Write structural formulas for the following compounds:
a. 2-methylhexane
b. 2,3-dimethylbutane
c. 4-ethyl-2,2-dimethylheptane
d. 2-bromo-4-methyloctane
e. 1,1-diiodocyclobutane
f. 2-chlorobutane
g. 1-isopropyl-1,3-dimethylcyclohexane
h. 1,1,2-trifluoropropane
i. 1,1,3,3-tetrachlorocyclopropan