In: Chemistry
Using the particle in the 1-D box model, estimate the first 4 energy levels of the π-network in hexatriene, C6H8 (H2C=CH–CH=CH–CH=CH2). To calculate the box length, assume that the molecule is linear and use the values 135 and 154 pm for the C=C and C–C bonds, respectively. Only 2 out of the 6 ‘π-electrons’ of the 6 C-atoms can occupy each energy level (Pauli exclusion principle). Ignore the rest of the electrons (forming the core and the ??-bonding network). Sketch and label an energy level diagram showing the occupied levels and the first unoccupied one. What is the wavelength of the photon required to induce the HOMO-LUMO transition? Derive the expression for the photon’s wavelength symbolically! How does your numeric result compare with the experimental value of 240 nm?