2. (10 pts). CH3F belongs to C3e group. Determine the symmetry of all the normal modes...
4. Determine the symmetry and the number of all normal modes of vibration for methane and chloroform and identify the modes that are IR active and modes that are Raman active. How many bands would you "see” in the IR and Raman spectra for each compound?
Geometry Point Group Reducible Representation For all atomic motions Vibrational modes Infrared-active modes Raman-active modes Number of IR absorptions Number of Raman emissions square planar
What does Density Functional Theory (DFT) enable someone to do that you cannot with group theory. I know that group theory enables you to assign a point group to a molecule which represents its overall symmetry, assign translational, rotational, and vibrational modes, and determine which of these vibrational modes are IR or Raman active. What does DFT offer that group theory doesn't?
Question One (10 points) Compounds containing the cube-shaped cluster Cu8 can be synthesized. Using group theory, determine the symmetry of the Cu-Cu bond stretches and indicate how many modes are infra-red active and/or Raman active. [Hint – follow which bonds move or don’t move under the symmetry operations of the group]
E11E.1(b) A carbon disulfide molecule belongs to the point group D The nine displacements of the three atoms span Ai+AA2E+E ar re the symmetry species of the normal modes of vbration?
E11E.1(b) A carbon disulfide molecule belongs to the point group D The nine displacements of the three atoms span Ai+AA2E+E ar re the symmetry species of the normal modes of vbration?
Question Three Compounds containing the cubic-shaped cluster Cus can be synthesized. Using group theory, determine the symmetry of the Cu-Cu bond stretches and indicate how many modes are infra-red active and/or Raman active. Hint-follow how bonds move or do not move under the symmetry operations of the group)
Use Web Mo for (pyrazine (C4H4N2)) Point group
is D2h
(a) Identify and clearly sketch by hand the symmetry elements of the molecule. (b) Calculate the number of degrees of freedom and number of vibrations for the molecule. (c) Determine how the degrees of freedom of the molecule are distributed amongst the irreducible representations of the point group show clearly all your working. (d) Subtract the translations and rotations and hence determine how the normal vibrations of the molecule are...
Cl 2. (15 points) For the SFsCl molecule: What is the point group? What is the total number of degrees of fredom -b gl 216 What is the total number of vibrational modes?3 What is the reducible representation and what are the irreducible representations of the vibrational modes? Identify which modes are Raman active, IR active, both active or neither. Determine the reducible representation. Then, determine the coefficients of the irreducible representations.
Cl 2. (15 points) For the SFsCl molecule:...
2. Determine the symmetry of the normal modes of vibration for the following mole- cules: (a) H C CC N (b) CO3 (c) PtCIZ-; (d) trans-glyoxal. 2- 2
3.28 Al,Clo belongs to the D2n point group: 3.32 E 3.33 (a) How many degrees of vibrational freedom does Al2Cl6 possess? (b) Use the D2h character table in Appendix 3 to determine the symmetries of the IR active stretching modes of vibration. D I E C₂(2) C ) C(x) i olxy) (x2) olyz) コート ---7777 iiii