The fundamental IR wavenumber of gaseous 14N16O is 1904 cm-1.

1.) When 14N16O is bound to hemoglobin A, an absorption band at 1615 cm-1 is observed and is believed to correspond to the bound NO species. If we assume that the oxygen in NO is bound to hemoglobin so that effective mass of the oxygen is infinite, we can compute a modified vibrational frequency. Apply this assumption of infinite oxygen effective mass to compute an adjusted vibrational frequency of hemoglobin-bound 14N16O. Assume that the force constant is the same as that for gaseous NO. How does your computed value compare to the experimental value of 1615 cm-1?

2.) Repeat the calculation from part c by assuming that the 14N (rather than 16O) is bound to hemoglobin.

3.) How might you use isotopic substitution to determine whether N or O is bound?