8144
Here , we show that halogen bonding between a pyridyl substituent in a bis ( pyridyl urea ) and 1 , 4 - diiodotetrafluorobenzene brings about gelation , even in polar media such as aqueous methanol and aqueous dimethylsulfoxide .
 Chemical: halogen; Chemical: pyridyl; Chemical: bis ( pyridyl urea ); Chemical: 1 , 4 - diiodotetrafluorobenzene; Chemical: methanol; Chemical: dimethylsulfoxide
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
 Chemical: halogen; Chemical: pyridyl; Chemical: bis ( pyridyl urea ); Chemical: 1 , 4 - diiodotetrafluorobenzene; Chemical: methanol; Chemical: dimethylsulfoxide