The exact chemical formula for 2-bromo-4-methylhexane is C7H15Br.
Decoding the Structure of 2-Bromo-4-methylhexane
Organic compound names, such as 2-bromo-4-methylhexane, follow systematic rules known as IUPAC nomenclature. These rules directly indicate the molecule's structure and elemental composition, allowing chemists to accurately determine its molecular formula.
Breaking Down the Name
To understand how the formula C7H15Br is derived, let's deconstruct each part of the name:
- Hexane: This is the parent hydrocarbon chain, indicating the longest continuous chain of carbon atoms in the molecule contains six (hex-) carbon atoms. A fully saturated six-carbon alkane (hexane) would typically have the formula C6H14.
- Methyl: This signifies the presence of a methyl group (-CH3). A methyl group is an alkyl substituent consisting of one carbon atom bonded to three hydrogen atoms, attached to the main carbon chain. Its position is indicated as being at the 4th carbon.
- Bromo: This indicates a bromine atom (-Br) attached to the carbon chain. A bromine atom is a halogen substituent, and its position is specified as being at the 2nd carbon.
Deriving the Molecular Formula
Let's trace the contribution of each part to the final formula:
- Start with the base chain: A hexane backbone has 6 carbon atoms.
- Add the methyl group: The "methyl" group adds one more carbon atom to the overall structure. This brings the total carbon count to 6 (from hexane) + 1 (from methyl) = 7 carbon atoms. If this were a simple heptane (7 carbons), its formula would be C7H16.
- Account for substituents: Both the methyl group and the bromine atom replace hydrogen atoms that would otherwise be present on a fully saturated heptane chain.
- One hydrogen is conceptually replaced by the methyl group's connection point (though the methyl itself brings carbons and hydrogens).
- One hydrogen is directly replaced by the bromine atom.
- Therefore, from a theoretical C7H16 (heptane) base, one hydrogen is removed and one bromine is added, leading to C7H15Br.
The elemental composition of 2-bromo-4-methylhexane is summarized in the table below:
| Element | Count |
|---|---|
| Carbon (C) | 7 |
| Hydrogen (H) | 15 |
| Bromine (Br) | 1 |
General Characteristics
2-bromo-4-methylhexane is classified as an alkyl halide (or haloalkane). These are organic compounds characterized by at least one halogen atom (like bromine) bonded to an alkyl group. Alkyl halides are versatile compounds frequently used as intermediates in various organic synthesis reactions.
- This compound is a specific isomer within the C7H15Br molecular formula family. Different arrangements of the same atoms result in different isomers, each with unique properties.
- The positional numbers (2-bromo and 4-methyl) are crucial in IUPAC nomenclature to define the exact connectivity and distinguish 2-bromo-4-methylhexane from other C7H15Br isomers, such as 1-bromo-2-methylhexane or 3-bromo-2,2-dimethylbutane.
