Infrared Spectroscopy (IR)
紅外線光譜學
1.有機化合物紅外線光譜特性吸收
2.缺H指數的計算及運用
A. Amines (胺類)的特性吸牧
• N-H stretching vibrations appear in the region
3100 to 3500 cm-1.
– 1° amines have two absorptions in this region.
– 2° amines have one.
– 3° amines have none.
B. Aldehydes & Ketones (醛類和酮類)的特性吸收
Aldehydes and ketones show strong C=O absorptions
between 1705 and 1780 cm-1.
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2. 缺氫指數
•缺氫指數
–分子環與 �p 鍵的總和。
Index of hydrogen deficiency (IHD): The sum
of the number of rings and pi bonds in a
molecule.
– To determine IHD, compare the number of H in
an unknown compound with the number in a
reference hydrocarbon with the same number of
carbons and with no rings or pi bonds.
– The molecular formula of the reference
hydrocarbon is CnH2n+2