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
Conjugated unsaturated systems have a p orbital on a carbon adjacent to a double bond The p orbital can come from another double or triple bond The p orbital may be the empty p orbital of a carbocation or a p orbital with a single electron in it (a radical)
4.1 卤代烃的分类 结构和命名 Classification, Structure, and Nomenclature of Alkyl Halides 4.2 卤代烃的物理性质 Physical Properties of Alkyl Halides 4.3 卤代烃的化学性质 Chemical properties of Alkyl Halides
More environment-friendly methods Natural insect attractants — instead pesticide Less reactive compounds organic refrigerants and aerosol propellant — instead Freon (that destroy the Earth’s ozone layer) Cars with more efficient combustion engines — reduce the massive amount of automobile
1858 ~ 1861, Kekulé, Couper, and Butlerov, laid the basis for one of the most fundamental theories in chemistry: the structural theory. Valence(化合价): C — tetravalent; O — divalent; H — monovalent