18086
According to our simulation , the electronic transition involves a displacement of the electron charge towards the external amidine groups and this feature makes the absorption energies very environment - sensitive while a much smaller sensitivity is seen in the fluorescence energies .
 amidine
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Chemical 
Text: {0} 
Answer:
 amidine