Originally posted by woelen
Quote: | Originally posted by DJF90
Strange how the analogous reaction does happen with iodine though. I wonder why chlorine and iodine both form nitrogen trihalides with ammonia but
bromine can't... |
The reactions with chlorine and iodine by no means are analogous. Clorine gives NCl3 with ammonium ion, not with ammonia. Formation of NCl3 does not
occur in alkaline environments. It must be on the acidic side of the pH scale.
The compound "NI3", which is formed with ammonia (not ammonium) and iodine also has a VERY different structure, compared with NCl3. NCl3 is a covalent
molecule, "NI3" is not a simple molecular species but some macromolecule, which also has ammonia molecules entrapped. The empirical formula is not
NI3, but NI3.nNH3, where n depends on method of preparation, concentration, temperature. The precise structure of "NI3" is amazingly complex, and IIRC
it still is only partially understood.
So, when looked at at first glance, there may seem to be an analogy between iodine and chlorine in this kind of reactions. In reality there is none,
not at all. |