1. Absorption
Absorption, in chemistry, is a physical or chemical phenomenon or a process in which atoms, molecules, or ions enter some bulk phase (gas, liquid, or solid material). This is a different process from adsorption, since molecules undergoing absorption are taken up by the volume, not by the surface (as in the case for adsorption). A more general term is "sorption", which covers absorption, adsorption, and ion exchange. Absorption is a condition in which something takes in another substance.
2. Absorption spectrum
Spectrum with gaps yield by the residual radiation when it is passed through a prism.
3. Auxochrome
Substituent that increase the intensity of the absorption and possibly the wavelength. Typical auxochrome include methyl, hydroxyl, alkoxy, halogen and amino groups.
4. Bathochromic shift
A shift to longer energy or longer wavelength (also called “red shift”).
5. Crhomophore
The group of atom producing such an absorption.
6. Excited stated
State of higher energy in electronic transition.
7. Exocyclic double bond
A double bond that lies outside of given ring. Exocyclic double bond may lie within one ring even thought it is outside enother ring. It is often found at junction point on the rings.
8. Ground state
State of low energy in electronic transition.
9. Hyperchromic effect
An increase in intensity.
10. Hypocrhomic effect
An decrease in intensiy.
11. Hypsochromic shift
A shift to higher energy or shorter wavelength (also called “blue shift”).
12. Molar absorptivity
A property of molecule undergoing electronic transition. It is not function of the variable prameter involved in preparing a solution.
13. Nonbonding orbital
Orbital that hold unshared pair.
14. Primary band
The allowed transition is not in the routine range of UV observable at 180 nm.
15. Second primary band
The forbidden transition is observed if substituent effects shift it into the observable region.
16. Ultraviolet Spectroscopy
Ultraviolet and visible spectroscopy primarily used to measure the multiple bond or aromatic conjugation within molecules. UV/Vis spectroscopy requires electromagnetic radiation of high energy. the visible region correspond to 800-400 nm and ultraviolet region to 400-200 nm.
17. UV Spectrum
Spectra result from UV/vis spectrometry analysis that representation of wavelength (x-axis) versus measured intensity absorbance (y-axis). This spectra obtained when substances or samples (with different colour and have any conjugation system) absorb light in uv or visible region.
18. Woodward-Fieser Rules
Techniques of identification in UV or UV-Vis spectroscopy. Studies of spectra for a large number of molecules led to the establishment of a correlation between structures and positions of the absorption maxima. The best known of these are the empirical rules due to Fieser, Woodward and Scott, which concern unsaturated carbonyl, dienes or steroids compounds.
Tidak ada komentar:
Posting Komentar