s 5-2-1. Huckel Molecular Orbital Theory (HMO) The main idea of hmo 1.Take o-rrorbitals Apart 20218/21 Chemistry Departme nt of Fudan University 16
Physical ChemistryI Chapter V Polyatomic Molecular Structure 2021/8/21 Chemistry Department of Fudan University 16 §5-2-1.Hückel Molecular Orbital Theory (HMO) 1.Take σ-πorbitals Apart 0 0 The main idea of HMO
2. To the tr orbitals, hmo assumes. (=j) H1=1B(-1=1) 0(≠jand-川≠1) 1o(≠j 20218/21 Chemistry Departme nt of Fudan University
Physical ChemistryI Chapter V Polyatomic Molecular Structure 2021/8/21 Chemistry Department of Fudan University 17 2.To the π orbitals, HMO assumes: − − = = = 0 ( 1) ( 1) ( ) i j and i j i j i j H i i j = = 0 ( ) 1 ( ) i j i j Si j
85-2-2.Illustrative Examples of HMO Straight chain alkene--butadiene 20218/21 Chemistry Departme nt of Fudan University 18
Physical ChemistryI Chapter V Polyatomic Molecular Structure 2021/8/21 Chemistry Department of Fudan University 18 §5-2-2.Illustrative Examples of HMO Straight chain alkene---butadiene
E B 0 0 B a-E B 0 B a-E B 00B E x100 s c-E 1x10 0 01x 001x 20218/21 Chemistry Departme nt of Fudan University
Physical ChemistryI Chapter V Polyatomic Molecular Structure 2021/8/21 Chemistry Department of Fudan University 19 0 0 0 0 0 0 0 = − − − − E E E E 0 0 0 1 0 1 1 1 1 0 1 0 0 = x x x x E x − =
x4-3x2+1=0 x,=-1.618 E1=a+1618B 12 =-0.618 E2=a+0.618B x2=0.618 E3=c-0.618B x4=1618 E4=a-1.6186 20218/21 Chemistry Departme nt of Fudan University
Physical ChemistryI Chapter V Polyatomic Molecular Structure 2021/8/21 Chemistry Department of Fudan University 20 x1 = −1.618 x2 = −0.618 x3 = 0.618 x4 = 1.618 E1 = +1.618 E2 = + 0.618 E3 = − 0.618 E4 = −1.618 3 1 0 4 2 x − x + =