Sodium Methallyl Sulfonate and Sodium Methylallyl Sulfonate are both organic sulfonate salts, but they differ in their molecular structures due to the position of the methyl group on the allyl chain. Here’s the key distinction:
- Sodium Methallyl Sulfonate (SMAS)
- Chemical Structure: CH₂=C(CH₃)CH₂SO₃Na
- IUPAC Name: Sodium 2-methylprop-2-ene-1-sulfonate
- Feature: The methyl group (–CH₃) is attached to the second carbon (C2) of the allyl group (C=C–C), making it a “methallyl” derivative (methyl-substituted at the double bond).
- Sodium Methylallyl Sulfonate (SMAS or NaMAS, sometimes ambiguous)
- Chemical Structure: CH₂=CHCH(CH₃)SO₃Na
- IUPAC Name: Sodium 2-methylprop-1-ene-1-sulfonate (if sulfonate is at C1)
- Feature: The methyl group is typically attached to the terminal carbon (C3) of the allyl group (C=C–C), though naming conventions can vary. This structure is less common and may sometimes be confused with methallyl sulfonate.
Key Difference:
- Methallyl: Methyl group on the middle carbon (C2) of the C=C double bond (more stable and widely used).
- Methylallyl: Methyl group on the end carbon (C3) of the allyl chain (less common, and naming may overlap with methallyl).
Note:
In practice, “Sodium Methallyl Sulfonate” is the more standardized term for CH₂=C(CH₃)CH₂SO₃Na, while “Sodium Methylallyl Sulfonate” might refer to a different isomer or be used ambiguously. Always check the structural formula for clarity.
