1.2价键理论基础回顾和分子轨道 理论简介 a(1 The aufbau priciple The closer the orbital is to the nucleus. the lower its energy 1s<2s<2p<3s≤3p<4s<3d<4p≤5s<4d<5p≤6s (2) The Pauli exclusion priciple Degenerate orbitals have the same energy (3)Hund's rule C: 1s2 2s2 2px12py12pz0
1.2 价键理论基础回顾和分子轨道 理论简介 ◼ (1) The aufbau priciple ◼ The closer the orbital is to the nucleus, the lower its energy ◼ 1s<2s<2p<3s<3p<4s<3d<4p<5s<4d<5p<6s… ◼ (2) The Pauli exclusion priciple ◼ Degenerate orbitals ---- have the same energy ◼ (3) Hund’s rule ◼ C: 1s2 2s2 2px12py12pz0
1.2价键理论基础回顾和分子轨道 理论简介 a 1.2.3 onic, Covalent, and Polar Bonds An atom is most stable if it has a filled shell or an outer shell of eight electrons and no electrons of higher energy ■ lonic bond:Lic a Covalent bond: H2, O2, cO2 C: 1s2 2s2 2px12py12pz0 Neither readily gives up electrons Nor readily accepts electrons a Nonpolar bond(H-H)and Polar bond(C-H, C-o)
1.2 价键理论基础回顾和分子轨道 理论简介 ◼ 1.2.3 Ionic, Covalent, and Polar Bonds ◼ An atom is most stable if it has a filled shell or an outer shell of eight electrons and no electrons of higher energy ◼ Ionic bond: LiCl ◼ Covalent bond: H2 , O2 , CO2 ◼ C: 1s2 2s2 2px12py12pz0 ◼ Neither readily gives up electrons ◼ Nor readily accepts electrons ◼ Nonpolar bond (H-H)and Polar bond ( C-H, C-O )
1.2价键理论基础回顾和分子轨道 理论简介 ■常见价键的表示方法: Lewis Structures o HC.O:H H-C-O-H Kekule structures H-C-O-H Condensed structures HCOH
1.2 价键理论基础回顾和分子轨道 理论简介 ◼ 常见价键的表示方法： ◼ Lewis Structures ◼ Kekule Structures ◼ Condensed Structures C O H O H H C O O H H C O O H HCO2H
1.2价键理论基础回顾和分子轨道 理论简介 ■思考题 ■共价键化合物与离子键化合物性质有哪些差异? ■请记住有机化合物中常见元素的电负性 Electronegativity ■H:2.1B:2.0c:2.5N:3.00:3.5 F:4.0c|:3.0Br:2.8:2.5 Li:1.0Mg:1.2
1.2 价键理论基础回顾和分子轨道 理论简介 ◼ 思考题 ◼ 共价键化合物与离子键化合物性质有哪些差异？ ◼ 请记住有机化合物中常见元素的电负性 ◼ Electronegativity: ◼ H: 2.1 B: 2.0 C: 2.5 N: 3.0 O: 3.5 ◼ F: 4.0 Cl: 3.0 Br: 2.8 I: 2.5 ◼ Li: 1.0 Mg: 1.2
1.2价键理论基础回顾和分子轨道 理论简介 1.2. 4 Introduction of Molecular Theory H H H: H s atomic 1s atomic orbital orbital bonding molecular orbital Orbitals are conserved - the number of atomic orbitals combined must equal the number of molecular orbitals formed
1.2 价键理论基础回顾和分子轨道 理论简介 ◼ 1.2.4 Introduction of Molecular Theory ◼ Orbitals are conserved ---- the number of atomic orbitals combined must equal the number of molecular orbitals formed = H H H : H 1s atomic orbital 1s atomic orbital bonding molecular orbital .