李艳梅有机化学.pptx

文档介绍：Content
Introduction
Molecule with one asymmetric carbon
Molecule with two asymmetric carbon
Molecule with more than two asymmetric carbon
Cyclic compound
Other chiral molecules
Measure of polarity and reslution of racemic compounds
Chirality
Nicol
Introduction
Plane-polarized light
平面偏振光（偏振光）
Nicol
Light source
Non-chiral compounds, like water
该化合物“无旋光性”
“无光学活性”
Nicol
Light source
Chiral compounds, like lactic acid
该化合物具有“旋光性”
为“旋光物质”或“光活性物质”
偏转角
旋光度
物质的旋光性：物质使偏振光振动平面发生旋转的性质
Specific rotation 比旋光度
[α] = 100α/(cl)
[α]D25 = 100α/(cl)
D: the D line of a sodium lamp (λ=)
The Polarimeter
α：旋光度
c： 样品的浓度（100mL溶液中样品的克数）
l： 盛液管的长度（单位：cm）
Asymmetric carbon atom
In the 19th century, several asymmetric crystals were discovered. Also, the solutions obtained from the asymmetric crystals were asymmetric.
Louis Pasteur
什么样的化合物具有旋光性？
not superposable
Chirality 手性
晶体结构中缺少某种对称因素，导致实物与镜像互不重合
从而推测具有手性的分子，其结构中也因缺少某种对称因素，导致实物与镜像互不重合