8432
Molecular adsorption shifts some of their vibrational frequencies with respect to the gas phase , mainly the C = C and the C = N stretching modes , in agreement with recent experimental measurements [ Tornero et al . , Phys . Chem . Chem . Phys . , 2011 , 13 , 8475 ] .
 Chemical: C = C; Chemical: C = N
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: C = C, C = N 
Answer:
 Chemical: C = C; Chemical: C = N