Completed notes of the course

Pagina 1

ORGANIC CHEMESTRY (15.09) Chemistry of carbon compounds Hydrocarbons are the main components of fossil fuel, they are made mainly of carbon and hydrogen. Biomass is more complex than hydrocarbon since it also contains oxygen. Tetravalency of carbon: carbon have the ability to form four bonds. Paraffin (or alkane): it is an acyclic saturated hydrocarbon. In other words, it consists of hydrogen and carbon atoms arranged in a tetradic structure in which all the carbon–carbon bonds are single. The general form of paraffins is 𝐶𝑛𝐻2𝑛+2 - Methane (𝐶𝐻4): it has 109,5° between bonds. - Ethane (𝐶2𝐻6) - Propane (𝐶3𝐻8) - Butane (𝐶4𝐻10) - … The main rule is that the carbon can made 4 bonds and the best companion is hydrogen which can make one bond. The carbon can be alone o bonded with other carbon, then all the other electrons are saturated. Alkyl and aromatic groups: - 𝐶𝐻3: methyl group (primary C) - 𝐶𝐻2: methylene group (secondary C) - Phenyl group which is a benzene without a hydrogen. - Benzyl group which is a phenyl group plus an ethyl group attached. In general, when a hydrogen atom is removed from an alkane the name of the correspondent group is “-yl” instead of “- ane”. 𝐶𝐻3+⋯+𝐶𝐻2+⋯+𝐶𝐻3 Linear alkanes: straight-chain alkanes, they are indicated by the prefix "n" for "normal". Branched alkanes: alkanes where a carbon atom can be bonded with 2 carbon atoms. The nomenclature provides to add “iso” in front of the name. This type of nomenclature does not allow to uniquely identify where the branches is, but there are more scientific nomenclatures like the one: position-methy-alcanes. They have the same molecular weight of correspondent linear alkanes but very different physical properties. For example: the boiling point of branched molecules is lower than the one of linear…