(a) Using Hückel's method, describe the energy of the molecular orbitals T of cyclobutadiene C4H4, which is a flat molecule made up of a square ring of carbons, as shown in the figure; (b) Do the same for 1,3-butadiene C4H6, which is an elongated planar molecule, as shown in the figure. (c) In both cases, draw an energy diagram indicating the filling of the orbitals and identifying the HOMO and the LUMO. Sketch by hand schematically (using two colors to distinguish the lobes from the 2pz orbitals) the result obtained for the orbitals, identifying them with the corresponding energy. If possible, you can use the Orbital Viewer program to plot the orbitals.

(a) Using Hückel's method, describe the energy of the molecular orbitals T of cyclobutadiene C4H4, which is a flat molecule made up of a square ring of carbons, as shown in the figure; (b) Do the same for 1,3-butadiene C4H6, which is an elongated planar molecule, as shown in the figure. (c) In both cases, draw an energy diagram indicating the filling of the orbitals and identifying the HOMO and the LUMO. Sketch by hand schematically (using two colors to distinguish the lobes from the 2pz orbitals) the result obtained for the orbitals, identifying them with the corresponding energy. If possible, you can use the Orbital Viewer program to plot the orbitals.

Principles of Modern Chemistry

8th Edition

ISBN:9781305079113

Author:David W. Oxtoby, H. Pat Gillis, Laurie J. Butler

Publisher:David W. Oxtoby, H. Pat Gillis, Laurie J. Butler

Chapter6: Quantum Mechanics And Molecular Structure

Section: Chapter Questions

Problem 26P: Following the pattern of Figure 6.21, work out the correlation diagram for the BeN molecule, showing...

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Following the pattern of Figure 6.21, work out the correlation diagram for the BeN molecule, showing the relative energy levels of the atoms and the bonding and antibonding orbitals of the molecule. Indicate the occupation of the MOs with arrows. State the order of the bond and comment on the magnetic properties of BeN.
For monocyclic conjugated polyenes (such as cyclobutadiene and benzene) with each of N carbon atoms contributing an electron in a 2p orbital, Huckel theory gives the fol lowing expression for the energies Ek of the resulting π molecular orbitals Calculate the energies of the 1t molecular orbitals of benzene and cyclooctatetraene. Comment on the presenceor absence of degenerate energy levels. (b) Ca lcu late and compare the delocalization energies of benzene and hexatriene using the expression from the preceding problem. What do you conclude from your results? (c) Calculate and compare the delocalization energies of cyclooctatetraeneand (linear) octatetraene. Are your conclusions for th is pair of molecules the same as for the pair of molecules investigated in part (b)?
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