembly and covalent tethering of the ruthenium complex

Abstract

A new copolymer (RuB-PSS) of ruthenium(II)bis-(2,2 0 -bipyridine)(4-vinyl 2,2 0 -bipyridine) and styrene sulfonate was prepared which tethers the ruthenium chromophore directly to the polymer backbone. The photophysical properties of the copolymer, and its luminescence quenching by viologens, were compared with those of ruthenium (II) influence forward-and reverse-electron transfer reactions depending on the charge and hydrophobicity of the reactants. In the context of small molecule binding, we find that PSS provides a tenable model for DNA.

Saccharide-induced modulation of photoluminescence lifetime in microgels

“…53 However, [Ru(bpy) 3 ] 2+ covalently attached to a microgel, does not show significant sensitivity to the presence of oxygen (Table S1 and Fig. 53 However, [Ru(bpy) 3 ] 2+ covalently attached to a microgel, does not show significant sensitivity to the presence of oxygen (Table S1 and Fig.…”

“…54,55 The emission lifetime is sensitive to solvent polarity and viscosity. Thus, the confined microenvironment 53 In the case of PBA-modified microgels, the viscosity effect could be enhanced because the microgels are less swollen, compared to the ones without PBA. 7.…”

“…56 To explain the significant changes in the luminescence of [Ru(bpy) 3 ] 2+ bound to the PBA-modified microgels, several factors have to be considered, as sketched in Fig. 53 However, the lifetime of [Ru(bpy) 3 ] 2+ in PSS solutions or covalently attached to PSS increased only up to 600 ns approximately. Firstly, the gel environment strongly contributes to the decrease of the mobility of [Ru(bpy) 3 ] 2+ .…”

Supramolecular Organization of Magnesium Octa[(4’-benzo- 15-crown-5)oxy]phthalocyaninate in Aqueous Solutions of Polyelectrolytes and Surfactants: Analysis by Spectral Methods

“…Therefore, in the absence of salt, PSS chains are essentially expanded and swollen. [28,29] With increase of ionic strength, PSS molecules 'shrink' to a more compact configuration due to a shielding effect of salt cations accompanied by decrease [30] of hydrodynamic radius (R H ) of the polyelectrolyte coil, [31,32] 'ejecting' a portion of solvent (water) and probably forming nonpolar regions. In combination with the formation of a supramolecular guest-host complex between Na + and a cavity formed by ethylene units and oxygen atoms of the crown ether in Mgcr 8 Pc, the generation of nonpolar (hydrophobic) regions in PSS provides an increase of the absorbance of the Q-band at l ~ 680 nm (spectral region of Pc monomer) even in the presence of single PSS.…”

Rotaxanes and pseudorotaxanes with threads containing viologen units

“…[50][51][52][53] Moreover viologens find a variety of applications due to their redox properties, they are promising for design of molecular machines and switches and construction of new materials, the rapid development of viologen chemistry has its reflection in many reports concerning these compounds. [54][55][56][57][58][59] In the paper rotaxanes and pseudorotaxanes with threads containing viologen units are described. They are divided into two classes: those containing crown ether as a ring, presented in the first part, and those containing the crown-based cryptand as a ring, shown in the second part.…”