Metanilic acid


Metanilic acid is an isomer of sulfanilic acid with molecular formula and molecular weight 173.18968 g/mol. It is a white powder that is slightly soluble in water.

Disappearing polymorph

The crystal structure called Form I is a disappearing polymorph that cannot be produced by researches anymore while Form II and III still exist. The reason for this is that Form I is converted to another polymorph upon contact with a seed crystal and most places are contaminated with tiny amounts of Form II or III that are enough to prevent any viable amounts of Form I to be produced.