1. Molecular Orbitals An approach to bonding in which orbitals encompass the entire molecule, rather than being localized between atoms. Muhammad Asif Pakistan

35. MO Diagram for O 2 2p 2p 2s 2s σ g σ * u σ g π u π * g σ * u The molecular orbital diagram for oxygen shows two unpaired electrons, consistent with experimental data. Muhammad Asif Pakistan

37. MO Diagram for O 2 2p 2p 2s 2s σ g σ * u σ g π u π * g σ * u The bond order of O 2 is: 8-4 = 2 2 This is consistent with a double bond. Muhammad Asif Pakistan

38. MO Diagram for O 2 2p 2p 2s 2s σ g σ * u σ g π u π * g σ * u This energy level diagram works well for atoms in which the 2s and 2p levels are fairly far apart. These are the elements at the right of the table: O, F and Ne. Muhammad Asif Pakistan

41. Muhammad Asif Pakistan

45. MO diagram for Li through N σ g σ g σ * u σ * u π u π * g Muhammad Asif Pakistan

46. MO diagram for N 2 N 2 has 10 valence electrons. Muhammad Asif Pakistan σ g σ g σ * u σ * u π u π * g

48. Experimental Evidence Muhammad Asif Pakistan σ g π u σ * u σ g σ g σ * u σ * u π u π * g

57. The highest occupied molecular orbital of CO is a molecular orbital which puts significant electron density on the carbon atom. Muhammad Asif Pakistan

58. The lowest unoccupied molecular orbital of CO is the π * orbitals. The lobes of the LUMO are larger on the carbon atom than on the oxygen atom. Muhammad Asif Pakistan

68. Group Orbitals of Water The 2s and 2p z orbital on oxygen have A 1 symmetry, the 2p x orbital has B 1 symmetry, and the 2p y has B 2 symmetry. Muhammad Asif Pakistan

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73. π Bonding of Benzene { z axis C′ 2 C″ 2 Muhammad Asif Pakistan D 6h E 2C 6 2C 3 C 2 3C′ 2 3C″ 2 i 2S 3 2S 6 σ h 3 σ d 3 σ v Г π

74. π Bonding of Benzene { z axis C′ 2 C″ 2 Muhammad Asif Pakistan D 6h E 2C 6 2C 3 C 2 3C′ 2 3C″ 2 i 2S 3 2S 6 σ h 3 σ d 3 σ v Г π 6 0 0 0 -2 0 0 0 0 -6 0 2

75. π Bonding of Benzene { z axis C′ 2 C″ 2 This reduces to: B 2g + E 1g + A 2u + E 2u Muhammad Asif Pakistan D 6h E 2C 6 2C 3 C 2 3C′ 2 3C″ 2 i 2S 3 2S 6 σ h 3 σ d 3 σ v Г π 6 0 0 0 -2 0 0 0 0 -6 0 2

79. π Bonding of Benzene Muhammad Asif Pakistan A 2u E 1g E 2u B 2g