结构化学chapter1.pptVIP

* * * * * * * * 方向： 纵波等通常是直线传播在气液界面会发生折射（refraction)，而宏观粒子在进入液体后，一方面由于惯性，另一方面会由于液体阻力，运动轨迹会变成曲线。 波在通过狭缝时会发生发生衍射(diffraction)，宏观粒子束在通过狭缝时只有通过狭缝的粒子继续前进。 * 量子栅栏 * A probability wave reflects the statistic probability of particles in space. * Drawing energy level diagram for He (or other elements) Draw energy axis at left. Label shells and subshells. Fill in appropriate number of electrons. Paramagnetic = at least one unpaired electron Diamagnetic = no unpaired electrons * The first thing we have to deal with, however is putting two electrons into the same orbital. Pauli’s exclusion principle dictates that no two electrons can have the same quantum numbers, so there is an extra quantum number ms that indicates what is called the spin of the electron. Electron spin is sometimes compared to clockwise vs counter-clockwise rotation but it really has nothing to do with rotation - it is a purely quantum mechanical property. Nuclei also have spins and the allowed values are more than just +-1/2. Spin is manifested in the direction of deflection of a particle beam - half go toward the north pole, half toward the south. It is a real phenomenon but really has nothing to do with rotation * This molecule has a linear pi-conjugation consisting of m+2 C atoms plus two N atoms and a total of 2m+4 pi-electrons. Approximately, such pi-conjugation can be regarded as a 1D-box containing 2m+4 free electrons. The molecular orbitals and the corresponding energy level can thus be obtained by following the 1D-box solution. * 1.4 Solution of free particle in a box –  a simple application of Quantum Mechanics 1.4.1 The free particle in a one  dimensional box 1. The Schr?dinger’s Equation and its solution In area I, III: 1D box (meaning no particle in area I and III). II: V=0 Boundary condition and continuous condition: ?(0)=0, ?(l)=0 Hence, ?(0) =Acos0+Bsin0 = A + 0 = 0 = A =0 ? ?=Bsin?x (B?0) ? (l) =Bsin?x =Bsin ?l=0, Thus, ?l=n?, ?=n?/l (n=1,2,…) Normali