Compounds were classified as being either aliphatic or aromatic in the latter part of the nineteenth century. To be classified as aliphatic meant then that the chemical behavior of a compound was “fatlike”. To be classified as aromatic meant then that the compound had a low hydrogen/carbon ratio and that it was “fragrant
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 hydrocarbon whose molecules contain two double bonds is called an alkadiene(alkatriene for three double bonds); A hydrocarbon with two triple bonds is called an alkadiyne; A hydrocarbon with a double and triple bond is called an alkenyne
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)
The reactivity of organometallic compounds increases with the percent ionic character of the carbon-metal bond. RLi and RMgX are of great importance in organic synthesis
