Connection between Concepts Revealed by the Electronic Structure

Connection between Concepts Revealed by the Electronic Structure of Carbon Monoxide 2008054050 이기헌 2011067006 김정은 J. Chem. Educ. 2012, 89, 355 -359

Roald Hoffmann said “Taken together, MO and VB theories constitute not an arsenal, but a tool kit… Insistence on a journey… equipped with one set of tools and not the other puts one at a disadvantage. Discarding any one of the two theories undermines the intellectual heritage of chemistry. ”

Molecular Orbital Diagram

s-p mixing

Carbon Monoxide �N 2 is isoelectronic with CO

Data of bond lengths and vibration frequencies relevant bonds when an electron is lost from different orbitals N 2 [(2σg)2(2σu)2(1πu)4(3σg)2] N 2+ [(2σg)2(2σu)1(1πu)4(3σg)2] 2σu 2373 cm− 1 [(2σg)2(2σu)2(1πu)4(3σg)1] 3σg 2175 cm− 1 [(2σg)2(2σu)1(1πu)3(3σg)2] 1πu 1873 cm− 1 N 2+ 2330 cm− 1 2σu : antibonding 3σg : bonding 1πu : bonding

Data of bond lengths and vibration frequencies relevant bonds when an electron is lost from different orbitals CO CO [(3σ)2(4σ)2(1π)4(5σ)2] 2159 cm− 1 [(3σ)2(4σ)2(1π)4(5σ)1] 5σ 2160 cm− 1 CO [(3σ)2(4σ)1(1π)4(5σ)2] 4σ 1690 cm− 1 + [(3σ)2(4σ)2(1π)3(5σ)2] 1π 1610 cm− 1 + 5σ : antibonding 4σ : bonding 1π : bonding

Molecular Orbital Diagram