New five mono- and dinuclear Ir hydrido complexes with polydentate nitrogen ligands, [Ir(H) 2(PPh 3) 2(tptz)]PF 6 ( 1), [Ir 2(H) 4(PPh 3) 4(tptz)](PF 6) 2 · 2H 2O ( 2 · 2H 2O), [Ir(H) 2(PPh 3) 2(tppz)]BF 4 ( 3), [Ir 2(H) 4(PPh 3) 4(tppz)](BF 4) 2 ( 4) and [Ir 2(H) 4(PPh 3) 4(bted)](BF 4) 2 · 6CHCl 3 ( 5 · 6CHCl 3), were systematically prepared by the reactions of the precursor Ir hydrido complex [Ir(H) 2(PPh 3) 2(Me 2CO) 2]X (X=PF 6 and BF 4) with 2,4,6-tris(2-pyridyl)-1,3,5-triazine (tptz), 2,3,5,6-tetrakis(2-pyridyl)pyrazine (tppz) and 1,4-bis(2,2 ′:6 ′,2″-terpyridine-4 ′-yl)benzene (bted), and their structures and properties were characterized in the solid state and in solution. Each of the Ir hydrido complexes with polydentate nitrogen ligands crystallographically described a unique coordination mode. Their 1H NMR spectra demonstrated unusual 1H NMR chemical shifts of pyridyl rings that are likely induced by the ring current effect of neighboring ligands.