Complex sentence: Further heating gives diiodine pentoxide (I 2 O 5) and oxygen rather than the expected anhydride "diiodine heptoxide"; this anhydride does not occur in nature but can be formed synthetically.
Split into simpler sentences: Further heating gives diiodine pentoxide (I 2 O 5) and oxygen. The anhydride "diiodine heptoxide" does not exist in nature but can be formed synthetically.