In the chemical literature this would be reported as
Lambert-Beer Rule; A = ε C L = - log I Io I --- 入 射 光 强 度 Io ---透 射 光 强 度 2,5-Dimethyl-2,4-hexadiene, λ max methanol 242.5 nm ( ε = 13.100 M-1 cm-1 ) In the chemical literature this would be reported as
UV与有机物分子结构的关系
UV 与有机物分子结构的关系 λ max methanol CH2 =CH2 171 nm CH2 =CHCH2 CH=CH2 CH2 =CHCH=CH2 λ max methanol 178 nm λ max methanol 217 nm non conjugate system conjugate system
We can understand how conjugation of multiple bonds brings about absorption of lght at longer wavelengths
We can understand how conjugation of multiple bonds brings about absorption of light at longer wavelengths λ max methanol 171 nm λ max methanol 217 nm CH2 =CH2 CH2 =CHCH=CH2 HOMO LUMO HOMO LUMO excitation excitation π π1 π2 π* π* π* Energy
The greater the number of conjugated multiple bonds a compound contains, the longer will be the wavelength at which the compound absorbs light
The greater the number of conjugated multiple bonds a compound contains, the longer will be the wavelength at which the compound absorbs light. λ max methanol 171 nm λ max methanol 217 nm CH2 =CH2 CH2 =CHCH=CH2 CH2 =CHCH=CHCH=CH2 λ max methanol 274 nm The wavelength move toward direction of long wavelength
β- Carotene胡罗卜素
β – Carotene 胡罗卜素 λ max methanol 497 nm (red orange) (Visible region)