PDF Downloads : Oriental Journal of Chemistry
From the slope of the data when the quantity of electricity was plotted against square root of time ( and ), the number of electrons (n) for processes I, II and III were found to be in ratio (3:2:1), suggesting that these processes are multi-electronic in nature while process IV or V is a singleelectron process. This result indicates that different electron transfer processes are involved between the ruthenium ion, phenanthrolyl and the anthracenyl groups [–].
Journal of Nanoscience and Nanotechnology
In an effort to develop new ruthenium(II) complexes, this work describes the design, synthesis and characterization of a ruthenium(II) functionalized phenanthroline complex with extended π-conjugation. The ligand were L1 (4,7-bis(2,3-dimethylacrylic acid)-1,10-phenanthroline), synthesized by a direct aromatic substitution reaction, and L2 (4,7-bis(trianthracenyl-2,3-dimethylacrylic acid)-1,10-phenanthroline), which was synthesized by the dehalogenation of halogenated aromatic compounds using a zero-valent palladium cross-catalyzed reaction in the absence of magnesium-diene complexes and/or cyclooctadienyl nickel (0) catalysts to generate a new carbon-carbon bond (C-C bond) polymerized hydrocarbon units. The ruthenium complex [RuL1L2(NCS)2] showed improved photophysical properties (red-shifted metal-to-ligand charge-transfer transition absorptions and enhanced molar extinction coefficients), luminescence and interesting electrochemical properties. Cyclic and square wave voltammetry revealed five major redox processes. The number of electron(s) transferred by the ruthenium complex was determined by chronocoulometry in each case. The results show that processes I, II and III are multi-electron transfer reactions while processes IV and V involved one-electron transfer reaction. The photophysical property of the complex makes it a promising candidate in the design of chemosensors and photosensitizers, while its redox-active nature makes the complex a potential mediator of electron transfer in photochemical processes.
All chemical and reagents were analytically pure and used without further purification. 4,7-Dibromo-1,10-phenanthroline was synthesized as described in the literature . 4,7-bis(2,3-dimethylacrylic acid)-1,10-phenanthroline and 4,7-bis(2,3-dimethylacrylic acidtrianthracenyl)- 1,10-phenanthroline were synthesized with slight modifications  (). All thin layer chromatography (TLC) analyses were done with aluminium sheet precoated with normal phase silica gel 60 F254 (Merck, 0.20 mm thickness) unless otherwise stated. The TLC plates were developed using any of the following solvent systems: Solvent system A: Dichloromethane-Methanol (9:1); Solvent system B: Dichloromethane-Methanol (7:3); Solvent system C: Dichloromethane- Benzene (3:7); Solvent system D: Chloroform-Methanol (1:1). Gel filtration was performed using Sephadex LH-20 previously swollen in specified solvent (s) prior to loading of extract onto the column (3.5 cm × 8.5 cm).