What is the Difference Between Iso and Sec in Organic Chemistry?
🆚 Go to Comparative Table 🆚In organic chemistry, the prefixes "iso" and "sec" are used to indicate the position of a functional group in a hydrocarbon chain. The difference between the two prefixes lies in the carbon atom to which the functional group is bonded.
- Iso: The prefix "iso" is used when the hydrocarbon has at most six carbon atoms in a chain and one carbon is present on the second last carbon atom of the chain. It is also used when all carbons except one form a continuous chain, and the functional group is bonded to the end of the chain. For example, iso-butyl has the structure CH3-CH-CH3.
- Sec: The prefix "sec" is used when the functional group is bonded to a secondary carbon atom, meaning that the carbon atom is attached to two other carbons. It is not used when the carbon chain is shorter than four. For example, sec-butyl has the structure CH3-C(CH3)3.
In summary:
- Use "iso" when the functional group is bonded to the end of a continuous chain of carbon atoms or to the second last carbon atom in a chain with at most six carbons.
- Use "sec" when the functional group is bonded to a secondary carbon atom, meaning the carbon atom is attached to two other carbons.
On this pageWhat is the Difference Between Iso and Sec in Organic Chemistry? Comparative Table: Iso vs Sec in Organic Chemistry
Comparative Table: Iso vs Sec in Organic Chemistry
The prefixes "iso" and "sec" in organic chemistry are used to indicate the position and attachment of substituents in branched alkanes. Here is a comparison table of the difference between "iso" and "sec" in organic chemistry:
Prefix | Meaning | Attachment | Example | IUPAC Name |
---|---|---|---|---|
iso | New Latin for "equal" or "rotated" | Substituent is attached to a primary carbon atom | n-pentane, iso-propanol | pentane, 1-propanol |
sec | Secondary | Substituent is attached to a secondary carbon atom | sec-butanol | 1-butanol |
- The prefix "iso" is used when all carbons except one form a continuous chain, and the substituent is attached to a primary carbon atom.
- The prefix "sec" stands for "secondary" and is used when the substituent is attached to a secondary carbon atom, which is a carbon atom attached to two other carbons.
Examples of the usage of these prefixes can be found in the structural names of alkanes with substituents:
- isobutane (same as 2-methylpropane)
- sec-butanol (same as 1-butanol)
These prefixes help chemists identify and name complex branched alkanes with ease.
Read more:
- Isobutyl vs Sec-butyl
- Organic Chemistry vs Inorganic Chemistry
- Acyclic vs Cyclic Organic Compounds
- Isoelectronic vs Isosteres
- Oxazole vs Isoxazole
- Organic vs Inorganic Molecules
- Organic vs Inorganic Sulfur
- Chain Isomerism vs Position Isomerism
- Isotopes vs Isomers
- Organic Acid vs Inorganic Acid
- Thiocyanate vs Isothiocyanate
- Isomerization vs Hydroisomerization
- Organic Compound vs Inorganic Compound
- Cis vs Trans Isomers
- Structural Isomers vs Stereoisomers
- Isostructural vs Isomorphous
- Optical vs Geometrical Isomerism
- Inorganic vs Organic Carbon
- Iso vs Neo Structures