In English, multiplying prefixes like di, tri, tetra, etc. start with a capital letter only when they are at the beginning of a sentence.
For example, we would write,
"Trichloromethane and diiodomethane are better known as chloroform and methylene chloride".
The rule holds even when there are numbers in front of the prefix:
"1,1,1,2-Tetrafluoroethane and 1,1,2,2-tetrafluoroethane are both tetrafluoroalkanes".