化學(xué)競賽雜化軌道理論(參考版)
2025-01-16 11:02本頁面
【正文】 Structure of ABn Molecules 2. AB3 i. Trigonal Pyramidal type (8, or 26 valence electron) ex. NH3 , PF3, PCl3, AsCl3 sp3 hybridization ii. Trigonal planar type (6, 24 valence electron) Centric atom B: sp2 hybridization 64?)4()3()2()1( 4321 ClClClB cccc ????? ? ???? 24 6 18 12 6 BC l C lC lIsoelectron analogy: AlF3, NO3, CO32, SO3, Cl2CO, (H2N)2C=O, Cl2C=S :e le c t r o ns ?antibonding nonbonding bonding For four atom angular type moleculars, forming one bonding, two nonbonding and one antibonding orbitals, in general Example: BH3 ex. BF3, NO3, CO32, SO3 sp2 FBFF?3 sp2 hybrid orbitals each with one electron. ?This one electron pairs with the hydrogen electron. ii. Trigonal planar type (6, 24 valence electron) 646432324 :e l e c t rons ?????ex. ClF3, BrF3, sp3d hybrid orbitals iii. T type (28 valence electron) 167。 from each other that are equivalent. You can figure out the normalization coefficients. 3dz2 3pz 3py 3px 3s sp3d2 3dx2y2 3s 3p S S* 3d S* (sp3d2) 3d F F F F F F Hybridization schemes spndm gives a “plete” set of hybrid orbitals for “any” geometry. sp Linear 直線 sp2 Trigonal planar 平面三角形 sp3 Tetrahedral 四面體 sp3d (dz2) Trigonal bipyramidal三角雙錐 sp3d(dx2y2) squarebased pyramidal四方錐 sp3d2 Octahedral八面體 sp2d Square planar平面四邊形 Valence bond theory treatment of ?bonding ?鍵的價鍵理論處理 sp 2p C*(sp) O 2s 2p O 2s 2p 2s 2p C ? ? ? The overlaps of the sp hybrid orbitals on C with the two 2p orbitals on O give the two ? bonds and it is the overlaps of the “l(fā)eft over” p orbitals on C with the appropriate p orbitals on O that form the (2p2p) ? bonds between each two atoms. ? O C O CO OValence bond theory treatment of ?bonding: the bonding in ethene There are three “objects” around each C so the geometry is trigonal planar at each carbon. The shape is given by AX3 for each carbon. C CHH HH2s 2p Each C sp2 2p C*(sp2) 1s 1s 1s 1s 4 H sp2 2p C*(sp2) ? ? ? ? ? ? Each C* The overlap of the sp2 hybrid orbitals on C with the the 1s orbitals on each H give the four terminal (sp21s) ? bonds. The double bond between the C atoms is formed by a (sp2 sp2) ? bond and the (2p2p) ? bond
法律信息相關(guān)推薦
鄂ICP備17016276號-1