QUESTION 3: (8 marks)

Neptunocene [Np(C₈H₈)₂] is a sandwich complex with Np⁴⁺ located between two parallel and eclipsed C₈H₈^2- rings and can be described by point group D_8h. The character table for point group D_8h is provided below.

D8h E 2C8 2C8³ 2C4 C2 4C2' 4C2" i 2S8 2S8³ 2S4 h 4d 4v

A1g 1 1 1 1 1 1 1 1 1 1 1 1 1 1

A2g 1 1 1 1 1 -1 -1 1 1 1 1 1 -1 -1

B1g 1 -1 -1 1 1 1 -1 1 -1 -1 1 1 1 -1

B2g 1 -1 -1 1 1 -1 1 1 -1 -1 1 1 -1 1

E1g 2 2 -(2) 0 -2 0 0 2 2 -(2) 0 -2 0 0

E2g 2 0 0 -2 2 0 0 2 0 0 -2 2 0 0

E3g 2 -(2) 2 0 -2 0 0 2 -(2) 2 0 -2 0 0

A1u 1 1 1 1 1 1 1 -1 -1 -1 -1 -1 -1 -1

A2u 1 1 1 1 1 -1 -1 -1 -1 -1 -1 -1 1 1

B1u 1 -1 -1 1 1 1 -1 -1 1 1 -1 -1 -1 1

B2u 1 -1 -1 1 1 -1 1 -1 1 1 -1 -1 1 -1

E1u 2 2 -(2) 0 -2 0 0 -2 -(2) 2 0 2 0 0

E2u 2 0 0 -2 2 0 0 -2 0 0 2 -2 0 0

E3u 2 -(2) 2 0 -2 0 0 -2 2 -(2) 0 2 0 0

a) Determine the symmetry species for the LGO (ligand group orbitals) made up of the pz orbitals on the

carbons as shown in the figure below (Np⁴⁺ is shown as a blue sphere in the center of the molecule).

b) Which of the following f-orbitals belongs to the same symmetry species as the LGO in question 3 a)? Explain your answer.

Neptunocene [Np(CH3)2] is a sandwich complex with Np++ located between two parallel and eclipsed CH32. rings and can be described by point group sh. The character table for point group Dan is provided below. 404 40 1 1 Dan Asg B1 B20 -1 -1 Eso E 2C9 20 2C 1 1 1 1 1 1 1 1 1 -1 -1 1 1 -1 -1 1 2 2 -(2) 2 0 0 2 -(21) 24 1 1 1 1 1 1 1 -1 -1 1 -1 -1 2 2 -(2) 2 0 0 2-(2) 24 0 Eag Eg AL AM B1 B2u NNN C2 4C2' 4C2" 1 1 -1 -1 -1 -1 1 0 0 0 1 1 1 -1 -1 1 -1 1 -1 1 -2 0 0 2 0 -2 0 0 NO ONO 11 11ooo111 Tool i 258 2593 254 1 1 1 1 1 1 1 1 1 -1 -1 1 1 -1 -1 1 2 2 -(2) 0 2 0 0 -2 2 -(2") 24 0 -1 -1 -1 -1 -1 -1 -1 1 1 -1 1 1 -1 -2 (2) 21 0 0 2 24 -(24) 0 -1 1 1 1 1 -2 2 -2 -1 -1 -1 -1 2 -2 2 DOO 1 -1 0 0 0 -1 1 -1 1 0 0 0 1 11ooo111ioo -1 Esu Ezu Ezu NNN 0 a) Determine the symmetry species for the LGO (ligand group orbitals) made up of the Pz orbitals on the carbons as shown in the figure below (Np is shown as a blue sphere in the center of the molecule). 10 b) Which of the following f-orbitals belongs to the same symmetry species as the LGO in question 3 a)? Explain your answer. fy/3x2-y?) fz(x2-ye) fyzz 2 N fxz? fxyz fx/x2-3y?) Neptunocene [Np(CH3)2] is a sandwich complex with Np++ located between two parallel and eclipsed CH32. rings and can be described by point group sh. The character table for point group Dan is provided below. 404 40 1 1 Dan Asg B1 B20 -1 -1 Eso E 2C9 20 2C 1 1 1 1 1 1 1 1 1 -1 -1 1 1 -1 -1 1 2 2 -(2) 2 0 0 2 -(21) 24 1 1 1 1 1 1 1 -1 -1 1 -1 -1 2 2 -(2) 2 0 0 2-(2) 24 0 Eag Eg AL AM B1 B2u NNN C2 4C2' 4C2" 1 1 -1 -1 -1 -1 1 0 0 0 1 1 1 -1 -1 1 -1 1 -1 1 -2 0 0 2 0 -2 0 0 NO ONO 11 11ooo111 Tool i 258 2593 254 1 1 1 1 1 1 1 1 1 -1 -1 1 1 -1 -1 1 2 2 -(2) 0 2 0 0 -2 2 -(2") 24 0 -1 -1 -1 -1 -1 -1 -1 1 1 -1 1 1 -1 -2 (2) 21 0 0 2 24 -(24) 0 -1 1 1 1 1 -2 2 -2 -1 -1 -1 -1 2 -2 2 DOO 1 -1 0 0 0 -1 1 -1 1 0 0 0 1 11ooo111ioo -1 Esu Ezu Ezu NNN 0 a) Determine the symmetry species for the LGO (ligand group orbitals) made up of the Pz orbitals on the carbons as shown in the figure below (Np is shown as a blue sphere in the center of the molecule). 10 b) Which of the following f-orbitals belongs to the same symmetry species as the LGO in question 3 a)? Explain your answer. fy/3x2-y?) fz(x2-ye) fyzz 2 N fxz? fxyz fx/x2-3y?)