15965
The Ar - CH2 bond rotational barrier for encapsulated ortho - substituted benzyl phosphonium guest molecules is sensitive to the size and shape of the host interior space .
 Chemical: Ar - CH2; Chemical: ortho - substituted benzyl phosphonium
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: Ar - CH2; Chemical: ortho - substituted benzyl phosphonium