Photoinduced electron transfer reactions between ruthenium(II) polypyridyl complexes and aromatic thiolate ions in micellar medium

The present work represents an attempt to prepare five ruthenium(II) or Ru(II) polypyridyl complexes (1a-1e) by a one-pot solvothermal synthesis in a manner that is greener than that in which the complexes are conventionally synthesised. Here,target compounds in very good yields have been achieved. The photochemical reduction of five different *[Ru(NN)3]2+ (triplet excited) species (where NN (a-e) = 2,2 -bipyridine,4,4 -dimethyl-2,2 -bipyridine,4,4 -di-tert-butyl-2,2 -bipyridine,1,10-phenanthroline and 4,7-diphenyl-1,10-phenanthroline) with various aromatic thiolate anions (ArS-) with different electronic and steric properties was studied in aqueous and anionic micellar (sodium dodecyl sulphate,SDS) solutions by the luminescence-quenching technique. The quenching rate constants,kq,for each photoredox reaction were determined by Stern-Volmer analysis. The results exhibit an interesting trend for all the quenchers depending on the type of quencher and medium used. Although the incremental increase in the SDS concentration initially hampered the rate,further increasing SDS did not alter the quenching rate. In very few cases,micellar catalysis was observed,which may be attributed to the hydrophobic interaction that overcomes the electrostatic repulsion.