Synthesis of SnI 4 Direct reaction of tin metal with iodine in methylene chloride yields SnI 4 as the principal product, with formation of SnI 2 as a side reaction. Sn + 2I 2 + SnI 4 Sn + I 2 + SnI 2 SnI 4 is a red-orange solid; SnI 2 is a yellow-red solid. Color due to polarizability of I – , probably involving charge transfer (I+ Sn).   SnI 2 is polar, and SnI 4 is non-polar, As a result SnI 2 is slightly more soluble in CH 2 Cl 2 . SnI 2 is somewhat more ionic and has a higher m.p. SnI 2 m.p. 330 C SnI 4 m.p. = 143-144 C