Halogeno Ligand‐Substitution Reactions of Ruthenium Complexes Bearing Ethylbis(2‐pyridylmethyl)amine to Synthesize New Complexes

Halogeno ligand‐substitution reactions of trihalogenoruthenium(III) complexes bearing ethylbis(2‐pyridylmethyl)amine (ebpma), fac ‐[Ru III X 3 (ebpma)] (X = Cl; [ 1 Cl ], Br; [ 1 Br ]) were investigated to derive various complexes of desired properties and reactivities. The number of substitution of halogeno ligand ( n ) was controlled. Through the reaction of [ 1 Cl ] with sulfuric acid in acetonitrile, a mono‐substituted acetonitrileruthenium(III) complex fac ‐[Ru III Cl 2 (NCCH 3 )(ebpma)] + ( n = 1, [ 2 ] + ) was obtained, while the one‐electron reduction reactions of the Ru(III) center of [ 1 X ] in a hydrophobic solution or in a water‐containing solution with Lewis base afforded fac ‐[Ru II X(L) 2 (ebpma)] + ( n = 2, L = CH 3 CN; [ 3 X ] + , C 5 H 5 N; [ 5 X ] + ) or fac ‐[Ru II (L) 3 (ebpma)] 2+ ( n = 3, L = CH 3 CN; [ 4 ] 2+ , C 5 H 5 N; [ 6 ] 2+ , NH 3 ; [ 7 ] 2+ ), respectively. The number of dissociating chlorido and the kind of incoming ligand could be controlled as expected in these synthetic strategies. The structures, redox behaviors and spectroscopic properties of the obtained ruthenium complexes were studied.