Reactions of matrix isolated fron atoms with nitric oxide

Abstract The matrix isolated binary nitrosyls, Fe(NO) x , x ⩽ 4, formed upon co-condensation of iron with nitric oxide have been studied by infrared and Mossbauer spectroscopies. Infrared data suggest that the unsaturated complexes ( x = 1, 2) contain linear NO ligands. The isomer shifts of all four complexes are consistent with covalently bonded Fe(0). In 100% NO, Fe(NO) 4 is the major product and gives the identical Mossbauer spectrum as Fe(NO) 4 made from the high pressure reaction of Fe(CO) 5 with NO. In addition, a second product, probably Fe(NO) 3 is detected in the Mossbauer spectmm of Fe(NO) 4 made by both procedures. Evidence is seen for a partially reversible temperature dependent equilibrium between Fe(NO) 3 and Fe(NO) 4 , with Fe(NO) 4 favored at low temperatures. The unusal reactivity of NO with iron atoms is discussed.