- 667 cm⁻¹: Rocking vibration of a terminal =C–H (alkene) – Medium sharp peak; consistent with terminal alkene (e.g., vinyl group). - 733 cm⁻¹: Rocking vibration of =C–H (alkene) – Medium sharp; supports terminal alkene presence. - 902 cm⁻¹: =C–H bending (alkene) – Strong broad; typical for terminal =C–H (e.g., vinyl group). - 954 cm⁻¹: =C–H bending (alkene) – Strong sharp; further confirms terminal alkene. - 1076 cm⁻¹: C–O stretching (alkoxy) – Strong broad; suggests ether or alcohol (e.g., –O–CH₃). - 1393 cm⁻¹: CH₃ bending (symmetric) – Weak broad; consistent with methyl group. - 1974 cm⁻¹: Weak sharp – Unusual; may indicate a rare vibration or impurity; not typical for common functional groups. - 2036 cm⁻¹: Weak broad – May suggest a C≡C–H stretch (alkyne), but weak intensity suggests low concentration or interference. - 2157 cm⁻¹: Weak sharp – Likely C≡C stretch (alkyne) – Weak intensity suggests terminal alkyne. - 2341 cm⁻¹: Weak sharp – May indicate C≡C stretch (alkyne) or CO₂ contamination; less likely for alkyne. - 2360 cm⁻¹: Weak broad – Similar to 2341 cm⁻¹; possibly CO₂ or weak alkyne. - 2987 cm⁻¹: C–H stretching (alkyl) – Weak broad; suggests –CH₃ or –CH₂– groups.
**Conclusion:** The spectrum indicates a terminal alkene (peaks 667–954 cm⁻¹) and a terminal alkyne (2157 cm⁻¹), along with ether/alcohol (1076 cm⁻¹). The presence of methyl groups (1393 cm⁻¹, 2987 cm⁻¹) and weak alkyne signals (2036–2360 cm⁻¹) supports a compound like a vinyl-alkyne or 1-alken-3-yne derivative. Likely structure: CH₂=CH–C≡C–R (e.g., 1-penten-3-yne).
This discussion presents an infrared spectral analysis combining
automated interpretation with reference comparison to support
functional group identification and structural assessment.
FTIR Spectrum Interpretation Summary
Comparative Analysis Conclusion
AI-assisted Interpretation Conclusion
- 667 cm⁻¹: Rocking vibration of a terminal =C–H (alkene) – Medium sharp peak; consistent with terminal alkene (e.g., vinyl group).
- 733 cm⁻¹: Rocking vibration of =C–H (alkene) – Medium sharp; supports terminal alkene presence.
- 902 cm⁻¹: =C–H bending (alkene) – Strong broad; typical for terminal =C–H (e.g., vinyl group).
- 954 cm⁻¹: =C–H bending (alkene) – Strong sharp; further confirms terminal alkene.
- 1076 cm⁻¹: C–O stretching (alkoxy) – Strong broad; suggests ether or alcohol (e.g., –O–CH₃).
- 1393 cm⁻¹: CH₃ bending (symmetric) – Weak broad; consistent with methyl group.
- 1974 cm⁻¹: Weak sharp – Unusual; may indicate a rare vibration or impurity; not typical for common functional groups.
- 2036 cm⁻¹: Weak broad – May suggest a C≡C–H stretch (alkyne), but weak intensity suggests low concentration or interference.
- 2157 cm⁻¹: Weak sharp – Likely C≡C stretch (alkyne) – Weak intensity suggests terminal alkyne.
- 2341 cm⁻¹: Weak sharp – May indicate C≡C stretch (alkyne) or CO₂ contamination; less likely for alkyne.
- 2360 cm⁻¹: Weak broad – Similar to 2341 cm⁻¹; possibly CO₂ or weak alkyne.
- 2987 cm⁻¹: C–H stretching (alkyl) – Weak broad; suggests –CH₃ or –CH₂– groups.
**Conclusion:**
The spectrum indicates a terminal alkene (peaks 667–954 cm⁻¹) and a terminal alkyne (2157 cm⁻¹), along with ether/alcohol (1076 cm⁻¹). The presence of methyl groups (1393 cm⁻¹, 2987 cm⁻¹) and weak alkyne signals (2036–2360 cm⁻¹) supports a compound like a vinyl-alkyne or 1-alken-3-yne derivative. Likely structure: CH₂=CH–C≡C–R (e.g., 1-penten-3-yne).
This discussion presents an infrared spectral analysis combining automated interpretation with reference comparison to support functional group identification and structural assessment.