I am trying to synthesize 2,6,9,10-tetracyanoanthracene and I need to discriminate it from other regioisomers. I am hoping to take advantage of the C2h symmetry under an IR spectrometer. I like to consider only one type of bond at a time to make things more simple for me. When I run down the reducible representations for the CN bonds, I get three IR active modes coming from the four nitriles. 1 coming from Au that is z active, and 2 coming from Bu that are x or y active. Can I interpret this as 2 asymmetric stretches and one bend?