(a) What is Hückel theory? Why is it used? What assumptions does it make? (b) Consider...
Use Hückel theory to write the secular determinant and determine the energies of the pi orbitals and total energy of the pi system for hexatriene
Consider the allyl radical C3Hs a. Briefly state the three Hückel Approximations b. Using these approximations, write down the secular determinant for C3Hs. c. Solve explicitly for the roots of this secular determinant. d. Is this radical stabilized by delocalization, and if so, what is the delocalization energy?
b) Benzene and ar Please fint mPle in the Picte: ter ange) fxoni low Estimating the delocalization energy within the Hückel appr tonian matrix Example 10E.2 Use the Hickel approxination to find the energies of the π s of cyclobutadiene, and estimate the delocalization αβ000 energy Method Set for butadiene, but note that atoms A and D are also now neigh bours Then solve for the roots of the secular equation and assess the total π-bond energy. For the delocalization...
Q 2(a) [70 Marks] The secular equations for describing the overlap of the four unhybridised p orbitals in butadiene (shown above) lead to a matrix of the form H11- ES ES12 H13- ES13H14-ES14 H21- ES21 H22- ES22 H23 - ES23 H24- ES24 H31- ES31 H32 - ES32 H33 - ES33 H34- ES34 41 - ES41 H42 - ES42 H43- ES43 H44- ES44 where Hy is the Hamiltonian integral for orbitals i and j and Sj is the overlap integral for...
Question 4 [31] For a diatomic molecule, the electronic wavefunction was descri bed by CA + €pB R (a)Express energy expectation value as a function of c, Ca and integral constants [3] (b) Derive and explain their chemical implications of Coulombic integral (a), Resonance Integral (B), and Overlap Integral (s). [3] (c)What are the key Hückel's approximations for a homonuclear molecule? [4] Question 4 [31]; Contin ued Propene Cyclopropene Cyclopropenyl Cation Using the Hückel molecular orbital theory, wavefunction of electrons...
calculation of geometries. Question 5 (8 points (2,3,3)) For a particular problem, the wavefunction is written as a superposition of two orthonormal functions (xi): Y = CX,+C2X2. The coefficients are determined with variation theory. The following integrals are given in eV): H, =Sxix, dt =-10 H2 = Sxixdr = -0.5 H,2 = xixdt =-1.0 a) Give the secular equations. b) Find the energies. c) Find the wavefunction for the state with the lowest energy (if you did not find the...