Neutral cyclo-octateraen (C_3H_g) has 8 pi electrons, divalent cyclo-octatetraen
ID: 999746 • Letter: N
Question
Neutral cyclo-octateraen (C_3H_g) has 8 pi electrons, divalent cyclo-octatetraen cation (C_8H_8^2+) has 6 pi electrons, and divalent cyclo-octatettraen cation (C_8H_8^2-) has 10 pi electrons. The can be modeled as particles on a (two-dimensional) ring, in which electron-electron interaction are neglected. For cyclo-octatettraen, the radius of the ring is 0.18 nm. Which of the following species can be paramagnetic based on the one-particle-on-a-ring model? (C_8H_8^2+ or C_8H_8^2- or none of three species or all three species)? Explain your choice. Copare the HOMO-LUMO transition of C_8H_8^2+ cation and C_8H_8^2- anion based on the model of particles on a ring. Which of the above molecules has a greater energy difference between HOMO and LUMO? (C_8H_8^2+ cation or C_8H_8^2- anion or same or others) Explain your choice. At the level of Huekel approximation, the eigen-eneregies of pi orbitals of neutral cyclo-oetatetraen (C_8H_8) are calculated to be alpha + 2beta, alpha + 1.41 beta, alpha, alpha, alpha-1.41 beta and alpa - 2beta. Note alpha: Coulomb integral: beta: resonance integral. Determine the delocalization energy of neutrual cyclo-octatetraen (C_8H_8). Show your calculation. Combination of which of the following experimental methods/measurements will allow us to estimate alpha and beta? (UV-VIS, IR, NMR, Ionization energies, Calorimetry or Microwave spectrum). NO explanation is needed.Explanation / Answer
6. A. C8H8+2 IS A PARAMAGNETIC SPECIS AS UNPAIRED ELECTRONS ARE PRESENT IN BONDING MOLECULAR ORBITALS.
B. THE ANION HAS HIGHER ELECTRON ELECTRON REPULSION (GREATER NO OF ELECTRONS IN ANION THAN CATION) SO HOMO OF ANIONIC SPECIES IS ENERGISED SO HOMO-LUMO GAP IS LOWERED FOR IT.
D. UV-VIS AND IONISATION ENERGY COMBINATION IS MUST FOR ESTIMATION