text: Yo, check it, Nitroxyl-iron(II) is a tricky one,
  Unstable in water, can't be outdone.
  Studying these complexes is a real tough task,
  Fe(II)-bound HNO, stayin' in the dark.
  
  But we ain't backin' down, we gotta find the truth,
  Using multinuclear NMR, we got the proof.
  With (1)H, (15)N, (17)O, we went all in,
  Investigated the acidity, made the pK(a) spin.
  
  In [Fe(CN)5(HNO)](3-) we dug deep,
  Found the pK(a) value, greater than 11, it's a leap.
  And HNO, it's quick to exchange with water,
  Acid or base, they both make it go harder.
  
  The dynamics of hydrogen exchange we've seen,
  For Fe(II)-bound HNO, it's a mean machine.
  Benchmark values obtained, combined with proteins,
  Inside globin proteins, the exchange slows, no weakenin'.
  
  The rate of hydrogen exchange, it's off the charts,
  Fe(II)-bound HNO, inside globin proteins, it's a work of art.
  Reduced by a factor of 10(6), that's the deal,
  Now we know the secrets, how these compounds feel.