The nitrido atom in the nitridomolybdenum porphyrin complexes donates
strongly to the metal centre with the formation of a strong triple bon
d, but it still retains enough electron density to be attacked by elec
trophiles such as iodo alkyls, forming organoimido-molybdenum porphyri
n complexes. It reacts with Lewis acids like boron trifluoride to affo
rd 1:1 adducts and with elemental sulphur, giving thionitrosyl molybde
num porphyrin complexes. Under severe conditions, the nitrido ligand i
n N drop Mo(TPP) behaves like an electrophile with tributylphosphine t
o give a phosphineiminato molybdenum porphyrin complex. The nitrido li
gand in N drop Mo(TPP) can also replace one CO ligand of M(CO)(6)(M =
Mo, W) to form (TPP)Mo drop N-M(CO)(5).