contestada

In Section 3.5, we applied the equations for a particle in a box to the TC electrons in butadiene. This simple model is called the free-electron model. Using the same argument, show that the length of hexatriene can be estimated to be 867 pm. Show that the first electronic transition is predicted to occur at 2.8 x 104 cm-1. (Remember that hexatriene has six TC electrons.)

Respuesta :

nuhulawal20

Answer: DeltaE = 2.83 * 10^4 cm^-1

Explanation:

hexatriene has six TC (pi) electrons

3 C = C BONDS : 3 * 135 = 405 pm

2 C - C  BONDS : 2 * 154 = 308 pm

also the TWO CARBON ATOMIC RADIUS AT EACH END : 2 * 44 = 154 pm

therefore length of molecule = 405pm + 308pm + 154pm = 867 pm

now

HoMo = E4 and CoMo = E3

DeltaE = E4 - E3 = (4^2h^2 / 8mL^2) - (3^2h^2 / 8mL^2)

DeltaE = 7h^2 / 8mL^2

DeltaE = 7 * (6.62 *10^-35 Js)^2 / ( 8 * 9.1*10^-31 kg * (867*10-12m)^2)

DeltaE = 5.62 * 10^-19 J

( 1J = 5.034 * 10^22 cm^-1)

therefore

DeltaE = 2.83 * 10^4 cm^-1

Otras preguntas