These are as primarily {HEAD ~ chlorofluorocarbons}, such as R12 and {TAIL ~ R22}, i.e., dichlorodifluoromethane and chlorodifluoromethane, respectively 
such as
These are as primarily { HEAD ~ chlorofluorocarbons } , such as R12 and { TAIL ~ R22 } , i.e. , dichlorodifluoromethane and chlorodifluoromethane , respectively
OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH REL REL OTH OTH TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH