A UV-Vis spectrophotometer measures the amount of light absorbed at each wavelength of the UV and visible regions of the electromagnetic spectrum. λmax— the wavelength of maximum absorption

A ring that contains at least one heteroatom (an atom other than carbon) is called a heterocycle, and a substance based on a heterocyclic ring is a heterocyclic compound. Heterocyclic compounds containing N, O or S are by far the most common

The most characteristic reactions of benzenoid arenes are the substitution reactions that occur when they react with electrophilic reagents. The electrophiles are either a positive ion (E+) or some other electron-deficient species with a large partial positive charge

Aldehydes are named by replacing the terminal –e of the corresponding alkane name with –al. The longest chain selected as the base name must contain the –CHO group, and the –CHO carbon is always numbered as carbon 1

Phenols are like alcohols in being able to form strong intermolecular hydrogen bonds. Phenols have higher boiling points than hydrocarbons of the same molecular weight. A modest solubility in water

Carbon’s ability to form strong covalent bonds to other carbon atoms is the single property of the carbon atom that — more than any other—accounts for the existence of a field of study called organic chemistry. Carbon’s ability to form as many as four strong bonds to other carbon atoms, and to form strong bonds to hydrogen, oxygen, sulfur, and nitrogen atoms as well

An acid is a substance that can donate (or lose) a proton, A base is a substance that can accept (or remove) a proton

Energy and the Relative Stability Kinetic energy is the energy an object has because of its motion. Potential energy is stored energy. It exists only when an attractive or repulsive force exists between objects

Cycloalkanes with only one ring are named by attaching the prefix cyclo- to the names of the alkanes possessing the same number of carbon atoms

The different arrangements of atoms caused by rotation about a single bond are called conformations (构象)of the molecule, and a specific conformation is called a conformer (构象异构体, conformation isomer). An analysis of the energy changes that a molecule undergoes as groups rotate about single bonds is called a conformational analysis (构象分析)