22755
The formation of long one - dimensional ( 1D ) supramolecular chain - like structures has been observed , associated to a physical linking of their ends which involved the rotation of the end thiophene rings in order to allow pi - pi stacking of these end - groups .
 Chemical: thiophene
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
 Entities: thiophene 
Answer:
 Chemical: thiophene