●物理化学 3-1 Covalence bond Theory H-h bond formation from isolated h atoms 600 Atoms too close together- nuclei repel 400 74 pm Potentia/“0 (T-n bond length Atoms far apar zero of energy energy (kJ/mol) 200 436 kI/mol 400 I-n bond energy) Minimun potential energy 600 stable H, molecule formed 100200300400500600 Distance between nuclei (pm) Har-ourt Brace Compary items and dar ied items copyright oissE y Harcourt Brace Compan
物理化学I 2021/8/21 复旦大学化学系 16 3-1 Covalence bond Theory
●物理化学 3-1 Covalence bond Theory WKolos- CC. Roothaan F=0.742A D=4.74e 2021/8/21 复旦大学化学系
物理化学I 2021/8/21 复旦大学化学系 17 W.Kolos- C.C.Roothaan r0 = 0.742A De = 4.74eV 3-1 Covalence bond Theory
●物理化学 3-1 Covalence bond Theory Electronic structure P=(2)=2+2sJ()(2)+(2(山 2+2S2 (2)+φ2(2)+2小(2(2)Sab Bonding 2[十的+2S Anti-bonding Pu [+一2S 经典 十 2021/8/21 复旦大学化学系
物理化学I 2021/8/21 复旦大学化学系 18 Electronic Structure ( ) + + = = 1 2 1 2 2 2 (1) (2) (2) (1) 2 2 1 1,2 d S d a b a b a b b a b a a b a b S S (2) (2) 2 (2) (2) 2 2 1 2 2 2 + + + = 2 2 2 2 1 2 2 1 I b a b a ab ab S S = = + + + 2 2 经典 = a +b 2 2 2 1 2 1 II b a b a ab ab S S = + − − 3-1 Covalence bond Theory Bonding Anti-bonding
●物理化学 3-1 Covalence bond Theory ab p1-典1+Sm S|>0 A(1)B(2) ab 经典 <0 2 b b A(2B(1) The Nature of the Covalent bond A(1)B(2)+A(2)B(1) Enhanced electron densit 2021/8/21 复旦大学化学系 19
物理化学I 2021/8/21 复旦大学化学系 19 1 0 1 2 2 2 − − − = a b a b a a b II S S S 经典 1 0 1 2 2 2 − + − = ab ab a ab I S S S 经典 The Nature of the Covalent Bond 3-1 Covalence bond Theory
●物理化学 3-1 Covalence bond Theory A contour map of the electron density 0 distribution(or the molecular charge distribution for H, in a plane containing the nuclei. Also shown is a e04 profile of the density distribution along the internuclear axis. The internuclear separation is 1. 4 au. The values of the contours increase in magnitude from the outermost one inwards towards the nuclei the values of the contours in this and all x5 succeeding diagrams are given in au; 1au=e/a3=6.749c/A3 2021/8/21 复旦大学化学系
物理化学I 2021/8/21 复旦大学化学系 20 A contour map of the electron density distribution (or the molecular charge distribution) for H2 in a plane containing the nuclei. Also shown is a profile of the density distribution along the internuclear axis. The internuclear separation is 1.4 au. The values of the contours increase in magnitude from the outermost one inwards towards the nuclei. The values of the contours in this and all succeeding diagrams are given in au; 1 au = e/ao 3 = 6.749 e/Å3 . 3-1 Covalence bond Theory