LAUSR

Abstract Cis-[Ru(bpy)2(OH2)2](OTf)2 (1·(OTf)2; OTf− = CF3SO3−) was reacted with 2-picolinamide (H2pia) in EtOH to form bis-heteroleptic complex [Ru(bpy)2(H2pia)]X2 (2·X2; X− = OTf− or Cl−). Crystal structures of 2·X2 revealed that H2pia was coordinated to Ru(II) through N of pyridyl group and O of amide group to form the N,O-coordination, and acted as a neutral ligand. Bond distances around the amide group and 1H NMR study for 22+ suggested that π-electron on the carbonyl group was delocalized to the whole amide group. Adding F− to the acetonitrile solution of 2·(OTf)2 changed the red solution to dark-red due to the transportation of π-electron on the amide group by the bound F− to the amide H. Absorption and 1H NMR spectroscopies revealed that the NH2 of 22+ undergoes selective two-step adduct reaction with F−: the H close to pyridyl group of H2pia first formed a 1:1 adduct (mono-F-adduct-22+), followed by the other H forming the 1:2 adduct (di-F-adduct-22+). Adding excess Li(OTf) to these F-adduct-22+ solutions changed the dark-red solution back to red, suggesting that the adducted F− was removed by Li+ to form 22+ and LiF.