Introduction to Organic Chemistry and IUPAC Nomenclature

$organic chemistry$$-$ chemistry concerning carbon-containing compounds

Why is Carbon Special?

• can form strong bonds with multiple atoms of itself in a chain
• can bond with many other elements like hydrogen, nitrogen, sulfur, oxygen, and phosphorus   * brings diversity in compounds that can be formed     * this allows it to be the basis of life
• carbon can also form double and triple bonds
• carbon is $tetravalent$- it can remove/gain 4 electrons
• $functional groups$- increase the functionality/reactivity of a molecule

Other Elements

• oxygen is $divalent$- it can gain 2 electrons
• nitrogen is $trivalent$- it can gain 3 electrons
• hydrogen is always $monovalent$- it can lose 1 electron

Types of Structures/Formulas & Other Conventions

• $lewis structures$$-$ show lone pairs as well as number & type of bond present in the molecule
• $condensed formula$$-$ writing the carbons with their hydrogens   * example- C20H42O can also be written as CH3(CH2)19OH
• **$bond line formula-$**shown below

• $<em>n-</em>$(insert molecular formula or name of hydrocarbon) means it’s “normal” & not branched   * example- *n-*butane
• $isomers$- molecules with the same molecular formula but different structures   * the number of isomers tends to increase as the number of carbons in the compound increases

Hydrocarbons

• made of only carbon and hydrogen
• not very functionally useful
• mostly used for energy
• 2 types   * $saturated$- maximum amount of hydrogens are in the molecule, all carbons have single bonds     * also called $alkanes$   * $unsaturated$- some carbons have double or triple bonds

IUPAC Nomenclature

• parent chain is the longest identifiable carbon chain present in the molecule   * if 2 chains have the same length, the parent chain is the one with the most substituents
• carbons in the chain are numbered so the substituents get the lowest number possible   * if some substituents have the same number no matter numbering from left to right, numbering starts from the end where the next substituent has the lowest number
• give the lowest number to the substituent whose letter is first in the alphabet
• if more than one of the same type of substituent is present, use the prefixes di- for 2, tri- for 3, tetra- for 4, etc. to indicate the number
• substituents are listed in alphabetical order   * ignore numerical prefixes in alphabetization (like di-, tri-, tetra-)   * don’t ignore positional prefixes like iso-
• names and numbers are separated by dashes

multiple numbers are separated by commas

• halogens as substituents   * F: fluoro-   * Cl: chloro-   * Br: bromo-   * I: iodo-

Example

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