Syntheses of ruthenium complexes bearing unsymmetric tridentate Ethyl(2-pyridylmethyl)aminoacetate

[Display omitted] •Unsymmetric ethyl(2-pyridylmethyl)aminoacetate has been designed and synthesized as a tridentate supporting ligand.•An aquadichloridoruthenium(III) and a series of ruthenium complexes have been synthesized.•Electronic structures of complexes can be changed depending on the nature of coligands. Unsymmetric ethyl(2-pyridylmethyl)aminoacetate (epmaa-) is consisted by the central ethylamine connected with pyridyl and carboxy groups by methylene arms and coordinates to a metal center as a tridentate ligand. An aquadichlorido complex of ruthenium(III) bearing epmaa-, fac-[RuCl2(OH2)(epmaa)] ([1]), has been synthesized using the Ru-blue solution of RuCl3·nH2O in EtOH-H2O, and is a useful starting material for syntheses of ruthenium complexes. Four fac-[RuCl2(X)(epmaa)]m-type complexes (X = Cl; m = -1, CH3CN, dmso and NO; m = 0) were synthesized from [1] with simple manners under ambient conditions. Herein structures and properties of these complexes are discussed.