Hollo to all

I want to know in which region the vibrational frequency of the functional group of azomethine appears in the IR spectrum.

Especially in the case of the azomethine functional group in 4,7-diphenyl-1,10-phenanthroline (bathophenanthroline)

I need to know if bathophenanthroline is coordinated to a metal ion, does the vibrational frequency of azomethine shift to a higher or lower region?

Thank you all in advance for your answers