Help: Why does FeCl2 exhibit higher melting and boiling points than Fecl3?

[Stasis]

Ok i know this is a very basic question the difference of m.p and b.p. of iron(ii)chloride and iron(iii)chloride. But what is the exact reason? is it because of their hybridizations? (sp and sp2 rspctvly) or is it because the ionization potential of Fe3+ is a lot more than Fe2+ ? . Please help. Nd thnx in advanec