Synthesis, structure, spectral and electron-transfer properties of octahedral-[CoIII(L)2]+/[ZnII(L)2] and square planar-[CuII(L){OC(O)CH3}] complexes incorporating anionic form of tridentate bis(8-quinolinyl)amine [N1C9H6–N2–C9H6N3, L−] ligand