Chemistry691,Exam2,Matlabportion,May4,2016

Conversionfactors:me=0.000548597a.m.u.1hartree=219474.6cm–1.

1. Thenaphthaleneandazulenemoleculeseachhave10πelectrons

WriteaMatlabscripttosetuptheHückelHamiltonianmatrixforeachofthese.

Diagonalizethesematricestoanswerthefollowingquestions:

A. WhatistheHOMO-LUMOgap(intermsofβ)innaphthaleneandazulene?B. Thelowestelectronictransitioninnaphthaleneoccursat320nm.Wherewouldyou

expectthesetransitiontooccurinazulene?C. DeterminetheHückelbondordersforthenaphthalenebonds1-2,2-3,1-9,and9-10;

andfortheazulenebonds4-10,4–5,5–6,3–10,2–3,and9–10.

2. CalculatedenergiesinHartreefortheX1Σg+anda3ΠustatesofC2aregiveninthefile:http://www2.chem.umd.edu/groups/alexander/chem691/matlab_files/C2_mrciq_energies.txt

WriteaMatlabscripttousethisdatatopredict,forthesetwoelectronicstates,thespectroscopicconstantsTe,Be,andωe.(giveanswersincm–1).

112

34

87

65

9

1010

Napthalene Azulene

1

34

87

6

5

9

1010

2