A series of bis-phosphinite and bis-phosphite PONOP iron complexes were prepared and characterized by NMR and IR spectroscopy. Bis-phosphinite PONOP iron dichloride complexes ( R PONOP)FeCl 2 ( R PONOP = 2,6-(R 2 PO) 2 (C 5 H 3 N) and R = i Pr, t Bu) were prepared through complexation of the free ligands with FeCl 2 and their solid-state structures were determined. Bis-phosphite PONOP iron complexes ( OEt PONOP)Fe(PMe 3 ) 2 and ( Cat PONOP)Fe(PMe 3 ) 2 (Cat = catechol) were synthesized through complexation of the free ligands to Fe(PMe 3 ) 4 . Carbonyl complexes of both bis-phosphinite and bis-phosphite PONOP were prepared and characterized by IR. The monocarbonyl ( i Pr PONOP)Fe(CO)Cl 2 was accessed through exposure of ( i Pr PONOP)FeCl 2 to an atmosphere of CO and the CO stretching frequency was observed at 1969 cm −1 . Dicarbonyl complexes ( i Pr PONOP)Fe(CO) 2 and ( OEt PONOP)Fe(CO) 2 were accessed through reduction of the corresponding chloride complexes with sodium amalgam under a CO atmosphere. Carbonyl stretching frequencies for ( i Pr PONOP)Fe(CO) 2 and ( OEt PONOPFe)(CO) 2 were observed at 1824 and 1876 cm −1 , and at 1871 and 1927 cm −1 respectively. The bis-phosphite PONOP complexes exhibit a less electron rich metal center than the bis-phosphinite PONOP complexes, as would be expected based on the stronger π-acceptor character of these ligands. The electronic properties of the bis-phosphinite PONOP and bis-phosphite PONOP iron complexes are intermediate between previously reported PNP and PDI iron complexes, with the PONOP ligands exhibiting stronger electron donating ability than PDI ligands, but promoting a less electron rich metal center than found in analogous PNP iron complexes.