Most molecules contain an even number of electrons

In the ground state, electrons in the same orbit have opposite spins, S-0. Molecular multiplet state M= 2S 1=1, ground singlet state (S).

Absorb energy and jump to the first and second excited singlets (S1,S)

Radiative transition, non-radiative transition

Transition selection law ΔS=0 (single single, double double, three one three)

deactivation process

Fluorescence efficiency and influencing factors

A curve drawn with the excitation wavelength as the abscissa and fluorescence intensity as the ordinate.

Fix the excitation wavelength and intensity, measure the fluorescence intensity at different wavelengths, and draw the relationship curve of fluorescence intensity with wavelength.

Light source: lamp, high-pressure mercury lamp, laser;

Two monochromators: excitation monochromator and emission monochromator

Sample cell: Quartz (optical material)

Detector: Photomultiplier tube, charge coupling element detector

Signal output conversion system

Analysis of Inorganic Compounds

Analysis of organic compounds

biochemical analysis

The optical radiation produced when the triplet state transitions to the ground state

Methods for identification and quantitative analysis of organic compounds using phosphorescence spectroscopy

At room temperature, phosphorescent substances lose their activity when they collide with solvent molecules.

As the temperature decreases, the intensity of thermal movement decreases, the probability of deactivation decreases, and the phosphorescence increases.

When the analyte is in liquid nitrogen (77K=-196C), the phosphorescence is stronger and the measurement sensitivity is higher.

Micellar Stable Room Temperature Phosphorescence

Solid surface room temperature phosphorescence

Sensitized room temperature phosphorescence

light source

monochromator

Sample cell

Detector

magnifying display device

Phosphoroscope

Dewar flask

PAHs and heterocycles

drug