A series of five [Rh(P2N2)(2)](+) complexes (P2N2 = 1,5-diaza-3,7-diphosphacyclooctane) have been synthesized and characterized: [Rh((P2N2Ph)-N-Ph)(2)](+) (1), [Rh(PPh2N2Bn)(2)](+) (2), [Rh((P2N2PhOMe)-N-Ph)(2)](+) (3), [Rh((P2N2Ph)-N-Cy)2](+) (4), and [Rh((P2N2PhOMe)-N-Cy)(2)](+) (5). Complexes 15 have been structurally characterized as square planar rhodium bis-diphosphine complexes with slight tetrahedral distortions. The corresponding hydride complexes 610 have also been synthesized and characterized, and X-ray diffraction studies of HRh(PPh2N2Bn)(2) (7), HRh((P2N2PhOMe)-N-Ph)(2) (8) and HRh((P2N2Ph)-N-Cy)(2) (9) show that the hydrides have distorted trigonal bipyramidal geometries. Equilibration of complexes 2-5 with H-2 in the presence of 2,8,9-triisopropyl-2,5,8,9-tetraaza-1-phosphabicyclo[3,3,3]undecane (Verkades base) enabled the determination of the hydricities and estimated pKas of the Rh(I) hydride complexes using the appropriate thermodynamic cycles. Complexes 1-5 were active for CO2 hydrogenation under mild conditions, and their relative rates were compared to that of [Rh(depe)(2)](+), a nonpendant-amine-containing complex with a similar hydricity to the [Rh(P2N2)(2)](+) complexes. It was determined that the added steric bulk of the amine groups on the P2N2 ligands hinders catalysis and that [Rh(depe)(2)](+) was the most active catalyst for hydrogenation of CO2 to formate.