3461
In this work we investigate the nature of the Cl . . . N interactions in complexes formed between substituted ammonium [ NHn ( X3 - n ) ( with n = 0 , 1 , 2 , 3 and X = - CH3 , - F ] as Lewis bases and F - Cl molecule as Lewis acid .
 Cl, N, NHn ( X3 - n ), CH3, F, Lewis bases, F, Cl, Lewis acid
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Chemical 
Text: {0} 
Answer:
 Cl, N, NHn ( X3 - n ), CH3, F, Lewis bases, F, Cl, Lewis acid