[asd34]

I'm trying to find the numbered peaks in the attached IR spectra. On the other hand I have to prove the metal-mesitylene bond with the spectra. For that I found a journal, which wrote that the mesitylene has a lower wavenumber (peak 4), because of the metal-ligandum interaction. I think
2,3-> Ar sp2 CH
4,5-> Ar C=C
6 -> =CH 1.3.5 trisub Ar ring
But I can't identify the peak1. Guessed water O-H, but the complex is decomposes in the presence of water.