I tried to find the potential energy distribution for the attached molecule. Actually, this molecule consists of 32 atoms and it has 34 bonds between the atoms. My doubt is that totally, there are 34 bond length coordinates, how many stretching will be possible. Rest of the other how many in-plane bending and out-of-plane bending coordinates. it does not meet the earlier literature results (for N atoms, N-1 stretching, N-2 in-plane bending and N-3 out-plane bending). Please help me to find the results. See the attachment for molecular structure.
All posible vibrational states for that molecule can be calculated as (3*N - 6). So, if there are 32 atoms then you have 3*32-6, that is 90 different intramolecular vibrational modes. Now, I think your molecule cant be characterized by out of the plane modes, I see your molecule is quite flexible so there is no one plane which you could use as reference. BTW, use http://webmo.net/demo/index.html to simulate your molecule, you could use PM3 or AM1 theory level to calculate the vibrational frequencies of your molecule and then you could visualize each one of them, it will help you to determine the stretching bending stuff.
I am running your molecule in opt in AM1 set ,35 stretching,53 in-plane and 76 out-of-plane bending
In agreement with A. F. C. Montanez above the molecule is non-planar. After performing Hartree-Fock geometry optimization on the molecule the structure appears to be two attached planar structures with the two planes related by a torsion angle near 40°. I have attached a Word docx file that shows the structure and planar relationship. The saturated nitrogen atom near the carbonyl group forces the non-planarity. After a vibrational analysis you may be able to identify local motions in each of the two planes that can be characterized as in-plane or out-of-plane relative to each local plane but motions over the entire molecule cannot be characterized that way as pointed out by A. F. C. Montanez.
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