What Is Ultraviolet Spectroscopy?

Accurate determination of the molecular structure of organic compounds is very important for understanding the physical world at the molecular level and promoting the development of modern organic chemistry. With modern instrumental analysis methods, the molecular structure of organic compounds can be determined quickly and accurately. The most widely used methods for determining molecular structure in organic chemistry are four major spectroscopic methods: ultraviolet, infrared, nuclear magnetic resonance, and mass spectrometry. Ultraviolet and visible spectrum is abbreviated as UV.

UV Spectrum Medicine

Ultraviolet spectrum has played an important role in analyzing the chemical structure of a series of vitamins, antibiotics and natural products, such as vitamin A ₁ , vitamin A ₂ , vitamin B ₁₂ , vitamin B ₁ , penicillin , streptomycin , oxytetracycline , fireflies Luminescent substance at the tail .

For example, reserpine has two conjugated structures, and hydrolysis results in reserpine acid and 3,4,5-trimethoxybenzoic acid. Reserpine acid is reduced to reserpine alcohol by LiAlH ₄ and its spectrum is similar to that of 2,3-dimethyl-6-methoxyindole. The spectral lines of the synthesized reserpine alcohol and 3,4,5-trimethoxybenzoic acid were superimposed on the absorption curve of reserpine, and the structure of reserpine was determined by synthesis. ^[4]

UV spectrum performance test

Photochromism refers to the phenomenon that the color changes reversibly under the irradiation of light. It can be tested by ultraviolet spectrum. For example, the cyclohexane solution of spiroxazine compound A has no color, but under continuous UV light irradiation at 365 nm, the solution turns blue, and absorption occurs in the visible region. With the extension of the irradiation time, the intensity of the absorption peak gradually increases until it no longer changes. When the solution of the compound is placed in a dark place, its absorption in the visible light region will gradually decrease.

Photochromic materials, as a new type of functional materials, have very broad application prospects. For example, it can be used as optical information storage materials, optical switches, optical converters, etc. These materials have great achievements in the fields of machinery, electronics, textiles, national defense and so on. The research and development of photochromic paint, photochromic glass, and photochromic ink have practical application significance. In addition to the above applications, photochromic materials can also be used as self-developing photosensitive films, holographic materials, protective and decorative materials, printing plates and printed circuits, and camouflage materials.

In particular, the research of photochromic compounds as erasable rewritable optical storage materials has been one of the research hotspots in the field of photochromics in recent years. As a photochromic optical storage medium that can be a rewritable optical storage material, it should meet conditions such as absorption, non-destructive readout, good thermal stability, excellent fatigue resistance, and fast response speed in the semiconductor laser wavelength range. . ^[4]